Reproductive performance, metabolic and hormonal profiles of Santa Inês ewes in winter and summer under tropical conditions

The study aimed to evaluate the reproductive, metabolic and hormonal profiles of Santa Inês ewes during winter and summer in the tropical climate of Rio de Janeiro State, Brazil. The ewes (n = 16) were prepared for induction of synchronised oestrus with a short-term hormonal treatment, and follicular dynamics were assessed with ultrasonography. Blood samples for biochemical and hormonal analyses were collected on days zero, six and eight of the protocol at 7, 13 and 19 h. Reproductive behaviour did not differ (P > 0.05) between seasons. Based on ultrasonography data, the ovulation rate was 100 % in summer and 81.3 % in winter. Most of the ewes showed double ovulation in summer, and the diameter of the largest and second largest follicles differed (P