Effects of Genotype, Birth Weight and Season of Birth on Some Reproductive Traits in Friesian Cows and Their First Cross

Abstract

The study was carried out to assess the effects of genotype, birth weight and season on lactation yield, age at first calving and calving interval on Friesian and Friesian x White Fulani cross from data collected from West African milk company-integrated dairy farm, Vom, Jos, Plateau state. Records from 130 Friesian and 129 Friesian x White Fulani cows that had three lactations were used for the study. The data were subjected to analysis of variance using SAS package and the means, where significant, were separated using the Least Significant Difference (LSD). There was a significant effect (p<0.05) of genotype, season of birth and birth weight on lactation yield, but not for age at 1^st calving. Season of birth also had influence (p<0.05) on 2nd calving interval but not on age at 1^st calving. Friesian had the shortest age at 1^st calving, higher lactation yield and longer calving intervals. Heaviest calves at birth had the highest lactation yield and longer calving intervals.