Conjugated linoleic acid contents in beef of cattle of organic farming

Conjugated linoleic acid (CLA) has been suggested to have immunomodulating, anticarcinogenic and antiarteriosclerotic properties. Conjugated linoleic acid, naturally present in food shows higher concentrations in products fro m ruminants. The CLA concentration in beef from cattle from ecologic farmin g was studied. The animals were kept on pasture until October and fed hay d uring winter. The heifer group comprised 25 animals (final weight 472.2+/-3 2.2kg, carcass weight 260.0+/-18.7 kg, dressing 56.7+/-1.6 %, 826+/- 57 day s). Another group comprised 28 calves (final weight 472.2+/-32.2kg, car cas s weight 147+/-15 kg, dressing 56+/-2 %, 232+/-18 days), reared on mother m ilk and kept on pasture with their mothers. CLA contents of meat fat from c alves (11.5%) and heifers (10.3%) were higher than literature data (0.7-1.7 %). Given that certain rumen microorganisms produce CLA from free linoleic acid, the present work confirms the importance of natural grazing for CLA l evels in beef.