EFFICACY OF AVOPARCIN AS A GROWTH PROMOTER FOR BROILER CHICKENS

Abstract

Two trials were conducted to test the effectiveness of a new antibiotic growth promoter, avoparcin, on growth and feed utilization of floor reared, mixed-sex, broiler chickens. Avoparcin 10 ppm, avoparcin 10 ppm + 3-nitro 50 ppm and lincomycin 2.2 ppm were tested in combination with various coccidiostats. To 28d (28 days), birds fed avoparcin were significantly (P < 0.05) heavier than those fed lincomycin, although neither group was heavier than control birds receiving no growth promoter. Growth promoter had no significant effect on body weight at 49d, although the coccidiostat, coban, resulted in a significant (P < 0.05) depression in growth rate. From 0 to 49d, birds fed avoparcin alone showed a significantly (P < 0.05) improved feed intake:body weight gain. In a second trial 10 and 20 ppm avoparcin were tested. Avoparcin 10 ppm resulted in a significant (P < 0.05) 3.7% increase in body weight and 4.1% improvement in feed efficiency at 49d of age relative to control birds. Increasing the level of 20 ppm resulted in no further improvement in these parameters. The effect of avoparcin was independent of the coccidiostats used in this experiment.