Influence of virginiamycin on performance of broilers fed two levels of energy

Biological trial of 42 days duration was conducted on broiler chicks to evaluate the effect of virginiamycin supplementation with two levels of energy 2900 and 2800 ME kcal/kg during starter and 2950 and 2850 ME kcal/Kg during finisher using 352, day-old chicks. Virginiamycin at the rate of 20 ppm during starter and 10 ppm during finisher was added to each test diet. Supplementation of low energy diets with virginiamycin significantly (P<0.05) improved the body weight over its corresponding unsupplemented group. Feed consumption remained unaffected. Feed efficiency was better in all the virginiamycin supplemented groups. Mortality rate of 1.25 and 5.00 percent was recorded in unsupplemented groups of normal energy and low energy groups respectively but no mortality was recorded in supplemented groups. Litter moisture did not differ significantly (P<0.05) among the groups. Litter score was significantly lower in normal energy with virginiamycin group compared to its unsupplemented control. Total bacterial and cocci counts differed significantly (P<0.05) between supplemented and control groups from second and fourth week onwards. Net economic returns per bird over feed cost was better in all the supplemented groups.