Location: Avian Disease and Oncology ResearchTitle: Effects of T-2 toxin on turkey herpesvirus–induced vaccinal immunity against Marek’s disease
|Kufuor-mensah, Eric - Antech Diagnostics|
|Reed, Willie - Purdue University|
|Sleight, Stuart - Michigan State University|
|Pestka, James - Michigan State University|
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2015
Publication Date: 3/1/2016
Publication URL: http://handle.nal.usda.gov/10113/62665
Citation: Kufuor-Mensah, E., Reed, W.M., Sleight, S., Pestka, J., Fadly, A.M., Dunn, J.R. 2016. Effects of T-2 toxin on turkey herpesvirus–induced vaccinal immunity against Marek’s disease. Avian Diseases. 60(1):56-62. doi: 10.1637/11245-072815-Reg.1.
Interpretive Summary: Mycotoxins such as T-2 toxin have received much attention because of possible adverse effects on the immune system of humans and animals. The objective of this study was to determine the effects of T-2 toxin on vaccination against Marek’s disease (MD) in poultry. Data from this study suggest that exposure of chickens to sublethal doses of T-2 toxin during the first week after hatch may lower the titer of HVT vaccine at 1 week post-vaccination, but the effect is only temporary. The data also suggest that such exposure may increase the incidence of MD lesions and mortality within 4 weeks of age, but only in unvaccinated chickens. Thus, subchronic exposure to T-2 toxin could lead to significant losses in flocks that are not vaccinated against MD, but should not negatively influence MD in countries where commercial broiler chickens are routinely vaccinated against MD.
Technical Abstract: T-2 toxin, a very potent immunotoxic Type A trichothecene, is a secondary metabolite produced primarily by Fusarium spp., which grows on cereal grains and can lead to contaminated livestock feed. Repeated exposure to T-2 toxin has been shown to cause immunosuppression and decrease the resistance of exposed animals to a variety of infectious diseases; however, the effects of T-2 toxin on Marek’s disease (MD) vaccinal immunity have not been reported. Four trials were conducted to determine the effects of T-2 toxin on vaccinal immunity against MD. Day-old, white leghorn chicks of Avian Disease and Oncology Laboratory line 15I5x71 were treated daily for 7 days via crop gavage with T-2 toxin at a sublethal dose of 1.25 mg/kg body weight. Treated and untreated chicks were also vaccinated with turkey herpesvirus (HVT) at hatch and were challenged with the JM strain of MD virus (MDV) at 8 days of age. Chickens were tested for HVT viremia at 1 wk post vaccination immediately before challenge, and for HVT and MDV viremia at 3 wk post challenge. Chickens were observed for the development of MD lesions and mortality within 8 wk of age. T-2 toxin significantly reduced body weight and titers of HVT viremia within 7 days after hatch. T-2 toxin shortened the incubation period for the development of MD lesions and mortality, but only in unvaccinated chickens. The percent MD protection in T-2–toxin-treated, HVT-vaccinated chickens ranged from 82% to 96% and was comparable to that in HVT vaccinated untreated control chickens (89%–100%). The data suggest that exposure of chickens to sublethal doses of T-2 toxin for 7 consecutive days after hatch may influence the development of 1) HVT viremia; and 2) MD lesions and mortality, but only in unvaccinated chickens.