Embryonic mortality and luteal profile in buffaloes administered GnRH at the onset of estrus or hCG 5 days after AI

Abstract

The aim of the present trial was to test the effects of 2 treatments in buffaloes, in an attempt to sustain the plasma progesterone and hence possibly reduce the embryonic mortality rates. Treatment 1 consisted of a GnRH i.m. injection (buserelin, 0.02 mg) at the onset of estrus and treatment 2 consisted of a 3000 IU hCG i.m. injection at day 5 after artificial insemination (AI). A set of 27 Murrah buffaloes from the same herd were assigned in different groups as: controls, GnRH and hCG. Buffaloes were inseminated 8–10 h after the onset of estrus and thereafter AI was repeated once or twice at 24 h interval based upon the occurrence of ovulation. Pregnancy status was assessed by transrectal ultrasonography at day 42 post–AI. Compared to controls, data of hCG group showed stimulation of luteal function without any reduction of the embryonic mortality rates, whereas data of GnRH group show less embryonic mortality rate without any stimulation of luteal functions.