Title: Response of restraint stress-selected lines of Japanese quail to heat stress and Escherichia coli challenge Authors
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 19, 2012
Publication Date: March 1, 2013
Citation: Huff, G.R., Huff, W.E., Wesley, I.V., Anthoney, N.B., Satterlee, D.G. 2013. Response of restraint stress-selected lines of Japanese quail to heat stress and Escherichia coli challenge. Poultry Science. 92(3):603-611. Interpretive Summary: Japanese quail that were genetically selected for different responses to restraint stress were evaluated for their disease resistance and pathogen colonization when exposed to heat stress and Escherichia coli challenge. Unselected control line birds (CS) had heavier body weights at 17 days, 25 days, and 32 days of age and higher mortality rates when compared to birds selected for either a high stress response (HS) or a low stress response (LS). Heat stress significantly increased the isolation of Salmonella from the intestines of these birds with LS birds having numerically lower percent colonization and HS birds having numerically higher percent colonization compared with the CS birds, however Campylobacter was not isolated. The LS line had one/third of the level of stress hormone compared to the HS line, which is the same difference seen in the orignal selection for restraint stress. These differences suggest that these quail lines may be useful as an efficient model for the study of stress induced immunosuppression in commercial poultry.
Technical Abstract: Japanese quail selected for divergent corticosterone (Cort) response to restraint stress were evaluated for their susceptibility to heat stress and challenge with Escherichia coli. These quail lines are designated as the high stress (HS), low stress (LS), and the random-bred control (CS) lines. Heat stress (35°C, 8h/d) began at 24d until the end of the study at 39d. Birds were challenged with an aerosol spray containing 2x109 cfu of E. coli at 25d and 32d. At 38d the surviving birds were necropsied and the intestinal tract was screened for both Salmonella and Campylobacter. Body weights of the CS birds were higher than both HS and LS at 17d, 25d, and 32d. At 32d there was no difference in mortality between males and females and the CS line had higher mortality compared with the LS line with the HS line being intermediate. At 38d, females of the CS line that were both heat stressed and challenged had a mortality incidence of 25%, which was significantly higher than male birds of the same line and treatment (5.3%). There was an increased incidence in Salmonella enterica serotype Agona isolation after heat stress, with the LS birds having less isolation than the HS birds. Mean Cort levels of male birds were not significantly affected by line, heat stress, or E. coli challenge, however the LS line subjected to heat stress had one third the level of the HS line, a difference identical to that seen in the original selection for response to restraint stress.