Study On The Growth Rule And Inflection Period Of Differentially Expressed Genes And The Age Of The Best Meat Quality Of Qing Yu Pig

The Qingyu pig,a traditional medium-sized breed native to southwestern China,is primarily distributed throughout the Daba Mountain area in the Sichuan province.The pig is revered for its superior meat quality and stress tolerance.In order to better study the growth and development of Qingyu pig.In this study,3 model of Gompertz、Logistic and Von Bertalanffy were established.The most suitable growth curve model of body weight(BW)and body measurement(BM)were obtained when the goodness of fit of the models were verified by residual standard error(RSE),the Akaike’s Information Criteria(AIC),Bayesian information criterion(BIC),Coefficient of determination(R~2)and Adjusted coefficient of determination(adj.R~2).The 3 points of the maximum growth rate(MGR)、the gradually increasing stage to rapidly increasing stage(GRI)and the rapidly increasing stage to slowly increasing stage(RSI)were found when the most suitable growth curve model were obtained.Moreover,the muscle sample of 3 points were RNA-seq to study gene expression differences at different growth stages.In the end,Qingyu pig is a traditional dual-usage breed for the meat consumption,it is necessary to study the meat quality of different days.The main results of the paper are as follow:1.The best model describing BW was Von Bertalanffy,but Logistic being the best optimized model about BM.The 3 inflection of the age of BW are 23.82d(GRI)、156.41d(MGR)and 288.97d(RSI),the weight are 3.14kg(GRI)、51.74kg(MGR)and 107.03kg(RSI).2.Research on the growth and development of BM(length,height,chest circumference,chest width,abdominal circumference and hip circumference),the growth time of BW was observed to be far greater than that of any BM parameter.The growth of L,H and CC are not synchronized.During the process of trunk development,the growth and development of CC and AC were nearly synchronized.The law of length index(LI)typically decreases initially,followed by an increase,which indicates that the relative growth intensity of H is faster than that of L in the early days of life,whereas the growth of L is better at later ages,as was also the case for the chest circumference index(CCI)and body index(BI),which increased with age to an eventual plateau stage.The hip circumference(HC)developed latest,and the development period is the shortest,which may be one of the reasons why the hindquarters of Qingyu pig was poor developed,BW was only significantly correlated with H after the RSI point of BW.3.The batch and sire had significant effects on weight growth.In brief,the batch effect appeared influence BW only at early ages.Because the batch effect is primarily caused by environmental factors,this suggests that environmental control should receive additional attention at the earliest stages of Qingyu pig breeding.The sire effect is not only predicted to impact the BW at early ages,but also affects slaughter weight.4.We sequenced muscle tissue by RNA-seq,the differential genes are mainly concentrated in cell proliferation,signal transduction,and development at the GRI.The focus is on cell metabolism,organelle chemical reaction,and protein synthesis at the MGR.The RSI is mainly the reaction of cells to organic matter,chemical reaction of organelles and lipid metabolism.Finally,we found that the immune system of the entire development process is more and more perfect with the development of the body.5.After the turning point of the maximum speed,the growth of the Qing Yu pig was mainly composed of fat deposits.Through principal component analysis(PCA)and meat quality comprehensive score,the meat quality of Qing Yu pig was best at 365 days.