Assessing productivity gains for cattle grazing “Redlands” (R12) leucaena in northern Queensland

Abstract

Productive leucaena based grazing systems can double annual live-weight gains and increase carrying capacity for beef enterprises. However, there has been very little adoption of leucaena in northern Queensland. One major reason for this is the reduction in productivity from attacks by psyllid insects.
‘Redlands’ is a psyllid resistant leucaena arising from a breeding program undertaken by the University of Queensland and supported by Meat and Livestock Australia. It has potential to open up large areas for leucaena based beef grazing systems in northern Australia but its performance under commercial scale grazing conditions has not been tested. This project established a large-scale grazing trial in north Queensland to evaluate the liveweight gain performance of Redlands relative to the existing commercial Wondergraze variety.
A 62 ha site initially selected at ‘St Ronans’ was prepared and planted over the 2015-16 northern wet season. Unfortunately, establishment was unsuccessful, due to heavy rain after planting and soil drainage issues. An alternative, 61 ha site was selected at nearby ‘Pinnarendi’ and developed for the trial during 2016. Leucaena planting at the site occurred during January and February 2017. The leucaena was successfully established at Pinnarendi over the following 18 months.
The first cattle were introduced to the trial in April 2018 at a low and cautionary stocking rate using Brahman-cross steers from the commercial herd on the property. Some of these animals were replaced in June 2018 with Droughtmaster steers from the Department of Agriculture and Fisheries ‘Spyglass’ Beef Research Facility.
The average entry weight was 228 kg and individual liveweight of all animals was monitored on three occasions to November 2018, coinciding with rotation of animals between trial paddocks (within the same treatments). Liveweight gains averaged 0.33 kg/day over this period.
Data from the ongoing grazing trial will assess any relative productivity advantage from using Redlands and help confirm the economics of leucaena in north Queensland. The site will also improve industry understanding of leucaena establishment and management in northern environments. A productive and psyllid resistant leucaena variety would improve profitability and sustainability of northern beef businesses through increased feedbase productivity and enabling access to premium slaughter markets.