Effect of exogenous prostaglandin and/or estrogen on luteolysis after electrocauterization of the largest follicles at the end of the bovine estrous cycle.
In cows, electrocauterization of large follicles at the end of the luteal phase, lengthened the life span of corpora lutea. Injection of 5 mg of estradiol valerate or of 1 mg of an analogue of prostaglandin F(2alpha) induced luteolysis; however, the injection of estrogen was associated with precocious estrus without either ovulation or corpus luteum growth. Injection of both estradiol valerate and prostaglandin analogue gave the same results as estradiol valerate alone. Deferred luteolysis, observed after electrocauterization of large follicles, seemed to be due to the withdrawal of estrogens and the consequent lack of prostaglandin F(2alpha) production.
Chupin
D
D
I.N.R.A. - Station de Physiologie de la Reproduction 37380 Nouzilly, France.
Saumande
J
J