Complementary grazing of native pasture and standing Townsville lucerne in the dry season at Katherine, NT

Abstract

In an experiment at Katherine, N.T., in the 1964, 1965, and 1966 dry seasons, Shorthorn steers were grazed on varying proportions of native pasture and standing Townsville lucerne pasture. The treatments were : a native pasture alone ; b Townsville lucerne two days, native pasture five days ; c Townsville lucerne four days, native pasture three days ; d Townsville lucerne alone. Liveweight gain over 16 weeks, from early June to late September, was linearly related to the number of days in the week on Townsville lucerne (21 = -74.9 + 2 7 . 9 ¦ 30.5, where! = gain in lb per head and x = number of days). The results were compared with earlier data from Katherine on dry season supplementation of cattle on native pasture with a high-protein concentrate. In terms of liveweight gain, a weekly fall in dry matter yield of Townsville lucerne of 100 lb per head was equivalent to the consumption of 0.5 lb per head per day of digestible crude protein in concentrate form. Of this quantity of legume, it appeared that approximately two-thirds was consumed and one-third wasted. Periodic sampling of the Townsville lucerne pastures confirmed earlier findings that cattle grazing standing Townsville lucerne in the dry season do not select for a high-protein diet. The pattern of liveweight gain on Townsville lucerne alone, with other evidence, suggested that they do select for a high-energy diet.