Environment and flock productivity in nine commercial broiler flocks during winter conditions

Research has shown the detrimental effect of high ammonia level on bird performance. This study documented that significant and surprisingly high ammonia levels (27 to 122 ppm on day of chick placement) and temperature stratification (38°C [5.4°F] below target at chick level at placement) were prevalent in the broiler houses under study. Three typical commercial houses were monitored over three flock cycles to document environment conditions (temperature, humidity, ammonia) during cold weather and relate these to bird productivity. Poor flock ranking and productivity followed exposure to ammonia above 80 ppm on day of chick placement. Some flocks were successfully raised under ammonia levels at double the recommended 25 ppm brooding threshold. The growers were not aware of the magnitude of the ammonia. Reused litter, ratherthan new litter, made the problem worse.