Probiótico a base de Bacillus amyloliquefaciens em dietas de poedeiras comerciais

Abstract

The objective of this study was to evaluate the use of a probiotic based on Bacillus amyloliquefaciens as an alternative additive to performance-enhancing antimicrobials in the diet of commercial laying hens. An experiment was conducted at the Experimental Poultry House of the Federal University of Goiás (UFG) with 320 commercial laying hens of the HyLine W-80 strain (from 54 to 72 weeks of age), with the first two weeks dedicated to the birds' adaptation to the cages and experimental feed. The birds were housed in commercial laying cages and distributed in a completely randomized design in a 2x2 factorial scheme, comprising four experimental treatments: with/without the commercial performance-enhancing antibiotic Zinc Bacitracin and with/without the commercial probiotic based on Bacillus amyloliquefaciens, with ten replicates of eight birds each. The experiment lasted 16 weeks, divided into four 28-day periods. At the end of each productive period, zootechnical performance variables and internal and external egg quality were measured. At the end of the experimental trial, at 72 weeks of age, 24 hens (6 per treatment) were euthanized for evaluation of intestinal morphometry. The data were subjected to analysis of variance and Ftest to determine the significance of the treatments, and a multiple comparison test by ScottKnott was applied using the R statistical software, with a significance level of 5%. For performance variables, no significant differences were observed (p>0.05) for the individual factors or their interaction (antibiotic and probiotic) across the productive periods evaluated. For internal and external egg quality variables, no significant differences were found for the individual factors or their interaction across the evaluated periods. For the histological variables, it was observed that birds fed the diet containing the probiotic Bacillus amyloliquefaciens showed greater villus height in the duodenum, jejunum, and ileum, and greater crypt depth in the jejunum and ileum, compared to the treatment using the performance-enhancing antibiotic. The probiotic represents a viable alternative to the use of performance-enhancing antibiotics in layer poultry production.