The Adverse Effects of Ammonia on Chickens Including Resistance to Infection with Newcastle Disease Virus

Abstract

Ammonia is a colorless, highly irritant gas with a specific gravity of 0.597. It is one of the products of bacterial deamination or reduction of nitrogenous substances. Recent changes in poultry management, such as winter rearing in confinement, reuse of litter, and an absence of roosts, have led to conditions favoring the continual release of ammonia from the litter into the air of the birds' environment. Anderson et al. (2) reported that reduced ventilation during winter months led to concentrations of ammonia as high as 50-100 parts per million (ppm) in the atmosphere of some commercial poultry houses in the North Central states. Bullis et al. (5) reported a keratoconjunctivitis of chickens observed in the diagnostic laboratory of the University of Massachusetts in 1943. The birds showed corneal lesions, a marked photophobia, rubbing of the eyes, and slight lacrimation. Reports from the flock owners on conditions associated with the outbreaks, together with the fact that no infectious agent could be demonstrated, suggested that the cause was environmental, particularly the ammonia in the houses. Faddoul and Ringrose (8) reproduced experimentally an ocular disorder clinically resembling, if not identical with, naturally occurring keratoconjunctivitis by exposing chickens for 5 weeks to a concentration of ammonia of 0.2%/o by volume (2000 ppm). Experimental ammonia gas poisoning in rabbits and cats was studied by Boyd et al. (4). They found that the naso-buccopharynx acted as a partial filter of ammonia, protecting the