Ammonia and poultry welfare: a review

Abstract

Atmospheric ammonia is a major aerial pollutant of poultry buildings. The current exposure limits for ammonia of 25 ppm are set on the basis of human safety rather than animal welfare. This paper reviews the evidence for ammonia exposure affecting various aspects of poultry welfare. The reviewed evidence suggests that ammonia exposure (1) causes irritation to the mucous membranes in the eyes and the respiratory system; (2) can increase the susceptibility to respiratory diseases; and (3) may affect food intake, food conversion efficiency and growth rate. The behavioural effects of ammonia on poultry have recently been investigated and suggest that there may be a threshold for ammonia detection or aversion at or below the current exposure limit. The available evidence for the effects of ammonia on poultry welfare should be considered when setting future guidelines for ammonia exposure in poultry houses.