Enzymatic complexes in mashes for broiler chickens / Complexos enzimÃticos em raÃÃes fareladas para frangos de corte.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Two experiments were conducted in the Department of Animal Science of the UFLA to evaluate the effect of the supplementation of enzymatic complexes on the performance, increment of metabolizable energy and intestinal characteristics of broiler chickens of both sexes. The diets used were: a positive control diet based on corn and soybean meal with meat and bone meal without an enzyme; a negative control diet formulated with 3% minus of metabolizable energy; diet three, negative control more 0.05% of complex A (600U/g of xylanase, 8000U/g of amylase and 800U/g of protease); diet four and five, negative control plus 0.03% and 0.04% of complex B (200 kNU/g of amylase and 350 FBG/g of glucanase), respectively and diet six, negative control plus mixture of 0.04% of complex B + 0.01% of enzyme C (1000 FXU/g of xylanase). An feeding program with 4 phases was adopted, its being distributed in pre-initial ration (1 to 7 days), initial (8 to 21 days), growth (22 to 35 days) and final (36 to 42 days). In experiment II, the experimental rations of the previous growth phase for the determination of corrected apparent metabolizable energy and coefficients of apparent digestibility of dry matter and crude protein of the diets were utilized. In the period of 1 to 7 days of the birdsâ age, no significant differences were found in performance (P>0.05), regardless of sex. From 1 to 21 days, significant difference occurred (P<0.05) for ration consumption in relation to sexes, the males having consumed more than the females. Diets four, five and six resulted into better weight gains only for males P(<0.05). The better results of feed conversion were from the use of the enzymatic complexes (P<0.05), the males responding better than the females (P<0.05). In the total period, the males and the females which were given the positive control, consumed less ration than the other diets (P<0.05). Diets four and five provided the best results of weight gain to the males (P<0.05). As regards feed conversion, significant sex and diet interaction was observed (P<0.05), where the males presented the best conversions from the use of diets four and five (P<0.05). The females that were given the positive control and diet six presented better (P<0.05) feed conversions. As to intestinal viscosity, there was significant sex and diet interaction (P=0.056). For the males which were given diets three and six, there was a reduction in the intestinal viscosity of digesta (P<0.01). The same effect was observed in the females that were given diet six (P<0.01) in relation to the other treatments. No significant differences were observed (P>0.05) of effect of the treatments for the yields of carcass, breast, abdominal fat, villus height, crypta depth and villus :crypta ratio. In trial II, no differences were found (P>0.05) for the apparent digestibility coefficients of dry matter and crude protein. The values of EMAn presented significant differences (P<0.05), the enzymatic complexes concerning treatments five and six improved metabolizable energy. It follows that the use of the enzymatic complexes were effective in recovering the birdsâ performance through the use of the diets with 3% minus of metabolizable energy and only the enzymatic complexes concerning diets five and six increased significantly the EMAn of the rations.

ASSUNTO(S)

nutricao e alimentacao animal frango de corte; complexo enzimÃtico; caracterÃstica intestinal; energia metabolizÃvel; desempenho broiler chickens; enzymatic complexes; intestinal characteristics; metabolizable energy; performance

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