An animal feed is provided that employs a substantially indigestible cation exchanger capable of binding ammonium cations and an acidogenic substance to acidify an animal's manure and thereby create ammonium cations that can be bound by the cation exchanger. The animal feed reduces ammonia emissions from manure produced by animals fed the animal feed compared to the emissions obtained from manure when an acidogenic substance is fed alone and compared to the emissions obtained from manure when a cation exchange capacity material is fed alone. Other aspects provide a method of lowering ammonia emissions from manure is provided. One embodiment provides a method for reducing soluble phosphorus levels in manure and a method for reducing total phosphorus levels in manure. In a further aspects present a method that yields manure that may be used alone or in concert with other materials to act as a fertilizer having advantageous ecological properties. Another aspect provides a method for reducing insect populations associated with manure. One embodiment is a composition for amending animal feed to produce animal waste that is lower in volatile ammonia and higher in nitrogen.