The effect of supplementary formalin treated soya-bean meal on feed intake, milk yield and live-weight gain of dairy cows fed ensiled fodder beets.

The present experiment compared formalin treated soya-bean meal (2 kg DM) with barley and urea (2.4 kg DM) as supplements for a mixture of ensiled beets and ammonium-treated straw given ad libitum in a cross over experiment with two periods of 6 weeks. Furthermore, these diets were compared to a traditional diet with fodder beets and ad libitum feeding with grass silage for a period of 12 weeks. The soya-bean meal increased the daily intake of beet-straw silage significantly from 13.1 to 14.1 kg DM (P < 0.01), the yield of milk protein (from 775 to 803 g; P < 0.05) and the live-weight gain (from 138 to 400 g; P < 0.05). Compared to the traditional diet, in which the total energy intake was close to that of the beet-straw silage diets, milk and protein yield (but not milk fat yield) were lower by the beet-straw silage feeding, although not significantly. However, this response seems to be typical and may indicate that not only the amino acid supply of the cows but also the supply of other glucogenic nutrients may be adversely affected when feeding ensiled beets.