Effect of Flavomycin on Performance, Gut Morphology and Intestinal Microflora in Broilers

This study was conducted to determine the effects of flavomycin on performance, gut morphology and the intestinal microflora of broilers. One hundred and twenty six, 1 day old, Arbor Acres broilers were divided into three treatments which were applied to six cages of birds with seven birds per cage. The treatments consisted of an unsupplemented basal diet or similar diets supplemented with 5 mg kg(-1) of flavomycin or virginiamycin. Broiler performance was measured from days 0-21, 22-42 and for the overall experiment. On days 21 and 42, one bird per pen was euthanized to evaluate intestinal morphology and intestinal microflora. During the period from days 0-21, the weight gain (p = 0.04) and feed conversion (p = 0.03) of birds fed flavomycin or virginiamycin were improved compared with birds fed the unsupplemented diet However, broiler performance was unaffected by treatment during the period from days 22-42 and during the overall experiment (p>0.05). Both flavomycin and virginiamycin significantly (p<0.05) increased villus height and reduced crypt depth in the duodenum, jejunum and ileum on day 21st while intestinal morphology was largely unaffected on day 42th. Cecal E. colt and Salmonella colony forming units in flavomycin or virginiamycin treated broilers were significantly lower (p<0.01) than those in the control group on both day 21st and 42th. The results indicate that flavomycin improved the performance, gut morphology and intestinal microflora of broilers in the starter phase. Based on these results, supplementation with antibiotics in the starter phase would result in the greatest economic benefit.