半胱胺和酵母培养物对奶牛瘤胃微生物蛋白产量和养分消化率的影响

摘要

本试验旨在研究半胱胺(CS)和酵母培养物(YC)不同添加量组合对奶牛瘤胃微生物蛋白(MCP)产量和养分消化率的影响.选取年龄、体重、产奶量及泌乳期相近的荷斯坦奶牛40头,分为10组,每组4头.对照组(C)饲喂基础日粮,试验组补饲添加3个水平的CS (L:17.5 g/d,M:20 g/d,H:22.5 g/d)和YC (L:90 g/d,M:100 g/d,H:110 g/d),共有LL、ML、HL、LM、MM、HM、LH、MH和HH 9个不同水平组合,测定不同组合的瘤胃MCP产量和养分消化率.结果表明:试验组能提高瘤胃MCP产量,其中HM组奶牛瘤胃MCP产量比对照组提高26.53％ (P＜0.01),效果最好;试验组日粮干物质、粗蛋白、钙、磷的表观消化率显著或极显著高于对照组(P＜0.05或P＜0.01).本试验条件下,综合考虑瘤胃MCP产量、养分表观消化率,CS和YC的最佳添加量组合分别为每头22.5、100 g/d.%This experiment was conducted to determine the effects of different combination supplemental levels of cysteamine (CS) and yeast culture(YC) on ruminal microbial protein production and nutrient digestibility.Forty Holstein cows with similar age,body weight,milk yield and lactation stage (110±12 day in milk) were divided into 10 groups,with 4 cows per group.Control group(C) was fed a basal diet,experimental groups were jointly supplemented with CS (L:17.5 g/d,M:20 g/d,H:22.5g/d) and YC (L:90 g/d,M:100 g/d,H:110 g/d) at 3 different levels.The experimental groups were LL,ML,HL,LM,MM,HM,LH,MH and HH,9 different combination supplemental levels.The ruminal MCP production and nutrient digestibility of different combination were detected.The results showed that the experimental groups could improve ruminal MCP production.The ruminal MCP production of HM group was 26.53％ higher than that of control group(P＜0.01).The apparent digestibilities of DM,CP,Ca and P in the experimental groups were significantly higher than those in control group((P＜0.05 or P＜0.01).Based on the data of ruminal MCP production and nutrient apparent digestibility,it can be concluded that the suitable supplement level of CS and YC was 22.5& 100 g/d in dairy cow under the condition in the present study.