不同精粗比饲粮对西藏地区娟珊牛泌乳性能、消化代谢、瘤胃发酵参数及免疫能力的影响OA北大核心CSTPCD

To explore the effects of diets with different concentrate to forage ratios on the lactation per-formance,digestion and metabolism,rumen fermentation parameters and immunity of Jersey cattle in Ti-bet,the experiment adopted a single-factor completely randomized block trial design,with different con-centrate to roughage ratios(group Ⅰ,40∶60;group Ⅱ,50∶50,and group Ⅲ,60∶40).Results show:(1)The dry matter intake,milk production and milk protein content of dairy cows in group Ⅲ and Ⅱ were significantly higher than those in group Ⅰ(P＜0.05).The ratio of feed to milk in group Ⅱ was signifi-cantly lower than that in group Ⅲ and Ⅰ(P＜0.05).The milk fat rate of group Ⅲ and group Ⅱ was sig-nificantly lower than that of group Ⅰ(P＜0.05).(2)The apparent digestibility of DM,NDF,ADF and CP in group Ⅲ and group Ⅱ was significantly higher than that in group Ⅰ(P＜0.05).(3)The content of TVFA and the proportion of propionic acid in the rumen fluid of dairy cows in group Ⅲ were significantly higher than those in group Ⅱ(P＜0.05),and that of group Ⅱ was significantly higher than group Ⅰ(P＜0.05).The contents of NH3-N and MCP in group Ⅲ and Ⅱ were significantly higher than those in groupⅠ(P＜0.05).(4)The TP content of dairy cows in group Ⅲ and Ⅱ was significantly higher than that in group Ⅰ(P＜0.05).Group Ⅲ and group Ⅱ had significantly higher content of serum IgA than group Ⅰ(P＜0.05).IL-4 content in group Ⅰ was significantly lower than that in other two groups(P＜0.05).The level of TNF-α in group Ⅰ was significantly higher than that in group Ⅲ and Ⅱ(P＜0.05).In summary,diets with concentrate to roughage ratio of 50∶50 and 60∶40 can significantly increase the milk produc-tion of the Jersey cattle,improve the digestibility of nutrients,and improve its immunity and anti-inflam-matory ability.