In a previous experiment outlined at last year's conference (Hyslop and Roberts, 1988), it was demonstrated that replacement of a proprietary pelleted concentrate with malt distillers grains (draff), should be limited to 15% of total dry matter intake (DMI) when draff is offered in two feeds per day. However there is little evidence to validate such a limitation when draff is used as a concentrate replacement in complete diets. This experiment examined the effect of replacing barley/soya with draff plus additional minerals in silage based complete diets.

In a cyclic changeover design experiment consisting of 4 three week periods, fifteen British Friesian cows in early lactation were offered five treatments. Cows were given ad libitum access to one of five complete diets based on grass silage (69 “D”). Draff plus additional minerals gradually replaced barley/soya at increasing rates in diets 0-4 respectively.