Increase of fertility and prolificity in FGA synchronizedpelibuey sheep, with BST and ECG injection
Aumento de la fertilidad y prolificidad en ovejas pelibuey sincronizadas con FGA e inyección de BST y ECG
Abstract
The bovine growing hormone (bST) increase the serum concen-tration of Insulin Grow Factor Type I (IGF-I). These hormones promote follicular development, fertilization and embryonic sur-vival rates. The administration of Equine Chorionic Gonadotropin (eCG) when removing the sponge with Fluorogestone Acetate (FGA), this progestogen increases the ovulation rate and the es-trous response. In this study, the administration of bST 5 days (d) before sponge removal and eCG when withdrawing treatment were tested to improve the estrous response, fertility and prolifica-cy in Pelibuey sheep. One hundred en vez de 100 Pelibuey ewes with different number of farrowings were used. All the sheep were inserted an intravaginal sponge impregnated with 45 milligrams (mg) of FGA for 12 d, 25 randomized sheep were distributed in four treatments: 1) bST received 125 mg of bST subcutaneously (SC) five d before removing the sponge with FGA; 2) eCG recei-ved 300 eCG International Units (IU) via SC at the time of sponge removal; 3) bST + eCG received 125 mg of bST via SC five da before removing the FGA sponge and 300 IU eCG Intramuscular (IM) at the time of removing the sponge with FGA; 4) witnessed or received bST or eCG. The proportion of ewes that presented estrus, Fertility and Prolificity were compared. The estrous res-ponse was similar (P> 0.05) between the groups. The conception percentage was higher (P <0.05) in the bST (83,%) and eCG + bST (100%) groups than in the control (65%), but it was similar (P> 0.05) in the eCG (66,%) and control (65.2%) groups. The pro-portion of ewes with multiple parturition was similar (P> 0.05) in the bST (35%) and control (20%) groups; however, it was higher in the eCG (69%) and eCG + bST (80%) groups. It is concluded that treatment with bST five d before removing the FGA plus eCG sponge at the time of removing the sponge increases fertility and prolificacy in Pelibuey sheep.
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References
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