Fertility and prolificacy of sheep synchronized with Fluorogestone Acetate

Abstract

The sheep were randomly assigned to six treatments: Group I (n=25) control with traditional feeding; Group II (n=25) control feeding with vegetable by-products; Group III (n=25) received traditional feeding and received 125 mg of bST via SC five days before the withdrawal of the progestin; Group IV (n=25) fed with vegetable by-products and received 125 mg of bST via SC five days before removing the sponge; Group V (n=25) traditional feeding received 300 IU of eCG via SC at the time of removing the sponge and Group VI (n=25) feeding with vegetable by-products and received 300 IU of eCG via SC at the time of removing the sponge. The proportion of ewes that presented estrus, the % of conception and the proportion of ewes with multiple births were compared. The estrous response was similar (p>0.05) between groups. The conception rate was higher (p<0.05) in the bST traditional diet groups (80% vs 84%) bST with vegetable by-products respectively (p>0.05) compared to the eCG groups, which was 64% in traditional diet and b72% with vegetable by-products (p<0.05). The proportion of ewes with multiple births was higher in the groups fed with vegetable by-products, standing out those treated with bST and eCG (1.6 vs 1.7 lambs per birth) respectively (p<0.05). The use of FGA for synchronization is effective in the presentation of estrus. However, the application of bST and/or eCG potentiate this effect with increased fertility and prolificacy due to a greater presence of viable follicles and therefore more oocyte production. bST administration substantially improves fertility, while eCG increases prolificacy.