Effects of social stress on response to ketamine anesthesia in chickens

Chickens were housed in low, high, and optimal social stress environments for 16 weeks before they were given ketamine IV. The sleep time was significantly (P < 0.01) longer in the groups exposed to the low (n = 14) and high (n = 30) social stress environments than in the group exposed to optimal-stress environment (n = 12) or controls (n = 12). Birds (n = 12) removed from optimal-stress environment and exposed to high-stress environment for 48 hours did not exhibit longer sleep time than the group in the optimal-stress environment. Long-term exposure to different social stress environments markedly altered ketamine-induced sleep time in chickens.