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

Summary

Leucaena based grazing systems can double annual liveweight gains and increase carrying capacity of beef enterprises, however, a major limit to producer's adopting leucaena is the reduction in productivity from psyllid insect attacks.

This project consists of two main phases: Phase 1 was completed in 2018 and focused on the establishment of a large-scale grazing trial in north Queensland, which incorporated a psyllid resistant leucaena (Redlands) and the current common variety of leucaena (Wondergraze). After the success of the leucaena trial site under Phase 1, Phase 2 was initiated in April 2018 and consists of a three-year grazing trial to evaluate the cattle liveweight gain performance of the two varieties (due for completion in 2022).

Preliminary liveweight performance data from Phase 1 showed initial gains of 0.33kg/animal/day, which is significantly superior to previous performance when using only native pastures (0.15kg/day).

Objectives

The main purpose of this project was to develop a trial site of psyllid resistant leucaena (Phase 1) and measure the liveweight gain performance and carcase characteristics of the grazing cattle (Phase 2), which would guide economic modelling to support the adoption and establishment of leucaena in north Queensland.

Key findings

• The results of Phase 1 showed that, during the dry season, liveweight gain of cattle averaged 0.33 kg/day over 133 days, which is notably higher to native pastures (0.15kg/day) in the same environment at the same time of year.
• The cost of Redlands leucaena establishment on red-earth sites is $370/ha, which is slightly higher than for typical sites in north Queensland ($336/ha), but there will be long-term productivity benefits of using a psyllid-resistant leucaena.
• Better planting success of the Redlands variety was observed when seed is placed at depths no greater than 25 mm with ample soil moisture.
• An aerial application of pesticide provided immediate and long-term control of grasshoppers during the Redlands establishment phase, which is an inexpensive method of pest management at such a critical stage of leucaena development.

Benefits to industry

A productive and psyllid-resistant leucaena variety would improve profitability and sustainability of northern beef businesses through increased feedbase productivity.

MLA action

MLA has partnered with The Leucaena Network to drive extension and encourage adoption of the outcomes of this project. The new project commenced in early 2020 and will run until August 2022, and will include the development of on-line tools, field days, and an annual general meeting and conference.

The Leucaena Network also facilitated the MLA Donor Company / Producer Innovation Fastrack project, "Redlands for Regions", where six North Queensland graziers undertook establishment trials for the Redlands variety. This project commenced in November 2017 and was completed in April 2019.

The Department of Agriculture and Fisheries of Queensland is also heavily involved in extension activities around leucaena.

Future research

Data from the ongoing grazing trials (Phase 2) will assess the long-term productivity advantages of using Redlands, help confirm the economics of leucaena in north Queensland and improve industry understanding of leucaena establishment and management in northern environments.