The effect of supplementation of acidifiers in diets for broiler chicks on performance na intestinal morphology was valuated. A total of 2,112 birds was allocated to eight diets, with six replicates, constituted by the addition of antibiotics or acidifiers blenders according to the phase development (from 1 to 7, from 8 to 21 and from 22 to 35 days old), in different composition: control - positive = bacitracin methylene disalicylate (BMD - 55 ppm) + colistin (10 ppm); control-negative = without antibiotic growth promoters or acidifiers; blend A = 8, 4.5 and 2.5 kg/t; blend B = 10, 6 and 3 kg/t; blend C = 4, 2 and 1 kg/t; blend C = 3, 3 and 1 kg/t; blend D = 5, 2.5 and 1 kg/t and blend D = 3, 3 and 1 kg/t. There was a general benefit with the use of acidifiers on feed conversion, which was similar to the use of antibiotics, except for blend B. Small intestine of birds of control-negative was heavier and had shorter villi height. The deeper Lieberkuhn crypt depth was not altered by the antibiots and by great part of the acidifiers. The use of acidifiers was efficient in maintenance of performance and morphological conditions of small intestines of broilers chicks, similar to the benefit of the use of antibiotics, except for Blend B. There was no difference among the blenders thea could be attributed the different composition, except for the duodenal crypt depth for birds fed Blend D (3/3/1 kg/t).
acidifier; broiler chicks; organic acid; small intestine morphology
