Effect of Different Dietary Energy and Protein Levels on Rumen Fermentation Parameters and Rumen Microflora in Growing Yaks
This experiment was conducted to investigate the effects of different dietary energy and protein levels on rumen fermentation parameters and rumen microflora in growing yaks.Forty-eight 1.5-year-old Niangya yaks with similar body weight and body condition were randomly divided into 6 groups with 8 replicates per group(half male and half female),and 1 yak per replicate according to different levels of comprehensive net energy(7.63,8.25,8.88 MJ/kg)and protein(10.84%,12.82%)using a 3×2 two-factor design.The pre-expriment period was 15 days,and the formal expriment period was 60 days.The results showed as follows:①In rumen fluid,the molar percentage of acetic acid in high energy group was significantly higher than that in medium energy group(P＜0.05),the molar percentage of propionic acid in medium energy group was significantly lower than that in low energy and high energy groups(P＜0.05),and the molar percentage of butyrate was significantly higher than that in low energy and high energy groups(P＜0.05).The molar percentage of isobutyric acid and isovalerate in high protein group were significantly higher than those in low protein group(P＜0.05).The interaction of dietary energy and protein levels had significant effects on the molar percentage of isobutyric acid,isovalerate and valerate(P＜0.05).②In rumen microflora,Chao1 and Shannon indices in low and medium energy groups were significantly higher than those in high energy groups(P＜0.05).Chao1 and Shannon indices in low protein group were significantly higher than those in high protein group(P＜0.05).The interaction of dietary energy and protein levels had significant effects on Chao1 and Shannon indices(P＜0.05).③The relative abundance of Kiritimatiellaeota in medium energy group was significantly higher than that in low energy group(P＜0.05).The interaction of dietary energy and protein levels had a significant effect on the relative abundance of Firmicutes,Bacteroidete,Synergistetes and Proteobacteria(P＜0.05).The relative abundance of bacteria F082 in high energy group was significantly higher than that in low and medium energy groups(P＜0.05),and the relative abundance of Rikenellaceae_RC9_gut_group in medium energy group was significantly higher than that in high energy group(P＜0.05).The relative abundance of bacteria F082 in high protein group was significantly higher than that in low protein group(P＜0.05),and the relative abundance of Bacteroidales_RF16_group was significantly lower than that in low protein group(P＜0.05).The interaction of dietary energy and protein levels had significant effects on the relative abundances of Christensenellaceae_R-7_group,bacteria F082 and Ruminococcaceae_NK4A214_group(P＜0.05).In conclusion,when the dietary energy and protein levels were 8.25 MJ/kg and 12.82%,respectively,it is beneficial to promote rumen fermentation and improve rumen flora environment of growing yaks.
万方数据
维普
