Genetic and genomic analyses for predicted methane-related traits in Japanese Black steers

The objectives of this study were to estimate genetic parameters and to perform a genome-wide association study (GWAS) for predicted methane-related traits in Japanese Black steers. The methane production and yield traits were predicted using on-farm measurable traits, such as dry matter intake and average daily gain. A total of 4,578 Japanese Black steers, which were progenies of 362 sires genotyped with imputed 551,995 single nucleotide polymorphisms (SNPs), had phenotypes of predicted methane-related traits during the total fattening period (52 weeks). For the estimation of genetic parameters, the estimated heritabilities were moderate (ranged from 0.57 to 0.60). In addition, the estimated genetic correlations of methane production traits with most of carcass traits and feed-efficiency traits were unfavorable, but those of methane yield traits were favorable or low. For the GWAS, no genome-wide significant SNP was detected, but a total of four quantitative trait locus (QTL) regions that explained more than 5.0% of genetic variance were localized on the genome, and some candidate genes associated with growth and feed-efficiency traits were located on the regions. Our results suggest that the predicted methane-related traits are heritable and some QTL regions for the traits are localized on the genome in Japanese Black steers.