Effects of dietary energy-protein level on rumen fermentation parameters and microflora of Tan sheep lambs

WANG Jin; LI Dun; TIAN Jin-yang; ZHAO Zheng-wei; MA Qing

doi:10.13557/j.cnki.issn1002-2813.2024.21.003

Abstract：The purpose of this experiment was to investigate the effect of dietary energy-protein level on rumen fermentation parameters and microflora of Tan sheep lambs.Sixty healthy Tan sheep lambs with similar birth dates and body weight of(5.00±0.46)kg were randomly divided into four groups with three replicates per group and five lambs per replicate.High energy high protein group,namely HEHP group(13.45 MJ/kg,20.55％).High energy low protein group,namely HELP group(13.26 MJ/kg,16.10％).Low energy high protein group,namely LEHP group(11.40 MJ/kg,20.50％).Low energy low protein group,namely LELP group(11.50 MJ/kg,16.00％).The pre-test lasted for seven days and the formal test lasted for 53 days.The results showed that the final weight and average daily gain of the LEHP group were significantly higher than those of the other groups(P＜0.05).The pH value of the LEHP group was the highest,extremely higher than that of the HEHP group(P＜0.01).The rumen ammonia nitrogen content of the HEHP group was the highest,extremely higher than the other three groups(P＜0.01).The microbial protein content of the HEHP group was the highest,extremely higher than the LELP group and HELP group(P＜0.01),and significantly higher than the LEHP group(P＜0.05).The acetic acid content of the HEHP group was extremely higher than that of the other groups(P＜0.01).The propionic acid content of the HEHP group was the highest,extremely higher than the LEHP group and HELP group(P＜0.01),and significantly higher than the LELP group(P＜0.05).The butyric acid content of the LELP group was the highest,significantly higher than the HELP group(P＜0.05).The LELP group had the highest OTU number,Ace index,Chao1 index,and Shannon index,significantly higher than the HEHP group(P＜0.05).All experimental groups were dominated by Firmicutes,Bacteroidetes,and Proteobacteria,with relative abundances all exceeding 88％.The relative abundance of Cyanobacteria in the rumen fluid of the HEHP group and LELP group was significantly higher than that of the HELP group and LEHP group(P＜0.05),and the relative abundance of Spirochaetes in the rumen fluid of the LELP group was extremely higher than that of the other three groups(P＜0.01).All experimental groups were dominated by Succinivibrio dextrinosolvens UCG-001,Prevotella,and Shuttleworthia,with the relative abundance of Shuttleworthia in the HEHP group and HELP group significantly higher than that of the LEHP group and LELP group(P＜0.05),and the relative abundance of Eubacterium in the rumen fluid of the HEHP group was significantly higher than that of the LEHP group(P＜0.05).The results show that early supplemental feeding of low energy high protein diet has a good effect on rumen fermentation parameters and microflora.