ALTERNATIVES TO THE USE OF ANTIBIOTIC GROWTH PROMOTERS FOR BROILER CHICKENS: 2. ORGANIC ACIDS AND PROBIOTICS

Abstract

An experiment was conducted to evaluate the effects of organic acids, antibiotic, probiotic and their combination on performance, carcass yield, and pH of some parts of crop, duodenum and ceca, and of the diets of broiler chickens. Also, the experiment aimed to verify the probiotic sensibility to the antibiotic and the coccidiostatic utilized. Fourteen hundred and forty one-day-old male chicks, Hubbard, were randomly distributed in a 3 x 3 factorial design: additives in the diet (without antibiotic, avoparcin, and probiotic composed by Streptococcus faecium, Lactobacillus acidophilus and Saccharomyces cerevisiae) and organic acids in the diet (without organic acids, fumaric acid, and propionic+formic acid), totaling nine treatments with four replicates of 40 birds each. It was verified that the microorganisms Streptococcus faecium and Lactobacillus acidophilus were sensible to avoparcin in the concentration wich was employed in the diets. However, the presence of sodic monensine did not inhibit the growth, in vitro, of the probiotic’s microorganisms. Organic acids, antibiotic, probiotic or their combinations did not affect the performance, carcass yield, and the pH of the crop, duodenum and cecum in relation to the control diet. Nevertheless, the fumaric acid promoted a reduction in the pH of the diet, and might contribute to an inhibition of the growth of undesirable microorganisms.

KEY WORDS: Additives, birds, carcass yield, parts yield, performance.