The feeding of Fusarium
mycotoxin-contaminated grains adversely affects the performance of swine and poultry. Very little information is available, however, on adverse effects associated with feeding these
mycotoxin-contaminated grains on the performance of horses. An experiment was conducted to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium
mycotoxins on feed intake, serum
immunoglobulin (Ig) concentrations, serum chemistry, and hematology of horses. A polymeric
glucomannan mycotoxin adsorbent (GM
polymer) was also tested for efficacy in preventing Fusarium
mycotoxicoses. Nine mature, nonexercising, light, mixed-breed mares were assigned randomly to one of three dietary treatments for 21 d. The horses were randomly reassigned and the experiment was subsequently replicated in time following a 14-d washout interval. Feed consumed each day was a combination of up to 2.8 kg of concentrates and 5 kg of mixed timothy/alfalfa hay. The concentrates fed included the following: 1) control, 2) blend of contaminated grains (36% contaminated wheat and 53% contaminated corn), and 3) blend of contaminated grains + 0.2% GM
polymer. Diets containing contaminated grains averaged 15.0 ppm of
deoxynivalenol, 0.8 ppm of 15-
acetyldeoxynivalenol, 9.7 ppm of
fusaric acid, and 2.0 ppm of
zearalenone. Feed intake by all horses fed contaminated grains was reduced (P < 0.001) compared with controls throughout the experiment. Supplementation of 0.2% GM
polymer to the contaminated diet increased (P = 0.004) feed intake of horses compared with those fed the unsupplemented contaminated diet. Serum activities of
gamma-glutamyltransferase were higher (P = 0.047 and 0.027) in horses fed the diet containing contaminated grain compared with those fed the control diet on d 7 and 14, but not on d 21 (P = 0.273). Supplementation of GM
polymer to the contaminated diet decreased (P < 0.05) serum
gamma-glutamyltransferase activities of horses compared with those fed unsupplemented contaminated diet on d 7 and 14. Other hematology and serum chemistry measurements including serum
IgM,
IgG, and
IgA, were not affected by diet. It was concluded that the feeding of grains naturally contaminated with Fusarium
mycotoxins caused a decrease in feed intake and altered serum
gamma glutamyltransferase activities. The supplementation of GM
polymer prevented these
mycotoxin-induced adverse effects.