EFFECT OF EXOGENOUS OXYTOCIN ON REPRODUCTION TRAITS OF BUFFALOES

摘要

Reports on some clinical cases indicate the long term use of oxytocin for the extraction of milk leads to irregular estrous cycle and infertility condition in buffaloes. However, no planned experiment has been conducted to establish the effect of chronic use of oxytocin and infertility problems in buffaloes. Oxytocin administered early in the luteal phase of the estrous cycle causes luteolysis in cattle (Armstrong and Hansel, 1959) and goat (Cooke and Knifton, 1981) and some degree of luteal regression in sheep (Milne, 1963) probably through a stimulatory effect on uterine prostaglandin (PG) F-2 secretion (Hansel and Wagner, 1960, Sharma and Fitzpatrick, 1974). Continuous oxytocin infusion from day 13 of estrous cycle in ewes, blocked the rise in uterine oxytocin receptor which inhibit the uterine production of PGF 2K possibly by down regulation of uterine oxytocin receptor (Flint and Sheldrick, 1985). A continuous administration of oxytocin may also associated with early termination of pregnancy (Senger, 1991).