Bioavailability of Phosphorus from Broiler Litter Ash for Chicks

Two experiments, each utilizing 180 Peterson × Hubbard male broiler chicks, were conducted to determine the biological value of phosphorus from broiler litter ash as compared with dicalcium phosphate dibasic dihydrate as the standard. The litter ash was produced from the burning of pine shaving-based litter that had been used for the production of one flock of broilers. Three-week body weight and tibia ash measurements were used in nonlinear bioassays to obtain the relative phosphorus biological value of the litter ash. The phosphorus biopotency from litter ash, determined from 3-wk body weight data, was estimated to be 79.1 and 82.9% of the standard in Experiment 1 and 2, respectively. Estimates based on tibia ash values were 77.6% for Experiment 1 and 81.4% for Experiment 2. Both estimates obtained in Experiment 2 were significantly different from the dicalcium phosphate standard.