Reduced energy density of close-up diets decrease ruminal pH and increase concentration of volatile fatty acids postpartum in Holstein cows
Reduced energy density of close-up diets decrease ruminal pH and increase concentration of volatile fatty acids postpartum in Holstein cows
复制标题
封闭式日粮能量密度的降低会降低荷斯坦奶牛瘤胃 pH 值并增加产后挥发性脂肪酸的浓度
DOI：
10.1111/asj.12835
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发表时间：
2017
影响因子：
2
通讯作者：
Cao Zhijun
中科院分区：
文献类型：
--
作者：
Huang Wenming;Tian Yujia;Li Shengli;Wu Zhaohai;Cao Zhijun
本研究的目的是确定降低近距离日粮能量密度对过渡期奶牛瘤胃发酵参数的影响。将14头荷斯坦干奶牛随机分为3组，分别饲喂高能量密度日粮（HD，1.62 Mcal泌乳净能（NEL）/kg干物质（DM））、中能量密度日粮（MD，1.47 Mcal NEL/kg DM）和低能量密度日粮（LD，1.30 Mcal NEL/kg DM）。降低能量密度的日粮降低了产后平均干物质采食量，并有增加产后平均干物质采食量的趋势。与其他两组相比，LD组瘤胃pH值在泌乳前显著升高，而在泌乳第一周显著降低。降低能量密度的日粮降低了瘤胃丙酸和丁酸的平均浓度，提高了总挥发性脂肪酸（VFA）的平均浓度。7 d时，LD组乳中溶纤丁酸弧菌和产黄瘤胃球菌的数量高于HD和MD组。总之，饲喂低能量密度日粮的奶牛具有较高的VFA浓度，但更容易发生产后亚急性瘤胃酸中毒。
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 (NEL)/kg dry matter (DM)), or a middle energy density diet (MD, 1.47 Mcal NEL/kg DM), or a low energy density diet (LD, 1.30 Mcal NEL/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 ofButyrivibrio fibrisolvensandRuminococcus flavefaciensrelative 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.