Broiler breeders, the hens and roosters that produce Canada's hatching eggs, live for about a year on the same litter, far longer than the broiler chickens raised for under 45 days, yet their barns had never been systematically studied for air quality. A team led by Marie-Lou Gaucher of Université de Montréal's Faculty of Veterinary Medicine has now filled that gap, publishing in the Journal of Applied Poultry Research with support from Canadian Hatching Egg Producers.
The study combined a national survey, answered by 27 producers across six provinces, with seasonal monitoring at 10 Quebec farms over three seasons, veterinary exams of the birds and a respiratory health questionnaire for 27 workers. Of 174 ammonia samples, 87 exceeded the 25 parts per million exposure limit, with an average of 32.5 ppm and peaks of 114 ppm. Levels rose sharply in autumn and winter, when producers close ventilation to retain heat, trapping gases released by the litter.
The news for workers and birds was more reassuring than the raw numbers suggest. Workers reported only occasional symptoms such as a stuffy nose or mild cough, though field visits showed respiratory protection was not always worn consistently despite 96 per cent claiming to use it. Bird exams found no eye or respiratory conditions, with about 30 per cent showing mostly mild footpad lesions. Gaucher's team frames the results as a first quantitative benchmark for better coordinating ventilation, humidity and litter management through Canada's cold months.