Effect of unwilted and wilted silages and hay, supplemented with different amounts of concentrate, on live-weight gain of calves

Abstract

ABSTRACTThree experiments were carried out to investigate the effect of different forage types on the performance of male British Friesian calves up to 6 months of age. Unwilted and wilted silages were compared in all experiments, and in experiment 1 hay was also compared with the two silages. All the forages were compared at different levels of concentrate supplementation ranging, in different experiments, from none to ad libitum.Calves fed wilted silage consumed 490, 90 and 200g/kg more forage dry matter respectively than those fed unwilted silage in the three experiments but this extra intake was generally not reflected in an increased rate of gain. Hay which was of lower digestibility than silage gave significantly lower live-weight gain. Quantities of silage consumed at an early age were small, with a mean daily intake over the first five weeks of 0·13 kg dry matter. Concentrate reduced silage dry-matter intake by 0·49 kg/kg concentrate dry matter consumed. Estimated mean concentrate intake required to achieve a daily gain of 0·75 kg in 1- to 6-month-old calves with silage offered ad libitum was 0·83 kg dry matter.