Genetic Parameter And Candidate Gene Selection Of Reproductive Traits In Angus Cattle In Ningxia Region

In this study,the genetic parameters of six reproductive traits(age at first serving,age at first calving,calving interval,breeding index,days open and calving to first service)in Angus cattle from three cattle farms in Ningxia region from 2014-2021 were collected and compiled,and the genetic parameters of the six reproductive traits were estimated using DMU software.Blood was collected from 211 Angus cows(females)and their reproduction-related genes were examined using simplified genome sequencing(dd-RAD)technology,and genome-wide association analysis was performed for four reproductive traits,namely,age at first serving,age at first calving,calving interval and breeding index,using a mixed linear model in TASSEL software,with the following results.(1)Data on reproductive traits of Angus cattle in Ningxia region were collected and compiled.The mean values of age at first serving,age at first calving,calving interval,breeding index,days open and calving to first service after parturition were 515.60,802.74,381.23,1.31,103.38 and 85.68 days,respectively.(2)The estimated heritability values for age at first serving,age at first calving,calving interval,breeding index,days open,and calving to first service were 0.0782,0.2045,0.0650,0.0285,0.1419,and 0.0604,respectively,with aga at first serving being of medium heritability and the rest of the traits being of low heritability,and the ranges of phenotypic and genetic correlation coefficients among the traits were-0.1730 to 0.9576 and-0.8405 to 0.9652,respectively.(3)The SLIT2,TEAD1,LAMA3 and MCC genes were screened as common candidates for age at first serving and age at first calving,the KCNC2 gene as a candidate gene affecting calving interval,and MNS1,PRDM9 and LOC784679 as candidates affecting breeding index.In this study,we estimated genetic parameters for Angus cattle reproductive traits to understand their potential genetic qualities,and used genome-wide association analysis to identify genetic markers and functional genes associated with Angus cattle reproductive traits,to obtain candidate genes affecting Angus cattle reproductive traits,and to provide a theoretical reference for Angus cattle core herd selection and molecular breeding.