Effects of supplements of urea and minerals on steers fed maize silage

Abstract

A mineral mixture (Ca, P, Na, Mg, S, Cu, Co, Zn, Mn, I, Fe) and urea (10 g/kg silage DM) were added separately and in combination to sole diets of maize silage (33% DM) fed to 16-month-old beef steers initially weighing 303 kg. Urea increased silage DM intake from 7.3 to 8.1 kg/day and increased carcass gain from 0.20 to 0.48 kg/day. Minerals increased silage DM intake from 7.1 to 8.3 kg/day and increased carcass gain from 0.22 to 0.46 kg/day with an indication (P < 0.1) of a positive interaction between urea and minerals on both intake and carcass gain. There was a significant interaction on live-weight gain with urea improving gain from 0.77 to 1.43 kg/day in the presence of and from 0.37 to 0.80 kg/day in the absence of, supplementary minerals. '