Environmental pressures on the agricultural industry to reduce the use of nitrogenous mineral fertiliser combined with a trend to more extensive systems of production has led to renewed interest in white clover for dairy systems. An EEC funded research project was initiated to investigate whole systems implications with regard to nitrogen efficiency. As part of the project the potential of barley grain or fodder beet as home-grown concentrates to supplement grass/clover silage was investigated.

Thirty early lactation muciparous Holstein Friesian cows were used in a 16 week continuous design experiment lasting from 13 December 1993 to 3 April 1994. The animals were allocated to three treatments on the basis of milk yield, liveweight and days calved. The treatments consisted of ad-libgrass/clover silage supplemented with 5 kg DMd-1 barley grain (B), 2.5 kg DM d-1 of barley grain and 2.5 kg DMd-1 of fodder beet (B/FB) or 5 kg DMd-l fodder beet (FB) daily. All animals received additionally a protein supplement consisting of 3 kg DMd-1 of soya bean meal. The silage was made from the primary growth of grass/white clover sward containing 12% white clover in the DM. The grass/clover herbage, barley and fodder beet were all produced without the use of nitrogenous mineral fertiliser.