过瘤胃蛋氨酸和肉桂醛对奶牛瘤胃微生物蛋白产量和养分消化率的影响

Effects of Rumen-Protected Methionine and Cinnamic Aldehyde on Ruminal Microbial Protein Production and Nutrient Digestibility of Dairy Cows

本试验旨在研究过瘤胃蛋氨酸(RPMet)和肉桂醛(CA)不同添加量组合对奶牛瘤胃微生物蛋白(MCP)产量和养分表观消化率的影响。选取年龄、体重、胎次、产奶量、乳成分相近及泌乳期为(90±15)d的荷斯坦奶牛40头,随机分为10组,每组4头。对照组(C)饲喂基础日粮,试验组补饲不同水平组合的RPMet和CA,其中RPMet添加量分别为20(L)、25(M)、30(H)g/d;CA添加量分别为15(L)、18(M)、21(H)g/d,共分为LL、ML、HL、LM、MM、HM、LH、MH、HH 9个不同水平的添加量组合。结果表明:试验组奶牛的瘤胃MCP产量明显提高,其中以HL组效果最好,瘤胃MCP产量比对照组极显著提高了29.31%(P<0.01);试验组饲粮干物质、粗蛋白、中性洗涤纤维和酸性涤纤维的表观消化率均明显高于对照组,均以HL组效果最好(P<0.01)。在本试验条件下,综合考虑奶牛瘤胃MCP产量和养分表观消化率,RPMet和CA的最适添加量组合为RPMet 30 g/d、CA 15 g/d。

This experiment was conducted to determine the effects of supplemental levels of rumen-protected methionine（RPMet） and cinnamic aldehyde （CA） on ruminal microbial protein production and nutrient digestibility of dairy cows. FortyHolstein lactating cows with similar age, body weight, parity, milk yield, milk composition and lactation period （90±15days post-calving） were randomly divided into 10 groups with 4 cows per group. The control group （C） was fed a basal diet,experimental groups were jointly supplemented with RPMet and CA at different levels. The supplemental level of RPMetwas designed as 20（L）, 25（M）, 30（H） g/d. The supplemental level of CA was designed as 15（L）, 18（M）, 21（H） g/d. Theexperimental groups were LL, ML, HL, LM, MM, HM, LH, MH and HH, 9 different supplemental levels. The resultsshowed that the experimental groups could improve ruminal microbial protein production, especially the HL, which wassignificantly increased by 29.31% compared with the control group（P〈0.01）. The apparent digestibility of DM, CP, NDFand ADF in the experimental groups were higher than those in control group, and HL group was the highest（P〈0.01）.Based on the data of ruminal microbial protein production and nutrient apparent digestibility, it could be concluded thatthe supplementation with 30 g RPMet and 15 g CA in diet per day for per cow was reasonable under the condition of thepresent study.