Efecto de la dosis de eCG sobre la inducción del celo en cabras mestizas luego de un tratamiento corto con Medroxiprogesterona

the aim of this study was to evaluate the effect of dosage of equine chorionic gonadotrophin (ecg) dose on the estrus induction after a short-term medroxyprogesterone treatment in crossbred goat under tropical conditions. goats (n = 32) received an intravaginal sponge containing 50 mg of medroxyprogesterone acetate (map) for six days, at time of sponge withdrawal goats were divided randomly in three groups: cg, control group (n=11), did not received ecg; the second group (g250, n=10), received 250 iu of ecg intramuscular and the third group (g500, n =11), received 500 iu of ecg im. treatment with ecg did not affect the rate of estrus presentation, being 81.8% (9/11) for gc group and 100% for groups g250 (10/10) and g500 (11/11), p>0.05. the interval to estrus was significantly shorter in group g500 (32.54 ± 3.00 hours, p<0.05) than gc and g250 (40.65 ± 3.27 y 42.20 ± 3.54 hours, respectively). estrus duration was not affected by ecg treatment (p>0.05). a shorter interestrus interval was observed in 27.3% (3/11) of goats in g500 and 10% (1/10) of goats in g250, while no goats in gc had a shorter interestrus interval. in conclusion, ecg is not necessary to induce estrus in goats treated for six days with an intragavinal sponges containing map, however the dose of 500 iu was necessary to shortens the interval to the estrus.