Effects of High Level Nutrition During Mating Period on the Reproductive Hormones and Performance of Goats

Abstract

The aim of this study was to investigate the effect of feeding above the maintenance requirement throughout the mating period on some hormones and reproduction traits in goats. The animal materials of study were consist of 75 adult hairy goats from 2-4 years old and six hairy bucks. The feeding program was started following the synchronization and continued for 40 days as 20 days prior to mating and 20 days after mating. During the feeding period, the goats in the first group were nourished at level of maintenance energy and protein requirements (1.58 Mcal ME, 61.98 g CP/head/day); the goats in second, third and fourth groups got nourishment matters as 1.25 (1.97 Mcal ME, 77.47 g CP/head/day), 1.50 (2.37 Mcal ME, 92.97 g CP/head/day) and 1.75 (2.76 Meal ME, 108.46 g CP/head/day) times of the maintenance requirements, respectively. While maintenance level in the all groups was met by meadow hay, above the maintenance requirement was met by barley in the others except the first group. Assessed reproductive efficiency traits showed that differences among groups were not statistically significant However, the fourth group of goats was found to have a higher rate of twins (29.40%) than the other groups. The mean of estradiol concentration of group four was found to be lower than group one and two (p<0.05). The blood progesterone concentration of fourth group of goats was higher than that of other groups. As a result, it can be said that feeding above the maintenance requirement throughout the mating period did not affect reproduction traits in. goats. It can also be said that data were found in this study question the relationships among nutrition, endocrine profile and reproductive performance in goats.