Influencia del selenio y factores ambientales en el rendimiento reproductivo en porcinos Pietrain

Objective. To determine the influence of selenium (Se), environmental temperature and Temperature-Humidity Index (THI) on litter size in Pietrain swine. Materials and Methods. The study was carried out in two seasons: summer and autumn. 4 boars and 10 sows of the Pietrain swine breed were used in a factorial design considering the factors treatment (control and experimental) and sex (male and female). The treatment in males consisted of 10 mg Se every 30 days from the age of 6 months until the end of the study. In females, 10 mg Se were administered 15 days before the insemination and at 30, 60 and 90 days of gestation. Temperature and humidity were recorded in a weather station to calculate the THI. The effect of Se and environmental factors on litter size was assessed with a factorial analysis of variance with a p<0.05 statistical significance. Results. The highest litter number (11.8 ± 1.1) we be observed in the autumn season, in experimental females inseminated with an experimental male. Quite the opposite happened in control females inseminated with males treated with selenium, with an average of 8.8 ± 0.5 piglets/birth in autumn. Conclusions. The administration of selenium to males and females, low temperatures and low THI levels promoted a significant increase on the reproductive performance in Pietrain swine.