INFLUENCE OF AFLATOXIN AND FUMONISIN B-1-CONTAINING CULTURE MATERIAL ON GROWING BARROWS

Aflatoxin (AF)-contaminated and fumonisin B-1 (FB1)-contaminated (cult ure material from Fusarium moniliforme) diets were fed singly and in c ombination to growing cross-bred barrows. Six barrows (3 replicates of 2 each; mean body weight, 17.5 kg) per group were fed: 0 mg of AF and 0 mg of FB1/kg of feed (control); 2.5 mg of AF/kg of feed; 100 mg of FB1/kg of feed; or 2.5 mg of AF plus 100 mg of FB1/kg of feed for 35 d ays. The effects on production performance, serum biochemical, hematol ogic, immunologic, and pathologic measurements were evaluated. Body we ight, gain, and feed consumption were significantly (P < 0.05) decreas ed by AF and AF plus FB1 diets. The FB1 diet decreased feed consumptio n, and although body weight was numerically decreased, it was not stat istically significant. Aflatoxin increased serum gamma-glutamyltransfe rase (GGT) activity and total iron concentration and decreased urea ni trogen concentration and unsaturated iron-binding capacity. The FB1-al one diet increased serum GGT activity, whereas the AF plus FB1 diet in creased serum aspartate transaminase, cholinesterase, alkaline phospha tase, and GGT activities, increased RBC count, triglycerides, and tota l iron concentrations, and decreased unsaturated iron-binding capacity and urea nitrogen concentration. For the most part, the effects of th e AF plus FB1 diet on body weight and hematologic measurements could b e considered additive. However, the effect of the AF plus FB1 diet on cholinesterase and alkaline phosphatase activities was greater than ad ditive and was a synergistic response. One pig in the FB1-diet group a nd 2 pigs in the combination-diet group died. Postmortem lesions in pi gs of the FB1-diet group consisted of ascites and increased liver weig ht. Observations at necropsy for pigs of the AF plus FB1-diet group co nsisted of hydrothorax, ascites, pulmonary edema, gastric erosions and ulceration, and increased liver and spleen weights. The AF diet incre ased relative liver weight and resulted in liver that was pale, rubber y and resistant to cutting. Histologic lesions consisted of hepatic ne crosis or degeneration, or both, with variable degrees of bile duct pr oliferation in barrows of the AF-diet groups. Renal tubular nephrosis was observed in barrows of the FB1-diet group, but this was not consis tent in the AF plus FB1-diet group. Cell-mediated immunity, as measure d by mitogen-induced lymphoblastogenic stimulation index, was decrease d in barrows of the AF and FB1-diet groups, and values in barrows give n the combination diet were significantly decreased from those in barr ows given the single toxin diets. It was concluded that AF and FB1 (fr om culture material), singly or in combination, can adversely affect c linical performance, serum biochemical, hematologic, and immunologic v alues and induce lesions in growing barrows. For most of the variables we evaluated under our study conditions and dosages of toxins, measur ements were affected more by the combination diet than by either singl e toxin diet, and the toxic responses could be described as additive o r more than additive, particularly for induction of liver disease.