This study was carried out to estimate the phenotypic and genetic parameters for the gestation length and birth weight of Brown Swiss cattle reared at the Bahri Bağdaş International Agricultural Research Institute. The experimental material consisted of 891 calving records and 666 gestation length records between 1989 and 2000. The least-squares means of birth weight and gestation length were 35.6 kg and 284 days, respectively. Except for the effect of the dam's age on gestation length, all other factors investigated in this study had significant effects on both gestation length and birth weight (P < 0.05-0.001). The estimations of heritability and repeatability for birth weight were 0.10 and 0.15, respectively. Estimated repeatability for gestation length was 0.14.

This study was carried out to estimate the phenotypic and genetic parameters for the gestation length and birth weight of Brown Swiss cattle reared at the Bahri Bağdaş International Agricultural Research Institute. The experimental material consisted of 891 calving records and 666 gestation length records between 1989 and 2000. The least-squares means of birth weight and gestation length were 35.6 kg and 284 days, respectively. Except for the effect of the dam's age on gestation length, all other factors investigated in this study had significant effects on both gestation length and birth weight (P < 0.05-0.001). The estimations of heritability and repeatability for birth weight were 0.10 and 0.15, respectively. Estimated repeatability for gestation length was 0.14.