Effects of chronic exposure of diets with reduced concentrations of aflatoxin and deoxynivalenol on growth and immune status of pigs1

Abstract

This study investigated the growth and immune responses of pigs fed diets containing reduced concentrations of aflatoxin (AF) and deoxynivalenol (DON) from naturally contaminated corn. Sixty gilts (13.9 ± 0.2 kg of BW) were randomly assigned to 4 treatments (5 replicate pens per treatment and 3 pigs per pen): A (a control diet without detectable AF and DON); B (a diet with 60 μg of AF/kg and 300 μg of DON/kg); C (a diet with 120 μg of AF/kg and 600 μg of DON/kg); and D (a diet with 180 μg of AF/kg and 900 μg of DON/kg). Pigs were allowed ad libitum access to feed and water for 33 d. Feed intake and BW were measured weekly and pigs were bled (8 mL) on d 33 to measure the numbers of blood cells, to conduct liver function tests, and to measure immunological variables including IgG, IgM, interferon γ, IL4, IL6, and tumor necrosis factor α. One pig representing the average BW of each pen was killed to obtain the liver, kidneys, and spleen for weight, tissue color measurement, and histological evaluation of tissue damage. When compared with A, pigs in C and D tended to have reduced ADG (0.52 vs. 0.43 and 0.41 kg/d, respectively; P = 0.058) and ADFI (1.04 vs. 0.92 and 0.88 kg/d, respectively; P = 0.061). White blood cell count of pigs in D (23.4 × 10(3) cells/μL) was greater (P < 0.05) than those in A, B, and C (18.4, 18.5, and 16.8 × 10(3) cells/μL, respectively. Serum tumor necrosis factor α concentration of pigs in D (335 pg/mL) differed (P < 0.05) from those in A and C (299 and 290 pg/mL, respectively). Pigs in B and D had greater (P < 0.05) fibrosis in liver tissues than those in A. Collectively, this study shows that diets containing both AF and DON greater than 60 and 300 μg/kg, respectively, may reduce growth and decrease feed intake, whereas diets containing 120 μg of AF/kg and 600 μg of DON/kg may result in altered immune health, systemic inflammation, and partial liver damage, causing further reduction in growth of pigs.

Evaluation of a mycotoxin adsorbent in swine diets containing barley naturally contaminated with Fusarium mycotoxins

“…Reduction of feed intake and consequent decrease of BW gain have been commonly observed when pigs are fed DON contaminated diets (Goyarts et al, 2005b;Chaytor et al, 2011b;Mok et al, 2013), and these were also observed in the present study. In addition, the ADFI of pigs fed the NC diet from d 0 to 7 was 24.3% less compared with those fed the PC diet, which was close to the predictive value (28.7%) of feed intake reduction calculated by the equation derived from the literature (Mok et al, 2013).…”

“…Several studies have showed the up-regulation of serum immunoglobulin subsets in pigs fed diets containing Fusarium mycotoxins (Swamy et al, 2002;Goyarts et al, 2005b) whereas other studies showed no alteration of immunoglobulin subsets Chaytor et al, 2011b). In the present study, immunoglobulin subsets were not altered by feeding pigs with contaminated diets.…”

Effects of dietary deoxynivalenol and zearalenone on apparent ileal digestibility of amino acids in growing pigs

“…Pigs are known to be very sensitive to dietary DON (Pestka, 2007) which may cause reduced feed intake, weight loss and immune system disorders (CAST, 2003;Pinton et al, 2008;Chaytor et al, 2011b). The DON has also been reported to damage the intestinal tract by altering barrier function of epithelial cells (Pinton et al, 2010), which may adversely affect the digestion and absorption of nutrients in diets.…”

Aflatoxins of type B and G affect porcine dendritic cell maturationin vitro

“…Besides their known carcinogenicity, AF cause immunosuppression in domestic animals and humans by impairing the innate and cell-mediated immunity (Chaytor et al, 2011;Gong et al, 2004;Luongo et al, 2013). Both cytolysis by natural killer (NK) cells and several macrophage functions, including phagocytosis, production of reactive oxygen species (ROS), and intracellular killing, are impaired by AF (Qureshi et al, 1998;Liu et al, 2002).…”