摘要
本试验旨在研究低蛋白质饲粮中添加过瘤胃蛋氨酸(RPMet)对奶牛产奶性能、血清生化指标、养分表观消化率和瘤胃微生物蛋白含量的影响。选取胎次[(2.20±0.11)胎]、泌乳天数[(141.50±7.95)d]、产奶量[(39.07±0.29)kg]、体重[(645.06±7.79)kg]相近的荷斯坦奶牛40头,随机分为4组,每组10头奶牛。HC组饲喂粗蛋白质水平为17.16%的常规饲粮,LC组饲喂粗蛋白质水平为14.88%的低蛋白质饲粮,LL和LH组分别饲喂在低蛋白质饲粮基础上添加0.034%和0.102%RPMet的试验饲粮。预试期15 d,正试期42 d。结果表明:1)与HC组相比,LC组乳产量、乳蛋白率、乳蛋白产量显著降低(P<0.05);与LC组相比,LH组乳产量、乳蛋白率、乳蛋白产量显著提高(P<0.05)。与HC组相比,LL、LH组乳尿素氮含量显著降低(P<0.05)。2)与HC组相比,LH组血清尿素氮含量显著降低(P<0.05)。3)与HC、LC组相比,LH组粗蛋白质表观消化率显著提高(P<0.05)。与LC组相比,LL、LH组中性洗涤纤维表观消化率显著提高(P<0.05)。4)与LC组相比,LH组瘤胃微生物蛋白含量显著提高(P<0.05)。5)与HC组相比,LH组多盈利0.75元/(d·头)。与LC组相比,LL、LH组分别多盈利2.83、8.03元/(d·头)。由此可见,低蛋白质饲粮中添加0.102%的RPMet对奶牛产奶性能无负面影响,但可降低乳中和血清中尿素氮含量,提高粗蛋白质和中性洗涤纤维表观消化率、瘤胃微生物蛋白含量及经济效益。
This experiment was conducted to study the effects of rumen-protected methionine(RPMet)supplementation in low-protein diets on milk performance,serum biochemical indices,nutrient apparent digestibility and rumen microbial protein contents of dairy cows.Forty Holstein cows with similar parity[(2.20±0.11)fetuses],lactation days[(141.50±7.95)days],milk yield[(39.07±0.29)kg]and body weight[(645.06±7.79)kg]were randomly divided into 5 groups with 10 cows in each group.The HC group was fed a conventional diet with crude protein level of 17.16%,the LC group was fed a low-protein diet with crude protein level of 14.88%,and the LL and LH groups were was fed the low-protein diets supplemented with 0.034%and 0.102%RPMet,respectively.The pre-experimental period lasted for 15 days,and the experimental period lasted for 42 days.The results showed as follows:1)compared with the HC group,the milk yield,milk protein rate and milk protein yield of the LC group were significantly decreased(P<0.05);compared with the LC group,the milk yield,milk protein rate and milk protein yield of the LH group were significantly increased(P<0.05).Compared with the HC group,the milk urea nitrogen content of the LL and LH groups was significantly decreased(P<0.05).2)Compared with the HC group,the serum urea nitrogen content of the LH group was significantly decreased(P<0.05).3)Compared with the HC and LC groups,the crude protein apparent digestibility of the LH group was significantly increased(P<0.05).Compared with the LC group,the neutral detergent fiber apparent digestibility of the LL and LH groups was significantly increased(P<0.05).4)Compared with the LC group,the rumen microbial protein content of the LH group was significantly increased(P<0.05).5)Compared with the HC group,it could make an additional profit of 0.75 CNY/(d·head)of the LH group.Compared with the LC group,it could make an additional profit of 2.83 and 8.03 CNY/(d·head)of the LL and LH groups.In conclusion,the supplementation of 0.102%RPMet in low-protein diet has no negative effect on the milk performance of dairy cows,but can reduce the content of urea nitrogen in milk and serum,improve the apparent digestibility of crude protein and neutral detergent fiber,rumen microbial protein content and the economic benefits.
作者
安亚龙
范高强
刘鸿飞
王超
韩旭
张贝贝
AN Yalong;FAN Gaoqiang;LIU Hongfei;WANG Chao;HAN Xu;ZHANG Beibei(College of Animal Science and Technology,Qingdao Agricultural University,Qingdao 266109,China;COFCO Feed(Xinji)Co.,Ltd.,Shijiazhuang 052300,China)
出处
《动物营养学报》
北大核心
2025年第11期7607-7616,共10页
CHINESE JOURNAL OF ANIMAL NUTRITION
关键词
奶牛
低蛋白质饲粮
过瘤胃蛋氨酸
产奶性能
血清生化
养分表观消化率
微生物蛋白
dairy cows
low-protein diet
rumen-protected methionine
milk performance
serum biochemical
nutrient apparent digestibility
microbial protein
