Immunological status of the progeny of breeder hens kept on ochratoxin A (OTA)- and aflatoxin B1 (AFB1)-contaminated feeds

Abstract

This study aimed to evaluate the immunological status of progeny of hens kept on ochratoxin A (OTA)- and aflatoxin B1 (AFB1)-contaminated feed. For this purpose, White Leghorn (WL) layer breeder hens (40-weeks-of-age) were divided into six groups (A–F). Hens in Group A were fed a commercial layer ration while those in Groups B and C were kept on a diet amended with 3 and 5 mg OTA/Kg, respectively. Group D was fed a ration containing 5 mg AFB1/Kg, while hens in Groups E and F were kept on feed amended with OTA and AFB1 each. All feedings were for 1, 2, or 3 weeks. Fertile eggs were set for hatching on a weekly basis to obtain progeny of each week separately. At 14 days-of-age, subsets of progeny were euthanized and the frequency of immunoglobulin(s)-bearing cells in their spleen and bursa of Fabricius assessed; at 16 days-of-age, other chicks in each set were utilized to determine their lymphoblastogenic responses against phytohemagglutinin (PHA-P). At 30 days-of-age, the final sub-set of chicks/group was euthanized and their peritoneal macrophages harvested for measurements of phagocytic potential and nitrite production. Relative weights of the bursa of Fabricius and of the spleen were significantly lower in the progeny of hens fed mycotoxin-contaminated diets for 14 and 21 days. The frequencies of IgA-, IgG-, and IgM-bearing cells were also significantly lower in the bursa of Fabricius and spleen of progeny chicks obtained from hens fed the OTA + AFB1 mixed diet. Feeding contaminated diets to breeder hens also resulted in significantly lower responses to PHA-P. In addition, the percentages of peritoneal macrophages displaying phagocytosis of sheep red blood cells (SRBC), the number of SRBC/macrophage, and nitrite production were each significantly lower in cells from progeny chicks from OTA- and AFB1-fed hens. The findings of the present study indicated there were severe immunosuppressive effects in progeny chicks as a result of exposure of their parent hens to OTA and AFB1 either alone or in combination. These studies provide emphasis for the need for mycotoxin regulation policy with respect to the ingredients used in poultry feed, since it is clear that feeding multi-mycotoxin-contaminated diets to breeder hens will almost certainly result in the hatching of manifestly unhealthy chicks.