Increasing the amount of leucaena on offer gives faster growth rates of grazing cattle in South East Queensland

Abstract

We measured the effect of increased supply of leucaena (Leucaena leucocephala cv. Peru) on the growth of steers grazing native pasture in South East Queensland. Steers grazed paddocks of black speargrass (Heteropogon contortus) pasture in which either 0, 25 or 100% of the area was sown to 3 m-wide rows of leucaena. In the 25% leucaena treatment, the leucaena portion was ungrazed in summer. Mimosine toxicity was avoided by dosing cattle with mimosine-detoxifying rumen bacteria. The growth rate of steers increased with the proportion of the paddock covered by leucaena. Steers grazing paddocks with 0, 25, and 100% of the paddock covered by leucaena rows gained 90, 127 and 205 kg/steer.year, respectively. The amount of leucaena foliage on offer appeared to be the major factor increasing steer growth.