Embryonic mortality in buffalo cows.

In buffalo species embryonic mortality is considered one of the major causes of fertility loss, especially in the animals that are not mated during their reproductive period. Embryonic loss in animals mated by artificial insemination (AI) is 20-40% during seasons characterized by high number of light hours. Also in buffalo naturally mated the incidence of embryonic mortality is about 20% and a higher incidence is observed between 28-60 days of gestation in buffaloes that conceive during increasing daylight length. A reduced capacity to secrete progesterone seems to explain in part this embryonic mortality but other as yet unidentified factors contribute between 40-50% to the embryonic losses. Treatments with hCG, GnRH agonist or progesterone on Days 5 after AI not always reduce embryonic mortality in buffalo species. Embryonic mortality in buffaloes appears to occur later (Day 25-40) than in cattle and P4 treatments should perhaps be applied later in buffaloes.