Aflatoxinas e desempenhos de duas linhagens de matrizes de corte e de suas progênies

Abstract

This study was conducted to investigate the effect of aflatoxins consumption (AFL), in broiler breeders of different strains. To evaluate reproductive and productive aspects of broiler breeders intoxicated with AFL were used 660 females and 60 males, distributed in a completely randomized design with factorial arrangement with three levels of AFL (0.0, 0.50 and 1.0 mg/kg diet) and two strains, Cobb 500® (LA) and Hybro PG® (LB), totalizing six treatments with five replicates pens of 22 females and 2 males each. The period of intoxication was from 24th to the 64th weeks of age, from 65th to the 70th weeks; all birds were fed a AFL free diet, with the objective of assessing the residual effects. To evaluate the progenies, three experiments were performed from 1 to 21 days. Each one used 600 day old males, from eggs produced by the breeders of the experiment above, at 32, 48 and 64 weeks of age. For each experiment, the same design used in the evaluation of breeders was used, in a total of six treatments with 10 replicates of 10 males each. The laying rate was depreciated by the addition of AFL in the diet. This negative effect was more pronounced when it was added 1mg of AFL/kg, indicating a dose-dependent effect. LB breeders had higher eggs production than LA. Breeders from LA, intoxicated with 0.5mg AFL/kg diet, showed a greater reduction in egg production than birds LB, intoxicated with the same level of AFL. The hatching was not influenced by the AFL in the breeders diets. LB breeders had a poorest fertility and hatching. The hatchability of eggs from breeders intoxicated with 1mg AFL/kg of diet was the lowest, caused by an increase in embryo mortality in the third week of incubation. Evaluating the interaction among AFL and strains, there was a negative effect on the fertility rate only in the LB, when 0.5 or 1.0mg AFL/kg were added to the diets. The progeny from breeders intoxicated with 1mg AFL/kg diet had the lowest body weight at birth and 21 days, in the three experiments. LA breeders produced the heaviest chicks at birth and at 21 days. Studying the interaction AFL and strain, it was observed that AFL intoxication in LB did not affect progeny s initial weight, but in LA, there was a decrease in day old chicks weight produced by intoxicated breeders. The studied levels of AFL influenced negatively the performance of breeders and their progeny. The two strains showed different responses in some of the parameters studied, when they were fed with diets containing AFL.