Intake by and performance of early-weaned calves offered unwilted or wilted silage supplemented with a cereal and protein concentrate or dried grass

Abstract

SUMMARYForty-two British Friesian castrated male calves of 1 to 3 weeks of age were offered ad libitum unwilted or wilted silage made from the same sward for 21 consecutive weeks. Both silages were supplemented with a cereal and protein concentrate at two restricted levels of intake or with dried grass cobs offered ad libitum. There was little difference i n the chemical composition ofthe two silages except for DM content. Dry-matter intake of wilted silage was slightly but not significantly greater than that of unwilted silage. Differences between silages in daily gain or final live weight were not significant.An increase in the intake of the cereal and protein concentrate led to a significant decrease (P < 0·001) in silage DM intake and a significant increase (P < 0·001) in daily gain andfinallive weight. Calves offered dried grass as a supplement to silage ate similar quantities of silage DM to calves offered an equal amount of the cereal and protein supplement but gained significantly less (P < 0·001) live weight. When intakes were presented on a unit metabolic live-weight basis, calves ate significantly more (P < 0·001) silage when supplemented with dried grass than calves offered the cereal and protein supplement.