稀土和过瘤胃赖氨酸对奶牛瘤胃微生物蛋白产量及血液生化指标的影响

Effects of Combination of Rare Earth and Rumen-Protected Lysine on Rumen MCP Production and Blood Biochemical Parameter of Dairy Cows

试验旨在研究稀土(RE)和过瘤胃赖氨酸(RPLys)不同添加水平组合对奶牛瘤胃微生物蛋白产量、养分消化率和血液生化指标的影响。选取体重(650±30)kg、胎次(2~3)胎、产奶量(34.31±1.17)kg、泌乳天数(90±20)d及乳成分相近的荷斯坦奶牛80头,随机分为10组,每组8头。对照(C)组饲喂基础日粮,试验组补饲不同水平的RE和RPLys。RE分别添加20.5(L)、23.0(M)、25.5(H)g/(d·头);RPLys分别添加27.5(L)、30.0(M)、32.5(H)g/(d·头),共组成LL、LM、LH、ML、MM、MH、HL、HM、HH 9个试验组。预试期15 d,正试期60 d。结果表明:各试验组微生物蛋白产量均极显著高于C组,其中HH组提高幅度最大,较C组提高了32.16%(P<0.01);HH组粗蛋白质消化率极显著高于C组,LH、MM、HM组显著高于C组;HH组中性洗涤纤维消化率极显著高于C组,ML、HL、HM组显著高于C组;各试验组(除LL外)血清总蛋白含量均极显著高于C组;各试验组血清尿素氮含量均极显著低于C组。在本试验条件下,以HH组,即RE 25.5 g/(d·头)、RPLys 32.5 g/(d·头)为最佳组合。

This experiment was conducted to determine the effects of different combinations of rare earth(RE)and rumenprotected lysine(RPLys)addition levels on rumen microbial protein production,nutrient digestibility and blood biochemical indexes in dairy cows.Eighty Holstein cows with similar body weight(650±30)kg,parity(2~3),milk yield(34.31±1.17)kg,lactation period(90±20)d and milk composition were randomly divided into 10 groups,each with 8 cows.The control group(C)was fed basic diet,while the experimental group was supplemented with different levels of RE and RPLys.RE was added 20.5(L),23(M),25.5(H)g/(d·head);RPLys was added 27.5(L),30(M),32.5(H)g/(d·head),to form 9 different test groups including LL,LM,LH,ML,MM,MH,HL,HM and HH.The pre-trial period was 15 d and the forward trial period was 60 d.The results showed that the production of MCP in each experimental group was significantly higher than that of C,in which HH increased the most,32.16%higher than C(P<0.01);CP digestibility in HH group was significantly higher than that in C,LH,MM and HM were significantly higher than C;NDF digestibility in HH group was significantly higher than that in C,ML,HL and HM were significantly higher than C;serum TP content in each experimental group(except LL)was significantly higher than that in C;serum BUN content in each experimental group was extremely significant lower than that in C.Under this test condition,HH group,RE 25.5 g/(d·head)and RPLys 32.5 g/(d·head)are the best combinations.