An experiment was carried out to evaluate the effects of growth promoters on the performance and body temperature of broiler chickens 1 to 42 days of age. The treatments were a basal diet unsupplemented (Control), or supplemented of 200 mg Cu/kg as copper sulfate pentahydrate (Sulfate), 75 mg Cu/kg as anhydrous copper citrate (Citrate), 20 mg/kg of virginiamycin (VM), or the combination Citrate + VM. The experiment in floor pens with reutilized litter was in randomized blocks and six replicates of 40 birds. There were no treatment effects in the initial period. Treatments did not affect feed intake and weight gain in the final period; VM resulted improved feed conversion compared to Control. In the overall period, liveweight, weight gain, feed intake and feed conversion were not affected by treatments. In the final and overall periods the viability of Sulfate birds was lower than Citrate, VM and Citrate + VM. No synergistic effect was found when VM + Citrate was fed. Rectal temperatures were not consistently affected by treatments. Cupric citrate was not more efficient than copper sulfate.
broilers; performance; copper; virginiamycin; body temperature
