Submitted to: Immunology Research Workshop
Publication Type: Abstract only
Publication Acceptance Date: 11/1/2003
Publication Date: 12/1/2003
Citation: Huff, G.R., Huff, W.E., Rath, N.C., Balog, J.M. 2003. Stress-related chronic disease in turkeys and the effects of nutritional and environmental immunomodulation. Immunology Research Workshop. p. 50-51. Interpretive Summary:
Technical Abstract: Our research using the synthetic glucocorticoid, dexamethasone (DEX), to suppress the immune response of turkeys to low doses of opportunistic bacteria has led to the development of a number of nutritional and environmental strategies for decreasing the impact of stress-induced immunosupression. The immunosuppressive effects of stress appear to be greater in male turkeys than in females. We have found that female turkeys are more resistant to colibacillosis and respiratory disease in a DEX-E.coli challenge infection than are males. The anti-bacterial activity of monocytes from male and female turkeys treated with 0.5 or 2.0 mg/Kg DEX was measured by monitoring the percentage of infected cells over time. Antibacterial activity was significantly decreased at both concentrations of DEX at both 8 and 16 hours post-infection in both sexes combined and was significantly lower in males as compared to females, suggesting that stress can reduce the ability of turkey mononuclear cells to kill bacteria, and that the difference in this function may be relevant to the sex-related difference in disease resistance. Water supplementation with vitamin D3, vitamin E, sodium salicylate, and ß-1,3/1,6-glucan, a helical polysaccharide derived from the cell wall of Saccharomyces cervisiae, have all shown immunomodulatory effects on male turkeys challenged with E. coli in our model. We have shown that excess handling or environmental enrichment during the first 2 weeks after hatch can lead to decreased resistance later in life. Our model has further suggested that a small population of male turkeys is highly susceptible to the immunosuppressive effects of stress, and that these individuals can be identified by their performance in a behavioral test utilizing a T-maze at 3 days of age. These individuals are also more susceptible to the immunosuppressive effects of excess environmental stimulation during the first two weeks after hatch. These studies illustrate the dramatic effects that stress can have on both production values and resistance to opportunistic infection, and suggest that a combination of genetic selection, nutritional immunomodulation, and environmental strategies to reduce stress may lead to healthier birds and a safer and a more wholesome product.