Growth performance and fertility of Windsnyer boars supplemented with α-tocopherol

The purpose of the present work was to determine the response in growth performance and spermatozoa characteristics of Windsnyer boars supplemented with progressive levels of α-tocopherol. Twenty Windsnyer boars aged 12 weeks with an average body weight of 19.5 ± 2.67 kg were used. Each boar was housed individually in a 1.54 × 0.8 m pen in environmentally controlled house with the temperature ranging from 22 to 25 °C. Five boars were randomly assigned to each diet containing 0, 40, 70 and 90 IU of α-tocopherol. The growth performance experiment lasted for 12 weeks. Subsequently, boars were humanely slaughtered for analyses of testicular development and spermatozoa characteristics. Polynomial regression was used to analyse data. There was a linear response (P < 0.05) in average daily gain and feed conversion ratio as α-tocopherol levels increased. Left and right testicular weights showed a linear increase (P < 0.05) with increasing levels of α-tocopherol. Weights of left and right epididymis exhibited quadratic response (P < 0.05). Seminiferous tube area responded in a quadratic fashion (P < 0.05). There was a quadratic relationship (P < 0.05) between semen volume, straight-line velocity and live spermatozoa. Dead spermatozoa and head abnormalities exhibited linear decrease (P < 0.05). In conclusion, inclusion of α-tocopherol improved growth performance and fertility of Windsnyer boars.