ARS | Publication request: The effect of a yeast extract feed additive on turkeys challenged with Escherichia coli and Listeria monocytogenes and subjected to transport stress

Submitted to: World Poultry Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 30, 2008
Publication Date: June 30, 2008
Citation: Huff, G.R., Huff, W.E., Dutta, V., Johnson, M.G., Nannapaneni, R. 2008. The effect of a yeast extract feed additive on turkeys challenged with Escherichia coli and Listeria monocytogenes and subjected to transport stress. In: Proceedings of the 23rd World Poultry Congress, Queensland, Brisbane, Australia. 2008 CDROM.

Interpretive Summary: Because the use of antibiotics in poultry production is being limited by worldwide effort to prevent the development of resistance, there is a need for other methods to control the deleterious effects of stress on bird immunity and pathogen colonization. A yeast extract feed supplement, Alphamune™ (YE), was added to the diet of turkeys which were exposed to E. coli and L. monocytogenes at 16 weeks of age using coarse spray and feed inclusion. Positive controls were also injected with dexamethasone (Dex), a compound that mimics the effects of stress. At 18 weeks a sample of birds was subjected to 12 hours of transport stress and all birds were bled and necropsied the following morning. Body weight and gain was improved by YE during wk 1. YE decreased mortality following Dex-challenge in females. YE tended to decrease the heterophil/lymphocyte (H/L) ratio, which is a measure of stress in birds. H/L ratio was increased by both Dex and transport stress and was higher in males as compared to females. A test that indirectly measures the ability of blood cells to kill bacteria was higher in males and in birds fed YE and was lower in challenged and in transported birds. These results suggest that dietary YE has potential for decreasing the impact of stress in turkey production.

Technical Abstract: There is a need to develop nutritional methods for controlling pathogens in poultry production. A yeast extract supplement, Alphamune™ (YE) was added to the diet of turkeys which were exposed to E. coli and L. monocytogenes Scott A at 16 wks of age using coarse spray and feed inclusion. Positive controls were also injected with dexamethasone (Dex). At 18 wks a sample of birds was subjected to a 12 h transport stress and all birds were bled and necropsied the following morning. BW and gain were improved by YE during wk 1 (P = < 0.0001). YE decreased mortality following Dex-challenge in females (P = 0.004). YE tended to decrease the heterophil/lymphocyte ratio (H/L)(P = 0.1) which was increased by both Dex and transport stress and was higher in males (P < 0.0001). There was a feed X stress X sex interaction for H/L ratio. Heterophil oxidative burst activity was higher in males and in birds fed YE (P < 0.0001) and was lower in challenged and in transported birds (P < 0.0001). These results suggest that dietary YE has potential for decreasing the impact of stress in turkey production.