Reports an experiment designed to impose factorial combinations of up to six environmental stressors known to affect the productive performance of poultry - aerial ammonia, beak trimming, coccidiosis, stray voltage, environmental heat, and loud noise - in order to determine how multiple concurrent stressors influence the chick's productive performance, salient blood parameters, and behaviour. Presents the findings and notes that the heterophil to limphocyte ratio was increased by only three stressors. Concludes the results suggest that the effects of unrelated stressors on performance trait of growing animals may be estimable to a first approximation by summing the known effects of the respective stressors when acting alone.

KEYWORDS: ammonia, electric shock, intermittent, heat stress, noise, animals, calculating, productivity, performance, poultry houses