THERE is a major reason why pasture-fed cattle in southern Australia are failing to make the grade in Meat Standards Australia's quality grading system: dark-cutting carcases.
This dark-coloured meat has lower consumer acceptance, shorter shelf life, variable tenderness and a dry taste.
Figures show that at certain times each year - early winter and late spring - SA and WA have dark-cutting rates at 20 per cent when the national average is less than 5pc.
A three-year Meat & Livestock Australia-funded project to be conducted by Murdoch University, the University of Adelaide, and the Department of Agriculture and Food Western Australia aims to find cost-effective solutions to this situation.
It is looking for producers with higher-than-average dark-cutting rates to participate in on-farm studies which will include supplementary feeding with whole oats, pelleted grain rations or other mixes.
Dark-cutting meat is a result of insufficient muscle energy (glycogen) levels leading to high pH meat at slaughter.
It is influenced by a number of factors including stress levels and growth rates before slaughter, but University of Adelaide School of Animal and Veterinary Sciences researcher Stephen Lee says they have hypothesised that the spike in MSA non-compliance seen each year may be due to nutritional imbalance in pastures.
"In early winter, at the break of the season, we think when the feed is short and green there may be a protein-energy imbalance in the pasture and even though steers may be growing and gaining weight they have low muscle glycogen levels, making them susceptible to dark-cutting," he said.
"Oats and pelleted rations provide higher amounts of metabolisable energy which may be useful in times when there are protein energy imbalances such as the start of winter, while lupins or other cost-effective protein sources could be used at the end of spring when both the protein and energy levels drop in feed."
Dr Lee said other feeding interventions being considered as protein and energy sources included a molasses-mineral-urea mix and even glycerol from biodiesel production.
*Full report in Stock Journal, November 7 issue, 2013.