CHARACTERIZATION OF ENDOCRINE EVENTS AT OESTRUS IN DWARF GOAT (CAPRA HIRCUS)

R. Kausar, S. A. Khanum and M. Hussain

Abstract

    This study was conducted to characterize the profiles of LH, estradiol and progesterone hormones during oestrus in Dwarf goats. Five does were synchronized into oestrus with 2 intramuscular injections of PGF_2µ at an interval of 10 days. Blood samples were drawn at 8 h intervals from 0 to 77 h after second injection and hormones were estimated by radioimmunoassay (RIA). One of the does did not show oestrus. In two goats, LH rises were observed from hours 25-45 and attained peak levels at h-70 after second PGF₂ injection. In two other does the rise in LH was significantly earlier and reached peak levels at 24-30 h. The concentration of LH ranged between 7.5 and 30 ng/ml (mean 19 ng/ml). The estradiol peaks in does were noticed at the same time as that of the LH. Estradiol concentrations varied between 9 and 16 pg/ml (mean 12 pg/ml). The progesterone remained at basal levels (0.1-0.2 ng/ml) throughout the oestrus in all animals. These results indicate that the estradiol and LH rises have temporal relationship with each other, rising almost at the same time and LH fall was earlier than estradiol.