Endocrine Control of the Estrous Cycle in Sheep in the Southern Altiplano of Peru (Control Endocrino del Ciclo Estrual en Ovinos del Altiplano sur del Peru)

摘要

A group of 88 ewes (46 Corriedale and 42 Criollo) was bred in June, and 95 ewes (46 Corriedale and 49 Criollo) was bred in November. Approximately half of the ewes served as control and the other half were synchronized using intravaginal sponges containing 40 mg of FGA (14 days) and 500 IU of PMSG. The mean incidence of estrus and ovulation, fertility at lambing and the fertilization failure and/or embryo-fetal loss did not differ statistically among age groups, breeds and breeding periods. The fertilization failure and/or embryo-fetal loss was higher (P < 0.05) in hormone treated (34.8%) than control ewes (17.7%).