Two experiments have been conducted to compare wilted, formic acid-treated red clover and unwilted, formic acid-treated grass silages for beef production, and to examine the effects of digestibility of red clover and level of concentrate supplementation on food intake and animal performance.
In experiment 1, 12 groups of four British Friesian steers (initial live weight 229 kg) were given red clover silages of high and low dry-matter digestibility (0·70 and 0·60 respectively) and grass silage (0·71) ad libitum for a period of 11 weeks. Silage dry-matter intake and live-weight gain for the steers given red clover of high digestibility, red clover of low digestibility and grass silages were 7·75, 0·89; 6·91, 0·69; and 5·59, 0·59 kg/day respectively.
In experiment 2, 12 groups of four British Friesian steers (initial live weight 332 kg) were given red clover silage with a dry-matter digestibility of 0·63 and grass silage with a value of 0·76 ad libitum, either unsupplemented or supplemented, with 2 kg/day of fortified barley per head for a period of 19 weeks. Silage dry-matter intake, live-weight gain and carcass gain were 8·52, 0·63, 0·32 and 6·98, 0·78, 0·43 kg/day for the unsupplemented and supplemented red clover silage treatments, and 6·82, 0·59, 0·31 and 5·75, 0·75, 0·44 kg/day for the unsupplemented and supplemented grass silage treatments respectively. The performance of the cattle offered red clover silage was similar to that of cattle offered grass silage of 0·12 higher digestibility, largely as the result of higher dry matter intakes achieved on red clover silage.