Use of antibiotic, probiotic and homeopathy, inoculated or not with Escherichia coli, for broilers reared under comfort environment

Para avaliar o efeito do uso de antibiótico, de probiótico e de homeopatia em frangos de corte, inoculados ou não com Escherichia coli, foram distribuídos 672 frangos machos, Avian Farm, em delineamento inteiramente casualizado em esquema fatorial com oito tratamentos (quatro aditivos x com ou sem inoculação) e seis repetições, tendo 14, 12 e 7 aves por unidade experimental, respectivamente, de acordo com os períodos 1 a 11, 12 a 21 e 22 a 42 dias de idade. As aves foram alojadas em salas climatizadas em ambiente de conforto, de acordo com o manual da linhagem. Os tratamentos foram constituídos de: controle negativo (sem aditivo), antibiótico (virginiamicina + nitrovin), probiótico (meio de cultura de Lactobacilus acidophillus, Enterococcus faecium e Saccharomices cerevisiae) e homeopatia (nosódio de Escherichia coli). Observou-se que as aves tratadas com antibiótico e probiótico apresentaram maior ganho de peso no período de 1 a 21 dias, com melhor conversão alimentar para aquelas tratadas com antibiótico, embora no período total de 1 a 42 dias não tenha havido diferença entre os tratamentos. A inoculação da Escherichia coli piorou o desempenho das aves, aumentando o peso relativo do coração, do fígado e dos intestinos, enquanto o uso de antibiótico e de probiótico melhorou o desempenho das aves no período de 1 a 21 dias.The effect of antibiotic, probiotic and homeopathy in broilers inoculated or not with Escherichia coli was evaluated. Six hundred and seventy two male broilers of Avian Farm strain were assigned to a completely randomized design, in a factorial scheme, with eight treatments (four additives x inoculation or not) and six replicates, with 14, 12 and 7 birds by experimental box, respectively, according to the periods from 1 to 11, from 12 to 21 and from 22 to 42 days of age. The birds were allotted to acclimatized chambers, under comfort environment, according to the strain recommendations. The treatments were constituted of: negative control (no additive), antibiotic (virginiamicine + nitrovin), probiotic (culture medium of Lactobacilus acidophillus, Enterococcus faecium and Saccharomices cerevisiae) and homeopathy (nosody of Escherichia coli). It was observed that birds fed antibiotic and probiotic showed higher weight gain from 1 to 21 days, and the birds fed antibiotic showed the best feed:gain ratio, although in the total period (from 1 to 42 days of age) there was no difference among treatments. The inoculation with Escherichia coli decreased the birds performance; the bacteria increased the relative weight of heart, liver and intestines. It was concluded that the use of antibiotic and probiotic improved the birds performance from 1 to 21 days of age