Net energy value of thirteen ingredients for broilers

The energy values of 13 raw ingredients (corn, wheat, paddy rice, broken rice, cassava pellet, full-fat soybean, soybean meal, canola meal, animal protein, rice bran, wheat bran, palm kernel meal, and palm kernel oil) were measured in broilers using a multiple regression method involving 23 diets. The inclusion levels of ingredients were variable and as independent as possible. Ross 308 male broilers were fed the 23 diets from 18 to 23 days of age in 12 open-circuit respiratory chambers (4 birds/chamber), with a minimum of eight replicates per diet. Apparent metabolizable energy (AME), AME corrected to zero nitrogen retention (AMEn) or for 60% nitrogen retention (AMEs) of diets, and heat production of the birds were measured, and diet net energy (NE) values were calculated. As expected, palm kernel oil showed the highest AME value. Among the cereals, the AME value (kcal/kg DM) was numerically higher for broken rice (4090) than for corn (3850) or wheat (3690). The AME values were lowest for the fiber- and protein-rich ingredients. The difference between AMEn and AME was 2 to 5% for most ingredients, but it was higher for high-protein ingredients such as animal protein, soybean meal, and canola meal (10 to 14%). The AMEs values were close (within ±3%) to the measured AME values. The AME efficiency for NE (NE/AME) varied from 55 to 60% for the fiber-rich canola meal and wheat bran to 86% for palm kernel oil; it averaged 79% for cereals and ranged from 70 to 80% for the other ingredients, according to their chemical composition. The ranking of ingredients differed among the AME (and AMEs), AMEn, and NE evaluation systems, which justifies the interest in moving to a NE system for poultry feeds. Finally, the measured NE values of the present study were consistent with those obtained from published NE prediction equations for most ingredients, validating the use of equations established on diets for predicting the NE content of ingredients.