Influence of Incubation Conditions on Turkey Poult Intestinal Development and Susceptibility to Poult Enteritis

Abstract

Exposure to environmental conditions that impact organ growth and function and overall performance may increase poult susceptibility to poult enteritis complex (PEC). Temperature and hypoxic stress during embryonic incubation may impact organ growth and development, development of immunocompetency, post-hatch performance and may predispose poults to enteric disease. The objective of the first study was to provide a baseline of responses to incubation conditions so that further studies could be conducted on whether these stressors may increase susceptibility to post-hatch infection. Commercial Hybrid turkey eggs were incubated at standard (37.5°C) conditions from embryonic day (ED) 0 to ED24. At ED24, eggs were divided into thirds for incubation at 37.5°C, 36.0°C, or 39.0°C from ED24 until hatch at ED28. The objective of the second study was to evaluate the effects of incubation temperature conditions on intestinal development and susceptibility to challenge with turkey coronavirus (TCV). Commercial Hybrid eggs were incubated at standard (37.5°C) conditions from ED0 to ED24. At ED24, one-third continued incubation at 37.5°C, one-third were incubated at 36.0°C, and one-third were incubated at 39.0°C from ED24 until hatch at ED28. At d 5 (0 days postinfection, dpi) half of the poults were administered 0.1mL of TCV inoculum (3 x 103 EID50/0.1 mL). The third study examined the effects of incubation temperature conditions on intestinal development and susceptibility to dual challenge with both TCV and enteropathogenic E. coli. Commercial Hybrid eggs were incubated at standard (37.5°C) incubation conditions from ED0 to ED25. At ED25, eggs were randomized and half continued incubation at 37.5°C and half were incubated at 36.0°C from ED25 until hatch at ED28. At d 5 (0 dpi) half of the poults were administered 0.1 mL of TCV inoculum (4 x 103 EID50/0.1 mL) and 0.1 mL of E. coli (2.4 x 108 CFU/mL) by oral gavage. Main effects (P≤0.05) of incubation temperature and challenge, as well as twoway interactions (P≤0.05) of temperature and challenge were observed for the parameters evaluated in each study. These studies suggest an influence of incubation temperature conditions or PEC-associated pathogens on intestinal development and early post-hatch turkey poult performance.