Estimation Of Genetic Parameter And Genome-wide Association Study For Female Reproductive Traits In XinJiang Brown Cattle

Based on the insemination and calving records of 2275 Xinjiang brown cattles from two dairy farms in Tacheng and Urumchi,11 reproductive traits of heifers and cows were counted totally and the influencing factors were statistically analyzed in this study.We used several models to analyze the variance components of reproductive traits of Xinjiang brown cattlc with different parities.In this study,11 reproductive traits were analyzed totally,which were mainly divided into two catcgories such as age at first service in heifer(H-AFS),age at first pregnancy in heifer(H-AFC),interval from first service to conception(H-FSTC,C-FSTC),gestation length(H-GL,C-GL),number of services(H-NS,C-NS),calving to first service in cow(C-CTFS),days open in cow(C-DO)and calving interval in cow(C-CI).The main results were as follows:(1)First,(co)variance components for reproductive traits across parities were investigated in Xinjiang brown cattle based on several statistic models.For the same traits,there were significant dif ferences between heifer and multiparous cow,but there were similar differences between different parity of Xinjiang brown cattle.(2)Used the program of REAIML and(AI)REMLF90 of BLUPF90 software to obtain genetic analysis.The estimated hcritability(h2)of all traits ranged from 0.00018(C-FSTC)to 0.39(H-NS).The h2 of traits in heifer and cow ranged from 0.0001(H-GL)to 0.39(H-NS)and 0.00018(C-FSTC)to 0.064(C-NS),respectively.(3)Among the common traits between heifer and cow,the h2 of heifer was generally higher than cows.Generally speaking,the heritability of reproductive traits of Xinjiang brown cattle was less than 0.1,which belongs to low heritability traits,except for H-NS and H-FSTC.H-FSTC,H-AFS,H-NS,C-CTFS and C-DO can be used as selection traits in future breeding.(4)Associated SNPs for reproductive traits were detected in Xinjiang brown cattle and used single-trait association analysis with DRP as response variable by using Farm CPU.Totally 6 genes STC1?VLDLR?CDH2?DPPA3?RAD50?HFM1 genes were recommended as related candidate genes for female reproductive traits of Xinjiang brown cattle for further study.This research estimated the genetic parameters targeted on Xinjiang brown reproductive traits in Xinjiang Brown cattle.Meanwhile,we implemented GWAS to detect genetic markers associated to related with reproductive traits and obtained the candidate genes for the first time.Therefore,our research provided theoretical basis to breed reproductive traits of Xinjiang Brown cattle through genetic breeding.