Liveweight of grazing steers supplemented with molasses, urea and sulfur in northern Queensland

Abstract

Steers grazing native pasture were supplemented with 0, 0.8 or 2.4 g of sulfur/head.d in addition to a molasses (230 or 115 g/head.d) and urea (60 g/head.d) supplement over four dry seasons. The unsupplemented animals lost most or gained least weight during the feeding period in all four years but the difference was significant (P< 0.05) in only two years. Adding sulfur to the molasses and urea tended to give the best results but the effect was not significant (P> 0.05) over the results achieved with feeding only molasses and urea. There was a tendency for liveweight performance to be better with the higher level of molasses, but again differences were not significant. Blood sulfate-sulfur levels during the feeding period increased with the level of sulfur fed but levels were not significantly correlated with liveweight change. Compensatory growth by unsupplemented groups after the feeding period eliminated liveweight advantages of supplemented groups. The results suggest that the level of molasses in a molasses and urea supplement for yearling cattle grazing native pastures on solodic soils during the dry season in northern Queensland can be reduced to 115 g/head.d without adversely affecting liveweight. These results may not apply on sulfur deficient soils and in dry years.