DIGESTION OF CALCIUM SOAPS OF RAPESEED OI L FATTY-ACIDS IN DRY COWS

Digestion of rapeseed fatty acids (FA) as calcium soaps was studied on three dry cows, equiped with three cannulae (rumen, duodenum, ileum). Dual marker technique was used for measurement of digestive flows. Ru minal biohydrogenation of unsaturated FA was about 80 %, and was incom plete for polyunsaturated FA, so that trans-vaccenic acid was found in duodenal digesta. Intestinal digestibility of FA was about 70 %, but large variations were observed among FA : monounsaturated FA were very efficiently absorbed whereas stearic acid was poorly absorbed.