26 April 1996 Leaner meat the target

The issue of lean and fatty meat goes back a long way – just think of the old nursery rhyme about Jack Spratt and his wife.

Today the matter – which can mean millions of dollars to commercial meat producers – is being addressed using the most scientific methodologies and staff of Lincoln University's Animal and Veterinary Sciences Group are among those at the forefront of research.

To help sheep breeders shift fat from where it is not wanted, in the carcass, to where it is useful, internally, Lincoln's Dr Mark Young and a visiting scientist from Scotland, Joanne Conington, have been using whole body x-ray scanning of animals (computed tomography) to measure changes in specific fat depots.

Ultimately this research may lead to selection for improved meat quality in hill sheep based on reducing carcass fat without compromising the sheep's ability to survive in climatically harsh regions.

"Fat reserves are extremely important if ewes are to survive, reproduce and rear a lamb in conditions such as exist in parts of the United Kingdom for example," says Dr Young, "and shifting fat from the carcass to internal fat depots would help both objectives."

Dr Young spent some time in 1988-89 at the Scottish Agricultural College, Edinburgh, where Joanne is based, and has subsequently helped establish a British Council funded exchange programme between the College and Lincoln to look at the genetic control of body composition in animals, with a second facet being aspects of parasitology.

In her work in Scotland, Joanne is investigating the consequences of reduced fatness in the Scottish Blackface sheep on two contrasting hill farming environments – one in the east of the country and the other in the west.

"As part of this programme, subcutaneous backfat and muscle depth are monitored by ultrasound techniques throughout the reproductive cycle of the ewes. However, with ultrasound technology it is not possible to investigate what is happening to other fat depots, such as internal fat, unless a proportion of ewes are slaughtered at strategic times, something you cannot do with sheep required for a breed improvement programme," says Dr Young.

"That's where X-ray computed tomography offers such an advantage."

The Community Diary. Produced by The Community Relations Centre, Lincoln University, New Zealand.