Saturday, September 6, 2008

CLA content varies in ewe milk

Conjugated linoleic acid (CLA) is a healthy fat found in the meat and milk of ruminants. While the concentration of CLA in meat and milk is influenced largely by the animal's diet, with grass-fed ruminants having more CLA than grain-fed ruminants, there is considerable variation among animals consuming the same diet.

Lambs nursingThe objectives of a study undertaken in New Zealand were to screen a group of Romney ewes in their 4th week of lactation to identify ewes with high and low CLA in their milkfat, and to determine if these differences were reflected in the CLA concentrations in the lean meat of their lambs.

Lambs slaughtered at 28 weeks of age (12 weeks post-weaning) from High CLA ewes had a 37% higher CLA concentration in their lean tissue than lambs from Low CLA ewes. Single-born lambs from the High and Low CLA groups had a 35% higher concentration than twin-born lambs from these groups, suggesting that differences in CLA concentration in the meat were due to differences in the ingestion of CLA in milk.

It was concluded that a higher concentration of CLA in the milkfat of ewes resulted in a higher concentration of CLA in the meat from their lambs and that the ranking of ewes for concentration of CLA in milkfat persisted for at least two lactations. Therefore, selecting and breeding sheep for high CLA concentrations in the ewes’ milkfat and in adipose tissue of their lambs is a possibility.

Read abstract.

Source: New Zealand Journal of Ag Research, 2004, Volume 7.