RESUMO
The effects of rice bran oil (RBO) as an alternative dietary energy source on nutritional properties and fatty acid deposition in broiler chickens are scarce in the literature. One-day-old chickens (broiler Ross 308) were assigned in a completely randomized design with three treatment diets and nine replicates of four chickens per replicate. A basal control diet contained 4~5% palm oil (T1) in the starter and finisher phases, respectively. Treatments 2 to 3 were fed diets formulated with 50% (T2) and 100% (T3) of RBO as a fat source instead of palm oil (PO). Replacing dietary PO with RBO improved the feed conversion ratio (FCR) by 6% (p = 0.017) over the total period of the experiment (1−38 d of age). The feeding of RBO (T3) showed the highest (p < 0.001) cooking loss values in the breast meat. However, compared with other groups, the blend of PO and RBO group (T2) displayed a lower cooking loss value in the thigh meat. In breast meat, the protein content was lowered (p = 0.007), while the fat content was higher (p < 0.001) in male broiler chickens fed dietary RBO (T2 and T3). Total inclusion of dietary RBO (T3) decreased (p = 0.034) the proportion of saturated fatty acids (ΣSFAs) but increased (p = 0.02) linoleic acid. In addition, α-linolenic acid (ALA) increased (p < 0.001) in male broiler chickens fed dietary RBO (T2 and T3), and the highest deposit level occurred by the total inclusion of RBO (T3). Total omega 3 fatty acids (∑n-3) increased (p = 0.013), while the ratio of n-6 to n-3 polyunsaturated fatty acid (PUFA) decreased (p = 0.046) in male broiler chickens fed dietary RBO (T3) as compared with the control diet (PO; T1). In conclusion, compared with dietary PO (control diet, T1), the total inclusion of dietary RBO at 50 kg/metric ton feed (T3) increased ∑n-3, ALA, and reduced n-6:n-3 PUFA ratio in the breast meat, but cooking loss values were larger in breast and thigh meats. The blend of dietary PO and RBO (T2) was better for both production performance targets (feed intake and FCR), cooking loss values, and deposition of ALA in the breast meat. The inclusion of dietary RBO into broiler diets needs further study, but the present experiment aids in expanding research knowledge to make that possible.
RESUMO
One-day-old male broiler chickens (Ross 308) were assigned to 3 dietary treatments in a completely randomized design with 8 replicates per treatment, and 4 birds per replicate. The control group was fed a basal control diet, and the 2 test groups were fed the basal control diet supplemented with 150 and 300 mg/kg of protected complex of biofactors and antioxidants [P(BF+AOX)], respectively. The P(BF+AOx) is a combination of vitamins, L-tryptophan and biofactors such as fermentation extracts (Jefo Nutrition Inc., Saint-Hyacinthe, QC, Canada). Dietary P(BF+AOX) did not affect growth performance and breast meat quality (water holding capacity, cooking loss, shear force, and texture profile analysis), but the addition of 150 mg/kg of P(BF+AOX) decreased the relative weight of liver, heart, and spleen (P < 0.05). The addition of 150 mg/kg of P(BF+AOX) tended to increase (P = 0.051) the cold carcass yield. The addition of 150 and 300 mg/kg of P(BF+AOX) decreased (P = 0.002) the cooler carcass shrink, but the relative weight of fat pad increased (P = 0.032) in chickens fed 300 mg/kg P(BF+AOx) than in those of birds fed the control diet. On the other hand, the addition of 300 mg/kg of P(BF+AOX) decreased (P = 0.041) the serum level of uric acid compared with those of birds fed the basal diet. Broiler chickens fed diets supplemented with 150 mg/kg of diet had higher (P < 0.05) mRNA expressions of jejunal SOD1 and interleukins 6 and 10 (IL-6, IL-10). The findings suggest that P(BF+AOX) could be considered as a functional nutrient in broiler diets up to a concentration of 150 mg/kg because of its favorable effects on maintaining intestinal barrier function as well as carcass traits, while excess levels (300 mg/kg) had exhibited superior effect on the serum level of uric acid compared with those of birds fed the control diet.