Abstract

FRAIRE-CORDERO, Silvia et al. Selenium and vitamin E in the fertility of Pelibuey ewes synchronized with progesterone. Universidad y ciencia [online]. 2013, vol.29, n.1, pp.33-44. ISSN 0186-2979.

Two experiments were carried out to evaluate selenium and vitamin E (Se-VE) in Pelibuey ewes. The application of Se-VE took place two days before progesterone (P) was no longer provided. The onset of estrus, the number of corpus luteum, fertility, lambing, fecundity and prolificacy were recorded. In the first experiment, 125 females were used and randomly assigned to one of eight treatments. P (T1; n = 12), P + Se-VE (T2; n = 12), P + Equine chorionic gonadotropin (eCG; T3; n = 12), P + Directed feeding (AD; T4; n = 12), P + Se-VE + eCG (T5; n = 12), P + Se-VE + AD (T6; n = 12), P + eCG + AD (T7; n = 12) and P + Se-VE + eCG + AD (T8; n = 12). Later, a ninth treatment was added (T9, Without drugs (SF), n = 29). In the second experiment, 178 females were used and randomly assigned to one of the following treatments. P (TI; n = 62), P + Se-VE + eCG (T2; n = 62) and SF (T3; n = 54). Data were analysed with a Chi-square test for variables in percentages, and with an analysis of variance for quantitative variables. In the first experiment, the beginning of estrus was different (p < 0.05) for T3 and T5. T9 was different from the other treatments (p < 0.05) for fertility, lambing and fecundity. In the second experiment, T2 was different (p < 0.05) for the onset of estrus. T2 and T3 were different (p < 0.05) for fertility, lambing and fecundity. It is suggested that the administration of Se-VE + eCG may be used as a strategy to improve estrus synchronisation and to homogenise its appearance in less time, without decreasing the reproductive efficiency of the Pelibuey ewes.

Keywords : Selenium; vitamin E; fertility; directed feeding; Pelibuey ewes.