Sex-related reduced weight gains in growing swine fed diets containing deoxynivalenol

A 5-wk feeding trial was conducted with 30 castrated male and 28 female, 5-wk-old crossbred piglets. Three different deoxynivalenol (DON) and zearalenone (Z)-contaminated diets were fed: 0.7, 3.1 and 5.8 ppm DON and 0, .05, and .1 ppm Z, respectively. The animals were fed their respective diets for 4 wk followed by the .7:0-ppm diet during wk 5. Feed intake and weight gain varied in a manner reciprocal to the levels of DON-Z in the diets during the first 4 wk (P < .05). The castrated males had an overall lower weight gain compared with the females receiving the same diet (P < .05). Gross postmortem changes were not different in either sex and tended to be most prominent in the pigs fed for the lower DON:Z-contaminated diets after the first week, although they were seen in pigs fed the higher DON:Z diets after 4 wk of feeding. Lesions included mild to moderated reddening of the fundic mucosa of the stomach, reddening of the mucosa of the small intestine, and mild to moderate enlargement and edema of the mesenteric lymph nodes. Similarly, the severity of histologic changes tended to vary inversely with the concentrations of DON:Z in the diets after the first week but varied with the concentrations of DON:Z after 4 wk. They consisted of vascular congestion with mild to moderate multifocal erosions and degeneration of the mucosa in the stomach and small intestine. Mild to moderate lymphoid degeneration and depletion were also observed in the Peyer's patches of the intestines, bronchial and mesenteric lymph nodes, spleen, tonsil and thymus. Deoxynivalenol was found in the plasma, urine and gastrointestinal contents. Only trace amounts (<50 ppb) of the parent compound were detected in the tissues analyzed. It is proposed that DON, not Z, was the cause of these effects.