Relationship between direct and maternal genetic effects on weaning weight of Limousin and crossbred beef calves

Abstract

Population genetic parameters, direct and maternal breeding value, the genetic trend in the weaning weight of Limousin beef cattle calves were estimated in the period 1992-2019. Data of 19 764 calves (15 437 purebred Limousin and 4 327 crossbred) were computed. Crossbred calves were sired by Limousin breeding bulls from Simmental dams. Calves in question came from 37 herds and from 240 sires in Hungary. DFREML and MTDFREML software was used for the estimation of population genetic parameters, BLUP animal model for breeding value estimation. Weighted linear regression model was used for describing genetic trends. The maternal heritability (h2m ± SE = 0.29 ± 0.03; 0.32 ± 0.10) was approximately half of the direct heritability (h2d ± SE = 0.63 ± 0.05; 0.68 ± 0.12). The direct maternal covariance is negative, the direct maternal genetic correlation coefficients (rdm ± SE = -0.80 ± 0.03 and -0.96 ± 0.07) are strong negative. The Spearman rank correlation between direct and maternal breeding value in purebred population is moderate and negative (rrank = -0.33; P < 0.01), in crossbred population it is strong and negative (rrank = -0.99; P < 0.01). According to direct and maternal breeding values of sires, the genetic trend of the weaning weight of purebred and crossbred Limousin calves appeared stagnant during the examined period (b = +0.01 kg/year to +0.19 kg/year).

Keywords

• heritability
• direct maternal correlation
• breeding value
• genetic tren