Corpus luteum function and embryonic mortality in buffaloes treated with a GnRH agonist, hCG and progesterone

The effect of treatment with a GnRH agonist, hCG or progesterone (P4) on corpus luteum function and embryonic mortality was investigated in buffaloes inseminated during mid-winter. Italian Mediterranean buffaloes (n = 309) were synchronized using the Ovsynch with timed-AI program and mated by AI at 16 h (Day 0) and 40 h after the second injection of GnRH. On Day 5, buffaloes were randomly assigned to four groups: Control (no treatment, n = 69), GnRH agonist (buserelin acetate, 12.6 mg, n = 73), hCG (1500 IU, n = 75) and P4 (PRID without E2 for 10 days, n = 77). Progesterone (pg/ml) was determined in milk whey on Days 5, 10, 15 and 20 and pregnancy diagnosis was undertaken on Day 26 by ultrasound and Day 40 by rectal palpation. Treatment with buserelin and hCG increased ( p &