Huang Wenming, Tian Yujia, Li Shengli, Wu Zhaohai, Cao Zhijun
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Department of Animal Science, Southwest University, Chongqing, China.
Anim Sci J. 2017 Nov;88(11):1700-1708. doi: 10.1111/asj.12835. Epub 2017 Jun 27.
The objective of this study was to determine the effect of reduced energy density of close-up diets on ruminal fermentation parameters in transition cows. Fourteen Holstein dry cows were blocked and assigned randomly to three groups fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation (NE )/kg dry matter (DM)), or a middle energy density diet (MD, 1.47 Mcal NE /kg DM), or a low energy density diet (LD, 1.30 Mcal NE /kg DM) prepartum, and were fed the same diet postpartum. The reduced energy density diets decreased the average dry matter intake (DMI) prepartum and tended to increase the DMI postpartum. The ruminal pH of the LD group was significantly higher prepartum and lower during the first week of lactation compared with the other two groups. The reduced energy density diet depressed the average ruminal concentration of propionate and butyrate prepartum, and increased the average concentration of total volatile fatty acids (VFA) postpartum. The LD group had higher populations of Butyrivibrio fibrisolvens and Ruminococcus flavefaciens relative to HD and MD groups on 7 days in milk. In conclusion, the cows fed reduced energy density diet prepartum had higher VFA concentration, but were more susceptible to subacute ruminal acidosis postpartum.
本研究的目的是确定围产前期能量密度降低的日粮对围产前期奶牛瘤胃发酵参数的影响。将14头荷斯坦干奶牛进行分组，并随机分配到三组，分别在产前饲喂高能量密度日粮（HD，泌乳净能（NE）1.62兆卡/千克干物质（DM））、中等能量密度日粮（MD，1.47兆卡NE/千克DM）或低能量密度日粮（LD，1.30兆卡NE/千克DM），产后饲喂相同日粮。能量密度降低的日粮降低了产前平均干物质摄入量（DMI），并使产后DMI有增加的趋势。与其他两组相比，LD组产前瘤胃pH值显著较高，泌乳第一周瘤胃pH值较低。能量密度降低的日粮在产前降低了瘤胃丙酸和丁酸的平均浓度，在产后增加了总挥发性脂肪酸（VFA）的平均浓度。在产奶7天时，相对于HD组和MD组，LD组的溶纤维丁酸弧菌和黄化瘤胃球菌数量更多。总之，产前饲喂能量密度降低日粮的奶牛挥发性脂肪酸浓度较高，但产后更易患亚急性瘤胃酸中毒。
