EFFECT OF DEOXYNIVALENOL (DON)-CONTAMINATED DIET FED TO GROWING-FINISHING PIGS ON THEIR PERFORMANCE AT MARKET WEIGHT, NITROGEN RETENTION AND DON EXCRETION

Abstract

In a feeding experiment, a total of 64 pigs (16–18 kg body weight) were assigned to four experimental diets. Three diets contained 70% wheat, one with clean wheat (C), another with DON-contaminated wheat (V) and the third a 50:50 mixture of the clean and contaminated wheats (CV). The fourth diet, included for comparative purposes only, was a barley-corn-soybean meal diet (PC). The DON content of each diet was 0.0, 0.0, 2.89 and 5.26 mg kg−1, respectively. Pigs were penned individually and offered the diets ad libitum until reaching 90 ± 5 kg body weight: a necropsy was conducted on each pig. In a metabolism trial, seven pairs of littermate barrows were fed two of the experimental diets (C and V). Feed and water allowances were based upon the voluntary intake (twice daily) of the littermate offered diet V. During a 5-d period, feces and urine were collected separately and samples taken for subsequent nitrogen and DON analyses. Pigs fed diet PC reached market weight earlier than those fed the other diets. Feed consumption and weight gain by the C and CV pigs were almost identical and these pigs averaged 9 d earlier to market weight than those fed diet V. Pigs reacted to the contaminated diets by an immediate and typical reduction of feed intake: although by the second week these feed intakes had improved, appetite and weight gain differences established in the first week persisted throughout the experiment. Increasing dietary intake of DON increased liver, kidney and uterus weights at necropsy, but the increases were not significant (P > 0.05). There was considerable variation in feed acceptance among pigs offered diet V in the metabolism trial. Those pigs rejecting diet V were not used, hence the pigs finally retained could not comprise a truly random sample. The fecal and urinary N output by pigs fed diet V was higher (P < 0.01) than that of pigs fed diet C but N retention was greater in the V pigs, due possibly to the higher N content of diet V. However, N retention as a percentage of N intake did not differ significantly between the two diets. Based upon the urinary recovery of DON and metabolite DON-1, at least 67% of the DON ingested was absorbed, a fact suggesting an explanation for the pig's sensitivity to DON. Key words: Pigs, N retention, deoxynivalenol, urinary-DON, metabolism, feeding