The effect of urea-salt-molasses supplements on the winter performance of beef cattle on improved pastures at Samford, south-eastern Queensland

Abstract

Hereford weaner cattle grazed improved pastures of Setaria sphacelata C.P.I. 28709 (Nandi Setaria) and Cbloris gayana C.P.I. 16144 (Samford Rhodes grass) at two beasts per acre for 98 days in winter 1962. Weight loss was similar for urea supplemented and control groups. Consumption of the urea-salt-molasses blocks (35 per cent urea) was significantly greater on the Rhodes grass than on the Setaria pastures (2.3 oz v. 2.0 oz per head per day). The higher intake was associated with the grass of lower nitrogen content. Animals grazing Rhodes grass lost a mean of 10 lb a head and those on Setaria a mean of 18 lb a head in liveweight over the trial period. The differences were not statistically significant. There was no interaction between grass species and supplementation. Pasture plucking to simulate selection by the animals indicated that a diet containing 1.0 per cent N or above was selected by the animals over most of the winter period. A marked improvement in the nitrogen and total sugar content of the diet occurred over the latter half of the trial but the animals continued to lose weight. The results are discussed in the light of other published results on the use of urea. It is suggested that on improved pastures where animals are able to select a diet containing 1 per cent N or above during the winter months there will be little response in animal performance to urea supplementation.