TERRY SIM

10 Oct, 2011 04:00 AM

NOT only has lucerne been found to give lamb a vitamin E and iron boost, increasing its retail shelf life, but the right genetics can also improve meat colour stability.

Retailers face millions of dollars in markdown losses with meat that loses its attractive red colour sooner, but Victorian research has confirmed industry knowledge that increasing vitamin E and iron levels in lamb can lengthen shelf life based on meat colour by at least one day.

Department of Primary Industries senior research scientist, Eric Ponnampalam, predicted that retailers’ profits could increase by as much as five to 10 per cent if vitamin E levels were increased before slaughter.

“This would also benefit producers who would have a higher value product which could ultimately increase retailer demand,” he said.

Meat and Livestock Australia’s lamb and sheepmeat research and development manager, Dr Alex Ball, said retail meat colour was a heritable trait, with meat from the progeny of some rams having extended shelf life based on meat colour.

Sheep Co-operative Research Centre (CRC) research has indicated that selection can alter retail meat colour stability and result in lamb that is less susceptible to browning during retail display.

Sheep CRC collaborator at Murdoch University in Western Australia, Professor David Pethick, said it was not understood how or why the expression of meat colour heritability worked, and it could be about 18 months before sires would be given an estimated breeding value for retail meat colour.

Dr Pethick said breeders collaborating with the Sheep CRC’s Information Nucleus flocks already have research breeding values for the trait, but five years of data and 10,000 records were needed to establish a breeding value with some degree of accuracy.

The Sheep CRC said for lambs finished under dry feed conditions that have not been supplemented previously, the addition of vitamin E to the ration will restore meat vitamin E concentration to a level that is adequate for good shelf life.

The recommended feeding rate for this is 250ppm for the last two to four weeks prior to slaughter, but it should be costed.

Dr Ponnampalam said lambs fed on a green grass diet were likely to have higher contents of vitamin E and haem iron in their muscle tissue than those fed on grain.

Supplementing the lambs’ diet with quality hay such as lucerne or chicory could increase vitamin E and iron levels. About 300-400 grams of quality lucerne hay for six to eight weeks before slaughter was needed to lift vitamin E levels to satisfactory levels in lambs not grazing green pasture.

“Our research found that the rate of deterioration in the meat’s colour and taste was reduced when the lambs had higher volumes of vitamin E and iron in their muscles at the time of slaughter.

“In fact, many of the grains that are fed to lambs can deplete the levels of vitamin E in the muscle,” Dr Ponnampalam said.

“But these levels can be restored and increased through simply replacing a portion of grain supplement by quality lucerne hay.”

Dr Ponnampalam said more research was needed to establish a test to determine which animals need supplementation to boost vitamin E and haem iron levels in meat.

The Sheep CRC Information Nucleus comprises eights flocks of ewes across Australia, with a total of 5000 ewes, mated to 100 industry sires annually for five years to generate a diverse range of phenotypes and massive amounts of genetic information to develop new and improved breeding values.

For more information, see the MLA Fact Sheet ‘Vitamin E stabilises the colour of ‘out of season’ lamb meat’ at www.mla.com.au