Feed phosphates are not only costly but they are becoming less scarce to extract from nature. Today, there is interest in recycling phosphorus from poultry litter ash (the remains of burning wood shavings litter), which contains about 10 percent phosphorus and over 15 percent calcium, along other minerals.
To this end, an experiment was conducted to evaluate increasing levels of poultry litter ash on broiler growth and calcium and phosphorus digestibility. Diets were designed to contain 0, 25, 50, 75 and 100 percent of poultry litter ash as a substitute for dicalcium phosphate; the poultry litter ash was substituted for dicalcium phosphate on a weight basis (1:1).
Results indicated decreased weight gain at 21 days from feeding poultry litter ash at the 100 percent substitution rate when compared with the 25 percent substitution rate. No effects on gain, feed consumption or feed efficiency were observed at the end of the trial (41 days). The 100 percent substitution rate of dicalcium phosphate did not cause any detrimental effects on growth performance of market age broilers.
Although femur ash percentages decreased with increasing levels of poultry litter ash, bone integrity was not compromised by the addition of poultry litter ash to the diet. Dry matter digestibility of dietary calcium (26.32-58.65 percent) and phosphorus (30.23-42.68 percent) increased with increasing levels of poultry litter ash (0-100 percent).
In conclusion, poultry litter ash resulting from the combustion of poultry litter can be used as an effective source of dietary phosphorus and calcium in broiler diets.