Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5.
The Research Center for Animal Science, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Japan 739-8528.
J Dairy Sci. 2021 Apr;104(4):4362-4374. doi: 10.3168/jds.2020-19611. Epub 2021 Jan 21.
The objective of this study was to evaluate the effects of the starch content of pre- and postpartum diets on productivity, plasma energy metabolites, and serum markers of inflammation of dairy cows during the calving transition period. Eighty-eight primiparous and multiparous cows were randomly assigned to pre- and postpartum dietary treatments balanced for parity and pretrial body condition score at d 28 ± 3 before expected calving date. Cows were fed either a control [Control; 14.0% starch, dry matter (DM) basis] or high-starch (High; 26.1% starch, DM basis) prepartum diet commencing 28 ± 3 d before expected calving date. Following calving, cows were fed either a high-fiber (HF; 33.8% neutral detergent fiber, 25.1% starch, DM basis) or high-starch (HS; 27.2% neutral detergent fiber, 32.8% starch, DM basis) postpartum diet for the first 20 ± 2 d following calving. Cows fed the High prepartum diet had greater DM intake (12.4 vs. 10.2 kg/d), plasma concentrations of insulin (1.72 vs. 14.2 ng/mL), glucose (68.1 vs. 65.0 mg/dL), and glucagon-like peptide-2 (0.41 vs. 0.32 ng/mL) before parturition, but increased plasma free fatty acid concentration (452 vs. 363 µEq/L) and milk fat yield (1.64 vs. 1.48 kg/d) after parturition. Cows fed the HS postpartum diet had lower plasma free fatty acid (372 vs. 442 µEq/L) and serum haptoglobin (0.46 vs. 0.70 mg/mL) concentrations over a 3-wk period after calving. In addition, there was a tendency for interaction between prepartum and postpartum diets for milk yield, where feeding the HS postpartum diet increased milk yield compared with the HF diet for cows fed the Control prepartum diet (40.8 vs. 37.9 kg/d) but not for cows fed the High prepartum diet. These results suggest that management efforts to minimize the change in diet fermentability during the calving transition by feeding the High prepartum diet, the HF postpartum diet, or both did not increase productivity of dairy cows but increased fat mobilization after calving. Our findings also suggest that feeding high-starch postpartum diets can decrease fat mobilization and serum indicators of systemic inflammation and increase milk production even with the transition from a low-starch prepartum diet.
本研究旨在评估产前和产后日粮淀粉含量对奶牛产犊过渡期生产性能、血浆能量代谢物和血清炎症标志物的影响。88 头初产和经产奶牛随机分为产前和产后日粮处理组，按胎次和产前体况评分在预计产犊日期前 28 ± 3 d 进行平衡。奶牛在预计产犊日期前 28 ± 3 d 开始分别饲喂对照（Control；淀粉含量 14.0%，干物质基础）或高淀粉（High；淀粉含量 26.1%，干物质基础）产前日粮。产后，奶牛饲喂高纤维（HF；中性洗涤纤维 33.8%，淀粉 25.1%，干物质基础）或高淀粉（HS；中性洗涤纤维 27.2%，淀粉 32.8%，干物质基础）产后日粮，产后 20 ± 2 d 内。饲喂高淀粉产前日粮的奶牛 DM 采食量（12.4 比 10.2 kg/d）、血浆胰岛素（1.72 比 14.2 ng/mL）、葡萄糖（68.1 比 65.0 mg/dL）和胰高血糖素样肽-2（0.41 比 0.32 ng/mL）在分娩前较高，但分娩后血浆游离脂肪酸浓度（452 比 363 µEq/L）和乳脂产量（1.64 比 1.48 kg/d）增加。产后饲喂 HS 日粮的奶牛在产后 3 周内血浆游离脂肪酸（372 比 442 µEq/L）和血清触珠蛋白（0.46 比 0.70 mg/mL）浓度较低。此外，产前和产后日粮之间存在相互作用的趋势，对于饲喂对照产前日粮的奶牛，饲喂 HS 产后日粮增加了产奶量（40.8 比 37.9 kg/d），而对于饲喂高淀粉产前日粮的奶牛则没有增加产奶量。这些结果表明，通过饲喂高淀粉产前日粮、高纤维产后日粮或两者结合，尽量减少产犊过渡期日粮发酵性变化的管理措施并未提高奶牛的生产性能，但增加了产后脂肪动员。我们的研究结果还表明，即使从低淀粉产前日粮过渡，饲喂高淀粉产后日粮也可以减少脂肪动员和血清全身炎症标志物，并增加产奶量。
