A cattle production trial that compared steers grazed on rehabilitated mine land and unmined land was described as an outstanding success despite harsh seasonal conditions.
In simple dollars and cents the 30 Charbray steers grazed on the rehabilitated land returned an extra $220 per head at the conclusion of the 20-month trial.
Their average carcase weight and fat depth meant they returned an extra 46 cents per kilogram dressed weight over the natural pasture grazed steers.
This equated to an additional gross return of $6588 for the steers on the rehabilitated land.
The trial was conducted by mining giant Glencore at their Liddell Open Cut Mine located between Muswellbrook and Singleton.
According to Glencore’s land and property manager Nigel Charnock the trial has gone some way to prove cattle can be successfully grazed on rehabilitated mine land.
He said the aims of the trial were to compare the performance of cattle grazing rehab land and unmined land, to establish rehab completion criteria for the mining industry and to demonstrate to the community cattle grazing was a viable option post mining.
“We understand there has been scepticism in the community about rehabilitated land and its productive worth and future uses,” he said.
“But this trial has shown what can be achieved even in the worst seasonal conditions and it addresses concerns about the sustainability of rehab land.”
A second comparison trial started in late November with the same aim and criteria but this time using slightly lower numbers with 20 steers in each section rather than 30.
To ensure the credibility of the trial the cattle selected were of the same age and genetic background and reared under similar conditions.
The 60 Charbray steers came from Glencore’s cattle operation Colinta Holdings, which runs between 4000 and 5000 head in NSW.
They were weighed and blood tested and soil and water tests were also carried out on the two grazing areas.
The rehabilitated site has undergone pasture improvements since it was reformed into grazing land in 2010. The land was also top dressed and then seeded with a pasture mix that included tropical (Rhodes Grass) and legumes plus kikuyu and fertiliser.
The unmined land was typical of the area with native grasses and light soils. Stocking rates were set at one steer per 2.4 hectares.
Cattle entered the trial in December 2012 with the natural pastures steers weighing on average 418kg and rehab steers 406kg.
Due to the season the steers lost weight during the winter of 2013 (April-August) before rain in November of that year improved pastures and their weight gain.
But a dry summer impacted on the steers before once again autumn rain enabled the cattle to gain weight before their slaughter in June.
At that time the average weight of the rehab steers was 662kg and the natural pastures steers 597kg resulting in a 25 per cent greater return from the steers grazed on the rehab land.
Blood results were also clear of any problems something that has also worried people in the community with cattle grazing on rehab land.
“This result was very encouraging from the rehab land and showed steers could be grazed on a commercial basis successfully on that land,” Mr Charnock said.