瘤胃投饲不同形式蛋氨酸对肉牛营养物质消化率和血液指标的影响

Study on Effects of Methionine Administrated Through the Rumen on Nutrient Digestive Rate and Blood Indexes of the Steers

选择安装瘤胃、十二指肠前端和回肠末端瘘管的肉牛4头,采用4×4拉丁方设计,研究瘤胃投饲不同形式蛋氨酸对肉牛营养物质消化率和血液指标的影响,瘤胃投饲蛋氨酸添加剂分别为0(Ⅰ组)、DL Met(Ⅱ组)、动物油包被Met(Ⅲ组)和吸附MHA(Ⅳ组)。试验结果表明,Ⅲ组日增重、可消化氮、沉积氮、沉积氮/可消化氮分别比Ⅰ组提高12 18%(P<0 05)、5 90%(P<0 05)、126 1%(P<0 05)和113 7%(P<0 05);Ⅲ组尿中尿素氮显著低于Ⅰ组(P<0 05)。Ⅲ组氮和NDF在小肠的表观消化率分别比Ⅰ组提高10 8%(P<0 05)和30 06%(P<0 05)。Ⅲ组血浆尿素氮显著低于Ⅰ组(P<0 05)。Ⅲ组和Ⅳ组血浆TAA、EAA、BCAA、Ser和Met均显著低于Ⅰ组(P<0 05);Ⅱ组、Ⅲ组和Ⅳ组血浆Asp显著低于Ⅰ组(P<0 05)。本试验条件下最佳保护蛋氨酸为动物油包被蛋氨酸。

4 steers fitted with fistula in the rumen,the proximal duodenum and dismal ileum were used to study the effects of methionine administrated through the rumen on nutrient digestibility and blood indexes of steers.The treatments in a 4×4 Latin square in the experiment were basal diet plus 0(Ⅰ),DL- Met(Ⅱ),G- Met(Ⅲ) and A- MHA(Ⅳ).The results showed that ADG,DN,RN and RN/DN of group Ⅲ compared with group Ⅰ increeased 12.18%,5.90%,126.1%,113.7% respectively,the difference was significant(P<0.05).Urine urea nitrogen of group Ⅲ was significantly lower than that of group Ⅰ(P<0.05).Digestibility of N,NDF in group Ⅲ were significantly higher than those in group Ⅰ(P<0.05),and were 10.8%,7.4% respectively higher than control.Plasma urea- N of group Ⅲ were significantly lower than group Ⅰ(P<0.05).Plasma TAA,EAA,BCAA,Ser and Met of group Ⅲ and Ⅳ were significantly lower than those of the rest(P<0.05).Asp of group Ⅱ,Ⅲ and Ⅳ was significantly lower than that of group Ⅰ(P<0.05).The optimal protected DL- Met under present experiment was the G- Met.