PROTEIN-QUALITY AND CALCIUM AVAILABILITY FROM EXTRUDED AND AUTOCLAVEDTURKEY HATCHERY RESIDUE

The protein quality of an extruded mixture of hatchery by-product meal and soybean meal (EHSM) and the calcium availability of autoclaved ha tchery by-product meal (AHBM) were determined. In Experiments 1 and 2, EHSM or soybean meal (SBM) were the only protein sources in diets for mulated to contain 16, 20, or 24% CP. In both experiments, there were five or six replicate pens randomly allotted to each level of dietary protein and each pen contained five poults. In Experiment 1, there was a significant increase in the Protein Efficiency Ratio (PER; P less t han or equal to 0.005) in poults from a fast-growing line compared wit h poults from a slow-growing line selected for egg production but no s ignificant differences between EHSM and SBM. In Experiment 2, PER was increased in poults fed EHSM (P less than or equal to 0.002). In both studies, there was a large decline in PER in those poults fed the 16% SBM diet, and this resulted in a significant source by level interacti on. There were no significant source or level of protein effects on th e Net Protein Ratio (NPR) or Net Protein Utilization (NPU) in Experime nt 2. In Experiment 3, AHBM, steamed bone meal and limestone were the primary sources of calcium in diets containing 0.6, 0.8/1.0, and 1.2% calcium. There were four replicate pens per level and source of calciu m. The length and width of the femur and tibia were measured along wit h fat-extracted bone weight and ash. Poults fed diets containing AHBM and limestone had improved feed efficiency (P less than or equal to 0. 008) compared with those fed bone meal. There were no significant diet effects on any bone measurements.