Insights on the Host Stress, Fear and Growth Responses to the Deoxynivalenol Feed Contaminant in Broiler Chickens
Fear and Growth Responses to the Deoxynivalenol Feed Contaminant
in Broiler Chickens. PLoS ONE 9(1): e87727. doi:10.1371/journal.pone.0087727
Insights on the Host Stress, Fear and Growth Responses to the Deoxynivalenol Feed Contaminant in Broiler Chickens
Khaled Ghareeb 0
Wageha A. Awad 0
Omer E. Sid-Ahmed 0
Josef Bo hm 0
Hemachandra Reddy, Oregon Health & Science University, United States of America
0 1 Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine , Vienna , Austria , 2 Department of Animal Hygiene , Behaviour and Management , Faculty of Veterinary Medicine, South Valley University , Qena, Egypt, 3 Clinic for Avian , Reptile and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine , Vienna , Austria , 4 Institute of Medical Biochemistry, Department of Biomedical Sciences, University of Veterinary Medicine , Vienna , Austria
Mycotoxins pose an important danger to human and animal health. Poultry feeds are frequently contaminated with deoxynivalenol (DON) mycotoxin. It is thus of great importance to evaluate the effects of DON on the welfare related parameters in poultry industry. In the present study, the effects of contamination of broiler diet with 10 mg DON/kg feed on plasma corticosterone and heterophil to lymphocyte (H/L) ratio as indicators of stress, tonic immobility duration as an index for fear response and growth performance of broiler chickens were studied. In addition, the effect of a microbial feed additive either alone or in combination with DON contamination on these different aspects was also evaluated. The results showed that DON feeding significantly affected the welfare related parameters of broiler chickens. The feeding of DON contaminated diet resulted in an elevation of plasma corticosterone, higher H/L ratio and increased the fear levels as indicated by longer duration of tonic immobility reaction. Furthermore, DON reduced the body weight and body weight gain during the starter phase definitely at the second and third week. However, during grower phase, feeding of DON decreased the body weight at the fourth week and reduced the body gain at the fifth week. Addition of the microbial feed additive, a commercial antidote for DON mycotoxin, was able to overcome DON effects on stress index (H/L ratio), fearfulness and growth parameters of broilers. In conclusion, we showed for the first time that the DON feeding increased the underlying fearfulness and physiological stress responses of broilers and resulted in a reduction in the welfare status as indicated by higher plasma corticosterone, higher H/L ratio and higher fearfulness. Additionally, feeding the microbial feed additive was effective in reducing the adverse effects of DON on the bird's welfare and can improve the performance of broiler chickens.
-
Funding: This work received the financial support from Biomin GTI GmbH, Herzogenburg, Austria. The funders had no role in study design, data collection and
analysis, decision to publish, or preparation of the manuscript.
Competing Interests: This work received the financial support from Biomin GTI GmbH, Herzogenburg, Austria. This does not alter the authors adherence to all
the PLOS ONE policies on sharing data and materials.
Deoxynivalenol (DON), commonly known as vomitoxin, is a
trichothecene mycotoxin produced by several fungal species, such
as Fusarium, Myrothecium, Cephalosporium, Verticimonosporium, and
Stachybotrys [1]. Cereal grains are the main constitutes of poultry
feeds which are frequently contaminated with DON mycotoxin
due to changes in the environmental condition such as
temperature and humidity. Thus exposure of broiler chickens to DON
contaminated diet can not be avoided. The impacts of DON
contamination of poultry feeds on a wide range of significant
health and immunological parameters were intensively studied
[2,3,4,5,6,7,8,9,10,11]. However, the effects of DON
contamination of broiler diet on the welfare related parameters are not
investigated, only a few studies showed that DON increased the
stress index (heterophil to lymphocyte ratio, H/L ratio) in broilers
[12,13].
Stress is the loss of homeostasis by stressors. It is known that
poultry in modern production have to deal with several stressors
during their life such as weighing, vaccination and a lot of
environmental and management procedures. These factors can
affect the behavioural, physiological, and performance responses
of birds. Among these factors are nutritional, climatic, social and
biological conditions [14,15,16,17]. These external factors are
considered stressors, led to higher plasma corticosterone levels and
inducing a state of stress response. Studies on the physiology of the
stress indicated that corticosterone produced during acute or
chronic stressor exposure is one of the final hormones of the
hypothalamic-pituitary adrenal axes (...truncated)