Genomic evaluation of genotype by prenatal nutritional environment interaction for maternal traits in a composite beef cattle breed

Abstract

Genes interact with both pre- and postnatal environments potentially affecting several important traits in beef cattle. The main objective of this study was to evaluate the existence of genotype by prenatal nutritional environment interaction using genomic information in growth traits, birth weight (BW), weaning weight (WW) and yearling weight (YW) in a composite beef cattle breed (50% Red Angus, 25% Charolais, and 25% Tarentaise). Dams were randomly assigned to be fed in two levels of harvested supplemental feed from Dec to March of each year that were expected to result in adequate (ADEQ) or marginal (MARG; ∼ 61% of the supplemental feed provided by ADEQ) levels of protein based on average quality and availability of winter forage. This design resulted in two prenatal nutritional environments: MARG and ADEQ. A total of 3,020 records were used in a two-trait model treating each environment as a different trait. Genetic parameters for all three traits were estimated using genomic information. The direct genetic correlations between environment ADEQ and MARG were 0.97, 0.97 and 0.99 for BW, WW and YW respectively. On the other hand, the maternal genetic correlations between the two environments were 0.62, 0.41 and 0.73 for BW, WW and YW respectively. Furthermore, direct and maternal genomic estimated breeding values (GEBVs) using single step genomic BLUP were computed and the solutions of SNP markers were back solved from the resulting GEBVs to compare genomic regions associated with the two environments. The present study demonstrated the existence of maternal genetic by prenatal nutritional environment interaction especially for BW and WW in beef cattle.