Cattle continue to perform on rehabilitated land
29 June 2015
The latest results of a scientific grazing trial to compare the livestock production performance of rehabilitated land with that of unmined land at Acland Pastoral Company (APC) has continued the trend of showing rehabilitated sites can outperform unmined land.
Grazing period 7 (Autumn 2015) was a 49 day graze between 14th April and 2nd June 2015.
The trials are being conducted by independent agricultural consultants Outcross Agri Services based in Armidale with the assistance of University of Southern Queensland and other independent industry experts including pasture agronomists, soil scientists, a veterinarian and an independent statistician.
Tom Newsome from Outcross Agri-Services said the project design enables a comparison of 3 years of rehabilitation with an unmined paddock.
“Three of the sites were previously mined and subsequently rehabilitated and sown to sub-tropical pastures; each representing a different age of rehabilitation (2007, 2010 and 2012 respectively) and pasture establishment.
An unmined paddock, sown to sub-tropical pastures in the same year as the youngest rehabilitated site (2012), was used as the control.
“Both the Rehab 3 and the control were sown down to a mix of sub-tropical grasses and legumes at the same time, incorporating the same establishment techniques.
“During each graze we calculate a site specific stocking rate that will enable the livestock to consume 10% of available pasture (Utilisation rate). This is considered to be a sustainable grazing amount that enables the pasture to survive in the long term.
“We also aim to have a minimum graze period of 42 days to enable livestock to settle in to the site and to achieve meaningful results. Each site is grazed for the same number of days.
“Rehab site 2 was the highest performing site, followed by rehab 1, rehab 3 and the control having the lowest performance in this graze. This ranking was maintained independent of sex and heifers performed better than steers.
“Interestingly Rehab 2 has outperformed all other sites since this trial commenced in 2013.
“The average daily gain across rehabilitated sites for this particular graze was 0.20 compared with 0.07 kg/ day on the unmined land, producing significantly more beef per hectare for this graze.”
“As was expected though, the performance of cattle was lower to previous grazes in the trial due to frost affected sub-tropical and a big rain event during that time.” Mr Newsome concluded.
Acland Pastoral Company (APC) Manager Ben Muirhead said the cattle on each site are split evenly between steers and heifers of the same breed, age and origin.
“The trial group were inducted on Tuesday 14th April with a 2 hour curfew period between mustering and weighing.
“The cattle were removed from the trial sites on Tuesday 2nd June and weighed under the same curfew conditions” he said.
The performance of cattle was lower than expected on all sites. Weight gain was influenced by seasonal conditions and frost affected sub-tropical pastures.
The research project will span 5 years and 20 different grazing events to measure the performance of a range of rehabilitation sites both within and between seasons.
New Hope established the Acland Pastoral Company in 2006, as a farming, grazing and land management enterprise based at the New Acland mine.
APC manages 10,000 hectares of land. Historically cattle numbers have been 2,800 head however due to the dry conditions numbers are considerably lower.
In conjunction with grazing APC grows both fodder and grain crops in suitable areas. Environmental areas are also managed to promote native species grass species such as Queensland Bluegrass and riparian areas along Lagoon Creek.
“We have been happy with the advances we have made so far in rehabilitating the mined land to grazing status,” New Hope’s Executive General Manager for Mining Jim Randell said.