Ovarian cyclicity and progesterone profile in postpartum anestrus cattle using a synthetic progestogen, norgestomet regime

Abstract

Study was conducted on progesterone profile, estrus response and fertility using norgestomet regime alone and alongwith PMSF and PGF₂ α in 28 anestrus cattle. Estrus resptonse, anset of estrous interval and fertility at induced estrus following withdrawal of implant was better in norgestomet+PMSG treated group (71.42%, 52.8 hr; 60%)than norgestomet alone (71.42%; 62.4 hr; 40%)and norgestomet+PGF₂α+PMSG (57.14%; 55.5 hr; 50.0%). The duration of estrus (19.0-18.8 hr) did not differ significantly among the treatment groups and control. Overall AI per conception and resumption of fertility were also higher in norgestomet+PMSG treated than in the other groups. The progesterone profile prior to insertion of implant fluctuated at the bases level (0.496-0.630 ng/ml) confirming the true anestrus state in the animals. Progesterone profile following onset of estrus after withdrawal of norgestomet implant increased significantly in all the treated group (2.16-2.62 ng/ml) indicating development of corpus luteum and efficacy of norgestomet implant in inducing ovulatory estrus.