Influence of Atmospheric Ammonia on Serum Corticosterone, Estradiol

Hormonal profiles of hens in curtain side-walled high-rise deep pit and flush-waste layer houses were initiated at placement of hens in cages in August and continued through a 50 weeks long laying trial. In mid-January, a cold weather-related incident caused the rupture of water lines and flooding of the manure pits in the deep pit layer house, allowing atmospheric ammonia to rise to a high of 135±29 ppm and remain high through mid-February when the pits were finally emptied. After removal of wet manure from the deep pit, atmospheric ammonia in the deep pit house decreased to 25±9 ppm compared to 21±4 ppm in the flushwaste house. Elevated atmospheric ammonia in the deep pit house caused the hens, compared to hens in the flush-waste house, to increase significantly (p<0.05) their serum corticosterone from mid-January through February followed by a decrease until June when it increased again in response to high summer temperatures. Serum progesterone and estradiol-17 in those hens in the deep pit house decreased significantly (p<0.05) in response to elevated atmospheric ammonia. Egg production of hens in the deep pit house was decreased from mid-January through February (p<0.05) followed by a slight rebound in March. Overall egg production remained lower in the deep pit house compared to production in the flush-waste house through July. Elevated atmospheric ammonia is a strong stressor, which will induce increased serum corticosterone that leads to loss of egg production associated with decreased serum concentrations of serum estradiol-17 and progesterone.