Lot-fed beef tastier, healthier

Animal Science

Animal science researchers at the Roseworthy Campus have discovered that pasture feeding limits the palatability and some health properties of beef.

A joint study by the University of Adelaide, CSIRO in Queensland and the Victorian Department of Primary Industries has found that pasture-reared cattle do not grow to maturity or fatten as rapidly as cattle reared on high-energy cereal-based diets. Cattle reared on pastures also produce higher levels of saturated fats and less mono-unsaturated fats.

The culprit is Vitamin A, a by-product of beta-carotene, which is inherent in pastures. Vitamin A limits the degree of fat desaturation that can occur, resulting in harder fat and, consequently, less palatable meat.

Senior Research Fellow Dr Brian Siebert said the findings explained why it had been difficult for Australian beef producers to raise the intramuscular fat levels (marbling) to the levels desired by the Japanese market.

"Vitamin A limits fat cell formation within meat. This is significant because higher marbling adds profoundly to the value of Australian export beef," he said.

Dr Siebert is part of the beef breeding and genetics research group within the Discipline of Agricultural and Animal Science at Roseworthy.

Australia exports about 60% of its beef and uses about 40% domestically. The Japanese market is worth around $2 billion a year to Australia.

Dr Siebert estimated that due to the tender, succulent qualities of marbled beef, which is so highly prized by the Japanese, up to 80% of the value of meat for Asian exports comes from cereal-fed beef in Australia.

"Long-term high-energy cereal feeding is an expensive exercise, producing a highly priced, high-fat product - the market for which is small in Australia.

"Cereal feeding for a limited time, however, can provide beef for an expanding Australian market that contains less saturated fat and a fat content that is well within fat consumption guidelines," he said.

About 35% of Australian beef cattle are now reared in feedlots. Dr Siebert said beef producers raising cattle on predominantly cereal-fed diets use supplements to prevent Vitamin A deficiency. However, the supplemented levels of Vitamin A are not so high as to prevent marbling.

The research group's findings were recently published in the internationally renowned American journal, Lipids.

Story by Candy Gibson

Open Day 2006

To hear more about Sciences at the University of Adelaide, visit Open Day on Sunday 20 August, North Terrace, 10am-4pm.

www.adelaide.edu.au/openday