ARS | Publication request: INFLUENCE OF HEN AGE ON RESPONSE OF TURKEY POULTS CHALLENGED WITH COLD STRESS AND ESCHERICHIA COLI TO ALPHAMUNE™, A DIETARY YEAST EXTRACT ANTIBIOTIC ALTERNATIVE

Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 20, 2005
Publication Date: N/A

Technical Abstract: Two battery trials were conducted using a yeast extract feed supplement, Alphamune™, to protect turkey poults from production losses due to cold stress and E. coli infection. Trial 1 used commercially hatched day-old male Hybrid Converter poults from 33-wk-old hens in their 2nd wk of lay and Trial 2 used male poults of the same line from 40 wk-old hens in their 8th wk of lay. In both trials poults were fed a standard unmedicated turkey starter diet or the same diet with either 1 lb/ton or 2 lb/ton Alphamune™. Challenged birds were exposed to intermittent cold stress (12-16 C) during wk 1-3 and inoculation of eye and nares by course spray of a 108 cfu culture of E. coli at 1 wk of age. Controls were neither stressed nor inoculated. Birds were bled and necropsied at 3 wk of age. In both trials, challenged birds had significantly decreased BW and feed conversion efficiency (FC) as compared to non-challenged controls. In Trial 1, BW was increased during the 1st wk pre-challenge by both levels of supplementation, with 1lb/ton resulting in significantly higher BW than 2 lb/ton. Both BW and FC of challenged poults were protected by both levels of supplementation. Total leukocyte numbers (WBC) were decreased by challenge of control-fed birds only, and there was no effect of challenge on the heterophil/lymphocyte (H/L) ratio. In Trial 2, neither level of Alphamune™ improved BW or FC and 1 lb/ton decreased BW of challenged birds relative to those challenged and not supplemented. In Trial 2, the WBC was decreased and the H/L ratio was increased in challenged control-fed birds. Alphamune™ resulted in increased basal H/L ratios of unchallenged birds, but there was no further increase due to challenge of the supplemented birds. These results suggest that poults from young breeder hens may have a differential response to stress compared to those from older hens, and that Alphamune™ may protect poults from young breeder flocks from the production losses due to cold stress and E. coli infection.