A. Ferlay et al., RUMINAL LIPID BALANCE AND INTESTINAL DIGESTION BY DAIRY-COWS FED CALCIUM SALTS OF RAPESEED OIL FATTY-ACIDS OR RAPESEED OIL, Journal of animal science, 71(8), 1993, pp. 2237-2245
The effects of supplemental calcium salts of rapeseed oil fatty acids
(FA) and rapeseed oil on ruminal metabolism and apparent digestibility
of lipids in the small intestine were studied using three multiparous
Holstein x Friesian cows in a 3 x 3 Latin square design. Cows fitted
with ruminal, duodenal, and ileal cannulas were fed restricted amounts
of a control diet (C) containing 65% corn silage and 35% concentrate
mix or diet C with supplemental calcium salts of rapeseed oil FA (S) o
r diet C supplemented with rapeseed oil (O). Fatty acid contents were
1.9, 8.4, and 7.6% for diets C, S, and O, respectively. The average fl
ow of total FA to the duodenum was lower than the intake for supplemen
ted treatments, suggesting catabolism of FA by ruminal microbes. Fatty
acid flows at the duodenum were higher (P < .10) for diets supplement
ed with fat than for diet C, except for C18: 3(n-3) and straight-chain
and branched-chain C15 and C17. Fat treatment affected total and indi
vidual FA flow to the ileum, except C14:0 and C18: 2(n-6) and excreted
amount of individual FA, except C14:0, C16:0, and total C18:1. In our
trial, the addition of fat, regardless of origin, affected small inte
stinal digestibilities of C14:0 and C18:2(n-6) and did not affect chan
ges in the amount of FA in the hindgut.