A Demonstration of Postpellet Application of Dry Phytase to Broiler Diets

SUMMARY A comparison of performance and P reduction in litter and manure from broilers fed rations with and without phytase enzyme was made with chickens reared on litter or in cages. Low-activity phytase supplemented as a dry powder to mash diets did not affect performance, but litter P accumulation was decreased 14 to 21% in the finisher phase. Manure P content of broilers in cages was reduced 14 to 19% during the starter and grower phases. Liquid phytase applied postpelleting to diets with 0.5% total P (0.3% available P) reduced litter P accumulation (14 to 19%) and reduced manure P content in starter, grower, and finisher phases of the study. Phosphorus content in raw manure was decreased by 55% during the finisher phase. Feed conversions of broilers in cages and on conventional litter-covered floors were improved significantly with postpellet application of liquid phytase. Feed conversion improvement was greater in birds in cages. Postpellet application of dry phytase was shown to be feasible based upon performance and reduction in litter P accumulation. Feed conversions were improved by 7 to 8 points (P < 0.05) when compared to those of birds given a normal P level (0.72% total P) diet without phytase. Litter P accumulation was reduced between 20.5 and 28.5% with dry phytase applied postpelleting. With liquid phytase applied postpelleting, litter P accumulation was reduced 26.6%. These reductions in litter P content represent about 4 lb of P per ton of litter.