The Effects of Feed Form, Grinding Method, Energy Level, and Gender on Broiler Performance in a Moderate (21 C) Environment

Abstract

Corn ground with either a hammer mill (HMC) or a roller mill (RMC) was used in a starter diet with 3142 kcal metabolizable energy (ME)/kg (fed 0 to 21 days) and in grower diets with 3032 and 3109 kcal ME/kg (fed 22 to 47 days). The diets were fed in either mash or crumble form to broilers reared sexes separate in a moderate (21 C) environment. For the 21-day starter period, mash prepared with HMC yielded significantly (P<.05) lower body weights and higher feed conversion ratios than either crumbles from RMC or HMC, or mash from RMC. At 47 days, broilers fed crumbles from HMC weighed significantly more than those fed mash from HMC; weights were increased 4.4% for the 3032-kcal ME/kg diet and 6.6% for the 3109-kcal ME/kg diet. Feed: body weight ratios were not significantly affected by crumbling the HMC but were reduced numerically .015 for 3032 kcal ME/kg and .031 for 3109 kcal ME/kg diet. Results for broilers fed the diets in mash form, prepared from RMC, were intermediate compared to results obtained with mash and crumbles prepared from HMC. The roller mill required 14.5% less energy for grinding than the hammer mill, and the particle size characteristics were materially different.