Effect of feeding pregnant and non-lactating dairy cows a supplement containing a high proportion of non-structural carbohydrates on post-partum production and peripartum blood metabolites

Animal Feed Science and Technology 116 (2004) 185–195

Effect of feeding pregnant and non-lactating dairy cows a supplement containing a high proportion of non-structural carbohydrates on post-partum production and peripartum blood metabolites U. Moallema,∗ , I. Bruckentala , D. Sklanb a

Department of Dairy Cattle, Institute of Animal Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel b Faculty of Agriculture, Hebrew University, Rehovot 76-100, Israel Received 3 October 2003; received in revised form 17 June 2004; accepted 10 July 2004

Abstract Ten pregnant heifers and 26 dry multiparous cows, 4 weeks before their expected parturitions, were blocked according to parity, BCS (body condition score) and BW (body weight) into two treatments: (1) control – cows fed until parturition with free choice of oat hay and 3 kg DM (dry matter) per day of a lactating cow diet, and (2) treatment – cows were fed as the control plus 0.75 kg (as fed, 860 g/kg DM) of a supplement containing 410 g/kg of non-structural carbohydrates (NSC) and 760 g/kg total carbohydrates. Post-partum, both groups were fed the same lactation diet (168 g/kg CP and 7.27 MJL /kg DM). The mean live-weight of the treatment cows 2 days post-partum was 22.0 ± 9.2 kg higher than control cows (P < 0.01). Mean daily milk and milk fat production during the first 120 days of the subsequent lactation were 38.5 and 36.9 kg (P < 0.0003) and 33.1 and 30.4 g/kg (P < 0.0004) for the treatment and control cows, respectively. Feeding a supplement containing a high proportion of NSC to dry cows reduced plasma glucose concentrations both pre-partum (P < 0.06) and post-partum (P < 0.01), and increased plasma insulin pre-partum (P < 0.04) and decreased it post-partum (P < 0.03) as compared with control cows. Pre-partum plasma ␤-hydroxybutyrate concentrations were enhanced (P < 0.04), and triglycerides reduced (P < 0.04), in the treatment cows

Abbreviations: BCS, body condition score; BW, body weight; NSC, non-structural carbohydrates; MJ, mega joule; DM, dry matter; CP, crude protein; NDF, neutral detergent fiber; ADF, acid detergent fiber; DIM, days in milk; VFA, volatile fatty acids; TG, triglycerides; NEFA, none esterifies fatty acids; TMR, total mixed ration; AST, aspartate-oxygultarate aminotransferase ∗ Corresponding author. Tel.: +972 3 9683374; fax: +972 3 9683952. E-mail address: [email protected] (U. Moallem). 0377-8401/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.anifeedsci.2004.07.004

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with no post-partum differences. Pre-partum feeding with a supplement containing a high proportion of NSC can produce long term changes in metabolism with enhanced BW at parturition and increased milk and milk fat production through 120 days of the subsequent lactation. © 2004 Elsevier B.V. All rights reserved. Keywords: Transition cow; Non-structural carbohydrates; Metabolites

1. Introduction The transition period of dairy cows has been defined as 3 weeks pre-partum and 3–4 weeks post-partum. This transition from a pregnant non-lactating cow with relatively low nutritional requirements to a non-pregnant high producing lactating cow with elevated nutritional requirements, and the rapid hormonal changes together with parturition stress, leads to a high susceptibility and to prevalence of metabolic health disorders. Health disorders in early lactation result in economic losses due to both decreases in milk production and the expenses of clinical treatment (Wallace et al., 1996; Rajala-Schultz et al., 1999). Nutritional inadequacy pre- and post-partum, has been thought to be one of the main factors in the high incidence of metabolic disorders during this period. The dramatic increase in mammary demand for glucose at the onset of lactation (Overton et al., 1999) and consequently the required rapid adaptation could also be the reason for some metabolic disorders. Much of the glucose is supplied by hepatic gluconeogenesis from proprionate (Lomax and Baird, 1983). Dirksen et al. (1985) demonstrated better development of rumen papillae with a reduced proportion of fiber in the pre-partum diets which are necessary to increase volatile fatty acids (VFA) absorption capacity early post-partum. Dann et al. (1999) reported an increase in post-partum milk production in response to pre-partum supplementation of 2.48 MJ/day non-structural carbohydrates (NSC). Fronk (1975) showed a higher molar proportion of rumen propionate, and elicited a higher insulin response with addition of propylene glycol compared to starch. In another report of feeding a non-structural carbohydrate supplement for 21 days pre-partum and 21 days post-partum, increased milk yield and yields of milk fat and protein (Ballard et al., 2001). The objectives of the present study were to investigate effects of pre-partum feeding of a supplement containing a high proportion of NSC to dry cows and pregnant heifers on production and metabolism in early lactation.

2. Materials and methods 2.1. Experimental design and treatments Twenty-six multiparous Israeli-Holstein cows and 10 heifers of the Volcani Center experimental dairy farm were assigned to two treatments commencing 4 week before their expected parturitions. The cows were housed in groups in covered, loose pens with adjacent outside yards. Cows were weighed and BCS (body condition score) was determined before blocking. Mature cows were blocked according to parity, BCS, body weight (BW) and milk

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Table 1 Ingredient and chemical composition (g/kg DM) of total mixed ration Ingredient composition Corn grain ground Barley grain rolled Wheat grain ground Sorghum grain ground Soybean meal (solvent extraction, 450 g/kg CP) Rapeseed meal (solvent extraction, 340 g/kg CP) Sunflower meal (solvent extraction, 330 g/kg CP) High fat protein supplement Corn gluten feed Cottonseed (Akala) Wheat silage Corn silage Wheat bran Wet citrus pulp Soybean hulls Sunflower hulls Pea hay Oat hay Non-protein nitrogen mixturea Magnesium oxide Soybean oil Salt Calcium bicarbonate Fish meal (Menhaden, 660 g/kg CP) Vitamins and mineralsb Calcium soaps of fatty acids Nutrient composition NEl c (MJ/kg) Crude protein Acid detergent fiber Neutral detergent fiber P Ca

178 83 24 24 51 37 71 15 43 11 72 115 81 19 16 24 32 65 1 2 2 13 4 9 1 8 7.27 168 194 339 5 8

a

Contained 800 g/kg urea and 200 g/kg ammonium sulfate. Contained 20,000,000 IU of vitamin A/kg, 2,000,000 IU of vitamin D/kg, 15,000 mg/kg of vitamin E, 6000 mg/kg of Mn, 6000 mg/kg of Zn, 2000 mg/kg of Fe, 1500 mg/kg of Cu, 120 mg/kg of 1, 50 mg/kg of Se, and 20 mg/kg of Co. c Calculated using NRC (1989) values. b

production during the first 120 days of the previous lactation, and heifers were blocked according to BCS and BW. During the 4 week before the expected parturition, the control group (control) was fed free choice oat hay and 3 kg dry matter (DM) of lactating cow diets (Table 1). The treatment group (treatment) received an additional 0.75 kg of a carbohydrate supplement (Sweet LacTM Transition Formula; Westway, Tomball, TX, USA) containing 60 g/kg crude protein (CP), 760 g/kg total carbohydrate, 192 g/kg neutral detergent fiber (NDF), 410 g/kg of NSC, and 270 g/kg total sugar (all on as fed basis). The supplements were com-

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prised of 220 g/kg cane molasses, 450 g/kg beet pulp, 170 g/kg propylene glycol, 160 g/kg calcium hydroxide and flavor additives (DM basis). The supplement was pre-mixed with the lactating diet component of the ration. After calving, all cows were assigned to one feeding group, and fed the same diet as a total mixed ration (TMR; Table 1). Cows were milked three times daily and milk production was recorded electronically. Milk solids content was determined from a composite of three consecutive milkings every 2 weeks until 120 days in milk (DIM). From parturition, cows were automatically weighed three times daily after each milking with a walking electronic scale. BCS on a 1–5 scale (Edmonson et al., 1989) was determined weekly from parturition until 120 DIM. The experimental protocol for this study was approved by the Volcani Center Animal Care Committee. 2.2. Chemical analyses Feed samples were dried at 65 ◦ C for 24 h and then ground to pass 1.0 mm screen (Retsch, type SM-100 C, Haan, West Germany). The ground samples were dried at 100 ◦ C for 24 h and analyzed for N (AOAC, 1990; method 984.13), NDF and ADF content was determined with Ankom equipment and was expressed without residual ash (Ankom Technology, Fairport, NY, USA; NDF using ␣-amylase and sodium sulfite; Van Soest et al., 1991), NEL using NRC values (NRC, 1989), Ca (AOAC, 1990; method 935.13), and P (AOAC, 1990; method 964.06). Milk fat, crude protein and lactose were determined by infrared analysis at the laboratories of the Israeli Cattle Breeders Association (Caesarea, Israel). Blood samples were collected weekly from 4 weeks before the expected parturition until 30 DIM, from the jugular vein into vacuum tubes (Becton Dickinson Vacutainer Systems, Cowley, England). Different blood samples were collected to tubes containing potassium fluoride for glucose analysis. Serum was separated from blood samples and stored at −18 ◦ C until analysis. Plasma glucose (Bonder and Mead, 1974), triglycerides (TG) (McGowan et al., 1983), total Ca (Bauer, 1981), aspartate-oxygultarate aminotransferase (AST) (Bergmeyer et al., 1978), ␤-hydroxybutyrate (Williamson et al., 1962) and non-esterified fatty acids (NEFA) (Johnson and Peters, 1993) were determined. Plasma insulin was determined by radioimmunoassay (Diagnostic Products, Los Angeles, CA, USA).

3. Statistical analysis Continuous variables were analyzed by analysis of variance where the treatments were the sources of variation using the General Linear Models procedure of SAS (1987). The model used was: Yijklmn = µ + TRi + Lj + Tri × Lj + Dk + Dk × TRi + Xl + DATm + Eijklmn where µ is the overall mean of the population, TRi the mean effect of treatment, Lj the mean effect of lactation number, 1 or ≥2, Dk the covariance variable effect of dependent variable in the previous lactation (multiparous only), DATm the covariance variable mean effect of date of observation, Eijklmn the random residual assuming normal independent distribution

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(Sklan et al., 1994). Least squares means and adjusted SEM are presented in the tables and P was <0.05 unless otherwise stated.

4. Results Feeding the supplement commenced at 247 ± 3 days of pregnancy and continued until parturition i.e. 28 ± 6 days. The duration of gestation was longer in control cows versus treatment cows (280 ± 1 versus 276 ± 1 days; P < 0.05). Daily milk production and milk solids are in Table 2 and Fig. 1. Average milk production of the treatment cows was 1.6 kg/days higher than the control cows during 120 DIM (P < 0.0003). Milk fat proportion (P < 0.0004) and yield (P < 0.0002) during the first 120 DIM were also higher in the treatment cows. A tendency towards decreased milk protein percentage was observed in the treatment cows (P < 0.1), but no effect on protein yield occurred. Cows were blocked by BW at the beginning of the experiment, however at parturition the treatment cows have a higher BW than controls (624 ± 9.1 versus 602 ± 9.3 kg; P < 0.01) and this difference was maintained throughout the 120 days of the experiment (Fig. 2). In contrast, BCS of the treatment cows decreased more than control cows until 42 days after calving (0.75 ± 0.07 versus 0.53 ± 0.07 BCS points; P < 0.05), when BCS of treatment cows began to increase (Fig. 2). Mean plasma concentrations of several metabolites, AST (aspartate-oxygultarate aminotransferase) and insulin during the 4 weeks pre-partum and the 4 weeks post-partum are in Table 3 and Fig. 3. Both pre-partum (P < 0.06) and post-partum (P < 0.01) glucose concentrations in plasma were lower in treatment cows (P < 0.006). Beta-hydroxybutyrate concentrations were higher pre-partum (P < 0.04) in treatment cows, whereas post-partum there were no differences. Higher plasma insulin concentrations were observed in treatment cows during the pre-partum period (P < 0.04), while lower insulin concentrations were observed post-partum (Fig. 2) in treatment cows (P < 0.03). In both groups a substantial decrease in TG plasma concentrations occurred at calving (Fig. 2). Pre-partum plasma concentrations of TG were higher in treatment cows (P < 0.04), whereas there were no differences in post-partum TG concentrations. Plasma concentrations of total calcium (data not shown), AST and NEFA were not different between treatments pre- or post-partum. Table 2 The effects of NSC supplementation for 4 weeks pre-partum on milk and milk solids during the first 120 days of the subsequent lactation

n, cows Milk (kg/day) Fat (g/kg) Fat (kg/day) Protein (g/kg) Protein (kg/day)

Control

Treatment

SEM

P-value

18 36.9 30.4 1.13 30.7 1.15

18 38.5 33.1 1.28 30.1 1.16

0.31 0.05 0.027 0.02 0.020

<0.001 <0.001 <0.001 <0.1 <0.6

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Fig. 1. Milk production and fat and protein percentage during 120 DIM of cows fed the control (
) or treatment diets (supplemented with NSC) at 4 weeks pre-partum (). Results are least squares means and SEM were 0.31, 0.05, and 0.02 for milk, fat and protein, respectively.

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Fig. 2. BCS and body weight changes during 120 DIM of cows fed control (
) or treatment diets (supplemented with NSC) at 4 weeks pre-partum (). Results are least squares means and SEM 0.1 and 15.8 for BCS and BW, respectively. Table 3 Glucose, ␤-hydroxybutyrate, triglycerides, total calcium, aspartate-oxygultarate aminotransferase (AST), NEFA and insulin concentrations in plasma at 4 weeks pre-partum and 4 weeks post-partum Pre-partum

n, cows Glucose (mg/dl) ␤-Hydroxybutyrate (mg/dl) NEFA (mequiv./l) Triglycerides (mg/dl) Calcium, total (md/dl) AST (IU/l) Insulin (ng/ml)

Control

Treatment

18 61.2 5.62 0.47 23.0 9.79 48.0 0.22

18 59.3 6.1 0.45 20.2 10.03 47.7 0.30

Post-partum SEM 0.72 0.16 0.02 0.98 0.15 1.3 0.02

P-value

Control

Treatment

SEM

P-value

<0.06 <0.04 <0.49 <0.04 <0.28 <0.9 <0.04

18 58.7 6.75 0.50 7.57 9.26 61.7 0.20

18 56.1 7.20 0.48 7.52 9.17 63.9 0.16

0.7 0.26 0.03 0.55 0.15 1.8 0.01

<0.01 <0.24 <0.66 <0.95 <0.63 <0.39 <0.03

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Fig. 3. Weekly changes in plasma concentrations (least squares means) of glucose, ␤-hydroxybutyrate, nonesterified fatty acids (NEFA), triglycerides (TG), aspartate-oxygultarate aminotransferase (AST), and insulin at 4 weeks pre-partum and 4 weeks post-partum of dry cows fed the control (
) or treatment diets (supplemented high NSC) at 4 weeks pre-partum (). Results are least squares means and SEM are 0.71, 0.21, 0.03, 0.76, 1.5 and 0.52 for glucose, ␤-hydroxybutyrate, NEFA, TG, AST and insulin, respectively.

No differences between treatments were observed in incidences of periparturient disorders in early lactation. Only one treatment cow showed clinical ketosis. Similar frequency of dystocia (2/18; 1/18), retained placenta (3/18; 3/18) and metritis (4/18; 5/18) occurred in control and treatment cows.

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5. Discussion Transition dairy cows fed a supplement containing a high proportion of NSC during the last 4 weeks of pregnancy produced 1.6 kg more milk and 0.27 kg more milk fat per day in the initial 120 days of the subsequent lactation (Table 2). This carryover effect of prepartum nutrition on milk production in the subsequent lactation is similar to some previous reports (Dann et al., 1999; Greenfield et al., 2000). Persistence of milk production, as a proportion of maximal production, was higher in treatment cows after 40 DIM. This was also observed by Ballard et al. (2001), who used a similar NSC supplement which, however, was supplied from 21 days pre-partum to 21 days post-partum. We speculate that enhanced milk production observed in treatment cows for only 6–7 weeks post-partum might be due to the higher milk fat yield in early lactation which competed for the limited energy resources in the early stages of lactation. Few studies have examined changes in metabolites in blood circulation of cows during the transition period (Studer et al., 1993; Park et al., 2002). The present study indicates that there is a decrease in plasma glucose concentration at calving in both groups, which remained low through 3–4 weeks post-partum (Fig. 3). The moderate decline in ␤-hydroxybutyrate and AST concentrations in plasma prior to parturition, followed by an increase post-partum (Fig. 3), reflects the transition from the low energy requirements in the pre-partum period to the intensive energy requirements of lactogenesis post-partum. The dramatic metabolic changes during the peripartum period include repartitioning of metabolites. In late pregnancy, uterine uptake of glucose and amino acids accounts for 46 and 72% of the maternal supply, respectively (Bell, 1995). The initiation of lactogenesis changes nutrient partitioning, channeling metabolites to the mammary gland. Lactogenesis increases the metabolic requirements for glucose, and at 4 days post-partum mammary glucose uptake is 2.66 times higher than that of the gravid uterus of a 250 days pregnant cow (Bell, 1995). In the current study, a decrease in plasma glucose concentration, both pre- and post-partum, occurred as a result of pre-partum NSC supplementation (Table 3; Fig. 3). Similar results, with no increase or even a tendency towards a decrease in glucose plasma concentration by feeding transition cows with glucogenic precursors was also reported by Ballard et al. (2001). In another report, Studer et al. (1993) demonstrated, in cows given a 1 L oral drench of propylene glycol during 10 days pre-partum, an increase in plasma insulin, whereas circulating glucose concentrations changed little. Likewise, enhanced carbohydrate consumption pre-partum increased blood insulin concentrations (Holtenius et al., 1993). In a metabolic study, increasing blood insulin concentration has been shown to decrease circulating glucose (Hayirli et al., 2002). The lower level of plasma glucose in cows fed a supplement with a high proportion of NSC post-partum might be explained by the increase of glucose uptake by the udder, as a result of the increased level of plasma insulin (Table 3). Moreover, plasma glucose concentration does not reflect glucose turnover, and this should be determined in further studies. However, results of the present study are consistent with both Christensen et al. (1997) and Ballard et al. (2001) who reported that feeding glucogenic compounds pre-partum resulted in higher circulating plasma insulin, and did not increase plasma glucose levels post-partum compared with control cows.

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Insulin also affects plasma NEFA concentration by depressing lipolysis and encouraging lipogenesis. These changes are reflected in plasma NEFA concentrations which increased towards parturition and than decreased post-partum (Fig. 3; Studer et al., 1993; Grummer, 1995). In contrast, TG plasma levels, that were high pre-partum, decreased sharply at parturition (Fig. 3). This may represent liver adaptation during the transition period when TG uptake increases at the onset of lactation to support the high fatty acid requirement for milk fat synthesis. 6. Conclusions Results suggest an extreme shortage of glucogenic precursors during the onset of lactation, whereas lipogenic compounds are more available. This may explain why milk production, which depends mainly on lactose biosynthesis, was higher in the NSC supplemented cows for only 6–7 weeks post-partum, whereas milk fat production responded to NSC supplementation immediately post-partum. Pre-partum plasma TG concentrations were lower in the NSC supplemented cows which might indicate on earlier utilisation of liver TG by the NSC supplemented cows, mediated by changes as yet undefined, in hepatic lipid metabolism. Furthermore, BW at parturition was improved by pre-partum NSC supplementation (Fig. 2) and, despite the enhanced milk and milk fat production, this increased tissue mass was not utilised for milk production. These changes suggest that pre-partum feeding with a supplement high in NSC can produce long term changes in metabolism which enhanced milk and milk fat production through 120 days of lactation. References AOAC, 1990. Official Methods of Analysis. Association of Official Analytical Chemists, Arlington, VA, USA, pp. 80–88. Ballard, C.S., Mandebvu, P., Sniffen, C.J., Emanuele, S.M., Carter, M.P., 2001. Effect of feeding an energy supplement to dairy cows pre- and postpartum on intake, milk yield, and incidence of ketosis. Anim. Feed Sci. Technol. 93, 55–59. Bauer, P.J., 1981. Affinity and stoichometry of calcium binding by arsenazo III. Anal. Biochem. 110, 61–72. Bell, A.W., 1995. Regulation of organic nutrient metabolism during transition from late pregnancy to early lactation. J. Anim. Sci. 73, 2804–2819. Bergmeyer, H.U., Scheibe, P., Wahlefeld, A.W., 1978. Optimization of methods for aspartate aminotransperase alanine aminotransperase. Clin. Chem. 24, 58–73. Bonder, A.J.L., Mead, D., 1974. Evaluation of glucose-6-phosphate dehydrogenase from leuconostoc mesenteroides in hexokinase method for determination glucose in serum. Clin. Chem. 20, 586–591. Christensen, J.O., Grummer, R.R., Rasmussen, F.E., Bertics, S.J., 1997. Effect of method of delivery of propylene glycol on plasma metabolites of feed-restricted cattle. J. Dairy Sci. 80, 563–568. Dann, H.M., Varga, G.A., Putnam, D.E., 1999. Improving energy supply to late gestation and early postpartum dairy cows. J. Dairy Sci. 82, 1765–1778. Dirksen, G.U., Liebich, H.G., Mayer, E., 1985. Adaptive changes of the ruminal mucosa and their functional and clinical significance. Bov. Pract. 20, 116–120. 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. Fronk, T.J., 1975. The effect of propylene glycol on milk fat depression. M.S. Thesis. University of Wisconsin, Madison, WI, USA.

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