The Effects Of Various Dietary Protein Levels On Production Performance And Muscle-related Gene Expression In Hu Sheep

Growth and meat quality traits in livestock have always been one of the important issues in the development of animal husbandry industry,as they are closely related to meat production and economic value.Therefore,improving the economic traits that contribute to meat production is an important aspect of modern genetic improvement programs for meat sheep.This study aimed to analyze the effects of dietary protein levels on the growth performance,meat production,and physiological indicators of Hu sheep.Transcriptome and proteome technologies were used to analyze the expression of muscle-related genes and screen molecular markers related to meat production traits.Further validation of candidate molecular markers was carried out at the cellular level to determine their role in regulating muscle differentiation.The main research results are as follows:(1)Effect of increasing the protein level of diets on meat production traits of lake sheep.Under the same feeding management conditions,the protein content of the control diet was 8.63% and that of the experimental group was 16.35%,and the sheep were fed for 7 d in the pre-test period and 57 d in the test period.Hu sheep feeding effects were analyzed by measuring growth performance,meat quality,and physiological indicators.The results showed that the minced weight and average daily gain of lake sheep with protein level of 16.35% were significantly higher than those in the control group(P < 0.05),and the material weight ratio was significantly lower than that of the control group(P < 0.05),and the slaughtering performance of pre-slaughter live weight,carcass weight,slaughter rate and net meat weight were significantly improved(P < 0.05),and the economic benefits were increased by 13.20%(P < 0.05).There was no significant difference in meat quality and physiological indicators between the two groups(P>0.05).(2)Expression of muscle development genes related to meat production traits in Hu sheep and screening of molecular markers.Based on the growth performance of the control and experimental groups,a total of 1721 differentially expressed genes and 178 differentially expressed proteins were identified using transcriptome and proteome analysis methods,combined with phenotype data mining of muscle development genes and molecular markers associated with meat production traits.Among them,18 differentially expressed genes were identified to have the same changes in m RNA and protein expression levels.At the same time,this study classified molecular markers into three categories for analysis,including m RNA-based screening of 26 candidate molecules,protein-based screening of 60 candidate molecules,and m RNA-protein-based screening of 18 candidate molecules.(3)Functional verification of the role of molecular marker ADIPOQ gene in regulating the proliferation and differentiation of Hu sheep myofibroblasts.Analysis by CCK-8,Ed U,cell cycle,immunofluorescence and RT-q PCR showed that overexpression of ADIPOQ inhibited the proliferative viability of myofibroblasts,blocked cell cycle progression and decreased the expression levels of PCNA and CDK2.In muscle differentiation,ADIPOQ was able to promote myogenic differentiation and increased the expression levels of My OD1,Myf5,and My HC.These results demonstrated the involvement of ADIPOQ in improving meat production performance of lake sheep by promoting myogenic differentiation.