Methods are provided for the treatment of livestock or poultry confinement facilities equipped with manure collection zones (e.g., a manure pit or litter), in order to reduce and mitigate the effects of gaseous ammonia within the facility. The treatment involves application of an aqueous mixture including a partial calcium salt of a maleic-itaconic copolymer and a partial ammonium salt of a maleic-itaconic copolymer. Preferably, the amount of the partial calcium salt copolymer is greater than the amount of the partial ammonium salt copolymer. The treatment methods provide prompt and lasting reductions in gaseous ammonia within the confinement facility.