Effects of feeding diets containing increasing proportions of bunt-infected wheat ( Tilletia caries) on performance and health of pigs

Tilletia caries is a fungus that mainly infects wheat, causing the disease bunt. Wheat bunt had been one of the most dangerous plant diseases before seed dressing was a common practice. However, it is still of importance in organic farming, since seed dressing is not permitted. Trimethylamine (TMA) is a metabolic product of T. caries known to cause a fishy odour of highly contaminated wheat. Therefore, contamination of feed is supposed to decrease feed intake. However, systematic studies on the effect of practically relevant proportions of bunt-infected wheat on performance and health of pigs are not available. Therefore, the aim of the present study was to investigate the effects of increasing proportions of bunt-infected wheat (0%, 10%, 20% and 30% of the diet) corresponding to a total spore content of 0%, 0.2%, 0.4% and 0.6% on the performance and health of piglets during a 5-week experiment starting after weaning. TMA was not detectable in the contaminated wheat and the feed intake of piglets remained unaffected. However, live weight gain decreased linearly and feed-to-gain ratio significantly increased as the proportion of contaminated wheat increased. Haematological and serum clinical-chemical characteristics as well as the viability of peripheral blood mononuclear cells were not influenced by dietary treatments. Based on the limited data of the present experiment it might be concluded from the adverse effects of bunt-infected wheat in piglet diets on the feed-to-gain ratio that a spore content of 0.2% of the complete diet should not be exceeded.