Effects of the level of feed intake and ergot contaminated concentrate on ergot alkaloid metabolism and carry over into milk

The aim of the present study was to examine the effects of ergot contaminated concentrate at differing levels of feed intake on ergot alkaloid metabolism and carry over into milk. Twelve double fistulated (in the rumen and the proximal duodenum) Holstein Friesian cows were fed either the control diet (on a dry matter (DM) base: 60% maize silage, 40% concentrate) or the contaminated diet (concentrate contained 2.25% ergot, which caused an alkaloid concentration of the daily ration between 504.9 and 619.5 mu g/kg DM) over a period of 4 weeks. Daily feed amounts were adjusted to the current performance which resulted in a dry matter intake (DMI) variation between 6.0 and 18.5 kg/day. The actual alkaloid exposure varied between 4.1 and 16.3 mu g/kg body weight when the ergot contaminated concentrate was fed. Approximately 67% of the alkaloids fed were recovered in the duodenal ingesta, and similar to 24% were excreted with the faeces. No alkaloid residues could be detected in the blood or milk samples.