Submitted to: Arkansas Nutrition Conference
Publication Type: Proceedings
Publication Acceptance Date: September 16, 1999
Publication Date: N/A
Interpretive Summary: Treatment of turkeys with vitamin C did not improve resistance to bacterial infections caused by treatment with a compound known to mimic the physical changes caused by stress. In fact, turkeys given a high level of vitamin C in drinking water tended to have higher mortality, lower body weights, and increased numbers of white blood cells compared to turkeys not given vitamin C. Treatment with vitamin D3 also did not improve disease resistance when turkeys were treated with the compound a single time. However, when turkeys which survived treatment at 5 weeks of age were treated with the compound again at 12 weeks of age, vitamin D3 protected the turkeys from disease.
Technical Abstract: Turkey osteomyelitis complex (TOC) is a disease syndrome characterized by the presence of green liver, synovitis, osteomyelitis of the proximal tibia, and soft tissue abscesses in the carcasses of processed turkeys. We have established that these lesions are caused by opportunistic bacterial infections in turkeys whose immune systems have been compromised due to stress. We have developed an experimental model in which all of the lesions of TOC can be reproduced using immunosuppression with a synthetic glucocorticoid, dexamethasone (DEX). When vitamin C was added to the drinking water of turkeys for one week before treatment through two weeks after treatment with DEX, there was a trend toward increased mortality of birds supplemented with 300 ppm vitamin C and treated with DEX compared to non-supplemented birds or birds treated with 150 ppm vitamin C. Birds which were supplemented with 300 ppm vitamin C and not treated with DEX tended to have lower body weights than non-supplemented, untreated birds. These same birds also had significantly higher numbers of white blood cells in peripheral blood 24 hours after DEX treatment. When poults were given 2064 IU/l vitamin D3 in their drinking water for the first 5 days of brooding and supplemented again at 4128 IU/l before, during, and after each stressful event, including weekly weighing and DEX treatment, there was no effect on birds given a single DEX treatment at 5 weeks of age and necropsied 2 weeks later. However, when surviving birds were given a second DEX treatment at 12 weeks, vitamin D3 supplementation significantly increased disease resistance and body weight, and decreased heterophil/lymphocyte ratios of DEX-treated birds.