Estimates of genetic and phenotypic parameters for the birth weight of calves of Holstein Friesian cattle reared organically

The aim of this study, was to estimate genetic and phenotypic parameters for birth weight and to determine the survival rate of calves of Holstein Friesian cattle reared organically. Aborting rate, still born rate and the calving difficulty rate were 4.6, 3.9 and 9.1 %, respectively. The average birth weight was 42.76±0.229 kg in present study. This value was quite higher than the birth weight in Holstein Friesian calves that breed conventionally in Turkey's conditions. The effect of calving season (p<0.01) and farming system (p<0.05) on birth weight were significant. Male calves had 2.69 kg higher birth weight than females and this difference was found significant (p<0.01). The mean birth weight of single calves was 6.26 kg (17%) higher than that of twin calves. The effect of the years on birth weight was not significant, because caring, feeding and the other breeding methods were made according to the conditions of the regulations. As the birth parity was increased, the birth weight decreased (p<0.05). Heritability and repeatability estimates belong to birth weight were found as 0.232±0.110 and0.206±0.073, respectively.