Ascaridia galli infection affects pullets differently when feed is contaminated with the Fusarium toxin deoxynivalenol (DON)
Introduction
The prevalence of endoparasitoses in gallinaceous poultry depends on the housing system. Hens kept on deep litter or outdoors might experience a higher infection pressure to the roundworm Ascaridia galli because of the permanent contact to parasite eggs present in excreta and soil, enabling the full A. galli infection cycle to run (Kaufmann et al., 2011).
In free ranging hens the prevalence of A. galli, Capillaria obsignata and Heterakis gallinarum was found to be 18, 28 and 16%, respectively, as reported for a screening of different production systems for the occurrence of various nematode species in Bavaria. In floor-kept hens the prevalence of these nematode infections varied between 5 and 7% while hens kept in cages were virtually free of these infections (Zeller, 1990).
This general trend was also confirmed for housing systems in Denmark where the prevalence of C. obsignata, A. galli and H. gallinarum infection were reported to be 54, 64 and 72% for free ranging hens, and 52, 42 and 19% for floor-kept hens, while cage kept hens were characterized by a low A. galli, prevalence of 5% (Permin et al., 1999).
In growing chickens an A. galli infection is manifested by an unspecific growth depression rather than by other overt clinical signs of an infection (Gauly et al., 2001).
It has been reviewed that this growth depression might also result from an infection related depression in feed intake (Chubb and Wakelin, 1963). Moreover, other host or nutrition derived factors might influence the overall outcome of an A. galli infection ranging from a pronounced growth depression via neutral effects to even a growth stimulation (e.g., Chubb and Wakelin, 1963). Based on the higher A. galli prevalence in housing systems which are increasingly practised today and on the uncertainties of the general outcome of an infection, the knowledge of infection influencing factors arising from feed is increasingly important.
A nutrition derived factor with the potential to affect both the host and the worm itself might be the presence of certain mycotoxins in feed. The Fusarium toxin deoxynivalenol (DON) is one of the most important feed contaminants worldwide as it occurs in diet concentrations high enough to adversely affect the health and performance of farm animals (EFSA, 2004). Gallinaceous poultry is generally regarded as relatively insensitive to DON as compared to other species, such as pigs, which is reflected by the different guidance levels for critical dietary DON concentrations of 5 and 0.9 mg DON/kg diet, respectively (EC, 2006).
DON acts as an immune-modulator in various species through interaction with ribosomes and transcription factors resulting in a disturbance of protein synthesis and deregulated cytokine interplay (Döll and Dänicke, 2011, Pestka, 2010). DON was shown to influence the synthesis of various proteins in broilers (Dänicke et al., 2011) and laying hens (Chowdhury and Smith, 2005), to affect white blood cells (Chowdhury et al., 2005) and decrease the antibody titres to the Newcastle disease virus in layers (Dänicke et al., 2002) and in broilers dose-dependently (Dänicke et al., 2003). Although in these experiments effects were observed mostly at DON concentrations higher than the mentioned guidance level of 5 mg DON/kg diet, it needs to be stressed that this critical dietary DON concentration applies for “normal” production conditions (EC, 2006). Additional stress factors might decrease the DON concentration in the diet for inducing adverse effects.
Thus, the aim of the experiment was to test the effects of DON on pullets which were either infected with A. galli or free from this helminth. Not only the consequences for various nutritional, morphological and pathophysiological characteristics of the pullets were examined but also the DON effects on the worms. Moreover, DON metabolism both in pullets and in worms was investigated.
Section snippets
Experimental design and procedures
Experimental design and procedures are summarized in Fig. 1; a total of 120 female one day-old chicks (Lohmann LSL) were used initially and randomly distributed to 2 floor pens with 60 chicks per pen at the experimental facilities of the Department of Animal Science, University of Göttingen. Chicks were kept according to the recommendations of the breeder. A vaccination against Newcastle disease was performed at days 1 and 21 of age. The chicks were fed the uncontaminated rearing diet 1 with
Live weight gain (LWG) and nutrient balances
LWG was not significantly influenced by diet type while pullets generally gained less live weight during the balance period 2 (Table 2). Independent of this effect of period, the A. galli infected animals were characterized by a significantly higher LWG. The significant interaction between diet type, infection and balance week was mainly the result of the marked increase from week 1 to week 2 in CON fed and infected birds (Group CON+) while such an effect was not detected for other treatment
Discussion
In interpreting the guidance value of 5 mg DON/kg diet as a critical dietary DON concentration for complete poultry feed it must be considered that this value only applies for so-called normal production conditions. Environmental, hygienic and dietary stress might challenge the adaptation capability of the animals which is supposed to decrease the critical dietary concentration for mycotoxins. Consequently, dietary DON levels lower than the guidance value might exert adverse effects on health.
Acknowledgements
The authors are grateful to the co-workers of the Institute of Animal Nutrition, Braunschweig; the Department of Animal Science, Göttingen, and of the Clinic for Poultry, Hannover, for their excellent assistance in performing the experiment and analyses.
References (34)
- et al.
Effect of addition of a detoxifying agent to laying hen diets containing uncontaminated or Fusarium toxin-contaminated maize on performance of hens and on carryover of zearalenone
Poult. Sci.
(2002) - et al.
The Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) in animal feeding
Prev. Vet. Med.
(2011) - et al.
Effect and repeatability of Ascaridia galli egg output in cockerels following a single low dose infection
Vet. Parasitol.
(2001) - et al.
Age-related differences of Ascaridia galli egg output and worm burden in chickens following a single dose infection
Vet. Parasitol.
(2005) - et al.
Genetic resistance to natural helminth infections in two chicken layer lines
Vet. Parasitol.
(2011) - et al.
The food contaminant deoxynivalenol, decreases intestinal barrier permeability and reduces claudin expression
Toxicol. Appl. Pharmacol.
(2009) - et al.
Tissue distribution and excretion of radioactivity following administration of 14C-labeled deoxynivalenol to White Leghorn hens
Fundam. Appl. Toxicol.
(1986) - et al.
Immunopathogenesis of Ascaridia galli infection in layer chicken
Dev. Comp. Immunol.
(2011) - et al.
World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the effectiveness of anthelmintics in chickens and turkeys
Vet. Parasitol.
(2003) - et al.
Effects of feeding grains naturally contaminated with Fusarium mycotoxins on hepatic fractional protein synthesis rates of laying hens and the efficacy of a polymeric glucomannan mycotoxin adsorbent
Poult. Sci.
(2005)
Effects of feed-borne Fusarium mycotoxins on hematology and immunology of laying hens
Poult. Sci.
Nutrition and helminthiasis in chickens
Proc. Nutr. Soc.
Effects of graded levels of Fusarium toxin-contaminated wheat and of a detoxifying agent in broiler diets on performance, nutrient digestibility and blood chemical parameters
Br. Poult. Sci.
Ascaridia galli infection of pullets and intestinal viscosity: consequences for nutrient retention and gut morphology
Br. Poult. Sci.
Effects of feeding a Fusarium toxin contaminated diet to infectious bursal disease virus-infected broilers on the protein turnover of the bursa of Fabricius and spleen
Arch. Anim. Nutr.
The effects of dietary non-starch polysaccharides on Ascaridia galli infection in grower layers
Parasitology
Vulnerability of polarised intestinal porcine epithelial cells to mycotoxin deoxynivalenol depends on the route of application
PLOS ONE
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