Effect of exogenous administration of insulin on follicular dynamics in goat

Abstract

Effect of insulin ovarian follicular dynamics was studied using ultrasonographic scanning in 14 cyclic, non descript goats for 2 consecutive oestrous cycles. The animals were divided randomly into 2 groups having 7 animals in each group. Animals of group A (treatment group) were treated with long acting purified bovine insulin @0.2 IU/kg body weight/ goat/day subcutaneously during their first cycle on days 7, 8, 9. The animals of group B (control) received normal saline instead of insulin on above days. The ovaries of all animals were subjected to transrectal ultrasonographic scanning using B-mode scanner equipped with 6 MHz linear array transducer on day 0,4,8 and 13 for 2 consecutive oestrous cycles. The result revealed significant increase in the population of small follicles on days 0,4, 8 and 13 following administration of insulin in thc second cycle than untreated control. Thc medium follicles following administration of insulin increased significantly on day 13 during first cycle and on days 0,4,8 in the second cycle than untreated control. The number of large follicles, however, did not differ significantly following administration of insulin during first and second cycle expect on day 13 in second cycle. The diameter of large follicles following administration of insulin increased significantly in both the cycles, however, diameter of medium size follicles did not increase during first and second cycle than untreated control. The corpus luteum control, as well as in insulin treated goats was detected on day 4 using ultrasonography. The numeber of CL did not differ significantly within and between groups.the diameter of CL increased significantly (p&lt0.01) in insulin treated goats on days 8 and 13 in the second cycle than untreated control.