Observations on the chemical and nutritive content of whith winter and spring wheats contaminated with deoxynivalenol (vomitoxin)

Abstract

The chemical and some nutritive values for two samples of white winter wheat and five samples of spring wheat that contained various levels of deoxynivalenol (0.04–7.6 mg DON kg −1) and zearalenone (0.007–0.46 mg kg −1) were determined. Adult White Leghorn cocks were used to estimate true metabolizable energy (TME), TME corrected to zero nitrogen balance (TME n), true available amino acids (TAAA), and true dry matter digestibility (TDMD). Aflatoxin, ochratoxin and T-2 toxin were not detected in any of the wheat samples. The crude protein, crude fibre, TME, TME n, TDMD and TAAA (mg per g DM) of the wheats containing DON (> 0.6 mg kg −1) tended to be higher, and the ash and nitrogen-free extract (NFE) lower, than for the “clean” wheats which contained only trace amounts of DON (< 0.05 mg kg −1). The fat content and TAAA (% available) tended to be lower in the DON-containing than the clean wheats, whereas DON level had little effect on 1000 kernel weight. Significant ( P < 0.05) relationships were observed between DON and zearalenone, crude protein, NFE, TME, TME n and TAAA (mg per g DM), and between crude protein and NFE, but the numbers of observations were small. The increase in crude protein of the DON-containing wheats might have been due to the decrease in NFE caused by the utilization of the starch by the Fusarium sp. fungus during its growth. However, further research is required to confirm this possibility. These results indicate that changes in chemical composition and nutrient availability of feedingstuffs produced by toxigenic fungi must also be considered when determining the effects of mycotoxins on livestock and poultry.