Get reliable rangeland science

The Victoria River District (VRD) in the Northern Territory supports extensive cattle grazing on native pastures. The pasture quality and quantity of this tropical savanna is subject to significant seasonal variability with most of the rain falling between December and March. During the dry months, pasture quality rapidly declines, and protein becomes the most limiting nutrient, which is commonly replaced with urea to supplement nitrogen (Silva et al. 2022). To address the seasonal protein deficits, the benefits of augmenting exotic legumes into the native pastures is being demonstrated at Victoria River Research Station (VRRS) situated 400km south-west of Darwin. The high protein content in legumes make them an ideal cattle feed to fill the protein gap that occurs naturally in rangelands when pasture dries off in the late dry season (August-December). The project includes a live weight gain trial for young heifers between 6 to 12 months old grazing an existing legume augmented pasture compared to a control paddock with <5% legume yield. Near Infra-Red Spectroscopy (NIRS) data was collected in October 20 23, December 2023 and May 2024 to compare crude protein content and metabolisable energy in the legume paddock versus the control. Early results from the first year suggest the weight gain of weaner heifers was significantly higher with naturalised Stylosanthes legumes.