Effect of Vitamin E Supplementation and High Stocking Density on the Performance and Stress Parameters of Broilers
ABSTRACT The present study was carried out to investigate the effect of dietary supplementation with vitamin E and stocking density on the mortality, body weight gain, feed conversion ratio, European production efficiency factor, heterophil/lymphocyte (H/L) ratio and liver glutathione (GSH) and malondialdehyde (MDA) levels of broilers. In total, 570 one-day-old Vencobb 400 broiler chickens were randomly assigned to three treatments, with six replicates each. G1 served as normal control and birds were provided a normal floor space (0.0465 m2/bird from day 1 to 21 and 0.0929 m2/bird from day 22 to 42) and basal diet containing vitamin E at 70 g/ton feed (n=150). G2 and G3 birds were subjected to high stocking density (0.0279 m2/bird from day 1 to 21 and 0.0557 m2/bird from day 22 to 42). G2 served as the high stocking density (HSD) control, birds were offered a basal diet with no vitamin E (n=210), whereas G3 birds were fed a basal diet containing vitamin E at 70 g/ton feed (n=210). The birds were fed with feed and water ad libitum throughout the study period. The supplementation of vitamin E to the birds subjected to HSD had a positive effect on body weight gain, feed conversion ratio (FCR), European Production Efficiency Factor (EPEF), H/L ratio, and liver GSH and MDA levels with those subjected to HSD and not supplemented with vitamin E. The results of the present study indicate that the supplementation of vitamin E at 70g/ton of feed to broilers subjected to HSD could effectively reverse the negative effects of HSD, and improve broiler performance.