Study On The Effects Of Dietary Lactobacillus Supplementation On Meat Characteristics And Related Genes Of Sunit Sheep

In this study,12 Sunit sheep were randomly divided into lactic acid bacteria group and control group,with 6 sheep in each group.The growth performance,slaughter performance and meat quality of Sunit sheep in the two groups were measured;the composition and content of fatty acids in Sunit sheep were determined by gas chromatography;transcriptome sequencing（RNA-seq）was used to sequence the longissimus dorsi muscle of the two groups of Sunit sheep,then the differential genes in two groups was screened out,and the functions and metabolic pathways involved in the obtained differential genes were analyzed;finally,the experimental results of RNA-seq were verified by q RT-PCR,the results are as follows:In terms of growth performance,slaughter performance,and meat quality:the eye muscle area of Sunit sheep in the lactic acid bacteria group was significantly higher than that in the control group（P<0.05）;there were no significant differences of the L*value,a*and b*value in the longissimus dorsi muscle of two groups（P>0.05）;and the p H₂₄ value was extremely significantly higher than that in the control group（P<0.01）,The cooking loss and shear force value of lactic acid bacteria group were significantly lower than those of the control group（P<0.01）,and the intramuscular fat content was significantly higher than that in the control group（P<0.05）;in the composition of monounsaturated fatty acids:the contents of oleic acid and myristoleic acid in the longissimus dorsi muscle in the lactic acid bacteria group were significantly higher than those in the control group（P<0.05）,and the contents of palmitoleic acid were lower than those in the control group（P>0.05）;in terms of polyunsaturated fatty acid composition,trans linoleic acidγ-The contents of linolenic acid,arachidonic acid and twenty-four carbon enoic acid were significantly higher than those in the control group（P<0.01）,and the contents of arachidonic acid and eicosapentaenoic acid were significantly higher than those in the control group（P<0.05）.It shows that dietary Lactobacillus supplementation can improve muscle tenderness and intramuscular fat content,improve meat quality and fatty acid composition of Sunit sheep.The RNA-seq results of the two groups were analyzed and screened,651 differentially expressed genes were screened,of which 416 genes were up-regulated and 235 genes were down-regulated.The results of GO function annotation and KEGG pathway analysis showed that the differentially expressed genes participate in the functional and metabolic pathways,651 DEGs annotated into KEGG database participated in a total of 265pathways,including MAPK metabolic pathway,PI3K-Akt signaling pathway,Fox O pathway,AMPK signaling pathway,apoptosis,cholesterol metabolism and so on.16 genes（KITLG,LDLR,FGF3,FGF6,FGFR3,PIK3R3,PPARGC1A,ITGA6,PLCB1,IL7R,MYLIP,TMEM140,FOXD3,MAFA,SH3RF3,SDHAF1）were randomly selected for q RT-PCR verification.The results showed that,the expression trend of 16 differential genes was consistent with that of RNA-seq,Therefore,the results of RNA-seq sequencing is accurate.PPARGC1A,FGF6,LDLR,and PIK3R3 can be considered as candidate genes for meat quality traits of Sunit sheep.