Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2003
Publication Date: 9/1/2003
Citation: Miles, D.M., Moore, P.A., Smith, D.R., Rice, D.W., Stillborn, H.L., Rowe, D.E., Lott, B.D., Branton, S.L., Simmons, J.D. 2003. Total and water-soluble phosphorus in broiler litter over three flocks with litter treatment and dietary inclusion of high available phosphorus corn and phytase supplementation. Poultry Science. 82:1544-1549. Interpretive Summary: Poultry litter, a mixture of sawdust bedding and poultry manure, has historically been applied as fertilizer to land adjacent to poultry houses. If applied improperly, nutrients in the litter, especially water soluble phosphorus, can reach natural waterways through runoff. This can be detrimental to aquatic life through the overgrowth of aquatic plants. Litter amendments, such as alum, have shown to reduce water-soluble phosphorus in runoff. Further, dietary modifications, like using a hybrid corn with more digestible phosphorus for the bird (known as high available phosphorus corn) or adding phytase, an enzyme to break down the non-digestible phosphorus in regular corn, have been shown to reduce total phosphorus in litter. The current research combines alum litter amendment and the dietary modifications to seek out the most environmentally sound options. This work shows water-soluble phosphorus in poultry litter can be reduced 60% by combining alum litter treatment and a poultry diet with high available phosphorus corn as the primary ingredient.
Technical Abstract: Three pen trials were conducted to determine the main effect of alum addition to litter on form of poultry litter phosphorus (P) using a 2X2 factorial structure of the subunit treatments: diets including high available phosphorus/low phytate corn (HAPC) and phytase (PHYT). Male broilers (1,760 per flock) were grown to 42 days having starter diets with 0.45% available P and grower diets with 0.35% available P. In the first trial, total litter P (tP) was most for the yellow dent corn (YDC) diet (12 k/kg) and least for the HAPC and PHYT combination (H&P) diet (6.9 g/kg) with the individual PHYT and HAPC diets falling in between at 9.1 g/kg and 9.4 g/kg tP. Also in the first trial, the litter water-soluble P (wP) was highest for PHYT (2.8 g/kg), least for the HAPC and H&P diets (1.5 g/kg) with the YDC diet in the middle (2.2 g/kg). Alum was added to the litter after the first experiment. In the second and third experiments, alum inclusion significantly reduced the wP over the treatments with no alum. In the third trial, the least wP was provided by the alum-HAPC treatment, revealing a synergistic relationship. Phytase, YDC, and HAPC diets with no alum litter treatment generated the most wP. Because these diets appear to have little difference with respect to quantity of wP, this work suggests that P species generated by alternative diets should be considered as criteria when attempting to reduce P in broiler litter applied to land.