Circulating corticosterone responses of feed and water deprived broilers and Japanese quail.

Experiments were conducted to delineate the acute stress response of commercial broilers to feed and water deprivation for 10 hr. The effect of method of nutrient deprivation, cooping versus removal of feed and water from broiler floor pens, was also considered. Bihourly plasma corticosterone measures were made during 10-hr withdrawal periods, and significant alterations in this adrenal steroid were considered indicative of stress. In all studies, feed and water deprivation produced significant elevations in plasma corticosterone concentrations. Cooped broilers exhibited a shorter onset and more exaggerated magnitude of adrenal responsiveness than floor penned broilers deprived of feed and water. There was also evidence that plasma corticosterone secretion in floor penned broilers was continual (linearly increasing) throughout the 10-hr withdrawal period. In contrast, maximal corticosterone responses followed by waning hormonal levels (an increasing quadratic function) were evident in cooped broilers. It was concluded that procedures involved in physically cooping birds, as well as the restraint cooping imposed, were acting additively to the stress associated solely with feed and water deprivation. Changes in plasma volume, as evidenced by percent packed cell volume changes during treatment periods, were not responsible for the corticosterone elevations observed. In a separate experiment, battery housed Japanese quail deprived of feed and water for 12 hr exhibited a temporal plasma corticosterone response very similar to that observed in floor penned broilers deprived of feed and water. Full-fed control quail exhibited only random temporal hormonal fluctuations during this time. It was likewise concluded that the practice of feed and water deprivation in quail constitutes a significant nonspecific stressor.