Effect of Dietary Vitamin E and Selenium Supplementation on Physiological Responses and Reproductive Performance in Holstein Friesian Bulls during Humid Hot Summer

The objective of this study was to assess the effect of dietary vitamin E (Vit. E) and Selenium (Se) supplementation on physiological and reproductive performance of bulls during humid hot summer in Pakistan. Eighteen Holstein Friesian bulls balanced by age and weight were divided into three treatment groups: 1) CTL, basal diet without Se and Vit. E supplementation; 2) SeS, basal diet supplemented with 3 g Selemax (R) (Biorigin, USA); 3) ESeS, basal diet with 3 g Selemax (R) and Vit. E @ 6000 IU/day). Basal diet consisted of 50% green fodder, 25% wheat straw and 25% concentrate on dry matter basis. Diets were offered for 13 weeks from July 2016 to October 2016 having temperature-humidity index ranging from 83 to 87. Data obtained were subjected to repeated measures ANOVA. Supplementation of Vit. E and Se did not affect dry matter intake, water intake, respiration rate, rectal temperature, and pulse rate. The ESeS treatment had higher sperm motility% compared to CTL and SeS (P<0.05). The amplitude of lateral head displacement (ALH) was higher in SeS and ESeS compared to CTL (P<0.05). Straightness was higher in SeS group compared to CTL and ESeS. However, Vit. E and Se had no effect on other semen traits including semen volume, concentration, progressive motility, DNA integrity, plasma membrane integrity, and live to dead ratio. Blood testosterone concentration was significantly higher in SeS and ESeS groups compared to CTL. Blood glucose and blood urea nitrogen were similar among the treatments. Current results indicated that supplementation of Vit. E and Se improved only sperm motility, ALH, straightness and testosterone level during humid hot summer in Holstein Friesian bulls. (C) 2019 PVJ. All rights reserved