Characteristics of meat production traits in the Hungarian Simmental herd selected for the simultaneous improvement of milk and meat production.

Phenotypic and genetic trends, population genetic parameters, and the heritability and breeding values of the fattening and slaughter traits - namely muscularity score (MUS), final fattening weight (FFW), weight gain per day of life (WGD), slaughter weight (SLW), carcass weight (CAR), dressing percentage (DRP), bone-meat production per day of life (BMP), SEUROP conformation and fat coverage score (EUR, FAT), and meat percentage (MEP) - of 1162 Hungarian Simmental bulls were evaluated with the progeny test database of the Association of Hungarian Simmental Breeders. Trends were calculated by weighted linear regression analysis, while the population genetic parameters and breeding values used the BLUP (best linear unbiased prediction) animal model and general linear model (GLM). According to the results, the lowest heritability value ($h^2=0.23$) was found in FAT. In the case of MUS, EUR and MEP, the values were moderate ($h^2=0.32$, 0.26 and 0.32), and in the case of the other traits, high heritability values ($h^2$ $=$ 0.42-0.52) were estimated. The phenotypic trends of the fattening and slaughter traits of bull progeny born between 2001 and 2019 showed a stagnant direction. Between the sires, the differences in the breeding values for some traits (WDG, CAR and BMP) were large, and with other traits (DRP, EUR and FAT), small differences were found. According to the data of the genetic-trend calculation, the steepness values of the evaluated traits were positive, and the genetic trends showed a slightly improving direction in the estimated period.