Delayed treatment with GnRH agonist, hCG and progesterone and reduced embryonic mortality in buffaloes

Abstract

The present study examined the effect of delayed treatment with tropic hormones and progesterone (P 4) on embryonic mortality in buffaloes. Buffaloes with a conceptus on Day 25 after AI were assigned to the following treatments: Control ( n = 41), i.m. physiological saline; GnRH agonist ( n = 36), i.m. 12 μg buserelin acetate; hCG ( n = 33), i.m. 1500 IU hCG; P 4 ( n = 38), i.m. 341 mg P 4 every 4 days on three occasions. Control buffaloes had an embryonic mortality of 41.4% (17/41) between Days 25 and 45, and this was reduced ( P < 0.01) by treatment with GnRH agonist (11.1%, 4/36), hCG (9.0%, 3/33) and P 4 (13.1%, 5/38). On Day 45, buffaloes treated with hCG and which ovulated had greater ( P < 0.05) concentrations of P 4 in whey (453 ± 41 pg/ml) than buffaloes in the same treatment that did not ovulate (297 ± 32 pg/ml). A similar but non-significant trend was observed for buffaloes treated with GnRH agonist. It was concluded from the findings that the treatment of buffaloes on Day 25 after AI with tropic hormones or P 4 is beneficial to processes associated with embryonic implantation.