Metabolizable energy and standardized ileal digestible amino acid contents of expeller-extracted canola meal fed to broiler chicks

Abstract

An experiment was conducted to determine the standardized ileal digestible amino acid (AA) and AMEn contents of expeller-extracted canola meal (EECM) fed to broiler chicks. One hundred forty-four broiler chicks were divided into 24 groups of 6 birds balanced for BW and fed 4 diets in a completely randomized design (6 groups per diet) from d 14 to 21 of age. The diets were a corn-soybean meal-based basal diet formulated to meet NRC nutrient requirements, the basal diet with energy- and AA-yielding ingredients replaced by 30% of either solvent-extracted canola meal (SECM) or EECM, and a low-protein casein-cornstarch-based diet. The SECM, which is commonly used in formulating poultry diets, was fed for comparison with EECM, whereas the casein-cornstarch-based diet was fed to estimate basal endogenous AA losses for determining standardized ileal digestibility of AA. All 4 diets contained titanium oxide (0.3%) as an indigestible marker, and nutrient digestibility and retention were determined by the substitution method. From d 19 to 21, excreta samples were collected for AMEn determination. On d 21, the birds were killed by cervical dislocation, and contents of the whole ileum were obtained for determination of AA digestibility. Expeller-extracted canola meal had greater (P<0.05) standardized ileal digestible contents of Gly, Leu, Ser, Thr, Asp, and Glu and tended to have greater (P<0.10) standardized ileal digestible contents of Ile, Lys, Phe, Ala, and Tyr than SECM. Compared with SECM, EECM had greater (P<0.001) AMEn (2,694 vs. 1,801 kcal/kg). The results show that the EECM evaluated in the current study had greater standardized ileal digestible AA and AMEn contents than SECM, and hence, it may be a better source of protein and energy for broiler chicks than SECM. The standardized ileal digestible AA and AMEn values of EECM used in the current study could be used when formulating broiler chicken diets using the same to minimize the N excretion and feeding cost.