Effect Of Expanded Straw Microbial Fermentation Feed On Fattening Effect Of Dorper×Han Crossbred Sheep

The purpose of this experiment is to study the fattening effect of expanded straw microbial fermentation feed on lambs,and the changes of lamb production performance,meat quality,rumen fermentation and rumen microflora during fattening.It can provide theoretical basis for the scientific use of expanded straw microbial fermentation feed fattening lambs.The experiment selected 81 3-month-old Dorper×Han crossbred lambs weighing 23Kg(±1.0Kg),randomly divided into 2 test groups and 1 control group,with 3 replicates in each test group and 9 trial lambs in each replicate,Fattening period 60 days.During the experiment,the 3 groups had the same concentrate formula,and the ratio of concentrate to roughage was 7:3.In the control group,30%(DM)crushed corn straw was fed as roughage;in the test group ? and ?,30%(DM)expanded straw microbial fermentation feed was fed;in the test group ?,expanded slow-release urea(NPN rough protein?100%)accounting for 10%of total protein(TP)concentration was added.The results showed that the feed intake and daily gain of lambs in group ? and group ? were significantly increased after feeding the puffed straw microbial fermentation feed(P<0.01).The carcass weight,liver weight,large intestine weight and total digestive tract weight of test group ? were significantly higher than those of test group ? and control group(P<0.05).The rumen volume of test group ? and test group ? was significantly higher than that of control group(P<0.05).There was no significant difference between the test groups(P>0.05).The color of rumen inner wall was more normal in the two groups.The gastrointestinal tissue section showed that the intestinal development of the two groups was better than that of the control group;In the determination of meat quality,the water loss rate and cooking loss of test group ? were significantly lower than that of test group I and control group(P<0.05),the crude fat content of test group ? was significantly lower than that of test group ? and control group(P<0.01),and other indexes were not significantly different(P>0.05);The concentrations of NH3-N and BCP in test group? were significantly higher than those in test group ? and control group(P<0.05),but there was no significant difference between test group ? and control group(P>0.05);By 16S RNA sequencing,it can be seen from Venn diagram that the microbial species in group ? were significantly more than those in the other two groups.According to species richness histogram,hierarchical clustering curve,Temaryplot analysis,OTUs clustering heat map,we can see that the species of beneficial bacteria in group ? is more than the other two groups,the species of pathogenic bacteria is less than the other two groups,and the species richness is higher than the other two groups.