Avaliação nutricional de derivados de moagem úmida do milho para frangos de corte industrial

Abstract

Several studies have demonstrated the influence of bird age on the digestive and absorptive processes, resulting in different recommendations on diet elaboration. This study observed the age effect on apparent (AMEn) and true metabolizable energy nitrogen corrected (TMEn) values and dry matter (DMMC) and crude energy metabolizability coefficient (CEMC) of whole corn germ (WCG), corn gluten meal (CGM), corn gluten feed (CGF) and corn starch (CS) using the total excreta collection method. Eight hundred and forty broilers were distributed in a completely randomized design with four treatments and five replicates. Treatments consisted in four ages: 1 to 10, 11 to 21, 22 to 32, 33 to 42 days, using 10, 8, 6 and 4 birds per replicate, respectively, for the ages mentioned above. In parallel, a group of birds was kept in fasting for 72h for each treatment. The number of birds per replicate at each age took into account animal welfare and manure volume produced. Diets were based in 40% of substitution of the reference diet (corn-soybean meal-based) by WCG, CGF and CS, except for CGM, with 30% of substitution. Average ages (5, 15, 25 and 35 days) were used as independent variable for regression analysis. DMMC had a positive linear tendency for CGF, a quadratic for CS and not significant for CGM. CEMC presented a quadratic effect for CGF and for CS; and was not significant for CGM. AME and AMEn of tested ingredients ranged from 989 to 4773 and from 939 to 4682 kcal·kg-1 of natural matter, respectively. Values of TMEn of GCF and CS presented linear behavior according to the age. There was no significant difference on TMEn among treatments for broilers fed CGM, suggesting that birds have similar ability in using proteic feed in every productive phase or that replacement level is not suitable to evaluate CGM. WCG values of TMEn were: 4093, 4179, 4251 and 4701 kcal·kg-1 of natural matter at the average ages of 5 15, 25 and 35 days, respectively. It was observed that there was an age effect on nutrient digestibility for the majority of the studied ingredients.