Dynamics of steroid hormones in prepubertal LWY crossbred gilts during induction and Estrus Synchronization

Abstract

The objective of this investigation was to understand the steroid hormone profiles in LWY cross-bred pre-pubertal gilts during estrus induction and synchronization, applying four protocols viz., 5 mg prostaglandin (Group I), 7.5 mg prostaglandin (Group II), a combination of 400 IU PMSG + 200 IU HCG (Group III), and 5 ml normal saline (Group IV) and to compare the responses between the summer and winter seasons. The mean serum progesterone on the day of synchronized estrus was 1.10±0.07 ng/ml (winter) and 1.82±0.05 ng/ml (summer), rising to 44.70±0.82 ng/ml and 41.41±1.09 ng/ml respectively on day 19 post-breeding. Mean serum oestrogen on day of estrus was 48.87±1.33 pg/ml (winter) and 46.84±1.48 pg/ml (summer), dropping to 15.70±0.73 pg/ml and 12.54±0.57 pg/ml respectively on day 19. Seasonal differences between protocols were not significant (P > 0.05), but significant differences occurred between synchronization treatments within each season (P< 0.05), with the 400 IU PMSG + 200 IU HCG protocol yielding optimal progesterone and highest oestrogen concentrations suggesting improved follicular development and estrus induction across seasons.