Effect of aluminum chloride and dietary phytase on relative ammonia losses from swine manure1

Ammonia (NH3) losses from swine manure contribute to odor problems, decrease animal productivity, and increase the risk of acid rain deposition. This study was conducted to determine whether aluminum chloride (AlCl3) or dietary manipulation with phytase could decrease relative NH3 losses from swine manure. Twenty-four pens of nursery pigs were used in two trials, and the pigs were fed normal or phytasesupplemented (500 IU/kg) diets. Aluminum chloride was added to manure pits (1.9 × 1.2 × 0.5 m) under each pen at 0, 0.25, 0.50, or 0.75% (vol:vol) of final manure volume. Manure pH and NH3 losses (measured by relative NH3 flux) were determined twice weekly. The addition of AlCl3 at 0.75% decreased (P < 0.05) manure pH from 7.48 to 6.69. Phytase decreased (P < 0.05) manure pH to 7.07 compared with 7.12 in the normal diet manure. Aluminum chloride administered at 0.75% without phytase reduced (P < 0.05) relative NH3 losses 52% for the entire 6-wk period. Relative NH3 losses were decreased (P < 0.05) from 109 mg of NH3/(m h) in pens containing pigs fed the normal diet