Dietary conjugated linoleic acid supplementation of laying hens: effects on egg fatty acid composition and quality

Conjugated linoleic acid (CLA) is a common term for a group of positional and geometric isomers of linoleic acid; the most commonly found in natural products is cis-9, trans-11-octadecanoic acid. Naturally occurring CLA is produced as an intermediate product of microbial metabolism of linoleic acid in the rumen. For this reason the CLA concentration is higher in ruminant products, such as milk, cheese and meat compared to products derived from monogastrics, particularly chicken meat and egg yolk. Recent investigations suggest that CLA have anticarcinogenic properties, antiatherosclerotic and antioxidant activity (Ip et al., 1995; Nicolosi et al., 1997; Du et al., 2001)..