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The labour input associated with calf care on Irish dairy farms
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Livestock Science 116 (2008) 82 – 89 www.elsevier.com/locate/livsci
The labour input associated with calf care on Irish dairy farms D. Gleeson ⁎, B. O'Brien, K. O'Donovan Teagasc, Dairy Production Research Centre, Moorepark, Fermoy, Co Cork, Ireland Received 16 May 2007; received in revised form 21 August 2007; accepted 23 August 2007
Abstract The objective of this study was to quantify the overall labour requirement for calf care and how it is influenced by enterprise scale and facilities, together with an evaluation of specific calf-feeding systems with respect to labour requirement and calf performance. One hundred and twenty nine spring-calving dairy herds participated in the investigation of overall labour input. Herds were categorized into three groups depending on herd size (small = b 50 cows, medium = 50 to 80 cows, large = N 80 cows). The total average time consumed by calf care per farm increased (P b 0.01) with herd size and the average time consumed per calf was highest in the small herd group (2.1 min/day). The proportion of farms bucket feeding was lower (P b 0.05) and the proportion feeding calves ad libitum and using cold milk was higher (P b 0.05) with the large group compared to the small herd group. Fiftyseven of the 129 herds participated in the measurement of labour input associated with specific calf-feeding systems. The labour input time per calf required for the task of milk feeding tended (P = 0.08) to be longer when calves were fed twice daily, using buckets or teats compared to automatic feeders, once daily feeding with teats and twice daily feeding with a trough. The labour input per calf for the cleaning of milk feeding equipment and for bedding and cleaning calf pens was greater (P b 0.05) with automatic feeding systems compared to the other feeding systems. A further sub-set of ten herds (from the 57 herds) underwent calf performance measurements. The mean calf weight at day 77 for automatic feeding, once daily feeding, twice daily feeding with teats and twice daily feeding with troughs was 95, 95, 93, 91 kg, respectively. In conclusion, labour input associated with calf care was influenced by herd size (and indirectly calf number), and calf-feeding system. Milk feeding of calves on a once daily basis tended to reduce the total labour input per calf and did not adversely affect calf performance. Thus, it is possible to improve efficiency of calf care by selecting time efficient methods of calf-feeding without affecting calf performance. © 2007 Elsevier B.V. All rights reserved. Keywords: Calves; Calf-feeding; Labour; Calf performance
1. Introduction Rearing the pre-weaned calf is one of the most challenging tasks on the dairy farm, particularly with compact calving in a spring milk production system. Proportionally 0.07 of labour input per day in a dairying enterprise is associated with calf care over a 12-month period (O'Brien et al., 2001). However, a peak labour ⁎ Corresponding author. Tel.: +353 25 42269. E-mail address: [email protected] (D. Gleeson). 1871-1413/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2007.08.019
requirement for calf care occurs during a 12-week calving period in spring-calving herds. A number of studies on calf rearing and related issues such as calf behaviour (Bak Jensen, 2003; Boe and Havrevoll, 1993) and housing (Jorgenson et al., 1970) have been carried out. However, few studies have addressed the issue of labour input in relation to calf care. Jorgenson et al. (1970) did suggest calves reared in outdoor hutches required less labour than those reared indoors in individual pens. Furthermore, Kung et al. (1997) showed rearing a calf indoors in a hutch required a
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
greater labour input (10 min/day) compared to rearing a calf indoors in a group pen (1 min/day). Since calffeeding is a big task within overall calf care, the methodology of calf-feeding may have a significant impact on labour input associated with calf care. One of the practical difficulties of bucket feeding calves twice daily is that feeding times tend to be at the beginning and end of the working day. Also, time (in addition to that required for feeding) is required for washing utensils. Fallon and Harte (1982) showed that teat feeding of milk to calves and individual bucket feeding of milk resulted in similar calf performance. Thickett et al. (1983) showed that ad libitum milk feeding of calves using teat systems resulted in improved liveweight gain at weaning and calf appearance. Furthermore, Fallon (1999) showed that teat feeding made group feeding of calves easier. Grouping of calves in pens has also been shown to have advantages in terms of weight gain after weaning, compared to individually housed calves (Chua et al., 2001). Jasper and Weary (2002) concluded that calves fed ad libitum will consume about double the milk compared to calves fed twice daily with buckets. Kung et al. (1997) also suggested that ad libitum computerized feeding represented a high feed cost system but this cost may be balanced with some labour saving economics associated with the ad libitum system. However, a different level of observation of calf health is required with an ad libitum feeding system compared to a bucket feeding systems. Once daily feeding of calves has been shown not to adversely affect calf performance (Burt, 1967; Williams et al., 1986; Fallon et al., 1985) compared to twice daily feeding. Therefore, once daily feeding may offer a reduction in the labour requirement for calf care without affecting calf performance or calf welfare. There is little information available on the effect of different management practises and feeding systems on the labour input required. Thus the objective of this study was to determine the overall labour requirement for calf care together with a description of the calf rearing facilities on dairy farms in Ireland and to further evaluate different calf-feeding systems with respect to the associated labour requirement and calf performance. 2. Materials and methods 2.1. Calf care labour demand and characteristics of calf management on farms Three hundred and forty farmers which represented a large number of dairy farms nationally, received written requests welcoming their participation in a farm labour study. The herds were selected from farmer discussion groups whose members
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were accustomed to recording data. However, unlike the participants, all Irish farmers are not members of discussion groups. Therefore the participant farmers were generally larger producers and may also have represented a more positive, innovative and enthusiastic subgroup of all dairy farmers nationally. One hundred and twenty nine spring-calving dairy herds agreed to participate in the study in which total labour input associated with calf care was measured during the months of February, March and April in year 1. The herds ranged in size from 35 to 280 cows. To determine the effect of herd size on the labour requirement of calf care, herds were categorized into 3 herd-size groups for the purpose of data analysis. The first group was considered a ‘small’ herd-size group of less than 50 cows, the second group represented a ‘medium’ size group of between 50 and 80 cows, and third group represented a ‘large’ herd-size group of greater than 80 cows. Eighty percent of Irish farms have a herd size within the small category. While the large category represents a small proportion (0.03) of Irish farmers the proportion is expected to increase rapidly in the near future. A herd size greater than 80 cows is also considered necessary in the future in order for farms to remain viable (McCarthy, 2000). Medium farms represent those farms that will need to expand to a herd size beyond 80 cows over the next decade. There were 32, 55 and 42 herds in the small, medium and large herd-size groups, with average herd sizes of 43, 63 and 136 cows and farms ranged in milk quota size from 135 × 103 to 1500 × 103 l. These herds had an average calf number of 25, 35, and 53, respectively. The total labour input per day associated with all tasks related to calf care, e.g. calf-feeding, calf house bedding and cleaning and veterinary attention was recorded on the 129 herds. The calf labour input per day referred to the management of all calves (0 to 8 weeks) including the feeding of newborn calves. Labour input required for individual tasks associated with calf care were not recorded. Total calf labour input in each herd was recorded using a timesheet for each of 3 consecutive days, on one occasion per month during the calving season (February, March and April). Herd data was included where at least two months labour input time was recorded by those herds. A separate timesheet was completed by each farm operative when work was undertaken in relation to calf care on each farm. A questionnaire survey on the management of calves was completed for each farm. 2.2. Definition of terms The farm tasks related to calf care are defined in the following terms in the remainder of the paper. ‘Milk transfer method’ describes the method of milk transfer from the dairy to the calf house. ‘Milk temperature fed to calves' describes the temperature of the milk offered to calves, i.e. hot or cold (exact temperature not recorded). ‘Calf-feeding method’ describes the method used to feed milk to calves, i.e. bucket, automatic feeder, teats and barrel, trough. ‘Feeding frequency’ refers to how frequently calves were fed milk, i.e. ad libitum, twice a day, or once a day. ‘Cleaning feed equipment’ refers to the cleaning of equipment used for feeding milk to calves,
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i.e. buckets, automatic feeders. ‘Total feed time’ includes the time taken to transfer milk, feed calves and clean equipment. ‘Veterinary’ describes the time taken for veterinary attention to calves. ‘Calves grouped’ refers to more than two calves in a pen. ‘Calf house cleaning method’ describes how calf houses were cleaned, i.e. mechanical loaders, manually cleaned using a fork with a barrow or manual fork with a loader. ‘Calf house cleaning frequency’ describes how frequently the calf pens were cleaned, i.e. daily, weekly or monthly. 2.3. Individual feeding systems and labour input To test the effect of individual calf-feeding systems on labour input, 57 dairy herds that had previously participated in year 1 and were willing to participate in year 2 were categorized into five different calf-feeding systems based on their individual calf-feeding system in operation in year 2. The feeding systems may be described as follows: (1) AU referred to all calves having ad libitum access to an automatic calf feeder (14 herds); (2) OT referred to once daily feeding of calves from a container with artificial teats (8 herds); (3) TB referred to twice daily feeding from individual buckets (8 herds); (4) TT referred to twice daily feeding of calves from a container with artificial teats (13 herds); (5) TR referred to twice daily feeding from a trough (14 herds records). There were 174, 90, 105, 130, and 156 days where labour input for calf care were recorded for AU, OT, TB, TT, and TR feeding systems, respectively. The average number of calves for feeding systems AU, OT, TB, TT, and TR was 34, 30, 25, 38, and 28, respectively. All farms offered concentrates daily and fed whole milk to calves. The amount of milk offered per calf was lowest for the OT system (4.0 to 4.9 l) compared to the AU, TT and TR systems which received between 4.0 and 9.0 l/day. Proportionally 0.15 of farms using the AU and TT systems offered cold milk, while 0.22 of farms with the OT and TR systems used cold milk. The time associated with the tasks of transfer of milk to the calf house, feeding of calves, cleaning of feed equipment, bedding and cleaning of calf pens and veterinary attention for each of the 5 feeding systems was recorded by each farm operative when the task was undertaken. The time required for the tasks related to calf care for calves between the ages of 8 days and 8 weeks of age was recorded daily for 7 consecutive days on one occasion during each of the months of March and April. 2.4. Individual feeding systems and calf performance Ten herds of the 57 herds participated in an investigation of the effect of individual calf-feeding systems on calf performance. The ten herds comprised of 3, 3, 2, and 2 herds having AU, OT, TT or TR feeding systems, respectively, which were used to determine the effect of individual calf-feeding system on calf performance. These herds were representative of each feeding system from the 57 herds and had agreed to participate in the calf performance study. There were 30, 34, 41 and 37 Friesian female calves, identified from feeding systems AU, OT, TT and TR,
respectively. Male calves were not used for measuring performance as many of these calves were sold off farm at b 10 weeks of age. These female calves were weighed on two occasions approximately sixty-three days apart by one operator using a mobile Tru-Test digital scale. Comparisons were made between the feeding systems for calf weight at day 77. In the instances where calves had not reached 77 days of age at the second weighing, the final weight was adjusted by multiplying the number of outstanding days by the previous calf daily liveweight gain. Calf mortality was recorded during this measurement period. The calves fed with the feeding systems AU, TT and TR were reared indoor (0 to 10 weeks) while the calves fed with the OT system were reared outdoor from 5 to 10 weeks. Calves were generally reared in groups N 15 for the AU and OT systems and in groups N 5 for the TT and TR systems. Concentrates were offered to calves daily on all systems throughout the 10 week rearing period. Calves in both the AU and the TR systems and proportionally 0.33 and 0.50 of the OT and TT systems, respectively, were offered warm whole milk daily. The roughage intake of calves was not recorded. 2.5. Statistical analysis The effect of herd size (small, medium and large) on the time required for calf care was determined using PROC GLM in SAS (SAS, 2006). Preliminary analyses of the mean calf labour input data for one hundred and twenty nine farms revealed that it was positively skewed. Hence, the data were transformed using the natural logarithm. The resulting transformed data was normally distributed based on the Kolmogorov–Smirnov test. The effect of herd size on time for the different calf rearing methods (milk transfer, milk temperature fed, calf-feeding method, feed frequency, calf house cleaning method, calf house cleaning frequency) practised on farms was tested. The proportion of herds having different calf rearing characteristics were analysed using the Chi-square test. There were no differences shown in total calf care between the months of March and April in year 2 for the 57 herds, thus the data was pooled for comparison of alternate calf-feeding systems. The effect of alternative calf-feeding systems (automatic feeder, once a day with teats, twice daily with buckets, twice daily with teats and twice daily with a trough) on the labour requirement for 57 herds was determined using generalized linear models (PROC GLM) in SAS (2006). Least squares means of the transformed data were extracted and backtransformed for ease of interpretation. Calf performance data was subjected to analysis of variance in PROC GLM (SAS, 2006). Herd was used as the experimental unit.
3. Results 3.1. Calf care labour demand and characteristics of calf management on farms The total work force on farms was represented by family full-time and part-time labour, hired full-time and
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
part-time labour. There were 1.28, 1.40, and 1.29 family full-time labour units on small, medium and large herds, respectively. In addition, there were 0.53, 0.89, and 0.81 family part-time labour units on small, medium and large herds, respectively. There was no hired full-time labour units employed on the small herds, but there was 0.13 and 0.76 labour units employed on medium and large herds, respectively. Hired part-time labour represented 0.09, 0.23, and 0.36 labour units on small, medium and large herds, respectively. The average total daily labour input associated with calf care during Feb, March and April of year 1, for different herd sizes is shown in Table 1. The average time consumed by calf care peaked in April with herds in the small, medium and large groups taking 63, 74, and 112 min/day, respectively. The average time consumed by calf care per farm increased (P b 0.001) with herd size. The large herd group had a higher (P b 0.001) labour requirement for calf care compared to the small and medium herds in both March and April and compared to the small herd group in February. Herds size groups of small, medium and large had average calf numbers of 25, 35, and 53, respectively, over the three month period, thus resulting in an average labour input per calf per day of 2.10 min, 1.70 min and 1.77 min, respectively. There were no significant interactions between herd group and time for the calf rearing practises tested which included milk transfer method, milk temperature, feeding method, feed frequency and calf house cleaning frequency. There was a significant interaction for the calf house cleaning method, with the large herd requiring a longer time for cleaning using the manual cleaning method (P b 0.01) compared to the mechanical method and compared to the small and medium groups (P b 0.001).
Table 1 Total daily labour input (min/day) (average transformed data in parenthesis) associated with calf care for small, medium and large herds during the months of February, March and April for year 1 Herd group Small Medium Large (b50 cows) (50 to 80 cows) (N80 cows) Number of herds
32
55
42
s.e.
Sig.
February (min/day) March (min/day) April (min/day)
31 (n = 11) (3.44a) 64 (n = 36) (4.16a) 63 (n = 28) (4.15a)
55 (n = 18) (4.00ac) 44 (n = 46) (3.79b) 74 (n = 40) (4.30b)
77 (n = 32) 0.126 ⁎⁎⁎ (4.34bc) 92 (n = 62) 0.128 ⁎⁎⁎ (4.52c) 112 (n = 64) 0.111 ⁎⁎⁎ (4.72c)
n = average number of calves. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
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Table 2 Proportion of herds practising different calf rearing methods within different small, medium and large herd groups, during the months of February, March and April for year 1 Herd group
Small Medium Large Sig. (b50 cows) (50 to 80 cows) (N80 cows) (n = 32) (n = 55) (n = 42)
Milk transfer method Bucket 0.53 0.52 Pump 0.16 0.25 Mechanical 0.31 0.23 Milk temperature fed to calves Cold 0.03a 0.15b Warm 0.97 0.85 Calf-feeding method Bucket 0.50a 0.33b Teats or 0.19a 0.45b Automatic Trough 0.31 0.22 Feed frequency Ad libitum 0.20a 0.47b Twice daily 0.80 0.53 Calf house cleaning method Loader only 0.28 0.22 Fork/barrow/ 0.95 0.82 loader Calf house cleaning frequency Daily 0.22 0.09 Weekly 0.34 0.65 Monthly 0.44 0.26
0.39 0.20 0.41
NS
0.23b 0.77
⁎
0.25b 0.49b
⁎
0.26 0.50b 0.50
⁎
0.17 0.73
NS
0.10 0.40 0.50
P = 0.06
n = number of herds. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
The proportion of herds within different herd groups practising different calf rearing methods is shown in Table 2. The proportion of herds using different methods for transferring milk between the dairy and calf house did not differ significantly across herds. However, mechanical methods of milk transfer were more frequently used by the large herd group. A higher proportion of the large herds (0.23) offered milk to calves at a cold temperature compared to the small (0.03) or medium herds (0.15) (P b 0.05). The occurrence of teat feeding systems or automatic feeding was higher for the large herds (0.49) compared to the small herd group (0.19), while bucket feeding was more prevalent with the small herd group (0.50) compared to the large herd (0.25) (P b 0.05). Ad libitum feeding was more prevalent with the large herd (0.50) group compared to the small herd (0.20) group (P b 0.05). There were no differences in the proportion of herds using trough feeding herds. The proportion of herds using either manual (fork and loader and fork and barrow) or mechanical only methods (loader) of cleaning calf houses were similar across groups. Calf house cleaning was generally carried
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out on a less frequent basis (P b 0.06) on the large herd group compared to herds in the small and medium groups. The proportion of herds grouping calves for ease of management did not differ between herd groups with 0.75, 0.85 and 0.83 of small, medium and large herds, respectively, grouping calves at less than two weeks of age. 3.2. Individual feeding systems and labour input The effect of individual calf-feeding system on the average labour input per calf over the months of March and April is shown in Table 3. There was no difference in the average total daily labour input between months. This was expected as the labour input was recorded only for calves from N 8 days to 8 weeks of age. Feeding calves twice daily, using TB or TT increased (P b 0.08) the milk feeding time per calf compared to systems AU, OT and TR. The labour input for cleaning of feeding equipment was significantly higher (P b 0.05) with the AU system compared to the other feeding systems. The time per calf taken for milk transfer from the dairy to the calf house was numerically lowest for the TB system (4 s) and highest for the AU system (9 s). There was no significant difference in the labour input per calf between feeding systems when the tasks of feeding, cleaning and milk transfer were combined. The labour input per calf associated with the combined tasks of application of calf bedding material and cleaning of calf
bedding areas was highest (P b 0.05) (13 s) for the AU system compared to the other feeding systems. The labour input for veterinary attention was 1, 2, 0, 4, and 5 s/calf/day for AU, OT, TB, TT, and TR feeding systems, respectively. The OT and the AU feeding systems had the lowest (23 s) and highest (38 s) labour requirement per calf for total calf care. When methods used for calf house cleaning (loader only, manual fork with loader and manual fork with barrow were evaluated for labour input, a significantly lower (P b 0.01) (s.e. = 1.66) labour requirement per calf was observed when a loader only (2.1 s) was used compared to systems using a combination of fork with loader (8.2 s) and fork with barrow (7.7 s). 3.3. Individual feeding systems and calf performance The effect of different calf-feeding systems on calf performance for the sub-set of 10 herds is shown in Table 4. The mean calf weight at day 77 for AU, OT, TT and TR feeding methods were 95, 95, 93, 91 kg, respectively (Table 4). Mean calf daily weight gain which was calculated from day 15 to 77 was lower (P b 0.001) (s.e.d. = 0.03) for the TR method (0.65 kg/day) and the AU method (0.70 kg/day) compared to the OT (0.79) and TT (0.80) methods. The range in calf daily weight gain between herds was less with the OT (0.72–0.89) and TT (0.79–0.81) systems compared to the AU (0.57– 0.80) and TR (0.51–0.76) systems. A questionnaire
Table 3 Effect of calf-feeding system on the daily labour input (back-transformed mean in parenthesis; s/calf/day) for each calf care task for calves (8 days to 8 weeks of age) (57 herds during the months of March and April) Calf-feeding system
Automatic feeder (AU)
Once daily with teats (OT)
Twice daily with buckets (TB)
Twice daily with teats (TT)
Twice daily with trough (TR)
(n = 14)
(n = 8)
(n = 8)
(n = 13)
(n = 14)
1
Milk feeding time Clean feed equipment Feed + clean time Transfer of milk Total milk feed time Bed + clean calf pens Total calf care time⁎
1
1
1
(n = 174)
(n = 90)
(n = 105)
(n = 130)
(n1 = 156)
1.96 (7) 2.16a (9) 2.79 (16) 2.17 (9) 3.16 (24) 2.54a (13) 3.63 (38)
2.13 (8) 1.33b (4) 2.35 (10) 1.63 (5) 2.83 (17) 1.27b (4) 3.14 (23)
2.89 (18) 1.34b (4) 3.09 (22) 1.45 (4) 3.28 (26) 1.77c (6) 3.45 (32)
2.51 (12) 1.64c (5) 2.84 (17) 1.75 (6) 3.15 (23) 1.86c (6) 3.59 (36)
1.92 (7) 1.25bc (3) 2.26 (10) 1.85 (6) 2.78 (16) 1.72c (6) 3.28 (27)
n = number of herds, n1 = number of days time was recorded, ⁎ Includes veterinary time. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
s.e.
Sig.
0.273
P = 0.08
0.245
⁎
0.254
NS
0.242
NS
0.182
NS
0.292
⁎
0.170
NS
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
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Table 4 Effect of calf milk feeding method on calf weight for Friesian female calves (10 herds) at 77 days and weight gain per day (day 15 to day 77) Feeding system Calf performance Number of calves weighed Calf weight at 77 days (kg) Calf weight gain per day (kg) Calf weight gain per day range between herds (kg)
Automatic feeder (AU) (n = 3)
Once daily with teats (OT) (n = 3)
Twice daily with teats (TT) (n = 2)
Twice daily with trough (TR) (n = 2)
s.e.d.
Sig.
30 95.0 0.70b 0.57–0.80
34 94.8 0.79a 0.72–0.89
41 93.2 0.80a 0.79–0.81
37 90.5 0.65b 0.51–0.76
– 2.3 0.03 –
– NS ⁎⁎⁎ –
n = number of herds. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
survey completed on the management of calves indicated that the milk intake figures differed between systems. Calves on the OT feeding method received less milk per day (4.9 l) than calves on the TT (7 l), AU (N9 l) and TR (9 l) systems. Calves on the TT system remained on milk longer before weaning than the AU or TR systems. The average calf age at weaning was 51, 56, 65, and 54 days for the AU, OT, TT, and TR feeding methods, respectively. The proportion of calf deaths were 0.00, 0.03, 0.01, and 0.04 for TT, TR, OT and AU feeding systems, respectively. The average daily intake of concentrates when calves were weaned off milk was 0.40, 0.80, 1.00 and 1.00 for AU, OT, TT and TR systems, respectively. 4. Discussion 4.1. Calf care labour demand and characteristics of calf management on farms
the fact that as herd size increased, herds tended to use less buckets for calf-feeding and for milk transfer from the dairy to the calf house. This also coincided with significantly more use of teat feeding from a container, automatic feeders and ad libitum feeding. Large farms were more likely to feed cold milk to calves, this allowed the task of calf-feeding to be carried out during an off-peak labour time during the day. There were no differences in the use of mechanization to clean calf houses. Inadequate access to calf houses to operate mechanical cleaning was the main factor why manual cleaning was used. The large herds also tended not to clean pens daily and tended towards a monthly basis. This data indicated that when calf numbers increased, herds tended to use more labour saving methods. Regardless of herd size, herds grouped calves at less than two weeks of age with the purpose of reducing the level of individual attention. 4.2. Individual feeding systems and labour input
The family labour input of both full-time and parttime people remained fairly constant across herd sizes. However, as herd size increased between groups so did the number of hired full-time and part-time people that were employed. In this study, the task of calf care was in the majority of cases undertaken by family part-time labour. As herd size increased, so also did the average number of calves reared and the total labour input per day as expected. However, the labour input per calf per day improved marginally (2.1 to 1.8 min) in efficiency as herd size increased. O'Shea et al. (1998) concluded that most farm tasks other than calf rearing were carried out more efficiently as herd size increased. As it is necessary for each calf to be individually managed for a period after birth, this may explain why the increase in efficiency was not greater with scale. In spring-calving herds the number of calvings would be expected to peak during March and therefore, a higher calf labour input would also be expected at this time. The improvement in efficiency that was evident with herd size may be due to
The TB system had low equipment cleaning time and milk transfer time, this may be due to the fact that buckets may not be cleaned between batches of calves and the transfer of milk may be included as calf-feeding time rather than seen as a separate task to feeding. The labour input for bedding and cleaning of calf houses was significantly higher for the AU system and lowest for the OT system. Extra urine and wet bedding are peculiar to the AU system (Fallon, 1999). The OT system had a numerically lower labour input per calf for total calf care (total feed time, bed and clean pens, veterinary). In addition, this feeding system allowed flexibility such as carrying out of the calf-feeding task at an off-peak time during the day. Calf house designs should allow for access of mechanical equipment to clean out pens between batches of calves, as significant reduction in labour input per calf was shown where loaders could be used for the complete cleaning process.
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4.3. Individual feeding systems and calf performance The ten farms selected for measuring calf performance may not be representative of the total herds studied for calf labour input; however these farms were representative of each of the calf-feeding systems used on the 57 farms. Once daily feeding of calves did not adversely affect calf performance in agreement with some previous studies. (Fallon, 1999; Williams et al., 1986). Appleby et al. (2001) also showed that calves gained weight more quickly from birth to weaning when fed ad libitum compared to calves fed twice daily by bucket. However, lower post-weaning weight gains may be expected with calves on the AU system as lower intakes of concentrates have been observed when calves were fed using an automatic feeder (Fallon and Harte, 1987; Broadbent, 1973). The lower intake of concentrates with ad libitum fed calves can lead to a postweaning lag in growth (Hepola, 2003). The period of time between weaning and calf weighing may explain the lower weight gain per day observed with the AU and TR systems in this study. 5. Conclusion There was considerable variation in time taken for calf care, irrespective of herd size. The main factors influencing labour input associated with calf care included the calf-feeding system and calf house cleaning methods. As herd size increased labour saving practises such as ad libitum feeding of milk were more likely to be used. Milk feeding of calves on a once daily basis tended to reduce the total labour input per calf and did not adversely affect calf performance. While calffeeding time was similar for all systems, the task of feeding calves was completed at one occasion with the once daily feeding system. Reduced labour input was required for bedding/cleaning of calves fed on a once daily basis and farmers also tended to put these calves outdoors at an earlier stage. Thus, it is possible to improve time efficiency of calf care by selecting time efficient methods of calf-feeding without affecting calf performance. All of the calf rearing systems operated in this study were within the European Communities Regulations, 1995/98 for the welfare of calves. Acknowledgements The authors wish to thank Dr. Richard Fallon for his helpful comments and advice and Mr Jonathon Kenneally for his skilled technical assistance. The
authors also wish to thank Dr. Donagh Berry for statistical analysis and the dairy farmers who participated in this study. In particular the authors would also like to acknowledge the contribution of the late Peter Daly. This research was part funded by Irish dairy farmers and by European Union Structural Funds (EAGGF). References Appleby, M.C., Weary, D.M., Chua, B., 2001. Performance and feeding behaviour of calves on ad libitum milk from artificial teats. Appl. Anim. Behav. Sci. 74, 191–201. Bak Jensen, M.B., 2003. The effects of feeding method, milk allowance and social factors on milk feeding behaviour and cross-suckling in group housed dairy calves. Appl. Anim. Behav. Sci. 80, 191–206. Boe, K., Havrevoll, O., 1993. Cold housing and computer-controlled milk feeding for dairy calves: behaviour and performance. Anim. Prod. 57, 183–191. Broadbent, P.J., 1973. A note on the effects of frequency and method of feeding milk substitute on the performance of Friesian and Ayrshire calves. Anim. Prod. 17, 333–336. Burt, A.W.A., 1967. A note on the effect of giving milk substitutes only once a day to early-weaned calves. Anim. Prod. 10, 113–116. Chua, B., Coenen, J., Van Delen, J., Weary, D.M., 2001. Effects of pair versus individual housing on the behaviour and performance of dairy calves. J. Dairy Sci. 85, 360–364. Fallon, R.J., 1999. General principles of management of calves. Proc. of Teagasc Symposium. Kildalton, Co., Kilkenny, Ireland, p. 46. 4th February. Fallon, R.J., Harte, F.J., 1982. Effect of Ad-Libitum Feeding of Normal and Acidified Milk Replacer on Calf Performance. . Anim. Prod. Res. Rep., vol. 4, 23. An Foras Taluntais, 19 Sandymount Avenue, Dublin, pp. 12–13. Published by. Fallon, R.J., Harte, F.J., 1987. Effect of Feeding Milk Replacer Ad Libitum for 28 or 35 days on Calf Performance. . Anim. Prod. Res. Rep., vol. 4, 28. An Foras Taluntais, 19 Sandymount Avenue, Dublin, p. 15. Published by. Fallon, R.J., Brockwa, y, J.M., Williams, P.E.V., 1985. The effect of the frequency of feeding of milk on the energetic efficiency of preruminant calves. Anim. Prod. 40, 570 (abstr). Hepola, H., 2003. Milk feeding systems for dairy calves in groups: effects on feed intake, growth and health. Appl. Anim. Behav. Sci. 80, 233–243. Jasper, J., Weary, D.M., 2002. Effects of ad libitum milk intake on dairy calves. J. Dairy Sci. 85 , 3054–3058. Jorgenson, L.J., Jorgenson, N.A., Schingoethe, D.J., Owens, M.J., 1970. Indoor versus outdoor calf rearing at three weaning ages. J. Dairy Sci. 53, 813–816. Kung, L.J.R., Demarco, S., Siebenson, L.N., Joyner, E., Haenlein, G.F.W., Morris, R.M., 1997. An evaluation of two management systems for rearing calves fed milk replacer. J. Dairy Sci. 80 , 2529–2533. McCarthy, D., 2000. Optimising profits on dairy farms. Opportunities for the New Millennium. Proc. of the Nat. Dairy Con., Cork, vol. 16, pp. 7–15. November 2000. O'Brien, B., O' Donovan, K., Gleeson, D., Ruane, D., Kinsella, J., 2001. Profiling the working year on Irish dairy herds. Proc. Irish Grass. and Anim. Prod. Ass. Con. , pp. 112–124.
D. Gleeson et al. / Livestock Science 116 (2008) 82–89 O'Shea, J., Kavanagh, A.J., Reid, P., 1998. Labour use on Irish dairy herds. Proc. Irish Grass. and Anim. Prod. Ass. Con., 22, pp. 112–120. SAS Institute, 2006. User's Guide Version 9.1: Statistics. SAS Institute, Cary, NC. Thickett, W.S., Cuthbert, N.H., Brigstocke, T.D.A., Lindeman, M.A., Wilson, P.N., 1983. A note on the performance and management of
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calves reared on cold acidified milk replacer fed ad libitum. Anim. Prod. 36, 147–150. Williams, P.E.V., Fallon, R.J., Brockway, J.M., Innes, G.M., Brewer, A.C., 1986. The effect of frequency of feeding milk replacer to preruminant calves on respiratory quotient and the efficiency of food utilization. Anim. Prod. 43, 367–375.
Livestock Science 116 (2008) 82 – 89 www.elsevier.com/locate/livsci
The labour input associated with calf care on Irish dairy farms D. Gleeson ⁎, B. O'Brien, K. O'Donovan Teagasc, Dairy Production Research Centre, Moorepark, Fermoy, Co Cork, Ireland Received 16 May 2007; received in revised form 21 August 2007; accepted 23 August 2007
Abstract The objective of this study was to quantify the overall labour requirement for calf care and how it is influenced by enterprise scale and facilities, together with an evaluation of specific calf-feeding systems with respect to labour requirement and calf performance. One hundred and twenty nine spring-calving dairy herds participated in the investigation of overall labour input. Herds were categorized into three groups depending on herd size (small = b 50 cows, medium = 50 to 80 cows, large = N 80 cows). The total average time consumed by calf care per farm increased (P b 0.01) with herd size and the average time consumed per calf was highest in the small herd group (2.1 min/day). The proportion of farms bucket feeding was lower (P b 0.05) and the proportion feeding calves ad libitum and using cold milk was higher (P b 0.05) with the large group compared to the small herd group. Fiftyseven of the 129 herds participated in the measurement of labour input associated with specific calf-feeding systems. The labour input time per calf required for the task of milk feeding tended (P = 0.08) to be longer when calves were fed twice daily, using buckets or teats compared to automatic feeders, once daily feeding with teats and twice daily feeding with a trough. The labour input per calf for the cleaning of milk feeding equipment and for bedding and cleaning calf pens was greater (P b 0.05) with automatic feeding systems compared to the other feeding systems. A further sub-set of ten herds (from the 57 herds) underwent calf performance measurements. The mean calf weight at day 77 for automatic feeding, once daily feeding, twice daily feeding with teats and twice daily feeding with troughs was 95, 95, 93, 91 kg, respectively. In conclusion, labour input associated with calf care was influenced by herd size (and indirectly calf number), and calf-feeding system. Milk feeding of calves on a once daily basis tended to reduce the total labour input per calf and did not adversely affect calf performance. Thus, it is possible to improve efficiency of calf care by selecting time efficient methods of calf-feeding without affecting calf performance. © 2007 Elsevier B.V. All rights reserved. Keywords: Calves; Calf-feeding; Labour; Calf performance
1. Introduction Rearing the pre-weaned calf is one of the most challenging tasks on the dairy farm, particularly with compact calving in a spring milk production system. Proportionally 0.07 of labour input per day in a dairying enterprise is associated with calf care over a 12-month period (O'Brien et al., 2001). However, a peak labour ⁎ Corresponding author. Tel.: +353 25 42269. E-mail address: [email protected] (D. Gleeson). 1871-1413/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2007.08.019
requirement for calf care occurs during a 12-week calving period in spring-calving herds. A number of studies on calf rearing and related issues such as calf behaviour (Bak Jensen, 2003; Boe and Havrevoll, 1993) and housing (Jorgenson et al., 1970) have been carried out. However, few studies have addressed the issue of labour input in relation to calf care. Jorgenson et al. (1970) did suggest calves reared in outdoor hutches required less labour than those reared indoors in individual pens. Furthermore, Kung et al. (1997) showed rearing a calf indoors in a hutch required a
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
greater labour input (10 min/day) compared to rearing a calf indoors in a group pen (1 min/day). Since calffeeding is a big task within overall calf care, the methodology of calf-feeding may have a significant impact on labour input associated with calf care. One of the practical difficulties of bucket feeding calves twice daily is that feeding times tend to be at the beginning and end of the working day. Also, time (in addition to that required for feeding) is required for washing utensils. Fallon and Harte (1982) showed that teat feeding of milk to calves and individual bucket feeding of milk resulted in similar calf performance. Thickett et al. (1983) showed that ad libitum milk feeding of calves using teat systems resulted in improved liveweight gain at weaning and calf appearance. Furthermore, Fallon (1999) showed that teat feeding made group feeding of calves easier. Grouping of calves in pens has also been shown to have advantages in terms of weight gain after weaning, compared to individually housed calves (Chua et al., 2001). Jasper and Weary (2002) concluded that calves fed ad libitum will consume about double the milk compared to calves fed twice daily with buckets. Kung et al. (1997) also suggested that ad libitum computerized feeding represented a high feed cost system but this cost may be balanced with some labour saving economics associated with the ad libitum system. However, a different level of observation of calf health is required with an ad libitum feeding system compared to a bucket feeding systems. Once daily feeding of calves has been shown not to adversely affect calf performance (Burt, 1967; Williams et al., 1986; Fallon et al., 1985) compared to twice daily feeding. Therefore, once daily feeding may offer a reduction in the labour requirement for calf care without affecting calf performance or calf welfare. There is little information available on the effect of different management practises and feeding systems on the labour input required. Thus the objective of this study was to determine the overall labour requirement for calf care together with a description of the calf rearing facilities on dairy farms in Ireland and to further evaluate different calf-feeding systems with respect to the associated labour requirement and calf performance. 2. Materials and methods 2.1. Calf care labour demand and characteristics of calf management on farms Three hundred and forty farmers which represented a large number of dairy farms nationally, received written requests welcoming their participation in a farm labour study. The herds were selected from farmer discussion groups whose members
83
were accustomed to recording data. However, unlike the participants, all Irish farmers are not members of discussion groups. Therefore the participant farmers were generally larger producers and may also have represented a more positive, innovative and enthusiastic subgroup of all dairy farmers nationally. One hundred and twenty nine spring-calving dairy herds agreed to participate in the study in which total labour input associated with calf care was measured during the months of February, March and April in year 1. The herds ranged in size from 35 to 280 cows. To determine the effect of herd size on the labour requirement of calf care, herds were categorized into 3 herd-size groups for the purpose of data analysis. The first group was considered a ‘small’ herd-size group of less than 50 cows, the second group represented a ‘medium’ size group of between 50 and 80 cows, and third group represented a ‘large’ herd-size group of greater than 80 cows. Eighty percent of Irish farms have a herd size within the small category. While the large category represents a small proportion (0.03) of Irish farmers the proportion is expected to increase rapidly in the near future. A herd size greater than 80 cows is also considered necessary in the future in order for farms to remain viable (McCarthy, 2000). Medium farms represent those farms that will need to expand to a herd size beyond 80 cows over the next decade. There were 32, 55 and 42 herds in the small, medium and large herd-size groups, with average herd sizes of 43, 63 and 136 cows and farms ranged in milk quota size from 135 × 103 to 1500 × 103 l. These herds had an average calf number of 25, 35, and 53, respectively. The total labour input per day associated with all tasks related to calf care, e.g. calf-feeding, calf house bedding and cleaning and veterinary attention was recorded on the 129 herds. The calf labour input per day referred to the management of all calves (0 to 8 weeks) including the feeding of newborn calves. Labour input required for individual tasks associated with calf care were not recorded. Total calf labour input in each herd was recorded using a timesheet for each of 3 consecutive days, on one occasion per month during the calving season (February, March and April). Herd data was included where at least two months labour input time was recorded by those herds. A separate timesheet was completed by each farm operative when work was undertaken in relation to calf care on each farm. A questionnaire survey on the management of calves was completed for each farm. 2.2. Definition of terms The farm tasks related to calf care are defined in the following terms in the remainder of the paper. ‘Milk transfer method’ describes the method of milk transfer from the dairy to the calf house. ‘Milk temperature fed to calves' describes the temperature of the milk offered to calves, i.e. hot or cold (exact temperature not recorded). ‘Calf-feeding method’ describes the method used to feed milk to calves, i.e. bucket, automatic feeder, teats and barrel, trough. ‘Feeding frequency’ refers to how frequently calves were fed milk, i.e. ad libitum, twice a day, or once a day. ‘Cleaning feed equipment’ refers to the cleaning of equipment used for feeding milk to calves,
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i.e. buckets, automatic feeders. ‘Total feed time’ includes the time taken to transfer milk, feed calves and clean equipment. ‘Veterinary’ describes the time taken for veterinary attention to calves. ‘Calves grouped’ refers to more than two calves in a pen. ‘Calf house cleaning method’ describes how calf houses were cleaned, i.e. mechanical loaders, manually cleaned using a fork with a barrow or manual fork with a loader. ‘Calf house cleaning frequency’ describes how frequently the calf pens were cleaned, i.e. daily, weekly or monthly. 2.3. Individual feeding systems and labour input To test the effect of individual calf-feeding systems on labour input, 57 dairy herds that had previously participated in year 1 and were willing to participate in year 2 were categorized into five different calf-feeding systems based on their individual calf-feeding system in operation in year 2. The feeding systems may be described as follows: (1) AU referred to all calves having ad libitum access to an automatic calf feeder (14 herds); (2) OT referred to once daily feeding of calves from a container with artificial teats (8 herds); (3) TB referred to twice daily feeding from individual buckets (8 herds); (4) TT referred to twice daily feeding of calves from a container with artificial teats (13 herds); (5) TR referred to twice daily feeding from a trough (14 herds records). There were 174, 90, 105, 130, and 156 days where labour input for calf care were recorded for AU, OT, TB, TT, and TR feeding systems, respectively. The average number of calves for feeding systems AU, OT, TB, TT, and TR was 34, 30, 25, 38, and 28, respectively. All farms offered concentrates daily and fed whole milk to calves. The amount of milk offered per calf was lowest for the OT system (4.0 to 4.9 l) compared to the AU, TT and TR systems which received between 4.0 and 9.0 l/day. Proportionally 0.15 of farms using the AU and TT systems offered cold milk, while 0.22 of farms with the OT and TR systems used cold milk. The time associated with the tasks of transfer of milk to the calf house, feeding of calves, cleaning of feed equipment, bedding and cleaning of calf pens and veterinary attention for each of the 5 feeding systems was recorded by each farm operative when the task was undertaken. The time required for the tasks related to calf care for calves between the ages of 8 days and 8 weeks of age was recorded daily for 7 consecutive days on one occasion during each of the months of March and April. 2.4. Individual feeding systems and calf performance Ten herds of the 57 herds participated in an investigation of the effect of individual calf-feeding systems on calf performance. The ten herds comprised of 3, 3, 2, and 2 herds having AU, OT, TT or TR feeding systems, respectively, which were used to determine the effect of individual calf-feeding system on calf performance. These herds were representative of each feeding system from the 57 herds and had agreed to participate in the calf performance study. There were 30, 34, 41 and 37 Friesian female calves, identified from feeding systems AU, OT, TT and TR,
respectively. Male calves were not used for measuring performance as many of these calves were sold off farm at b 10 weeks of age. These female calves were weighed on two occasions approximately sixty-three days apart by one operator using a mobile Tru-Test digital scale. Comparisons were made between the feeding systems for calf weight at day 77. In the instances where calves had not reached 77 days of age at the second weighing, the final weight was adjusted by multiplying the number of outstanding days by the previous calf daily liveweight gain. Calf mortality was recorded during this measurement period. The calves fed with the feeding systems AU, TT and TR were reared indoor (0 to 10 weeks) while the calves fed with the OT system were reared outdoor from 5 to 10 weeks. Calves were generally reared in groups N 15 for the AU and OT systems and in groups N 5 for the TT and TR systems. Concentrates were offered to calves daily on all systems throughout the 10 week rearing period. Calves in both the AU and the TR systems and proportionally 0.33 and 0.50 of the OT and TT systems, respectively, were offered warm whole milk daily. The roughage intake of calves was not recorded. 2.5. Statistical analysis The effect of herd size (small, medium and large) on the time required for calf care was determined using PROC GLM in SAS (SAS, 2006). Preliminary analyses of the mean calf labour input data for one hundred and twenty nine farms revealed that it was positively skewed. Hence, the data were transformed using the natural logarithm. The resulting transformed data was normally distributed based on the Kolmogorov–Smirnov test. The effect of herd size on time for the different calf rearing methods (milk transfer, milk temperature fed, calf-feeding method, feed frequency, calf house cleaning method, calf house cleaning frequency) practised on farms was tested. The proportion of herds having different calf rearing characteristics were analysed using the Chi-square test. There were no differences shown in total calf care between the months of March and April in year 2 for the 57 herds, thus the data was pooled for comparison of alternate calf-feeding systems. The effect of alternative calf-feeding systems (automatic feeder, once a day with teats, twice daily with buckets, twice daily with teats and twice daily with a trough) on the labour requirement for 57 herds was determined using generalized linear models (PROC GLM) in SAS (2006). Least squares means of the transformed data were extracted and backtransformed for ease of interpretation. Calf performance data was subjected to analysis of variance in PROC GLM (SAS, 2006). Herd was used as the experimental unit.
3. Results 3.1. Calf care labour demand and characteristics of calf management on farms The total work force on farms was represented by family full-time and part-time labour, hired full-time and
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
part-time labour. There were 1.28, 1.40, and 1.29 family full-time labour units on small, medium and large herds, respectively. In addition, there were 0.53, 0.89, and 0.81 family part-time labour units on small, medium and large herds, respectively. There was no hired full-time labour units employed on the small herds, but there was 0.13 and 0.76 labour units employed on medium and large herds, respectively. Hired part-time labour represented 0.09, 0.23, and 0.36 labour units on small, medium and large herds, respectively. The average total daily labour input associated with calf care during Feb, March and April of year 1, for different herd sizes is shown in Table 1. The average time consumed by calf care peaked in April with herds in the small, medium and large groups taking 63, 74, and 112 min/day, respectively. The average time consumed by calf care per farm increased (P b 0.001) with herd size. The large herd group had a higher (P b 0.001) labour requirement for calf care compared to the small and medium herds in both March and April and compared to the small herd group in February. Herds size groups of small, medium and large had average calf numbers of 25, 35, and 53, respectively, over the three month period, thus resulting in an average labour input per calf per day of 2.10 min, 1.70 min and 1.77 min, respectively. There were no significant interactions between herd group and time for the calf rearing practises tested which included milk transfer method, milk temperature, feeding method, feed frequency and calf house cleaning frequency. There was a significant interaction for the calf house cleaning method, with the large herd requiring a longer time for cleaning using the manual cleaning method (P b 0.01) compared to the mechanical method and compared to the small and medium groups (P b 0.001).
Table 1 Total daily labour input (min/day) (average transformed data in parenthesis) associated with calf care for small, medium and large herds during the months of February, March and April for year 1 Herd group Small Medium Large (b50 cows) (50 to 80 cows) (N80 cows) Number of herds
32
55
42
s.e.
Sig.
February (min/day) March (min/day) April (min/day)
31 (n = 11) (3.44a) 64 (n = 36) (4.16a) 63 (n = 28) (4.15a)
55 (n = 18) (4.00ac) 44 (n = 46) (3.79b) 74 (n = 40) (4.30b)
77 (n = 32) 0.126 ⁎⁎⁎ (4.34bc) 92 (n = 62) 0.128 ⁎⁎⁎ (4.52c) 112 (n = 64) 0.111 ⁎⁎⁎ (4.72c)
n = average number of calves. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
85
Table 2 Proportion of herds practising different calf rearing methods within different small, medium and large herd groups, during the months of February, March and April for year 1 Herd group
Small Medium Large Sig. (b50 cows) (50 to 80 cows) (N80 cows) (n = 32) (n = 55) (n = 42)
Milk transfer method Bucket 0.53 0.52 Pump 0.16 0.25 Mechanical 0.31 0.23 Milk temperature fed to calves Cold 0.03a 0.15b Warm 0.97 0.85 Calf-feeding method Bucket 0.50a 0.33b Teats or 0.19a 0.45b Automatic Trough 0.31 0.22 Feed frequency Ad libitum 0.20a 0.47b Twice daily 0.80 0.53 Calf house cleaning method Loader only 0.28 0.22 Fork/barrow/ 0.95 0.82 loader Calf house cleaning frequency Daily 0.22 0.09 Weekly 0.34 0.65 Monthly 0.44 0.26
0.39 0.20 0.41
NS
0.23b 0.77
⁎
0.25b 0.49b
⁎
0.26 0.50b 0.50
⁎
0.17 0.73
NS
0.10 0.40 0.50
P = 0.06
n = number of herds. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
The proportion of herds within different herd groups practising different calf rearing methods is shown in Table 2. The proportion of herds using different methods for transferring milk between the dairy and calf house did not differ significantly across herds. However, mechanical methods of milk transfer were more frequently used by the large herd group. A higher proportion of the large herds (0.23) offered milk to calves at a cold temperature compared to the small (0.03) or medium herds (0.15) (P b 0.05). The occurrence of teat feeding systems or automatic feeding was higher for the large herds (0.49) compared to the small herd group (0.19), while bucket feeding was more prevalent with the small herd group (0.50) compared to the large herd (0.25) (P b 0.05). Ad libitum feeding was more prevalent with the large herd (0.50) group compared to the small herd (0.20) group (P b 0.05). There were no differences in the proportion of herds using trough feeding herds. The proportion of herds using either manual (fork and loader and fork and barrow) or mechanical only methods (loader) of cleaning calf houses were similar across groups. Calf house cleaning was generally carried
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out on a less frequent basis (P b 0.06) on the large herd group compared to herds in the small and medium groups. The proportion of herds grouping calves for ease of management did not differ between herd groups with 0.75, 0.85 and 0.83 of small, medium and large herds, respectively, grouping calves at less than two weeks of age. 3.2. Individual feeding systems and labour input The effect of individual calf-feeding system on the average labour input per calf over the months of March and April is shown in Table 3. There was no difference in the average total daily labour input between months. This was expected as the labour input was recorded only for calves from N 8 days to 8 weeks of age. Feeding calves twice daily, using TB or TT increased (P b 0.08) the milk feeding time per calf compared to systems AU, OT and TR. The labour input for cleaning of feeding equipment was significantly higher (P b 0.05) with the AU system compared to the other feeding systems. The time per calf taken for milk transfer from the dairy to the calf house was numerically lowest for the TB system (4 s) and highest for the AU system (9 s). There was no significant difference in the labour input per calf between feeding systems when the tasks of feeding, cleaning and milk transfer were combined. The labour input per calf associated with the combined tasks of application of calf bedding material and cleaning of calf
bedding areas was highest (P b 0.05) (13 s) for the AU system compared to the other feeding systems. The labour input for veterinary attention was 1, 2, 0, 4, and 5 s/calf/day for AU, OT, TB, TT, and TR feeding systems, respectively. The OT and the AU feeding systems had the lowest (23 s) and highest (38 s) labour requirement per calf for total calf care. When methods used for calf house cleaning (loader only, manual fork with loader and manual fork with barrow were evaluated for labour input, a significantly lower (P b 0.01) (s.e. = 1.66) labour requirement per calf was observed when a loader only (2.1 s) was used compared to systems using a combination of fork with loader (8.2 s) and fork with barrow (7.7 s). 3.3. Individual feeding systems and calf performance The effect of different calf-feeding systems on calf performance for the sub-set of 10 herds is shown in Table 4. The mean calf weight at day 77 for AU, OT, TT and TR feeding methods were 95, 95, 93, 91 kg, respectively (Table 4). Mean calf daily weight gain which was calculated from day 15 to 77 was lower (P b 0.001) (s.e.d. = 0.03) for the TR method (0.65 kg/day) and the AU method (0.70 kg/day) compared to the OT (0.79) and TT (0.80) methods. The range in calf daily weight gain between herds was less with the OT (0.72–0.89) and TT (0.79–0.81) systems compared to the AU (0.57– 0.80) and TR (0.51–0.76) systems. A questionnaire
Table 3 Effect of calf-feeding system on the daily labour input (back-transformed mean in parenthesis; s/calf/day) for each calf care task for calves (8 days to 8 weeks of age) (57 herds during the months of March and April) Calf-feeding system
Automatic feeder (AU)
Once daily with teats (OT)
Twice daily with buckets (TB)
Twice daily with teats (TT)
Twice daily with trough (TR)
(n = 14)
(n = 8)
(n = 8)
(n = 13)
(n = 14)
1
Milk feeding time Clean feed equipment Feed + clean time Transfer of milk Total milk feed time Bed + clean calf pens Total calf care time⁎
1
1
1
(n = 174)
(n = 90)
(n = 105)
(n = 130)
(n1 = 156)
1.96 (7) 2.16a (9) 2.79 (16) 2.17 (9) 3.16 (24) 2.54a (13) 3.63 (38)
2.13 (8) 1.33b (4) 2.35 (10) 1.63 (5) 2.83 (17) 1.27b (4) 3.14 (23)
2.89 (18) 1.34b (4) 3.09 (22) 1.45 (4) 3.28 (26) 1.77c (6) 3.45 (32)
2.51 (12) 1.64c (5) 2.84 (17) 1.75 (6) 3.15 (23) 1.86c (6) 3.59 (36)
1.92 (7) 1.25bc (3) 2.26 (10) 1.85 (6) 2.78 (16) 1.72c (6) 3.28 (27)
n = number of herds, n1 = number of days time was recorded, ⁎ Includes veterinary time. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
s.e.
Sig.
0.273
P = 0.08
0.245
⁎
0.254
NS
0.242
NS
0.182
NS
0.292
⁎
0.170
NS
D. Gleeson et al. / Livestock Science 116 (2008) 82–89
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Table 4 Effect of calf milk feeding method on calf weight for Friesian female calves (10 herds) at 77 days and weight gain per day (day 15 to day 77) Feeding system Calf performance Number of calves weighed Calf weight at 77 days (kg) Calf weight gain per day (kg) Calf weight gain per day range between herds (kg)
Automatic feeder (AU) (n = 3)
Once daily with teats (OT) (n = 3)
Twice daily with teats (TT) (n = 2)
Twice daily with trough (TR) (n = 2)
s.e.d.
Sig.
30 95.0 0.70b 0.57–0.80
34 94.8 0.79a 0.72–0.89
41 93.2 0.80a 0.79–0.81
37 90.5 0.65b 0.51–0.76
– 2.3 0.03 –
– NS ⁎⁎⁎ –
n = number of herds. Values, within rows, without a common superscript are significantly different (P b 0.05).
abc
survey completed on the management of calves indicated that the milk intake figures differed between systems. Calves on the OT feeding method received less milk per day (4.9 l) than calves on the TT (7 l), AU (N9 l) and TR (9 l) systems. Calves on the TT system remained on milk longer before weaning than the AU or TR systems. The average calf age at weaning was 51, 56, 65, and 54 days for the AU, OT, TT, and TR feeding methods, respectively. The proportion of calf deaths were 0.00, 0.03, 0.01, and 0.04 for TT, TR, OT and AU feeding systems, respectively. The average daily intake of concentrates when calves were weaned off milk was 0.40, 0.80, 1.00 and 1.00 for AU, OT, TT and TR systems, respectively. 4. Discussion 4.1. Calf care labour demand and characteristics of calf management on farms
the fact that as herd size increased, herds tended to use less buckets for calf-feeding and for milk transfer from the dairy to the calf house. This also coincided with significantly more use of teat feeding from a container, automatic feeders and ad libitum feeding. Large farms were more likely to feed cold milk to calves, this allowed the task of calf-feeding to be carried out during an off-peak labour time during the day. There were no differences in the use of mechanization to clean calf houses. Inadequate access to calf houses to operate mechanical cleaning was the main factor why manual cleaning was used. The large herds also tended not to clean pens daily and tended towards a monthly basis. This data indicated that when calf numbers increased, herds tended to use more labour saving methods. Regardless of herd size, herds grouped calves at less than two weeks of age with the purpose of reducing the level of individual attention. 4.2. Individual feeding systems and labour input
The family labour input of both full-time and parttime people remained fairly constant across herd sizes. However, as herd size increased between groups so did the number of hired full-time and part-time people that were employed. In this study, the task of calf care was in the majority of cases undertaken by family part-time labour. As herd size increased, so also did the average number of calves reared and the total labour input per day as expected. However, the labour input per calf per day improved marginally (2.1 to 1.8 min) in efficiency as herd size increased. O'Shea et al. (1998) concluded that most farm tasks other than calf rearing were carried out more efficiently as herd size increased. As it is necessary for each calf to be individually managed for a period after birth, this may explain why the increase in efficiency was not greater with scale. In spring-calving herds the number of calvings would be expected to peak during March and therefore, a higher calf labour input would also be expected at this time. The improvement in efficiency that was evident with herd size may be due to
The TB system had low equipment cleaning time and milk transfer time, this may be due to the fact that buckets may not be cleaned between batches of calves and the transfer of milk may be included as calf-feeding time rather than seen as a separate task to feeding. The labour input for bedding and cleaning of calf houses was significantly higher for the AU system and lowest for the OT system. Extra urine and wet bedding are peculiar to the AU system (Fallon, 1999). The OT system had a numerically lower labour input per calf for total calf care (total feed time, bed and clean pens, veterinary). In addition, this feeding system allowed flexibility such as carrying out of the calf-feeding task at an off-peak time during the day. Calf house designs should allow for access of mechanical equipment to clean out pens between batches of calves, as significant reduction in labour input per calf was shown where loaders could be used for the complete cleaning process.
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4.3. Individual feeding systems and calf performance The ten farms selected for measuring calf performance may not be representative of the total herds studied for calf labour input; however these farms were representative of each of the calf-feeding systems used on the 57 farms. Once daily feeding of calves did not adversely affect calf performance in agreement with some previous studies. (Fallon, 1999; Williams et al., 1986). Appleby et al. (2001) also showed that calves gained weight more quickly from birth to weaning when fed ad libitum compared to calves fed twice daily by bucket. However, lower post-weaning weight gains may be expected with calves on the AU system as lower intakes of concentrates have been observed when calves were fed using an automatic feeder (Fallon and Harte, 1987; Broadbent, 1973). The lower intake of concentrates with ad libitum fed calves can lead to a postweaning lag in growth (Hepola, 2003). The period of time between weaning and calf weighing may explain the lower weight gain per day observed with the AU and TR systems in this study. 5. Conclusion There was considerable variation in time taken for calf care, irrespective of herd size. The main factors influencing labour input associated with calf care included the calf-feeding system and calf house cleaning methods. As herd size increased labour saving practises such as ad libitum feeding of milk were more likely to be used. Milk feeding of calves on a once daily basis tended to reduce the total labour input per calf and did not adversely affect calf performance. While calffeeding time was similar for all systems, the task of feeding calves was completed at one occasion with the once daily feeding system. Reduced labour input was required for bedding/cleaning of calves fed on a once daily basis and farmers also tended to put these calves outdoors at an earlier stage. Thus, it is possible to improve time efficiency of calf care by selecting time efficient methods of calf-feeding without affecting calf performance. All of the calf rearing systems operated in this study were within the European Communities Regulations, 1995/98 for the welfare of calves. Acknowledgements The authors wish to thank Dr. Richard Fallon for his helpful comments and advice and Mr Jonathon Kenneally for his skilled technical assistance. The
authors also wish to thank Dr. Donagh Berry for statistical analysis and the dairy farmers who participated in this study. In particular the authors would also like to acknowledge the contribution of the late Peter Daly. This research was part funded by Irish dairy farmers and by European Union Structural Funds (EAGGF). References Appleby, M.C., Weary, D.M., Chua, B., 2001. Performance and feeding behaviour of calves on ad libitum milk from artificial teats. Appl. Anim. Behav. Sci. 74, 191–201. Bak Jensen, M.B., 2003. The effects of feeding method, milk allowance and social factors on milk feeding behaviour and cross-suckling in group housed dairy calves. Appl. Anim. Behav. Sci. 80, 191–206. Boe, K., Havrevoll, O., 1993. Cold housing and computer-controlled milk feeding for dairy calves: behaviour and performance. Anim. Prod. 57, 183–191. Broadbent, P.J., 1973. A note on the effects of frequency and method of feeding milk substitute on the performance of Friesian and Ayrshire calves. Anim. Prod. 17, 333–336. Burt, A.W.A., 1967. A note on the effect of giving milk substitutes only once a day to early-weaned calves. Anim. Prod. 10, 113–116. Chua, B., Coenen, J., Van Delen, J., Weary, D.M., 2001. Effects of pair versus individual housing on the behaviour and performance of dairy calves. J. Dairy Sci. 85, 360–364. Fallon, R.J., 1999. General principles of management of calves. Proc. of Teagasc Symposium. Kildalton, Co., Kilkenny, Ireland, p. 46. 4th February. Fallon, R.J., Harte, F.J., 1982. Effect of Ad-Libitum Feeding of Normal and Acidified Milk Replacer on Calf Performance. . Anim. Prod. Res. Rep., vol. 4, 23. An Foras Taluntais, 19 Sandymount Avenue, Dublin, pp. 12–13. Published by. Fallon, R.J., Harte, F.J., 1987. Effect of Feeding Milk Replacer Ad Libitum for 28 or 35 days on Calf Performance. . Anim. Prod. Res. Rep., vol. 4, 28. An Foras Taluntais, 19 Sandymount Avenue, Dublin, p. 15. Published by. Fallon, R.J., Brockwa, y, J.M., Williams, P.E.V., 1985. The effect of the frequency of feeding of milk on the energetic efficiency of preruminant calves. Anim. Prod. 40, 570 (abstr). Hepola, H., 2003. Milk feeding systems for dairy calves in groups: effects on feed intake, growth and health. Appl. Anim. Behav. Sci. 80, 233–243. Jasper, J., Weary, D.M., 2002. Effects of ad libitum milk intake on dairy calves. J. Dairy Sci. 85 , 3054–3058. Jorgenson, L.J., Jorgenson, N.A., Schingoethe, D.J., Owens, M.J., 1970. Indoor versus outdoor calf rearing at three weaning ages. J. Dairy Sci. 53, 813–816. Kung, L.J.R., Demarco, S., Siebenson, L.N., Joyner, E., Haenlein, G.F.W., Morris, R.M., 1997. An evaluation of two management systems for rearing calves fed milk replacer. J. Dairy Sci. 80 , 2529–2533. McCarthy, D., 2000. Optimising profits on dairy farms. Opportunities for the New Millennium. Proc. of the Nat. Dairy Con., Cork, vol. 16, pp. 7–15. November 2000. O'Brien, B., O' Donovan, K., Gleeson, D., Ruane, D., Kinsella, J., 2001. Profiling the working year on Irish dairy herds. Proc. Irish Grass. and Anim. Prod. Ass. Con. , pp. 112–124.
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