Effect of first insemination age and weight on milk and reproduction traits in jersey cattle

Abstract

Data of milk and reproductive charcteristics belonging to 107 female Jersey cattle raised at karaköy state farm are investigated. First 305 days milk yield was affected at a singificant level by furst conception weight. In third and fourtmh conception weight groups (226.8 ± 7.8 and 269 ± 20.03), the averages of 305 days milk yield (2706. 1 ± 83.4 kgs and 2777.8 ± 85.5 kgs, respectively) were significantly higher than in the first and second (175.4 ± 10.5 and 202.3 ± 7.5 kg7 groups (2525.3 ± 90.08 kgs and 2641.7 ± 140.5 kgs, respectiveely). Partial correlation coefficients wer found between 305 days milk yield and varuous reproduction charcteristics as follows: Character r ± Sr First calving age .210 ± .103 * First conception age .178 ± .115 First conception weight .378 ±. 113 ** First calving weight .277 ± .104 ** First calving interval .240 ± .123 First service period .238 ±. 123 According to the obtained findings, we may conclude that the most suitable averages of first conception age and weight are 600.02 ± 100 days and 226.8 ±7.75 kgs, respectively, under the present management and nutrition conditions and genotype level at the Karaköy State Farm.