Dietary influences on bovine milk cis-9,trans-11-conjugated linoleic acid content

The effects of grass dry matter (DM) allowance and dietary supplements of full fat rapeseeds on levels of cis-9,trans-11 octadecadienoic (CLA) acid in bovine milk were investigated. Grass allowance of 16 kg/(cow*day) resulted in reduced (p<0.05) milk fat CLA levels (3.91 mg CLA/g fat) compared to 20 kg/(cow*day) after 19 wk treatment. CLA levels increased in milk fat from cows on a high-rapeseed-supplemented diet (p<0.001) (1650 g/(cow*day) full fat rapeseed) compared to the control (pasture) and low rapeseed (p<0.01) (825 g/(cow*day) full fat rapeseed) supplemented diets. The variation in milk fat CLA levels among individual cows over both trials was 1.5-16 mg/g.