Energy value of rice, broken rice, and rice bran for broiler chickens by the regression method

The objective of this study was to determine the ileal digestible energy (IDE), ME, and ME_n of rice, broken rice, and rice bran. The birds were fed a standard starter diet from day 0 to 14 and experimental diets from day 15 to 21 after hatching. A total of 336 birds were grouped by BW and assigned to 7 diets, each diet comprised 8 replicates with 6 birds per replicate. The diets comprised a reference diet (RD) and 6 test diets (TD). The TD contained 2 levels of rice, broken rice or rice bran that partly replaced the energy sources in the RD at 120 or 240 g/kg (rice and broken rice) or 150 or 300 g/kg (rice bran). Addition of rice or broken rice to RD linearly increased (P < 0.01) ileal digestibility of DM, energy, as well as total tract metabolizability of DM, energy, and N-corrected energy in the TD. The inclusion of rice bran in the TD linearly decreased (P < 0.01) energy digestibility and utilization in the test diet. Regressions of rice-associated, broken rice-associated, or rice bran-associated IDE, ME, or ME_n intake in kcal against rice, broken rice, or rice bran intake were as follows: IDE = Y = 2 (6) + 3,185 (73) × Rice + 3,199 (72) × Broken Rice + 2,562 (61) × Rice Bran, r2 = 0.98; ME = Y = 8 (6) + 3,103 (72) × Rice + 3,190 (71) × Broken Rice + 2,709 (60) × Rice Bran, r2 = 0.98; ME_n = Y = 4 (5) + 3,014 (68) × Rice + 3,092 (101) × Broken Rice + 2,624 (57) × Rice Bran, r2 = 0.98; Based on the regression equations, the IDE, ME, ME_n values (kcal/kg of DM) of rice were 3,185, 3,103 and 3,014, respectively, while for broken rice, the values were 3,199, 3,190, and 3,092 and for rice bran, the values were 2,562, 2,709, and 2,624, respectively.