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The effect of early lactation concentrate build-up strategy on milk production, reproductive performance and health of dairy cows
Livestock Science 184 (2016) 103–111
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The effect of early lactation concentrate build-up strategy on milk production, reproductive performance and health of dairy cows A.J. Dale a,n, B. Hunter a, R. Law a, A.W. Gordon b, C.P. Ferris a a b
Agri-Food and Biosciences Institute, Hillsborough, Co Down BT26 6DR, Northern Ireland, United Kingdom Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, United Kingdom
art ic l e i nf o
a b s t r a c t
Article history: Received 16 July 2015 Received in revised form 22 December 2015 Accepted 30 December 2015
The objective of this study was to examine the effect of two early lactation concentrate build-up strategies on cow performance, fertility and health. The study was undertaken on five Northern Ireland dairy farms, and involved 385 multiparous Holstein-Friesian cows. Cows were allocated to either an ‘Immediate’ or ‘Delayed’ concentrate build-up strategy postpartum. All cows were offered a ‘basal’ diet comprising forage and concentrates (mean, 7.4 kg concentrate/cow/day), with a target crude protein (CP) and starch concentration of 145 and 170 g/kg dry matter (DM), respectively. An additional 7.0 kg of concentrate (mean across the five farms) was then introduced into the diet of each cow, at an incremental rate of approximately 0.5 kg/day, over days 1–14 of lactation (‘Immediate build-up’) or over days 21–35 of lactation (‘Delayed build-up’), with the target CP and starch concentration of the total diet being 175 and 200 g/kg DM, respectively. While average daily milk yield and fat-plus-protein yield was reduced (P o0.05) during weeks 2 to 5 of lactation with the Delayed concentrate build-up strategy, treatment had no effect on milk yield, milk composition or milk fat and protein concentration over the first 305 days of lactation. Cows on the Delayed build-up strategy produced milk with a higher somatic cell score (P o0.05), while no treatment time interactions were observed on body condition score during the experimental period. Conception rate to first service was higher with the Delayed build-up strategy (P ¼0.047), although treatment had no effect on conception to first and second service, calving interval and cows confirmed pregnant during the study (P 40.05). The Delayed build-up strategy tended (P ¼0.051) to reduce the incidence of fertility related health issues within the first 30 days of lactation, but increased the incidence of mastitis (P o0.05). Treatment had no effect on any other health measures, the reasons that cows were culled, or the stage of lactation when cows were culled (P40.05). Although concentrate build-up strategy had short-term effects on milk yield and fertility in early lactation, no long term benefits in performance, fertility, health or survival were observed with the Delayed Build-up strategy. & 2016 Elsevier B.V. All rights reserved.
Keywords: Concentrate build-up strategy Dairy cows Fertility Survival
1. Introduction Within the annual production cycle of a dairy cow, the period immediately prior to calving and the period immediately postcalving (transition period) presents the greatest nutritional challenges (Roche et al., 2013). In addition, genetic selection has resulted in increasing milk yields in many countries (Ingvartsen and Moyes, 2013), especially during this early lactation period. As a consequence, during the first eight weeks of lactation high yielding dairy cows are generally unable to consume enough dry matter (DM) to meet their energy requirements for milk production, and n Corresponding author at: Agri-Food and Biosciences Institute, Large Park, Hillsborough, Co Down BT26 6DR, Northern Ireland. E-mail address: [email protected] (A.J. Dale).
http://dx.doi.org/10.1016/j.livsci.2015.12.016 1871-1413/& 2016 Elsevier B.V. All rights reserved.
may enter a period of negative energy balance. The prevalence of negative energy balance (NEB) has been well documented (Mulligan et al., 2006; Ingvartsen and Moyes, 2013; Roche et al., 2009; Reksen et al., 2001; Crowe et al., 2014; Drackley and Cardoso, 2014), and many authors have reported the detrimental effect that NEB, and the associated mobilisation of body tissue, have on the subsequent health, production, fertility and longevity of dairy cows. As a consequence, high yielding cows suffer a much greater incidence of health problems during the first few weeks postcalving than at any other time during lactation (Ingvartsen, 2006; Drackley and Cardoso, 2014). To help meet the nutrient requirements of high yielding cows in early lactation, concentrate inclusion amounts in dairy cow diets have increased considerably in recent years. Although the inclusion of concentrate feeds can improve the energy density of the diet, offering high amounts of concentrates can have a
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detrimental effect on rumen health. Sub-acute rumen acidosis (Krause and Oetzel, 2006; Kleen et al., 2003) occurs when rumen pH is depressed to between 5.5 and 5.0, and in this environment intake can be adversely affected as fibre digestion and rumen microbial activity are impaired. Furthermore, although there is evidence that increased amounts of concentrate feed normally leads to improved nutrient intakes (Ferris et al., 2001), energy balance may not necessarily improve dramatically as cows with a high genetic potential for milk production may exhibit a milk yield response to the additional concentrates offered. Given that there is evidence (Ingvartsen, 2006) that the risk of disease is related to the rate of acceleration in milk production during the early lactation period, a reduction in this acceleration in milk yield could have beneficial effects on cow health. It is known that dietary energy (Law et al., 2011b) and protein concentration (Law et al., 2009; Gilmore et al., 2011; Sinclair et al., 2014; Whelan et al., 2014) can be used to modify the milk yields of cows in early lactation, while Law et al. (2009) demonstrated that dietary protein concentration can be reduced from 173 to 144 g/kg DM without any detrimental effect on total dry matter intake, with these levels adopted up to 150 days post-calving. These authors also reported that increases in dietary protein content decreased average daily energy balance. Thus it may be possible, by diet manipulation, to reduce the rate at which milk yield increases postpartum, and thus delay the attainment of peak-yield, with peak yield being better aligned with maximum DM intake. Practically, this approach could be administered by making changes to concentrate supplementation during early lactation (Ingvartsen et al., 2001; Kokkonen et al., 2004; Law et al., 2011a; Andersen et al., 2012). For example, reducing dietary protein concentration, and delaying the build-up of concentrates in the diet from immediately postpartum to day 28 postpartum, reduced the acceleration of milk yield in early lactation, but had no detrimental effect on milk production when considered over the full lactation (305 days) (Law et al., 2011a). Furthermore, the authors reported an improvement in forage intake when concentrate allocation was delayed. Despite evidence that a delayed concentrate allocation strategy, combined with lower protein diets, can reduce the duration and severity of negative energy balance and reduce the acceleration in milk yield (Law et al., 2011a), there is little evidence of benefits in cow health and fertility. Thus the current study, which was conducted on five commercial dairy farms to increase the number of cows involved, was designed to examine the effect of two contrasting early lactation concentrate build-up strategies on cow performance, health and fertility. The study was designed to test two hypotheses; 1. Adoption of a delayed concentrate build-up strategy post-calving can reduce the rate of increase in milk production in early lactation, without having a detrimental effect on overall milk yield or quality during the lactation, compared to an immediate concentrate build-up strategy; 2. A reduction in the rate of increase in milk production post-calving has beneficial effects on cow health and fertility.
2. Materials and methods 2.1. Participating farms and cows This experiment was conducted on five Northern Ireland dairy farms between October 2012 and June 2014. During the year prior to the study, average annual concentrate inputs and milk outputs on the five farms were 2880 (s.d., 81) kg/cow and 8780 (s.d., 1112) litres/cow, respectively. The study involved 385 multiparous Holstein-Friesian cows (mean parity 3.0; s.d. 0.87), which calved between October 2012
Fig. 1. An overview of the two early lactation concentrate build-up strategies imposed on the five farms during this study.
and April 2013, with all cows calving during this period (with the exception of primiparous cows) eligible for inclusion within the study. Cows that were identified as ‘to be culled’ during the subsequent lactation, based on a number of factors including their history of chronic health issues, were not allocated to the study. Cows were allocated to one of two experimental treatments at calving, comprising either an ‘Immediate’ or ‘Delayed’ concentrate build-up strategy. Treatment groups on each farm were balanced for parity, for body condition score assessed approximately two weeks prior to the expected calving date, calving interval, calving date, and milk yield (305 days), milk composition and somatic cell count during the previous lactation. There were 57, 75, 67, 72 and 114 experimental cows on Farms 1 to 5, respectively. 2.2. Experimental design Following calving all experimental cows were offered a ‘basal’ diet (Fig. 1), with this diet comprising conserved forage (either grass silage only, or grass silage mixed with maize silage or whole crop wheat silage) and concentrates. The concentrate inclusion rate (as fed) within the basal diet ranged from 6.0–9.0 kg/cow/day across the five farms (mean; 7.4 kg/cow/day), while the target CP, starch and metabolisable energy (ME) concentration of the basal diet was 145 g/kg DM, 170 g/kg DM and 12.2 MJ/kg DM. Rations offered were formulated by each farms own nutritionist, in conjunction with the lead researcher, with each farm using a different nutritionist. Ration formulation was based on the equations contained within ‘Feed Into Milk’ (Agnew et al., 2004), the current UK dairy feed rationing system, and the ME and intake potential of the forages available on each farm, as determined by near-infra-red reflectance spectroscopy (Gordon et al., 1998). Predicted forage intakes were monitored by the nutritionist against actual group intakes being achieved. Cows managed on the ‘Immediate’ build-up strategy had additional concentrates introduced into the diet (‘build-up’ concentrate) during the first 14 days post-calving, with concentrates being increased in 0.5 kg increments daily (approximately), up to an average of 7.0 kg/cow/day (range across farms, 6.0–8.0 kg/cow/ day). Cows managed on the ‘Delayed’ build-up strategy were not offered additional concentrates until day 21 postpartum, with concentrates then introduced gradually into the diet of these cows in 0.5 kg increments daily (approximately) during a 14-day period (days 21–35 postpartum), to achieve the same concentrate amount as adopted with the Immediate build-up strategy (on each farm). These build-up concentrates were offered either in-parlour during milking or via out-of-parlour feeders, with total daily concentrate allowance being 14.0, 14.0, 14.0, 15.0 and 15.2 kg/cow across the five farms. Within one to two weeks of cows reaching their full ‘experimental’ concentrate allocation (day 14 (Immediate) and day
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
35 (Delayed)), cows on all farms moved to a ‘feed-to-yield’ concentrate allocation strategy, with each farm following their own individual feeding strategy from this time onwards, and with the same strategy being adopted for cows on both treatments. The target CP, starch and metabolisable energy concentration of the total diet once the full ’experimental’ concentrate allocation had been achieved was 175 g/kg DM, 200 g/kg DM and 12.5 MJ/kg DM, respectively. All cows remained indoors during the first 35 days of lactation. On one of the farms cows remained confined throughout the lactation, while on the other four farms cows were given access to grazing from May to September, approximately. 2.3. Measurements All farms were visited fortnightly by a trained technician from October 2012 to July 2013, and then on a monthly basis until January 2014. Thereafter farms were visited on a further three occasions to collect data, with the final visit taking place in June 2014. 2.4. Animals All five herds participated in official milk recording schemes, with milk recording undertaken approximately fortnightly during the first two months of lactation, and then either monthly or once every six weeks thereafter. Data provided by the recording agencies included individual cow test-day milk yields, milk fat concentration, milk protein concentration and somatic cell count (000/ml), and 305-day milk production data. In addition, on four of the farms milk yields for each cow were recorded daily using inline milk meters, with these data used to determine weekly milk yields during the experimental period. The parlour on one of the farms did not facilitate automatic recording of daily milk yields, and on this farm weekly milk yields were determined from the lactation curve which was fitted to the yield data recorded monthly within the official milk recording scheme, as detailed above. During each visit the body condition score of cows that were due to calve during the subsequent two-week period, and of all lactating cows on the experiment, were assessed. Body condition score was assessed as described by Edmonson et al. (1989). However, to facilitate additional precision, an additional ‘plus’ or ‘minus’ was added to a score when appropriate. Thus a cow with a conventional score of 2.25 could be scored as either 2.15, 2.25 or 2.35. In addition, rumen fill was assessed at each visit until June 2013, at which point all cows were a minimum of 80 days postcalving, although some cows were monitored up until 250 days post-calving. Rumen fill was assessed according to the methodology described by Zaaijer and Noordhuizen (2003), with the observer standing at the left hind side of the cow. As rumen fill is influenced by management factors such as time since last feed, the data were adjusted to allow comparisons to be made between farms and between visits. Therefore, individual animal rumen fill scores were adjusted to a deviation from a mean rumen fill score for the visit in question. This deviation allows rumen fill across visits and farms to be compared. Information on calving date, ‘fertility’, health and culling were recorded by the farmer. Fertility data included date of first observed heat, date of first and subsequent services and details of treatments relating to reproductive problems (for example; follicular cysts, luteal cysts, anoestrous and synchronisation). All incidences of ill-health and associated treatments during the experimental period were recorded by the farmer. This included metabolic, infectious and digestive problems. Metabolic problems included milk fever (staggering or downer cows), infectious diseases included clinical metritis (cows treated for metritis after
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7 days post-calving), clinical mastitis and lameness and digestive problems included displaced abomasum (veterinary diagnosis). For each cow culled, the date and reasons for culling were recorded. 2.5. Feeds The forages offered to the experimental cows were sampled once every six weeks approximately from October 2012 to May 2013 (n ¼34), and analysed using near infra-red reflectance spectroscopy (NIRS), as described by Park et al. (1998). All concentrates offered were sampled on a single occasion mid way through the main winter feeding period, with samples dried at 60 °C for 48 h and subsequently analysed for nitrogen and starch concentration. Concentrate CP (total nitrogen 6.25) concentration was determined using the Kjeldahl method (Tecator Kjeltec Auto 2400/ 2460 Analyzer/Sampler System, Hilleroed, Denmark), while starch concentration was determined using a Megazyme kit (McCleary et al., 1994). 2.6. Statistical analysis Full lactation (305 days) milk production data (based on individual cow data), days to first observed heat, days to first service and calving interval data were analysed by Analysis of Variance ANOVA (Genstat Sixteenth Edition, 2013, Lawes Agricultural Trust, Rothamsted, UK), with the model used including treatment (Immediate or Delayed concentrate build-up strategy), farm (1–5) and parity (defined as 2 (n ¼ 152), 3 (n ¼ 94) or 43 (n¼ 139)), while corresponding milk production values from the previous lactation were used as covariates for the milk data. Milk production data for cows completing o 200 days of lactation (n ¼15) were excluded from the analysis. Mean milk yield data (weekly until day 150 of lactation, and at 30-day intervals thereafter, until day 305 of lactation) and milk composition data (recorded every 4–6 weeks, until day 305 of lactation) were analysed by Residual Maximum Likelihood (REML) analysis, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (week of lactation), farm (1–5), and parity (2, 3, 4 3), and treatment x time. In addition, previous lactation data (milk yield and milk composition) were used within the model. Body condition score data over the lactation were analysed by REML, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (weeks postcalving), farm (1–5) and parity (2, 3, 4 3) within the model, and pre-calving body condition score as a covariate. ‘Weeks’ represented data collected at 14-day intervals up to day 150 of lactation, and subsequently 30-day intervals up to day 305 of lactation. Rumen fill data were analysed by REML, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (weeks post calving), farm (1–5) and parity (2, 3, 43) within the model. ‘Weeks’ represented data collected at 14-day intervals up to day 150 of lactation, and subsequently 30-day intervals up to day 250 of lactation. The proportion of cows which calved again, conception rates to first and second service, and animal health and culling data were analysed as a binomial distribution, including parity (2, 3, 4 3) and farm (1– 5) within the model (ANOVA). In addition, the shape of the lactation curve for milk yield and fat plus protein yield was determined for individual cows by fitting an exponential model curve (Wilmink, 1987):
Yt = a + b × e−0.05 × t + c × t
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Within this model, a, b and c parameters relate to the intercept, the incline and the decline of the curve, respectively, and Yt relates to milk production on day t. REML analysis was used to identify treatment effects on each of the parameters.
3. Results 3.1. Feeds offered The mean DM, CP and ME concentration of the grass silages offered across the farms were 309 (s.d., 47.9) g/kg, 139 (s.d., 14.1) g/ kg DM and 11.6 (s.d., 0.28) MJ/kg DM, respectively. The mean CP and starch concentration of the concentrates offered across the farms was 232 (s.d., 15.8: range, 217–259) g/kg DM and 248 (s.d., 86.4: range, 139–358) g/kg DM, respectively. Based on predicted silage DM intakes, the CP, ME and starch concentrations of the basal diets offered were calculated to range from 146 to148 g/kg DM, 11.9 to12.8 MJ/kg DM and 128 to 179 g/kg DM, respectively. Similarly, the CP, ME and starch concentrations of the total diets offered across the five farms were calculated to range from 170 to 171 g/kg DM, 12.2 to 13.0 MJ/kg DM and 168 to 200 g/kg DM, respectively.
Fig. 2. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on daily milk production over the 305-day experimental period (error bars represent standard errors). Main effects of treatment, week and treatment x week examined (SED; 0.43, 0.34, 0.57, respectively) (SIG; NS, ***, **, respectively).
3.2. Animal performance 3.2.1. Milk yield Concentrate build-up strategy had no effect (P 40.05) on either total milk output, milk composition or the yield of milk fat, protein or fat plus protein over the first 305 days of lactation (Table 1). Milk produced by cows on the Immediate and Delayed build-up strategies had mean somatic cell counts of 282,000 and 315,000 cells/ml, respectively, with somatic cell scores being significantly higher with the Delayed build-up strategy (Po 0.05). Although there was no overall effect of treatment on average daily milk yield or fat plus protein yield, cows on the Delayed build-up strategy had a lower milk yield (Fig. 2) and fat plus protein yield (Fig. 4) during weeks 2, 3, 4 and 5 (P o0.05) of lactation than those on the Immediate build-up strategy. Milk yield (Fig. 2), milk fat and milk protein concentration (Fig. 3), milk fat plus protein yield (Fig. 4) and somatic cell score (Fig. 5) all varied with week of lactation (P o0.001), while there was a significant treatment x week of lactation interaction for milk yield (P 40.01) and fat plus protein yield (P o0.05).There was no significant (P 40.05) treatment x week of lactation interaction for body condition score (Fig. 6). While rumen fill (deviation) varied with week of lactation (P4 0.001), there was no significant effect of treatment and no significant treatment week of lactation Table 1 Effect of concentrate build-up strategy on animal performance over the first 305 days of lactation. Concentrate build-up strategy SED
Total milk output (kg/ cow) Milk fat (g/kg) Milk protein (g/kg) Total milk fat yield (kg/ cow) Total milk protein yield (kg/cow) Total milk fat plus protein yield (kg/cow) Somatic cell score (loge)
Fig. 3. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on the fat and protein concentration of the milk produced over the 305day experimental period (error bars represent standard errors).
Fig. 4. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on daily milk fat-plus-protein yield over the 305-day experimental period (error bars represent standard errors).
Significance
Immediate
Delayed
10,063
9914
145.4
NS
39.3 32.0 393
39.4 32.1 388
0.31 0.16 5.9
NS NS NS
322
317
4.4
NS
714
705
9.9
NS
11.70
11.93
0.110
*
Fig. 5. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on milk somatic cell score (loge) over the 305-day experimental period (error bars represent standard errors).
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
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Table 2 Effect of concentrate build-up strategy on fertility performance (number of cows contributing to each value in parenthesis). Concentrate build-up strategy Immediate
Fig. 6. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on body condition score over the 305-day experimental period (error bars represent standard errors).
Days to first ob62 served heat Days to first service 76 Conception to first 23 service (%) 47 Conception to first and second service (%) Cows confirmed 70 pregnant (%)a 394 Calving interval (days)b
SED Significance
Delayed
(187)
60
(190)
3.0
NS
(177) (45)
76 32
(179) (61)
3.1 4.4
NS 0.047
(92)
50
(96)
5.0
NS
(137)
72
(136)
4.5
NS
(129)
389
(129)
6.6
NS
a Confirmed pregnant by 1 June 2014, by which time all cows were 4413 days post-calving. b For cows confirmed pregnant and still on the farm until the subsequent calving.
Fig. 7. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on the deviation in rumen fill over the first 250 days of the experimental period (error bars represent standard errors).
interaction (P 40.05) (Fig. 7). Parameters of the Wilmink curve (a, b and c) describe the lactation profiles for the daily yield and fat plus protein yield for both treatments. Build-up strategy had no effect on daily yield (P 40.05) in terms of parameter a (Immediate, 51.2 vs. Delayed, 50.0: P ¼0.230, s.e.d. 0.86), describing the starting milk yield (intercept) of the lactation curve; parameter b (Immediate, 24.4 vs. Delayed, 25.5; P ¼0.491, s.e.d. 1.54;), describing the slope and peak of the curve (incline); or parameter c (Immediate, 0.10 vs. Delayed, 0.10; P ¼0.846, s.e.d. 0.0008;), describing the persistency of lactation (decline). Similarly, build-up strategy had no effect on daily fat plus protein yield (P4 0.05) in terms of parameter a (Immediate, 3.5 vs. Delayed, 3.4: P¼ 0.102, s.e.d. 0.05); parameter b (Immediate, 1.3 vs. Delayed, 1.6; P ¼0.155, s.e.d. 0.18;); or parameter c (Immediate, 0.007 vs. Delayed, 0.006; P ¼0.094, s.e.d. 0.0003;).
percentage of cows on the Immediate build-up strategy to be treated for fertility related health issues by day 30 post calving, than with the Delayed build-up strategy (Table 3), although the percentage treated by either day 60 or day 90 post-calving was unaffected by treatment (P4 0.05). Of the 25 cows treated for fertility related health issues by day 30 post-calving, 23 received an ‘intrauterine washout’. Although concentrate build-up strategy had no effect on the incidence of mastitis by day 30 post-calving (P4 0.05), the incidence of mastitis was higher with the Delayed concentrate buildup by day 60 post-calving (9.5% vs. 4.2%) and throughout the entire study period (19.0% vs. 12.0%) (P o0.05). Concentrate build-up strategy had no effect on the incidence of lameness during the study, or on the percentage of cows treated for milk fever or rumen health issues (P 40.05). 3.2.4. Culling Of the 127 cows that did not calve again prior to the study end date (1 June 2014), 113 cows were culled (Table 4), while the remaining 14 cows were still present within the herds. Concentrate build-up strategy had no effect on the percentage of cows culled due to ‘legs/feet’, mastitis, infertility, or ‘other’ reasons (P 40.05), the percentage of cows culled at any of the four time intervals examined (Table 4), or the total number of cows culled (P4 0.05). Few cows (n ¼11) were culled prior to day 200 post-calving.
4. Discussion 3.2.2. Cow fertility Concentrate build-up strategy had no effect (P 40.05) on days to first observed heat or days to first service (Table 2). Conception to first service was higher with the Delayed concentrate build-up strategy (P o0.05), however build-up strategy had no effect on conception to first and second service (P4 0.05). At the end of the experiment (1 June 2014), 273 of the 385 cows on the study had been confirmed pregnant, although concentrate build-up strategy had no effect on the proportion of cows confirmed pregnant. Concentrate build-up strategy had no effect on overall calving interval (P 40.05). 3.2.3. Cow health The percentage of cows treated with either an ‘intrauterine washout’, prostaglandin or progesterone was unaffected by treatment (Table 3: P 40.05). There was a trend (P ¼0.051) for a greater
The primary objective of the current study was to examine the effect of adopting either an Immediate or Delayed concentrate build-up strategy in early lactation on dairy cow performance, with the study designed to complement the findings of an earlier study by Law et al. (2011a). While the treatments examined in the current study were broadly similar to those examined by Law et al. (2011a), the current study was conducted on five commercial dairy farms. The primary reason for this was to increase the number of experimental cows beyond what would be possible within the constraints of most research farms, thus allowing possible effects of build-up strategy on cow health and fertility performance to be identified. In addition, on-farm research is recognised as having many other benefits, including the testing of treatments under what many farmers consider to be ‘real’ farm conditions, and the provision of a highly effective platform for disseminating research
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Table 3 Effect of concentrate build-up strategy on a range of cow health events, and the timing of these events (number of cows contributing to each value in parenthesis). Concentrate build-up strategy Immediate Fertility treatments (%) Cows treated by day 30 post-calving Cows treated by day 60 post-calving Cows treated by day 100 post-calving Cows treated during the study Cows treated with an ‘intrauterine washout’ Cows treated with prostaglandin Cows treated with progesterone Mastitis treatments (%) Cows treated by day 30 post-calving Cows treated by day 60 post-calving Cows treated during the study Lameness treatments (%) Cows treated by day 60 post-calving Cows treated during the study Other health problems (%) Cows treated for milk fever by day 60 post-calving Cows treated for rumen health issues by day 60 post-calving
Immediate Reason for culling (%) ‘Legs/feet’ problems Mastitis Infertility Othera Stage of lactation when culled (%) o60 days postcalving o120 days postcalving o200 days postcalving o300 days postcalving Total number of cows culledb
4 12 24 35 11 19 13
(8) (23) (46) (67) (21) (37) (25)
2.5 3.2 4.2 4.6 3.1 4.0 3.5
0.051 NS NS NS NS NS NS
2 4 12
(3) (8) (23)
3 10 19
(7) (19) (38)
1.6 2.5 3.6
NS * *
2 5
(3) (10)
3 5
(6) (10)
1.4 1.9
NS NS
3 2
(6) (3)
1 2
(3) (3)
1.3 1.3
NS NS
Delayed
(9)
2
(5)
1.8
NS
3 11 13
(4) (20) (23)
4 13 10
(7) (25) (19)
1.8 3.3 3.1
NS NS NS
1
(2)
0
(0)
0.6
NS
2
(3)
1
(1)
1.1
NS
3
(5)
3
(6)
1.8
NS
10
(18)
8
(15)
2.9
NS
31
(57)
28
(56)
4.5
NS
Delayed
(17) (23) (56) (77) (25) (45) (31)
SED Significance
5
Significance
9 12 28 39 13 23 15
Table 4 The effect of concentrate build-up strategy on the number of cows culled, the reason cows were culled and the stage of lactation when cows were culled (numbers of cows contributing to each value in parenthesis). Concentrate build-up strategy
SED
a Other reasons for culling includes speed of milking, age and temperament of cow, injury, low yields and on farm deaths for ‘other reasons’. b Culled between calving and the study end date (1 June 2014). Cows not calved again by study end date were classified as ‘not culled’ (n¼ 14).
outcomes. Nevertheless, ‘on-farm’ research has limitations, including the precision with which treatments can be imposed, the inability to record information such as individual cow intakes, the reduced frequency with which other data (such as body condition score) can be recorded, and the risk of data being recorded either inaccurately, or not recorded at all. Notwithstanding these limitations, the benefits of on-farm research are considerable, with Drackley and Dann (2008) recognising the role of ‘semi-controlled field trials conducted with larger numbers of farms and cows to generate answers to ‘big picture’ questions’. 4.1. Diet quality and possible intake effects At the outset it was recognised that the approach adopted in the current study would only be feasible on farms where high
quality forage was available. Placing a high reliance on moderate or poor quality forage during the critical few weeks post-calving is something that cannot be advocated. In general, the forages offered on the five participating farms were of good quality, thus these forages were appropriate for the evaluation of the experimental strategies undertaken. Concentrate amounts adopted during the ‘build-up’ phase were relatively similar across the five farms, with mean concentrate amounts in the basal diet ranging from 6.0–9.0 (mean, 7.4) kg/ cow/day, and target total concentrate intakes once ‘build-up’ was complete ranging from 14.0–15.2 (mean, 14.4) kg/cow/day. The range in concentrate feed between farms reflects differences in cow genetic merit and differences in forage quality. With the Delayed build-up treatment, the total ‘theoretical’ saving in concentrates during days 1–35 of lactation was 150 kg/cow (weighted mean across the five farms). However, on four of the five farms the basal diet comprised a concentrate-forage mixture, and consequently cows on the Delayed build-up strategy on these farms are likely to have consumed more of the basal diet (including concentrates) than cows on the Immediate build-up strategy. Thus the difference in concentrate intakes between build-up strategies during this early lactation period will not have been as large as the ‘theoretical’ difference highlighted. For example, within the study by Law et al. (2011a) the total concentrate intake during the first 42 days of lactation was 135 kg/cow lower with the Delayed buildup strategy, compared to a ‘theoretical’ concentrate saving of 214 kg/cow. On the fifth farm all concentrates were offered via an out-of-parlour feeder, and consequently cows on the Delayed build-up strategy were unable to consume additional concentrates from the basal diet. While lower concentrate intakes are normally associated with lower total DM intakes (Mayne and Gordon, 1984; Kuoppala et al., 2004), previous research has demonstrated that the protein concentration of dairy cow diets can be reduced to 144 g/kg DM without having a negative effect on DM intake (Law et al., 2009). While the effect of build-up strategy on forage DM intake and total DM intake could not be measured on the farms, rumen fill assessment, a ‘proxy’ for intake, provided no evidence of differences in intakes between treatments. Nevertheless, Law et al. (2011a) found clear evidence that adopting a delayed concentrate ‘build up’ strategy resulted in higher forage intakes during the period when concentrate amounts were reduced, with these higher forage intakes persisting for a considerable period of time (week 15
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post-calving) after all cows had moved to a common diet. Similarly, during weeks 2 to 4 of lactation, Ingvartsen et al. (2001) observed increased forage intakes with cows managed on a slow rather than a fast post-calving concentrate build-up strategy (an increase of either 0.3 or 0.5 kg/day), although Kokkonen et al. (2004) reported no such effect of concentrate build-up strategy in a similar study. However, as a result of the magnitude of reduction in concentrate offered during the current study it is likely that cows on the Delayed build-up treatment did have a higher forage intake. 4.2. Milk yield The lower concentrate intakes and the lower amount of dietary protein adopted in early lactation were designed to slow the rate of increase in milk production at this time. Therefore the significantly lower daily milk yields (1.8, 2.4, 2.5 and 1.4 kg/day lower during weeks 2, 3, 4 and 5 post-calving, respectively) with the Delayed build-up treatment in early lactation were not unexpected, and support the first hypothesis for the study. Law et al. (2011a), in a study involving a similar delayed build-up strategy, observed a similar effect, with daily milk yields reduced by 3.5 kg/ day during weeks 3–6 of lactation. Once cows on both treatments moved to a ‘common diet’ at day 35 of lactation, no significant differences in mean weekly milk yields were observed during the remainder of the experiment, although small numerical differences were observed until week 8 of lactation (Fig. 2). This supports the first hypothesis, whereby there were no detrimental effects on overall milk yield during the lactation. The results of the current study are supported by the findings of Gilmore et al. (2011), namely that short term reductions in the amount of dietary protein can be used to reduce milk production, while cows are able to respond quickly when the amount of dietary protein is increased. Although the impact of delaying concentrate build-up in early lactation does not appear to have been examined previously, a number of studies have compared the impact of adopting different rates of concentrate build-up postpartum. For example, Ingvartsen et al. (2001) examined two concentrate build-up rates (0.3 or 0.5 kg/day), until cows were offered 10.2 kg concentrate/day, while Andersen et al. (2012) examined four build-up rates (0.3, 0.5, 0.7 and 1.0 kg/day) on Norwegian dairy farms. Furthermore, Kokkonen et al. (2004) compared a slow (0.5 kg/day for 10 days, followed by 0.3 kg/day) and a fast (2.0 kg/day for 2 days, followed by 1.0 kg/day for 2 days, and then 0.5 kg/day) concentrate build-up strategy (until intakes were 15.0 kg/day). The results of each of these studies indicate that adopting a slow concentrate build-up strategy had no effect on milk yield over the first 10–12 weeks of lactation. However, in the study by Ingvartsen et al. (2001), milk fat concentration was increased with the slower build-up strategy, with these authors attributing this to the higher proportion of forage in the diet. 4.3. Body condition score Law et al. (2011a) found that adopting a delayed concentrate build-up strategy in early lactation improved energy balance, with cows on this treatment entering positive energy balance at seven weeks post-calving, compared to 18 weeks post-calving with cows on the Immediate build-up strategy. In the current study, body condition score provides a ‘proxy’ for energy balance. Differences in body condition score during the first few weeks of lactation, when treatments were imposed, were small, although numerically higher with cows on the delayed build up strategy. If cows on the Delayed build-up strategy did indeed experience an improved energy status during this early lactation period, it is possible that
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this effect would not have been identified as differences in body condition score during the relatively short period during which treatments were imposed. The actual difference in mean body condition score between treatments in this study was of no practical significance (Fig. 6). 4.4. Fertility While many authors have examined the influence of concentrate feed level on the fertility of dairy cows (McNamara et al., 2003), the current study differs in that the reduction in concentrate feed level was combined with a reduction in dietary CP over the first five weeks of lactation. For example, McNamara et al. (2003), offered two concentrate feed amounts (4.0 vs. 8.0 kg/day) over the first eight weeks of lactation, and whilst they established an improved energy balance with the higher concentrate feed amount, no effects on cow fertility were identified. The fertility outcomes presented in Table 2 are broadly in line with those presented by previous authors for farm data (Butler et al., 1995; Royal et al., 2000; Mayne et al., 2002; Law et al., 2009). For example, Mayne et al. (2002) recorded an interval to first service of 84 days and a calving interval of 407 days in an earlier on-farm survey in Northern Ireland involving 2471 cows. However, the mean conception rate to first service in the former study (37%) was higher than in the current study (28%). While there was no evidence that the Delayed build-up strategy resulted in earlier resumption of visible oestrus, conception rate to first service was higher with the Delayed build-up strategy. This effect was apparent on three of the five farms, with build-up strategy having little effect on conception rate to first service on the remaining two farms. On one of these latter farms, conception rates to first service were exceptional (47%), with improvements in fertility performance less likely to be observed when overall conception rates are high. This improved conception to first service with the Delayed build-up strategy is likely linked to the lower number of cows on this treatment that were treated for ‘fertility issues’, primarily intrauterine washouts to treat metritis, during the first 30 days post calving. Previous research has shown that negative energy balance can lead to an increased incidence of metritis, with this having negative effects on fertility outcomes (Crowe et al., 2014; Drackley and Cardoso, 2014). The uterus is exposed to a wide range of bacteria at calving, and it has been reported that even in the absence of clinical signs of metritis, subclinical metritis may be present in up to 50% of cows which are 40–60 days calved (Sheldon et al., 2008; LeBlanc, 2014), and this will reduce conception rates. Therefore, it is likely that the reduction in uterine infection immediately post-calving within the current study had a positive effect on conception rate to first service. The findings of the current study lend support to the findings of Law et al. (2011a), whereby cows managed on a Slow build-up strategy had a lower incidence of uterine infections (18% less) than those managed on a Rapid concentrate build-up strategy. However, while there was clear evidence of short-term fertility benefits arising from the Delayed build-up strategy, overall fertility performance was unaffected by build-up strategy. Earlier studies involving alternative concentrate build-up strategies in early lactation have also reported no effects on fertility (Law et al., 2011a; Andersen et al., 2012), and this may be due to the relatively short time-frame during which the different nutritional strategies were imposed, and the fact that the milk yield response curves in the current study ‘joined’ shortly after cows were moved to the common nutritional strategy.
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4.5. Cow health The significantly higher somatic cell score observed with cows on the Delayed concentrate build-up treatment (Table 1) was associated with a higher incidence of clinical mastitis (Table 3). There is no obvious explanation for these effects, especially as there was no difference in the incidence of mastitis between treatments during the first 30 days of lactation, the time when the different nutritional strategies were being imposed. In addition, no such effect was observed in other studies which examined either delayed or slow concentrate build-up strategies in early lactation (Law et al., 2011a; Andersen et al., 2012). Furthermore, when examining factors affecting milk somatic cell count, Ayareh and Mirzaei (2014) concluded that one of the main drivers was the incidence of clinical mastitis in the previous lactation, something that treatment groups were not balanced for in this experiment. Whilst it is important to recognise the effect of build-up strategy on somatic cell count and incidence of mastitis given their potential impact on the quality and consequently the saleability of milk (Geary et al., 2013; Ruegg and Pantoja, 2013), it remains unclear if the effects observed in this study were a direct consequence of the concentrate build-up strategies imposed. There was no evidence that the incidence of lameness, or any of the other health problems recorded, were influenced by concentrate build-up strategy. This is in contrast to earlier studies whereby the incidence of lameness and sole lesions increased with higher concentrate feed amounts (Manson and Leaver, 1988), although these concentrate feed amounts were fed over a longer period than in the current study. 4.6. Culling While cows are culled from herds for many reasons, culling data can provide an additional picture of cow health during the lactation and overall fertility outcomes. In particular, the numbers of cows culled in the early lactation period is a good indicator of early lactation management, as cows culled at this stage will normally be ‘involuntary’ culls, namely cows that are injured or chronically sick. However, relatively few cows were culled during this period in the present study. This is in contrast to the relatively high numbers of cows that have been previously reported as leaving the herd prior to day 60 post-calving. For example, Dechow and Goodling (2008) in a study involving 2574 dairy herds in Pennsylvania also noted that 7.6% of cows were culled within 60 days post-calving. In contrast, the majority of cows culled in the present study were culled after day 300 of lactation, with the results demonstrating that early lactation concentrate allocation strategy had no impact on the number of cows culled at any stage of the experiment, or on the reasons why cows were culled. In agreement with previous studies (Esslemont and Kossaibati, 1997; Mayne et al., 2002), infertility was the predominant single reason for culling (45 out of 113 cows culled) in the current study. Overall, while the results highlight that the build-up strategies adopted in early lactation had a number of short term health and fertility benefits, the second hypothesis is rejected in that these did not result in longer term benefits.
5. Conclusions The increased automation of concentrate feeding on many farms facilitates the adoption of alternative concentrate build-up strategies. Adopting a delayed build-up strategy, in combination with lower protein concentrates, had no adverse effects on milk production over the entire lactation. Short term benefits in terms of improved conception rates to first service with the Delayed
build-up strategy were not reflected in an overall improvement in fertility performance. However, the incidence of mastitis increased with the Delayed build-up strategy, although the reason for this effect is unclear. Based on the outcomes of this experiment, there is little evidence to support the adoption of a delayed concentrate build-up strategy in early lactation.
Acknowledgements The authors acknowledge the assistance of the five participating farmers, their families, their nutritionists and the milk recording agencies during the completion of this study. Financial support from the Department of Agriculture and Rural Development Northern Ireland (via Research Challenge Fund) and the AgriSearch Dairy Committee is gratefully acknowledged.
References Agnew, R.E., Yan, T., France, J., Kebreab, E., Thomas, C., 2004. Feed Into Milk. A New Applied Feeding System for Dairy Cows. Nottingham University Press, Nottingham. Andersen, F., Osteras, O., Fjuk, G.H.E., Volden, H., 2012. Effect of concentrate escalation postpartum on the shape of the lactation curve and health parameters of Norwegian dairy cattle. Livest. Sci. 143, 249–258. Ayareh, M., Mirzaei, A., 2014. Factors affecting milk somatic cell count of cows with clinical mastitis. J. Vet. Res. 69, 127–132. Butler W.R., Cherney D.J.R., Elrod C.C, 1995. Milk urea nitrogen analysis: field trial results on conception rates and dietary inputs. In: Proceedings of the Cornell Nutrition Conference, Rochester, New York, USA, pp. 89 –95. Crowe, M.A., Diskin, M.G., Williams, E.J., 2014. Parturition to resumption of ovarian cyclicity: comparative aspects of beef and dairy cows. Animal 8, 40–53. Dechow, C.D., Goodling, R.C., 2008. Mortality, culling by sixty days in milk, and production profiles in High- and Low-survival Pennsylvania herds. J. Dairy Sci. 91, 4630–4639. Drackley, J.K., Dann, H.M., 2008. A scientific approach to feeding dry cows. Recent Adv. Anim. Nutr. 2007 (1), 43–74. Drackley, J.K., Cardoso, F.C., 2014. Prepartum and postpartum nutritional management to optimise fertility in high-yielding dairy cows in confined TMR systems. Animal 8, 5–14. Edmonson, A.J., Lean, I.J., Weaver, L.D., Farver, T., Webster, G., 1989. A body condition scoring chart for Holstein dairy cows. J. Dairy Sci. 72, 68–78. Esslemont, R.J., Kossaibati, M.A., 1997. Culling in 50 dairy herds in England. Vet. Rec. 140, 36–39. Ferris, C.P., Gordon, F.J., Patterson, D.C., Kilpatrick, D.J., Mayne, C.S., McCoy, M.A., 2001. The response of dairy cows of high genetic merit to increasing proportion of concentrate in the diet with a high and medium feed value silage. J. Agric. Sci. 136, 319–329. Geary, U., Lopez-Villalobos, N., O'Brien, B., Garrick, D.J., Shalloo, L., 2013. Examining the impact of mastitis on the profitability of the Irish dairy industry. Ir. J. Agric. Food Res. 52, 135–149. Gilmore, H., Young, F.J., Patterson, D.C., Wylie, A.R.G., Law, R.A., Elliot, C., Mayne, C. S., 2011. An evaluation of the effect of altering nutrition and nutritional strategies in early lactation on reproductive performance and estrous behavior of high yielding Holstein-Friesian dairy cows. J. Dairy Sci. 94, 3510–3526. Gordon, F.J., Cooper, K.M., Park, R.S., Steen, R.W.J., 1998. The prediction of intake potential and organic matter digestibility of grass silages by near infrared reflectance spectroscopy analysis of undried samples. Anim. Feed. Sci. Technol. 70, 339–351. Ingvartsen, K.L., Aaes, O., Andersen, J.B., 2001. Effects of pattern of concentrate allocation in the dry period and early lactation on feed intake and lactational performance in dairy cows. Livest. Prod. Sci. 71, 207–221. Ingvartsen, K.L., 2006. Feeding- and management-related diseases in the transition cow. Physiological adaptations around calving and strategies to reduce feedingrelated diseases. Anim. Feed. Sci. Tech. 126, 215–236. Ingvartsen, K.L., Moyes, K., 2013. Nutrition, immune function and health of dairy cattle. Animal 7, 112–122. Kleen, J.L., Hooijer, G.A., Rehage, J., Noordhuizen, J.P.T.M., 2003. Subacute ruminal acidosis (SARA): A Review. J. Vet. Med., Ser. A – Physio. Pathol. Clin. Med. 50, 406–414. Kokkonen, T., Tesfa, A., Tuori, M., Syrjala-Qvist, L., 2004. Concentrate feeding strategy of dairy cows during transition period. Livest. Prod. Sci. 86, 239–251. Krause, K.M., Oetzel, G.R., 2006. Understanding and preventing subacute ruminal acidosis in dairy herds: a review. Anim. Feed. Sci. Technol. 126, 215–236. Kuoppala, K., Yrjanen, S., Jaakkola, S., Kangasniemi, R., Sariola, J., Khalili, H., 2004. Effects of increasing concentrate energy supply on the performance of loosehoused dairy cows fed grass silage-based diets. Livest. Prod. Sci. 85, 15–26. Law, R.A., Young, F.J., Patterson, D.C., Kilpatrick, D.J., Wylie, A.R.G., Mayne, C.S., 2009.
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
Effect of dietary protein content on fertility of dairy cows during early and mid lactation. J. Dairy Sci. 92, 2737–2746. Law, R.A., McGettrick S., Ferris C.P, 2011a. Effect of concentrate build-up strategy in early lactation on production performance, health and fertility of high yielding dairy cows. In: Proceedings of the British Society of Animal Science, p. 5. Law, R.A., Young, F.J., Patterson, D.C., Kilpatrick, D.J., Wylie, A.R.G., Ingvarsten, K.L., Hameleers, A., McCoy, M.A., Mayne, C.S., Ferris, C.P., 2011b. Effect of precalving and postcalving dietary energy level on performance and blood metabolite concentrations of dairy cows throughout lactation. J. Dairy Sci. 94, 808–823. LeBlanc, S.J., 2014. Reproductive tract inflammatory disease in postpartum dairy cows. Animal 8, 54–63. McCleary, B.V., Solah, V., Gibson, T.S., 1994. Quantitative measurement of total starch in cereal flours and products. J. Cereal Sci. 20, 51–58. McNamara, S., Murphy, J.J., Rath, M., O'Mara, F.P., 2003. Effects of different transition diets on energy balance, blood metabolites and reproductive performance in dairy cows. Livest. Prod. Sci. 84, 195–206. Manson, F.J., Leaver, J.D., 1988. The influence of concentrate amount on locomotion and clinical lameness in dairy cattle. Anim. Prod. 47, 185–190. Mayne, C.S., Gordon, F.J., 1984. The effect of type of concentrate and level of concentrate feeding on milk production. Anim. Prod. 39, 65–76. Mayne, C.S., McCoy, M.A., Lennon, S.D., Mackey, D.R., Verner, M., Catney, D.C., McCaughey, W.J., Wylie, A.R.G., Kennedy, B.W., Gordon, F.J., 2002. Fertility of dairy cows in Northern Ireland. Vet. Rec. 150, 707–713. Mulligan, F.J., O'Grady, L., Rice, D.A., Doherty, M.A., 2006. A herd health approach to dairy cow nutrition and production diseases of the transition cow. Anim. Reprod. Sci. 96, 331–353. Park, R.S., Agnew, R.E., Gordon, F.J., Steen, R.W.J., 1998. The use of near infrared d reflectance spectroscopy (NIRS) on undried samples of grass silage to predict chemical composition and digestibility parameters. Anim. Feed. Sci. Technol.
111
72, 155–167. Reksen, O., Gröhn, Y.T., Havrevoll, O.S., Bolstad, T., Waldmann, A., Ropstad, E., 2001. Influence of concentrate allocation and energy balance on postpartum ovarian activity in Norwegian cattle. J. Dairy Sci. 84, 1060–1068. Roche, J.R., Friggens, N.C., Kay, J.K., Fisher, M.W., Stafford, K.J., Berry, D.P., 2009. Invited review: Body condition score and its association with dairy cow productivity, health and welfare. J. Dairy Sci. 92, 5769–5801. Roche, J.R., Bell, A.W., Overton, T.R., Loor, J.J., 2013. Nutritional management of the transition cow in the 21st century – a paradigm shift in thinking. Anim. Prod. Sci. 53, 1000–1023. Royal, M.D., Darwash, A.O., Flint, A.P.F., Webb, R., Wooliams, J.A., Lamming, G.E., 2000. Declining fertility in dairy cattle: changes in traditional and endocrine parameters of fertility. Anim. Sci. 70, 487–501. Ruegg, P.L., Pantoja, J.C.F., 2013. Understanding and using somatic cell counts to improve milk quality. Ir. J. Agric. Food Res. 52, 101–117. Sheldon, I.M., Williams, E.J., Miller, A.N.A., Nash, D.M., Herath, S., 2008. Uterine diseases in cattle after parturition. Vet. J. 176, 115–121. Sinclair, K.D., Garnsworthy, P.C., Mann, G.E., Sinclair, L.A., 2014. Reducing dietary protein in dairy cow diets: implications for nitrogen utilisation, milk production, welfare and fertility. Animal 8, 262–274. Whelan, S.J., Mulligan, F.J., Gath, V., Flynn, B., Pierce, K.M., 2014. Short communication: Effect of dietary manipulation of crude protein content and nonfibrous-to-fibrous carbohydrate ratio on energy balance in early lactation dairy cows. J. Dairy Sci. 97, 7220–7224. Wilmink, J.B.M., 1987. Adjustment of lactation yield for age at calving in relation to level of production. Livest. Prod. Sci. 16, 321–334. Zaaijer, D., Noordhuizen, J.P.T.M., 2003. A novel scoring system for monitoring the relationship between nutritional efficiency and fertility in dairy cows. Ir. Vet. J. 56, 145–151.
Contents lists available at ScienceDirect
Livestock Science journal homepage: www.elsevier.com/locate/livsci
The effect of early lactation concentrate build-up strategy on milk production, reproductive performance and health of dairy cows A.J. Dale a,n, B. Hunter a, R. Law a, A.W. Gordon b, C.P. Ferris a a b
Agri-Food and Biosciences Institute, Hillsborough, Co Down BT26 6DR, Northern Ireland, United Kingdom Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, United Kingdom
art ic l e i nf o
a b s t r a c t
Article history: Received 16 July 2015 Received in revised form 22 December 2015 Accepted 30 December 2015
The objective of this study was to examine the effect of two early lactation concentrate build-up strategies on cow performance, fertility and health. The study was undertaken on five Northern Ireland dairy farms, and involved 385 multiparous Holstein-Friesian cows. Cows were allocated to either an ‘Immediate’ or ‘Delayed’ concentrate build-up strategy postpartum. All cows were offered a ‘basal’ diet comprising forage and concentrates (mean, 7.4 kg concentrate/cow/day), with a target crude protein (CP) and starch concentration of 145 and 170 g/kg dry matter (DM), respectively. An additional 7.0 kg of concentrate (mean across the five farms) was then introduced into the diet of each cow, at an incremental rate of approximately 0.5 kg/day, over days 1–14 of lactation (‘Immediate build-up’) or over days 21–35 of lactation (‘Delayed build-up’), with the target CP and starch concentration of the total diet being 175 and 200 g/kg DM, respectively. While average daily milk yield and fat-plus-protein yield was reduced (P o0.05) during weeks 2 to 5 of lactation with the Delayed concentrate build-up strategy, treatment had no effect on milk yield, milk composition or milk fat and protein concentration over the first 305 days of lactation. Cows on the Delayed build-up strategy produced milk with a higher somatic cell score (P o0.05), while no treatment time interactions were observed on body condition score during the experimental period. Conception rate to first service was higher with the Delayed build-up strategy (P ¼0.047), although treatment had no effect on conception to first and second service, calving interval and cows confirmed pregnant during the study (P 40.05). The Delayed build-up strategy tended (P ¼0.051) to reduce the incidence of fertility related health issues within the first 30 days of lactation, but increased the incidence of mastitis (P o0.05). Treatment had no effect on any other health measures, the reasons that cows were culled, or the stage of lactation when cows were culled (P40.05). Although concentrate build-up strategy had short-term effects on milk yield and fertility in early lactation, no long term benefits in performance, fertility, health or survival were observed with the Delayed Build-up strategy. & 2016 Elsevier B.V. All rights reserved.
Keywords: Concentrate build-up strategy Dairy cows Fertility Survival
1. Introduction Within the annual production cycle of a dairy cow, the period immediately prior to calving and the period immediately postcalving (transition period) presents the greatest nutritional challenges (Roche et al., 2013). In addition, genetic selection has resulted in increasing milk yields in many countries (Ingvartsen and Moyes, 2013), especially during this early lactation period. As a consequence, during the first eight weeks of lactation high yielding dairy cows are generally unable to consume enough dry matter (DM) to meet their energy requirements for milk production, and n Corresponding author at: Agri-Food and Biosciences Institute, Large Park, Hillsborough, Co Down BT26 6DR, Northern Ireland. E-mail address: [email protected] (A.J. Dale).
http://dx.doi.org/10.1016/j.livsci.2015.12.016 1871-1413/& 2016 Elsevier B.V. All rights reserved.
may enter a period of negative energy balance. The prevalence of negative energy balance (NEB) has been well documented (Mulligan et al., 2006; Ingvartsen and Moyes, 2013; Roche et al., 2009; Reksen et al., 2001; Crowe et al., 2014; Drackley and Cardoso, 2014), and many authors have reported the detrimental effect that NEB, and the associated mobilisation of body tissue, have on the subsequent health, production, fertility and longevity of dairy cows. As a consequence, high yielding cows suffer a much greater incidence of health problems during the first few weeks postcalving than at any other time during lactation (Ingvartsen, 2006; Drackley and Cardoso, 2014). To help meet the nutrient requirements of high yielding cows in early lactation, concentrate inclusion amounts in dairy cow diets have increased considerably in recent years. Although the inclusion of concentrate feeds can improve the energy density of the diet, offering high amounts of concentrates can have a
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detrimental effect on rumen health. Sub-acute rumen acidosis (Krause and Oetzel, 2006; Kleen et al., 2003) occurs when rumen pH is depressed to between 5.5 and 5.0, and in this environment intake can be adversely affected as fibre digestion and rumen microbial activity are impaired. Furthermore, although there is evidence that increased amounts of concentrate feed normally leads to improved nutrient intakes (Ferris et al., 2001), energy balance may not necessarily improve dramatically as cows with a high genetic potential for milk production may exhibit a milk yield response to the additional concentrates offered. Given that there is evidence (Ingvartsen, 2006) that the risk of disease is related to the rate of acceleration in milk production during the early lactation period, a reduction in this acceleration in milk yield could have beneficial effects on cow health. It is known that dietary energy (Law et al., 2011b) and protein concentration (Law et al., 2009; Gilmore et al., 2011; Sinclair et al., 2014; Whelan et al., 2014) can be used to modify the milk yields of cows in early lactation, while Law et al. (2009) demonstrated that dietary protein concentration can be reduced from 173 to 144 g/kg DM without any detrimental effect on total dry matter intake, with these levels adopted up to 150 days post-calving. These authors also reported that increases in dietary protein content decreased average daily energy balance. Thus it may be possible, by diet manipulation, to reduce the rate at which milk yield increases postpartum, and thus delay the attainment of peak-yield, with peak yield being better aligned with maximum DM intake. Practically, this approach could be administered by making changes to concentrate supplementation during early lactation (Ingvartsen et al., 2001; Kokkonen et al., 2004; Law et al., 2011a; Andersen et al., 2012). For example, reducing dietary protein concentration, and delaying the build-up of concentrates in the diet from immediately postpartum to day 28 postpartum, reduced the acceleration of milk yield in early lactation, but had no detrimental effect on milk production when considered over the full lactation (305 days) (Law et al., 2011a). Furthermore, the authors reported an improvement in forage intake when concentrate allocation was delayed. Despite evidence that a delayed concentrate allocation strategy, combined with lower protein diets, can reduce the duration and severity of negative energy balance and reduce the acceleration in milk yield (Law et al., 2011a), there is little evidence of benefits in cow health and fertility. Thus the current study, which was conducted on five commercial dairy farms to increase the number of cows involved, was designed to examine the effect of two contrasting early lactation concentrate build-up strategies on cow performance, health and fertility. The study was designed to test two hypotheses; 1. Adoption of a delayed concentrate build-up strategy post-calving can reduce the rate of increase in milk production in early lactation, without having a detrimental effect on overall milk yield or quality during the lactation, compared to an immediate concentrate build-up strategy; 2. A reduction in the rate of increase in milk production post-calving has beneficial effects on cow health and fertility.
2. Materials and methods 2.1. Participating farms and cows This experiment was conducted on five Northern Ireland dairy farms between October 2012 and June 2014. During the year prior to the study, average annual concentrate inputs and milk outputs on the five farms were 2880 (s.d., 81) kg/cow and 8780 (s.d., 1112) litres/cow, respectively. The study involved 385 multiparous Holstein-Friesian cows (mean parity 3.0; s.d. 0.87), which calved between October 2012
Fig. 1. An overview of the two early lactation concentrate build-up strategies imposed on the five farms during this study.
and April 2013, with all cows calving during this period (with the exception of primiparous cows) eligible for inclusion within the study. Cows that were identified as ‘to be culled’ during the subsequent lactation, based on a number of factors including their history of chronic health issues, were not allocated to the study. Cows were allocated to one of two experimental treatments at calving, comprising either an ‘Immediate’ or ‘Delayed’ concentrate build-up strategy. Treatment groups on each farm were balanced for parity, for body condition score assessed approximately two weeks prior to the expected calving date, calving interval, calving date, and milk yield (305 days), milk composition and somatic cell count during the previous lactation. There were 57, 75, 67, 72 and 114 experimental cows on Farms 1 to 5, respectively. 2.2. Experimental design Following calving all experimental cows were offered a ‘basal’ diet (Fig. 1), with this diet comprising conserved forage (either grass silage only, or grass silage mixed with maize silage or whole crop wheat silage) and concentrates. The concentrate inclusion rate (as fed) within the basal diet ranged from 6.0–9.0 kg/cow/day across the five farms (mean; 7.4 kg/cow/day), while the target CP, starch and metabolisable energy (ME) concentration of the basal diet was 145 g/kg DM, 170 g/kg DM and 12.2 MJ/kg DM. Rations offered were formulated by each farms own nutritionist, in conjunction with the lead researcher, with each farm using a different nutritionist. Ration formulation was based on the equations contained within ‘Feed Into Milk’ (Agnew et al., 2004), the current UK dairy feed rationing system, and the ME and intake potential of the forages available on each farm, as determined by near-infra-red reflectance spectroscopy (Gordon et al., 1998). Predicted forage intakes were monitored by the nutritionist against actual group intakes being achieved. Cows managed on the ‘Immediate’ build-up strategy had additional concentrates introduced into the diet (‘build-up’ concentrate) during the first 14 days post-calving, with concentrates being increased in 0.5 kg increments daily (approximately), up to an average of 7.0 kg/cow/day (range across farms, 6.0–8.0 kg/cow/ day). Cows managed on the ‘Delayed’ build-up strategy were not offered additional concentrates until day 21 postpartum, with concentrates then introduced gradually into the diet of these cows in 0.5 kg increments daily (approximately) during a 14-day period (days 21–35 postpartum), to achieve the same concentrate amount as adopted with the Immediate build-up strategy (on each farm). These build-up concentrates were offered either in-parlour during milking or via out-of-parlour feeders, with total daily concentrate allowance being 14.0, 14.0, 14.0, 15.0 and 15.2 kg/cow across the five farms. Within one to two weeks of cows reaching their full ‘experimental’ concentrate allocation (day 14 (Immediate) and day
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
35 (Delayed)), cows on all farms moved to a ‘feed-to-yield’ concentrate allocation strategy, with each farm following their own individual feeding strategy from this time onwards, and with the same strategy being adopted for cows on both treatments. The target CP, starch and metabolisable energy concentration of the total diet once the full ’experimental’ concentrate allocation had been achieved was 175 g/kg DM, 200 g/kg DM and 12.5 MJ/kg DM, respectively. All cows remained indoors during the first 35 days of lactation. On one of the farms cows remained confined throughout the lactation, while on the other four farms cows were given access to grazing from May to September, approximately. 2.3. Measurements All farms were visited fortnightly by a trained technician from October 2012 to July 2013, and then on a monthly basis until January 2014. Thereafter farms were visited on a further three occasions to collect data, with the final visit taking place in June 2014. 2.4. Animals All five herds participated in official milk recording schemes, with milk recording undertaken approximately fortnightly during the first two months of lactation, and then either monthly or once every six weeks thereafter. Data provided by the recording agencies included individual cow test-day milk yields, milk fat concentration, milk protein concentration and somatic cell count (000/ml), and 305-day milk production data. In addition, on four of the farms milk yields for each cow were recorded daily using inline milk meters, with these data used to determine weekly milk yields during the experimental period. The parlour on one of the farms did not facilitate automatic recording of daily milk yields, and on this farm weekly milk yields were determined from the lactation curve which was fitted to the yield data recorded monthly within the official milk recording scheme, as detailed above. During each visit the body condition score of cows that were due to calve during the subsequent two-week period, and of all lactating cows on the experiment, were assessed. Body condition score was assessed as described by Edmonson et al. (1989). However, to facilitate additional precision, an additional ‘plus’ or ‘minus’ was added to a score when appropriate. Thus a cow with a conventional score of 2.25 could be scored as either 2.15, 2.25 or 2.35. In addition, rumen fill was assessed at each visit until June 2013, at which point all cows were a minimum of 80 days postcalving, although some cows were monitored up until 250 days post-calving. Rumen fill was assessed according to the methodology described by Zaaijer and Noordhuizen (2003), with the observer standing at the left hind side of the cow. As rumen fill is influenced by management factors such as time since last feed, the data were adjusted to allow comparisons to be made between farms and between visits. Therefore, individual animal rumen fill scores were adjusted to a deviation from a mean rumen fill score for the visit in question. This deviation allows rumen fill across visits and farms to be compared. Information on calving date, ‘fertility’, health and culling were recorded by the farmer. Fertility data included date of first observed heat, date of first and subsequent services and details of treatments relating to reproductive problems (for example; follicular cysts, luteal cysts, anoestrous and synchronisation). All incidences of ill-health and associated treatments during the experimental period were recorded by the farmer. This included metabolic, infectious and digestive problems. Metabolic problems included milk fever (staggering or downer cows), infectious diseases included clinical metritis (cows treated for metritis after
105
7 days post-calving), clinical mastitis and lameness and digestive problems included displaced abomasum (veterinary diagnosis). For each cow culled, the date and reasons for culling were recorded. 2.5. Feeds The forages offered to the experimental cows were sampled once every six weeks approximately from October 2012 to May 2013 (n ¼34), and analysed using near infra-red reflectance spectroscopy (NIRS), as described by Park et al. (1998). All concentrates offered were sampled on a single occasion mid way through the main winter feeding period, with samples dried at 60 °C for 48 h and subsequently analysed for nitrogen and starch concentration. Concentrate CP (total nitrogen 6.25) concentration was determined using the Kjeldahl method (Tecator Kjeltec Auto 2400/ 2460 Analyzer/Sampler System, Hilleroed, Denmark), while starch concentration was determined using a Megazyme kit (McCleary et al., 1994). 2.6. Statistical analysis Full lactation (305 days) milk production data (based on individual cow data), days to first observed heat, days to first service and calving interval data were analysed by Analysis of Variance ANOVA (Genstat Sixteenth Edition, 2013, Lawes Agricultural Trust, Rothamsted, UK), with the model used including treatment (Immediate or Delayed concentrate build-up strategy), farm (1–5) and parity (defined as 2 (n ¼ 152), 3 (n ¼ 94) or 43 (n¼ 139)), while corresponding milk production values from the previous lactation were used as covariates for the milk data. Milk production data for cows completing o 200 days of lactation (n ¼15) were excluded from the analysis. Mean milk yield data (weekly until day 150 of lactation, and at 30-day intervals thereafter, until day 305 of lactation) and milk composition data (recorded every 4–6 weeks, until day 305 of lactation) were analysed by Residual Maximum Likelihood (REML) analysis, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (week of lactation), farm (1–5), and parity (2, 3, 4 3), and treatment x time. In addition, previous lactation data (milk yield and milk composition) were used within the model. Body condition score data over the lactation were analysed by REML, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (weeks postcalving), farm (1–5) and parity (2, 3, 4 3) within the model, and pre-calving body condition score as a covariate. ‘Weeks’ represented data collected at 14-day intervals up to day 150 of lactation, and subsequently 30-day intervals up to day 305 of lactation. Rumen fill data were analysed by REML, with cow included as the repeated measure, and with the model including treatment (Immediate or Delayed concentrate build-up strategy), time (weeks post calving), farm (1–5) and parity (2, 3, 43) within the model. ‘Weeks’ represented data collected at 14-day intervals up to day 150 of lactation, and subsequently 30-day intervals up to day 250 of lactation. The proportion of cows which calved again, conception rates to first and second service, and animal health and culling data were analysed as a binomial distribution, including parity (2, 3, 4 3) and farm (1– 5) within the model (ANOVA). In addition, the shape of the lactation curve for milk yield and fat plus protein yield was determined for individual cows by fitting an exponential model curve (Wilmink, 1987):
Yt = a + b × e−0.05 × t + c × t
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Within this model, a, b and c parameters relate to the intercept, the incline and the decline of the curve, respectively, and Yt relates to milk production on day t. REML analysis was used to identify treatment effects on each of the parameters.
3. Results 3.1. Feeds offered The mean DM, CP and ME concentration of the grass silages offered across the farms were 309 (s.d., 47.9) g/kg, 139 (s.d., 14.1) g/ kg DM and 11.6 (s.d., 0.28) MJ/kg DM, respectively. The mean CP and starch concentration of the concentrates offered across the farms was 232 (s.d., 15.8: range, 217–259) g/kg DM and 248 (s.d., 86.4: range, 139–358) g/kg DM, respectively. Based on predicted silage DM intakes, the CP, ME and starch concentrations of the basal diets offered were calculated to range from 146 to148 g/kg DM, 11.9 to12.8 MJ/kg DM and 128 to 179 g/kg DM, respectively. Similarly, the CP, ME and starch concentrations of the total diets offered across the five farms were calculated to range from 170 to 171 g/kg DM, 12.2 to 13.0 MJ/kg DM and 168 to 200 g/kg DM, respectively.
Fig. 2. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on daily milk production over the 305-day experimental period (error bars represent standard errors). Main effects of treatment, week and treatment x week examined (SED; 0.43, 0.34, 0.57, respectively) (SIG; NS, ***, **, respectively).
3.2. Animal performance 3.2.1. Milk yield Concentrate build-up strategy had no effect (P 40.05) on either total milk output, milk composition or the yield of milk fat, protein or fat plus protein over the first 305 days of lactation (Table 1). Milk produced by cows on the Immediate and Delayed build-up strategies had mean somatic cell counts of 282,000 and 315,000 cells/ml, respectively, with somatic cell scores being significantly higher with the Delayed build-up strategy (Po 0.05). Although there was no overall effect of treatment on average daily milk yield or fat plus protein yield, cows on the Delayed build-up strategy had a lower milk yield (Fig. 2) and fat plus protein yield (Fig. 4) during weeks 2, 3, 4 and 5 (P o0.05) of lactation than those on the Immediate build-up strategy. Milk yield (Fig. 2), milk fat and milk protein concentration (Fig. 3), milk fat plus protein yield (Fig. 4) and somatic cell score (Fig. 5) all varied with week of lactation (P o0.001), while there was a significant treatment x week of lactation interaction for milk yield (P 40.01) and fat plus protein yield (P o0.05).There was no significant (P 40.05) treatment x week of lactation interaction for body condition score (Fig. 6). While rumen fill (deviation) varied with week of lactation (P4 0.001), there was no significant effect of treatment and no significant treatment week of lactation Table 1 Effect of concentrate build-up strategy on animal performance over the first 305 days of lactation. Concentrate build-up strategy SED
Total milk output (kg/ cow) Milk fat (g/kg) Milk protein (g/kg) Total milk fat yield (kg/ cow) Total milk protein yield (kg/cow) Total milk fat plus protein yield (kg/cow) Somatic cell score (loge)
Fig. 3. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on the fat and protein concentration of the milk produced over the 305day experimental period (error bars represent standard errors).
Fig. 4. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on daily milk fat-plus-protein yield over the 305-day experimental period (error bars represent standard errors).
Significance
Immediate
Delayed
10,063
9914
145.4
NS
39.3 32.0 393
39.4 32.1 388
0.31 0.16 5.9
NS NS NS
322
317
4.4
NS
714
705
9.9
NS
11.70
11.93
0.110
*
Fig. 5. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on milk somatic cell score (loge) over the 305-day experimental period (error bars represent standard errors).
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
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Table 2 Effect of concentrate build-up strategy on fertility performance (number of cows contributing to each value in parenthesis). Concentrate build-up strategy Immediate
Fig. 6. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on body condition score over the 305-day experimental period (error bars represent standard errors).
Days to first ob62 served heat Days to first service 76 Conception to first 23 service (%) 47 Conception to first and second service (%) Cows confirmed 70 pregnant (%)a 394 Calving interval (days)b
SED Significance
Delayed
(187)
60
(190)
3.0
NS
(177) (45)
76 32
(179) (61)
3.1 4.4
NS 0.047
(92)
50
(96)
5.0
NS
(137)
72
(136)
4.5
NS
(129)
389
(129)
6.6
NS
a Confirmed pregnant by 1 June 2014, by which time all cows were 4413 days post-calving. b For cows confirmed pregnant and still on the farm until the subsequent calving.
Fig. 7. Effect of concentrate build-up strategy (...... Immediate; ____ Delayed) in early lactation on the deviation in rumen fill over the first 250 days of the experimental period (error bars represent standard errors).
interaction (P 40.05) (Fig. 7). Parameters of the Wilmink curve (a, b and c) describe the lactation profiles for the daily yield and fat plus protein yield for both treatments. Build-up strategy had no effect on daily yield (P 40.05) in terms of parameter a (Immediate, 51.2 vs. Delayed, 50.0: P ¼0.230, s.e.d. 0.86), describing the starting milk yield (intercept) of the lactation curve; parameter b (Immediate, 24.4 vs. Delayed, 25.5; P ¼0.491, s.e.d. 1.54;), describing the slope and peak of the curve (incline); or parameter c (Immediate, 0.10 vs. Delayed, 0.10; P ¼0.846, s.e.d. 0.0008;), describing the persistency of lactation (decline). Similarly, build-up strategy had no effect on daily fat plus protein yield (P4 0.05) in terms of parameter a (Immediate, 3.5 vs. Delayed, 3.4: P¼ 0.102, s.e.d. 0.05); parameter b (Immediate, 1.3 vs. Delayed, 1.6; P ¼0.155, s.e.d. 0.18;); or parameter c (Immediate, 0.007 vs. Delayed, 0.006; P ¼0.094, s.e.d. 0.0003;).
percentage of cows on the Immediate build-up strategy to be treated for fertility related health issues by day 30 post calving, than with the Delayed build-up strategy (Table 3), although the percentage treated by either day 60 or day 90 post-calving was unaffected by treatment (P4 0.05). Of the 25 cows treated for fertility related health issues by day 30 post-calving, 23 received an ‘intrauterine washout’. Although concentrate build-up strategy had no effect on the incidence of mastitis by day 30 post-calving (P4 0.05), the incidence of mastitis was higher with the Delayed concentrate buildup by day 60 post-calving (9.5% vs. 4.2%) and throughout the entire study period (19.0% vs. 12.0%) (P o0.05). Concentrate build-up strategy had no effect on the incidence of lameness during the study, or on the percentage of cows treated for milk fever or rumen health issues (P 40.05). 3.2.4. Culling Of the 127 cows that did not calve again prior to the study end date (1 June 2014), 113 cows were culled (Table 4), while the remaining 14 cows were still present within the herds. Concentrate build-up strategy had no effect on the percentage of cows culled due to ‘legs/feet’, mastitis, infertility, or ‘other’ reasons (P 40.05), the percentage of cows culled at any of the four time intervals examined (Table 4), or the total number of cows culled (P4 0.05). Few cows (n ¼11) were culled prior to day 200 post-calving.
4. Discussion 3.2.2. Cow fertility Concentrate build-up strategy had no effect (P 40.05) on days to first observed heat or days to first service (Table 2). Conception to first service was higher with the Delayed concentrate build-up strategy (P o0.05), however build-up strategy had no effect on conception to first and second service (P4 0.05). At the end of the experiment (1 June 2014), 273 of the 385 cows on the study had been confirmed pregnant, although concentrate build-up strategy had no effect on the proportion of cows confirmed pregnant. Concentrate build-up strategy had no effect on overall calving interval (P 40.05). 3.2.3. Cow health The percentage of cows treated with either an ‘intrauterine washout’, prostaglandin or progesterone was unaffected by treatment (Table 3: P 40.05). There was a trend (P ¼0.051) for a greater
The primary objective of the current study was to examine the effect of adopting either an Immediate or Delayed concentrate build-up strategy in early lactation on dairy cow performance, with the study designed to complement the findings of an earlier study by Law et al. (2011a). While the treatments examined in the current study were broadly similar to those examined by Law et al. (2011a), the current study was conducted on five commercial dairy farms. The primary reason for this was to increase the number of experimental cows beyond what would be possible within the constraints of most research farms, thus allowing possible effects of build-up strategy on cow health and fertility performance to be identified. In addition, on-farm research is recognised as having many other benefits, including the testing of treatments under what many farmers consider to be ‘real’ farm conditions, and the provision of a highly effective platform for disseminating research
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Table 3 Effect of concentrate build-up strategy on a range of cow health events, and the timing of these events (number of cows contributing to each value in parenthesis). Concentrate build-up strategy Immediate Fertility treatments (%) Cows treated by day 30 post-calving Cows treated by day 60 post-calving Cows treated by day 100 post-calving Cows treated during the study Cows treated with an ‘intrauterine washout’ Cows treated with prostaglandin Cows treated with progesterone Mastitis treatments (%) Cows treated by day 30 post-calving Cows treated by day 60 post-calving Cows treated during the study Lameness treatments (%) Cows treated by day 60 post-calving Cows treated during the study Other health problems (%) Cows treated for milk fever by day 60 post-calving Cows treated for rumen health issues by day 60 post-calving
Immediate Reason for culling (%) ‘Legs/feet’ problems Mastitis Infertility Othera Stage of lactation when culled (%) o60 days postcalving o120 days postcalving o200 days postcalving o300 days postcalving Total number of cows culledb
4 12 24 35 11 19 13
(8) (23) (46) (67) (21) (37) (25)
2.5 3.2 4.2 4.6 3.1 4.0 3.5
0.051 NS NS NS NS NS NS
2 4 12
(3) (8) (23)
3 10 19
(7) (19) (38)
1.6 2.5 3.6
NS * *
2 5
(3) (10)
3 5
(6) (10)
1.4 1.9
NS NS
3 2
(6) (3)
1 2
(3) (3)
1.3 1.3
NS NS
Delayed
(9)
2
(5)
1.8
NS
3 11 13
(4) (20) (23)
4 13 10
(7) (25) (19)
1.8 3.3 3.1
NS NS NS
1
(2)
0
(0)
0.6
NS
2
(3)
1
(1)
1.1
NS
3
(5)
3
(6)
1.8
NS
10
(18)
8
(15)
2.9
NS
31
(57)
28
(56)
4.5
NS
Delayed
(17) (23) (56) (77) (25) (45) (31)
SED Significance
5
Significance
9 12 28 39 13 23 15
Table 4 The effect of concentrate build-up strategy on the number of cows culled, the reason cows were culled and the stage of lactation when cows were culled (numbers of cows contributing to each value in parenthesis). Concentrate build-up strategy
SED
a Other reasons for culling includes speed of milking, age and temperament of cow, injury, low yields and on farm deaths for ‘other reasons’. b Culled between calving and the study end date (1 June 2014). Cows not calved again by study end date were classified as ‘not culled’ (n¼ 14).
outcomes. Nevertheless, ‘on-farm’ research has limitations, including the precision with which treatments can be imposed, the inability to record information such as individual cow intakes, the reduced frequency with which other data (such as body condition score) can be recorded, and the risk of data being recorded either inaccurately, or not recorded at all. Notwithstanding these limitations, the benefits of on-farm research are considerable, with Drackley and Dann (2008) recognising the role of ‘semi-controlled field trials conducted with larger numbers of farms and cows to generate answers to ‘big picture’ questions’. 4.1. Diet quality and possible intake effects At the outset it was recognised that the approach adopted in the current study would only be feasible on farms where high
quality forage was available. Placing a high reliance on moderate or poor quality forage during the critical few weeks post-calving is something that cannot be advocated. In general, the forages offered on the five participating farms were of good quality, thus these forages were appropriate for the evaluation of the experimental strategies undertaken. Concentrate amounts adopted during the ‘build-up’ phase were relatively similar across the five farms, with mean concentrate amounts in the basal diet ranging from 6.0–9.0 (mean, 7.4) kg/ cow/day, and target total concentrate intakes once ‘build-up’ was complete ranging from 14.0–15.2 (mean, 14.4) kg/cow/day. The range in concentrate feed between farms reflects differences in cow genetic merit and differences in forage quality. With the Delayed build-up treatment, the total ‘theoretical’ saving in concentrates during days 1–35 of lactation was 150 kg/cow (weighted mean across the five farms). However, on four of the five farms the basal diet comprised a concentrate-forage mixture, and consequently cows on the Delayed build-up strategy on these farms are likely to have consumed more of the basal diet (including concentrates) than cows on the Immediate build-up strategy. Thus the difference in concentrate intakes between build-up strategies during this early lactation period will not have been as large as the ‘theoretical’ difference highlighted. For example, within the study by Law et al. (2011a) the total concentrate intake during the first 42 days of lactation was 135 kg/cow lower with the Delayed buildup strategy, compared to a ‘theoretical’ concentrate saving of 214 kg/cow. On the fifth farm all concentrates were offered via an out-of-parlour feeder, and consequently cows on the Delayed build-up strategy were unable to consume additional concentrates from the basal diet. While lower concentrate intakes are normally associated with lower total DM intakes (Mayne and Gordon, 1984; Kuoppala et al., 2004), previous research has demonstrated that the protein concentration of dairy cow diets can be reduced to 144 g/kg DM without having a negative effect on DM intake (Law et al., 2009). While the effect of build-up strategy on forage DM intake and total DM intake could not be measured on the farms, rumen fill assessment, a ‘proxy’ for intake, provided no evidence of differences in intakes between treatments. Nevertheless, Law et al. (2011a) found clear evidence that adopting a delayed concentrate ‘build up’ strategy resulted in higher forage intakes during the period when concentrate amounts were reduced, with these higher forage intakes persisting for a considerable period of time (week 15
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
post-calving) after all cows had moved to a common diet. Similarly, during weeks 2 to 4 of lactation, Ingvartsen et al. (2001) observed increased forage intakes with cows managed on a slow rather than a fast post-calving concentrate build-up strategy (an increase of either 0.3 or 0.5 kg/day), although Kokkonen et al. (2004) reported no such effect of concentrate build-up strategy in a similar study. However, as a result of the magnitude of reduction in concentrate offered during the current study it is likely that cows on the Delayed build-up treatment did have a higher forage intake. 4.2. Milk yield The lower concentrate intakes and the lower amount of dietary protein adopted in early lactation were designed to slow the rate of increase in milk production at this time. Therefore the significantly lower daily milk yields (1.8, 2.4, 2.5 and 1.4 kg/day lower during weeks 2, 3, 4 and 5 post-calving, respectively) with the Delayed build-up treatment in early lactation were not unexpected, and support the first hypothesis for the study. Law et al. (2011a), in a study involving a similar delayed build-up strategy, observed a similar effect, with daily milk yields reduced by 3.5 kg/ day during weeks 3–6 of lactation. Once cows on both treatments moved to a ‘common diet’ at day 35 of lactation, no significant differences in mean weekly milk yields were observed during the remainder of the experiment, although small numerical differences were observed until week 8 of lactation (Fig. 2). This supports the first hypothesis, whereby there were no detrimental effects on overall milk yield during the lactation. The results of the current study are supported by the findings of Gilmore et al. (2011), namely that short term reductions in the amount of dietary protein can be used to reduce milk production, while cows are able to respond quickly when the amount of dietary protein is increased. Although the impact of delaying concentrate build-up in early lactation does not appear to have been examined previously, a number of studies have compared the impact of adopting different rates of concentrate build-up postpartum. For example, Ingvartsen et al. (2001) examined two concentrate build-up rates (0.3 or 0.5 kg/day), until cows were offered 10.2 kg concentrate/day, while Andersen et al. (2012) examined four build-up rates (0.3, 0.5, 0.7 and 1.0 kg/day) on Norwegian dairy farms. Furthermore, Kokkonen et al. (2004) compared a slow (0.5 kg/day for 10 days, followed by 0.3 kg/day) and a fast (2.0 kg/day for 2 days, followed by 1.0 kg/day for 2 days, and then 0.5 kg/day) concentrate build-up strategy (until intakes were 15.0 kg/day). The results of each of these studies indicate that adopting a slow concentrate build-up strategy had no effect on milk yield over the first 10–12 weeks of lactation. However, in the study by Ingvartsen et al. (2001), milk fat concentration was increased with the slower build-up strategy, with these authors attributing this to the higher proportion of forage in the diet. 4.3. Body condition score Law et al. (2011a) found that adopting a delayed concentrate build-up strategy in early lactation improved energy balance, with cows on this treatment entering positive energy balance at seven weeks post-calving, compared to 18 weeks post-calving with cows on the Immediate build-up strategy. In the current study, body condition score provides a ‘proxy’ for energy balance. Differences in body condition score during the first few weeks of lactation, when treatments were imposed, were small, although numerically higher with cows on the delayed build up strategy. If cows on the Delayed build-up strategy did indeed experience an improved energy status during this early lactation period, it is possible that
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this effect would not have been identified as differences in body condition score during the relatively short period during which treatments were imposed. The actual difference in mean body condition score between treatments in this study was of no practical significance (Fig. 6). 4.4. Fertility While many authors have examined the influence of concentrate feed level on the fertility of dairy cows (McNamara et al., 2003), the current study differs in that the reduction in concentrate feed level was combined with a reduction in dietary CP over the first five weeks of lactation. For example, McNamara et al. (2003), offered two concentrate feed amounts (4.0 vs. 8.0 kg/day) over the first eight weeks of lactation, and whilst they established an improved energy balance with the higher concentrate feed amount, no effects on cow fertility were identified. The fertility outcomes presented in Table 2 are broadly in line with those presented by previous authors for farm data (Butler et al., 1995; Royal et al., 2000; Mayne et al., 2002; Law et al., 2009). For example, Mayne et al. (2002) recorded an interval to first service of 84 days and a calving interval of 407 days in an earlier on-farm survey in Northern Ireland involving 2471 cows. However, the mean conception rate to first service in the former study (37%) was higher than in the current study (28%). While there was no evidence that the Delayed build-up strategy resulted in earlier resumption of visible oestrus, conception rate to first service was higher with the Delayed build-up strategy. This effect was apparent on three of the five farms, with build-up strategy having little effect on conception rate to first service on the remaining two farms. On one of these latter farms, conception rates to first service were exceptional (47%), with improvements in fertility performance less likely to be observed when overall conception rates are high. This improved conception to first service with the Delayed build-up strategy is likely linked to the lower number of cows on this treatment that were treated for ‘fertility issues’, primarily intrauterine washouts to treat metritis, during the first 30 days post calving. Previous research has shown that negative energy balance can lead to an increased incidence of metritis, with this having negative effects on fertility outcomes (Crowe et al., 2014; Drackley and Cardoso, 2014). The uterus is exposed to a wide range of bacteria at calving, and it has been reported that even in the absence of clinical signs of metritis, subclinical metritis may be present in up to 50% of cows which are 40–60 days calved (Sheldon et al., 2008; LeBlanc, 2014), and this will reduce conception rates. Therefore, it is likely that the reduction in uterine infection immediately post-calving within the current study had a positive effect on conception rate to first service. The findings of the current study lend support to the findings of Law et al. (2011a), whereby cows managed on a Slow build-up strategy had a lower incidence of uterine infections (18% less) than those managed on a Rapid concentrate build-up strategy. However, while there was clear evidence of short-term fertility benefits arising from the Delayed build-up strategy, overall fertility performance was unaffected by build-up strategy. Earlier studies involving alternative concentrate build-up strategies in early lactation have also reported no effects on fertility (Law et al., 2011a; Andersen et al., 2012), and this may be due to the relatively short time-frame during which the different nutritional strategies were imposed, and the fact that the milk yield response curves in the current study ‘joined’ shortly after cows were moved to the common nutritional strategy.
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4.5. Cow health The significantly higher somatic cell score observed with cows on the Delayed concentrate build-up treatment (Table 1) was associated with a higher incidence of clinical mastitis (Table 3). There is no obvious explanation for these effects, especially as there was no difference in the incidence of mastitis between treatments during the first 30 days of lactation, the time when the different nutritional strategies were being imposed. In addition, no such effect was observed in other studies which examined either delayed or slow concentrate build-up strategies in early lactation (Law et al., 2011a; Andersen et al., 2012). Furthermore, when examining factors affecting milk somatic cell count, Ayareh and Mirzaei (2014) concluded that one of the main drivers was the incidence of clinical mastitis in the previous lactation, something that treatment groups were not balanced for in this experiment. Whilst it is important to recognise the effect of build-up strategy on somatic cell count and incidence of mastitis given their potential impact on the quality and consequently the saleability of milk (Geary et al., 2013; Ruegg and Pantoja, 2013), it remains unclear if the effects observed in this study were a direct consequence of the concentrate build-up strategies imposed. There was no evidence that the incidence of lameness, or any of the other health problems recorded, were influenced by concentrate build-up strategy. This is in contrast to earlier studies whereby the incidence of lameness and sole lesions increased with higher concentrate feed amounts (Manson and Leaver, 1988), although these concentrate feed amounts were fed over a longer period than in the current study. 4.6. Culling While cows are culled from herds for many reasons, culling data can provide an additional picture of cow health during the lactation and overall fertility outcomes. In particular, the numbers of cows culled in the early lactation period is a good indicator of early lactation management, as cows culled at this stage will normally be ‘involuntary’ culls, namely cows that are injured or chronically sick. However, relatively few cows were culled during this period in the present study. This is in contrast to the relatively high numbers of cows that have been previously reported as leaving the herd prior to day 60 post-calving. For example, Dechow and Goodling (2008) in a study involving 2574 dairy herds in Pennsylvania also noted that 7.6% of cows were culled within 60 days post-calving. In contrast, the majority of cows culled in the present study were culled after day 300 of lactation, with the results demonstrating that early lactation concentrate allocation strategy had no impact on the number of cows culled at any stage of the experiment, or on the reasons why cows were culled. In agreement with previous studies (Esslemont and Kossaibati, 1997; Mayne et al., 2002), infertility was the predominant single reason for culling (45 out of 113 cows culled) in the current study. Overall, while the results highlight that the build-up strategies adopted in early lactation had a number of short term health and fertility benefits, the second hypothesis is rejected in that these did not result in longer term benefits.
5. Conclusions The increased automation of concentrate feeding on many farms facilitates the adoption of alternative concentrate build-up strategies. Adopting a delayed build-up strategy, in combination with lower protein concentrates, had no adverse effects on milk production over the entire lactation. Short term benefits in terms of improved conception rates to first service with the Delayed
build-up strategy were not reflected in an overall improvement in fertility performance. However, the incidence of mastitis increased with the Delayed build-up strategy, although the reason for this effect is unclear. Based on the outcomes of this experiment, there is little evidence to support the adoption of a delayed concentrate build-up strategy in early lactation.
Acknowledgements The authors acknowledge the assistance of the five participating farmers, their families, their nutritionists and the milk recording agencies during the completion of this study. Financial support from the Department of Agriculture and Rural Development Northern Ireland (via Research Challenge Fund) and the AgriSearch Dairy Committee is gratefully acknowledged.
References Agnew, R.E., Yan, T., France, J., Kebreab, E., Thomas, C., 2004. Feed Into Milk. A New Applied Feeding System for Dairy Cows. Nottingham University Press, Nottingham. Andersen, F., Osteras, O., Fjuk, G.H.E., Volden, H., 2012. Effect of concentrate escalation postpartum on the shape of the lactation curve and health parameters of Norwegian dairy cattle. Livest. Sci. 143, 249–258. Ayareh, M., Mirzaei, A., 2014. Factors affecting milk somatic cell count of cows with clinical mastitis. J. Vet. Res. 69, 127–132. Butler W.R., Cherney D.J.R., Elrod C.C, 1995. Milk urea nitrogen analysis: field trial results on conception rates and dietary inputs. In: Proceedings of the Cornell Nutrition Conference, Rochester, New York, USA, pp. 89 –95. Crowe, M.A., Diskin, M.G., Williams, E.J., 2014. Parturition to resumption of ovarian cyclicity: comparative aspects of beef and dairy cows. Animal 8, 40–53. Dechow, C.D., Goodling, R.C., 2008. Mortality, culling by sixty days in milk, and production profiles in High- and Low-survival Pennsylvania herds. J. Dairy Sci. 91, 4630–4639. Drackley, J.K., Dann, H.M., 2008. A scientific approach to feeding dry cows. Recent Adv. Anim. Nutr. 2007 (1), 43–74. Drackley, J.K., Cardoso, F.C., 2014. Prepartum and postpartum nutritional management to optimise fertility in high-yielding dairy cows in confined TMR systems. Animal 8, 5–14. Edmonson, A.J., Lean, I.J., Weaver, L.D., Farver, T., Webster, G., 1989. A body condition scoring chart for Holstein dairy cows. J. Dairy Sci. 72, 68–78. Esslemont, R.J., Kossaibati, M.A., 1997. Culling in 50 dairy herds in England. Vet. Rec. 140, 36–39. Ferris, C.P., Gordon, F.J., Patterson, D.C., Kilpatrick, D.J., Mayne, C.S., McCoy, M.A., 2001. The response of dairy cows of high genetic merit to increasing proportion of concentrate in the diet with a high and medium feed value silage. J. Agric. Sci. 136, 319–329. Geary, U., Lopez-Villalobos, N., O'Brien, B., Garrick, D.J., Shalloo, L., 2013. Examining the impact of mastitis on the profitability of the Irish dairy industry. Ir. J. Agric. Food Res. 52, 135–149. Gilmore, H., Young, F.J., Patterson, D.C., Wylie, A.R.G., Law, R.A., Elliot, C., Mayne, C. S., 2011. An evaluation of the effect of altering nutrition and nutritional strategies in early lactation on reproductive performance and estrous behavior of high yielding Holstein-Friesian dairy cows. J. Dairy Sci. 94, 3510–3526. Gordon, F.J., Cooper, K.M., Park, R.S., Steen, R.W.J., 1998. The prediction of intake potential and organic matter digestibility of grass silages by near infrared reflectance spectroscopy analysis of undried samples. Anim. Feed. Sci. Technol. 70, 339–351. Ingvartsen, K.L., Aaes, O., Andersen, J.B., 2001. Effects of pattern of concentrate allocation in the dry period and early lactation on feed intake and lactational performance in dairy cows. Livest. Prod. Sci. 71, 207–221. Ingvartsen, K.L., 2006. Feeding- and management-related diseases in the transition cow. Physiological adaptations around calving and strategies to reduce feedingrelated diseases. Anim. Feed. Sci. Tech. 126, 215–236. Ingvartsen, K.L., Moyes, K., 2013. Nutrition, immune function and health of dairy cattle. Animal 7, 112–122. Kleen, J.L., Hooijer, G.A., Rehage, J., Noordhuizen, J.P.T.M., 2003. Subacute ruminal acidosis (SARA): A Review. J. Vet. Med., Ser. A – Physio. Pathol. Clin. Med. 50, 406–414. Kokkonen, T., Tesfa, A., Tuori, M., Syrjala-Qvist, L., 2004. Concentrate feeding strategy of dairy cows during transition period. Livest. Prod. Sci. 86, 239–251. Krause, K.M., Oetzel, G.R., 2006. Understanding and preventing subacute ruminal acidosis in dairy herds: a review. Anim. Feed. Sci. Technol. 126, 215–236. Kuoppala, K., Yrjanen, S., Jaakkola, S., Kangasniemi, R., Sariola, J., Khalili, H., 2004. Effects of increasing concentrate energy supply on the performance of loosehoused dairy cows fed grass silage-based diets. Livest. Prod. Sci. 85, 15–26. Law, R.A., Young, F.J., Patterson, D.C., Kilpatrick, D.J., Wylie, A.R.G., Mayne, C.S., 2009.
A.J. Dale et al. / Livestock Science 184 (2016) 103–111
Effect of dietary protein content on fertility of dairy cows during early and mid lactation. J. Dairy Sci. 92, 2737–2746. Law, R.A., McGettrick S., Ferris C.P, 2011a. Effect of concentrate build-up strategy in early lactation on production performance, health and fertility of high yielding dairy cows. In: Proceedings of the British Society of Animal Science, p. 5. Law, R.A., Young, F.J., Patterson, D.C., Kilpatrick, D.J., Wylie, A.R.G., Ingvarsten, K.L., Hameleers, A., McCoy, M.A., Mayne, C.S., Ferris, C.P., 2011b. Effect of precalving and postcalving dietary energy level on performance and blood metabolite concentrations of dairy cows throughout lactation. J. Dairy Sci. 94, 808–823. LeBlanc, S.J., 2014. Reproductive tract inflammatory disease in postpartum dairy cows. Animal 8, 54–63. McCleary, B.V., Solah, V., Gibson, T.S., 1994. Quantitative measurement of total starch in cereal flours and products. J. Cereal Sci. 20, 51–58. McNamara, S., Murphy, J.J., Rath, M., O'Mara, F.P., 2003. Effects of different transition diets on energy balance, blood metabolites and reproductive performance in dairy cows. Livest. Prod. Sci. 84, 195–206. Manson, F.J., Leaver, J.D., 1988. The influence of concentrate amount on locomotion and clinical lameness in dairy cattle. Anim. Prod. 47, 185–190. Mayne, C.S., Gordon, F.J., 1984. The effect of type of concentrate and level of concentrate feeding on milk production. Anim. Prod. 39, 65–76. Mayne, C.S., McCoy, M.A., Lennon, S.D., Mackey, D.R., Verner, M., Catney, D.C., McCaughey, W.J., Wylie, A.R.G., Kennedy, B.W., Gordon, F.J., 2002. Fertility of dairy cows in Northern Ireland. Vet. Rec. 150, 707–713. Mulligan, F.J., O'Grady, L., Rice, D.A., Doherty, M.A., 2006. A herd health approach to dairy cow nutrition and production diseases of the transition cow. Anim. Reprod. Sci. 96, 331–353. Park, R.S., Agnew, R.E., Gordon, F.J., Steen, R.W.J., 1998. The use of near infrared d reflectance spectroscopy (NIRS) on undried samples of grass silage to predict chemical composition and digestibility parameters. Anim. Feed. Sci. Technol.
111
72, 155–167. Reksen, O., Gröhn, Y.T., Havrevoll, O.S., Bolstad, T., Waldmann, A., Ropstad, E., 2001. Influence of concentrate allocation and energy balance on postpartum ovarian activity in Norwegian cattle. J. Dairy Sci. 84, 1060–1068. Roche, J.R., Friggens, N.C., Kay, J.K., Fisher, M.W., Stafford, K.J., Berry, D.P., 2009. Invited review: Body condition score and its association with dairy cow productivity, health and welfare. J. Dairy Sci. 92, 5769–5801. Roche, J.R., Bell, A.W., Overton, T.R., Loor, J.J., 2013. Nutritional management of the transition cow in the 21st century – a paradigm shift in thinking. Anim. Prod. Sci. 53, 1000–1023. Royal, M.D., Darwash, A.O., Flint, A.P.F., Webb, R., Wooliams, J.A., Lamming, G.E., 2000. Declining fertility in dairy cattle: changes in traditional and endocrine parameters of fertility. Anim. Sci. 70, 487–501. Ruegg, P.L., Pantoja, J.C.F., 2013. Understanding and using somatic cell counts to improve milk quality. Ir. J. Agric. Food Res. 52, 101–117. Sheldon, I.M., Williams, E.J., Miller, A.N.A., Nash, D.M., Herath, S., 2008. Uterine diseases in cattle after parturition. Vet. J. 176, 115–121. Sinclair, K.D., Garnsworthy, P.C., Mann, G.E., Sinclair, L.A., 2014. Reducing dietary protein in dairy cow diets: implications for nitrogen utilisation, milk production, welfare and fertility. Animal 8, 262–274. Whelan, S.J., Mulligan, F.J., Gath, V., Flynn, B., Pierce, K.M., 2014. Short communication: Effect of dietary manipulation of crude protein content and nonfibrous-to-fibrous carbohydrate ratio on energy balance in early lactation dairy cows. J. Dairy Sci. 97, 7220–7224. Wilmink, J.B.M., 1987. Adjustment of lactation yield for age at calving in relation to level of production. Livest. Prod. Sci. 16, 321–334. Zaaijer, D., Noordhuizen, J.P.T.M., 2003. A novel scoring system for monitoring the relationship between nutritional efficiency and fertility in dairy cows. Ir. Vet. J. 56, 145–151.