DIGESTIBILITY OF FATTY-ACIDS IN THE GASTROINTESTINAL-TRACT OF DAIRY-COWS FED WITH TALLOW OR SATURATED FATS RICH IN STEARIC-ACID OR PALMITIC ACID

Fatty acid digestibility was studied with five lactating cows fed three different fat sources in a 5 x 5 latin square experiment. The treatments were 500 g of tallow, 500 or 1000 g of saturated fat rich in stearic acid (C18:0) (SARF) or 500 or 1000 g of saturated fat rich in palmitic acid (C16:0) (PARF) per day. The total daily fatty acid intake was about 1100 g in rations with the highest fat inclusion. The fatty acid digestibilities were 76% for tallow. 74 and 64% for 500 and 1000 g SARF, respectively, and 87 and 81% for 500 and 1000 g of PARF, respectively. When compared to fatty acid digestibility for tallow predicted from a model based on literature values. PARF had a higher fatty acid digestibility at both fat intakes, and SARF had a lower fatty acid digestibility, especially at high fat intake.