Effects of Subcutaneous Ochratoxin-A Exposure on Immune System of Broiler Chicks

Abstract

Ochratoxin A (OTA), an immunosuppressive mycotoxin, can increase the risk of many infectious diseases and contribute to economic losses to the poultry industry. The immunosuppressive effect has mainly been investigated through oral exposure; however, birds may also be contaminated through skin absorption. The present study investigated the influence of OTA exposure on the defense system of broiler chicks through the subcutaneous route and including low doses. Groups of broiler chicks (Cobb), 05 days old, were exposed to subcutaneous inoculation of OTA at concentrations of 0.1; 0.5; 0.9; 1.3; and 1.7 mg OTA/kg body weight. The size of the lymphoid organs, circulating immune cells, and total IgY and IgA levels were evaluated 21 days post inoculation. Subcutaneous OTA exposure decreased the weight of the thymus, spleen, and bursa of Fabricius, and leukocytopenia (p < 0.05) was detected in chicks of the OTA treated groups. In a dose-dependent way, decreased levels of circulating lymphocytes and heterophils (p < 0.05), and increased levels of monocytes (p < 0.05) were detected. Decreased IgY and IgA serum concentrations were noted in the OTA treated groups (p < 0.05). In conclusion, subcutaneous OTA exposure induces immunosuppression even at low levels.

Effect of a Mycotoxin Binder (MMDA) on the Growth Performance, Blood and Carcass Characteristics of Broilers Fed Ochratoxin A and T-2 Mycotoxin Contaminated Diets

“…The inclusion of the additive in the mycotoxin contaminated feed, led to a reduction in the number of monocytes that could indicate less intestinal inflammation, which would represent a beneficial effect for chickens. It has been described that subcutaneous OTA exposure increased levels of monocytes in broiler chickens [ 31 ]. Other blood parameters were not affected by dietary treatments.…”

“…Moreover, it was reported that OTA or T-2 mycotoxin could affect the immune system by the atrophy of the lymphoid organs along with depletion of lymphocytes and the enlargement of the kidney and liver [ 9 , 13 , 31 ]. However, in the current research, the combination of OTA and T-2 mycotoxin at levels examined in broilers feed did not affect the relative weights of liver, gizzard, kidneys, and spleen ( p > 0.05).…”

Detoxification of Selenium Yeast on Mycotoxins and Heavy Metals: a Review

“…Mycotoxins can also cause atrophy and failure of immune organs and other histopathological changes [ 98 ]. Khan et al significantly detected leucopenia and the decrease of IgY and IgA concentrations in serum, as well as the weightlessness of thymus, spleen, and bursa in chicks after OTA exposure [ 99 ]. To sum up, mycotoxin exposure can induce immunosuppression.…”

Avian Physiology: Are Birds Simply Feathered Mammals?

“…Similarly, corticosterone decreases the weights of the primary immune organs, thymus and bursa Fabricius, in birds (e.g., young chickens: Mehaisen et al, 2017 ). Spleen weights are also decreased following exposure to toxicants (Aflatoxin B 1 : Grozeva et al, 2017 ; Ochratoxin A: Khan et al, 2019 ; T-2 toxin: Hayes and Wobeser, 1983 ) (see Table 6 ). In contrast, spleen weights were increased after viral challenges or administration of E. coli lipopolysaccharide (see Table 6 ) ( Boa-Amponsem et al, 1999 ; Zhang et al, 2017 ; Bai et al, 2019 ; Yang et al, 2019 ).…”