Growth and meat quality target of research

The most comprehensive data ever assembled on growth and meat quality for lambs growing into hoggets could eventually put an end to the debate about lamb branding.

Scientists from across the nation are working collaboratively under the banner of the Australian Sheep Industry Cooperative Research Centre to gain a better understanding of factors influencing traits like the tenderness of meat from prime lambs and yearling sheep.

Their work is part of a major research project on fat and muscle development that is expected to define the difference between weaned lambs and hoggets in terms of meat quality.

A resource flock generating progeny to be used in strategic studies on fat and muscle development has been established at the NSW Department of Primary Industries' (NSW DPI) Centre for Sheep Development at Cowra.

A successful artificial insemination program last year saw over 80 per cent of the ewes pregnant, with 630 lambs available for the experiment.

NSW DPI senior research scientist David Hopkins said the lambs were assigned to one of four slaughter dates from four to 20 months.

"At each slaughter a number of 'base measurements' for tenderness, meat colour, pH and intramuscular fat are taken on the carcases," Dr Hopkins said.

"Half carcasses are sent to DPI in Victoria for compositional scanning using a DEXA, which operates in a similar fashion to a CAT scan.

"Additional samples are being examined for various traits to help us identify the role of genotype and animal age and to improve our understanding of muscle fibre."

In a second experiment, which commenced this year, progeny will be used to determine whether selection for muscling has a negative impact on eating quality.

"The experiment will also explore whether there are defined periods in the development cycle of prime lambs where nutritional restriction will have a negative effect on muscling," Dr Hopkins said.

"Nutritional restriction may interact with the estimated breeding values for muscling and weight and we are particularly interested in what the research reveals."

Progeny will be weaned at either 20 or 30 kg live weight, with some grown from weaning to 50 kg.

Carcases from slaughter of progeny from this experiment will be scanned using the DEXA and sampled for eating quality using the Sheep Meat Eating Quality protocols developed by Meat and Livestock Australia.

A wide range of samples and measurements will also be taken for analysis by the large group of collaborating scientists.

Media Contact: David Hopkins, Senior research scientist, NSW DPI Cowra

Issued by: Annette Cross, NSW DPI Tamworth, telephone

A high resolution digital image is available from Annette Cross