Estimate of dominance on the genetic parameter estimation for carcass quality traits

Non-additive genetic variance is caused by interactions between alleles at the same locus, dominance, or between alleles at different loci, epistasis [1]. . In beef cattle, few studies have applied the effect of dominance and epistatic on genetic parameters [2] and [3]. The objective of this study was to estimate the genetic parameters and study of dominance effects on these parameters. Using Illumina 50K genotypes for 4200 beef cattle, Performed genome-wide association analyses with two models, additive and dominance model, for carcass traits. Results estimation of heritability for carcass quality traits showed that most of the traits have a high heritability, but heritability for Ultrasonic Rib Eye Area (UREA) and Hot Carcass Weight (HCW) was low (0.15 and 0.11, respectively). In Ultrasonic Back Fat (UBFT), Ultrasonic Rib Eye Area (UREA), HCW and Rib Eye area (REA) traits, dominance effect play an important role (0.13, 0.44, 0.89 and 0.33 respectively). In other traits, Final Marbling (UMAR), Back Fat (FAT), Marbling Score (MBS), Lean Meat Yield (LMY) and Grade yield (GY), dominance effect were very low. Our results demonstrated that if portion of dominance variance is high, gblup and animal rank base on gblup is different when compute dominance variance.