Effects Of Different Fattening Modes On Performance,Meat Quality,Rumen Flora Of Sunit Sheep

This experiment was conducted to explore the effects of different fattening modes on the average daily gain,production performance,rumen fermentation indexes and rumen microflora of Sunite lambs,so as to provide a theoretical basis for scientific fattening of Sunite lambs in pastoral areas and improve the economic benefits of herdsmen breeding Sunite sheep.Sixty healthy Sunite lambs with similar age and uniform body weight(22.2±3.0kg)were selected as experimental animals.The experiment lasted for 74 days,including the pre-feeding period of 14 days and the trial period of 60 days,during which the lambs in the three groups were free to drink water.According to the principle of random grouping,the experimental sheep were divided into grazing group,semi-house feeding group and house feeding group,with 20 sheep in each group.The grazing group adopted the fattening mode of natural grazing.Lambs in the half-house feeding group were fed a small range grazing and supplementary feeding mode.After returning to pasture in the first week,each lamb was initially fed 0.3 kg/d supplementary feed per day,then 50 g concentrate supplement was added every week,and the next day diet was adjusted every other week.The fattening mode of the whole house feeding group was adopted.The results showed as follows: under different fattening modes,the average daily gain was significantly different among groups(P<0.01),the average daily gain was the highest in shelter feeding group and the lowest in grazing group.Carcass weight,large intestine weight and total digestive tract weight were increased by 38.79% and 44.02%,34.27% and58.15% respectively,and 14.06% and 13.54%,respectively,in semi-enclosed feeding group compared with enclosed feeding group.The economic benefit of house feeding group was 17.60 yuan/animal and 68.36 yuan/animal higher than that of half house feeding group and grazing group,respectively.The heart weight of barn feeding group was 10.85%and 16.67% higher than that of grazing group and half barn feeding group,respectively.The rumen inner wall morphology of lambs in grazing group was better than that in house feeding group.Under different fattening modes,the crude lipid content in muscle of the house feeding group and the half house feeding group was increased by 92.88% and107.12%,respectively,compared with that of the grazing group(P<0.05).The cooking loss of grazing group was increased by 11.05% and 10.34%,respectively,compared with that of semi-enclosed feeding group.Different fattening patterns affect the quality of mutton;The meat color of the semi-enclosed feeding group and the enclosed feeding group was better than that of the grazing group,and the tenderness of the grazing group was better than that of the other two groups.Different fattening modes had no significant effect on rumen fluid microbial protein of Sunit sheep(P> 0.05),and rumen p H value in grazing group was significantly higher than that in house feeding group(P<0.01).The ammonia nitrogen concentration and volatile fatty acid content of lambs in house and semi-house feeding groups were significantly higher than those in grazing group(P<0.05).According to the comprehensive analysis of Venn diagram,Alpha diversity analysis and Beat diversity analysis,different fattening modes had significant differences in rumen microbial richness and diversity(P<0.05),and lambs in grazing group were higher than those in half-house feeding group and house feeding group.The rumen microbes in grazing group showed obvious adaptability to coarse fiber herbage,while the rumen microbes in the feedlot group were easier to digest concentrate feed,so they grew faster,and the half-feedlot group was in the middle position.Under the three fattening modes,the daily gain,slaughter rate,carcass weight and meat production performance of grazing group were significantly lower than those of semi-enclosed feeding group and enclosed feeding group.The semi-enclosed feeding group and enclosed feeding group could improve the income,but the enclosed feeding group had the highest income,indicating that the enclosed fattening mode was suitable for promoting and applying in the actual production of pastoral areas.