Two experiments were conducted to evaluate the inhibitory bio-hydrogenation effects of fish oil (FO) and doses in
combination with linseed oil (LSO). Experiment 1 was a 4×4 Latin square design and the treatments were comprised of: 1) no oil
(control); 2) LSO; 3) 1:1 w/w LSO+FO; and 4) Ca-salt of LSO. The results found that feeding LSO+FO significantly increased
t11-C18:1 and C22:6n-3, whereas C18:0 decreased. The ruminal acetic acid content was reduced at 4 and 6 h after feeding
(P<0.05). In Experiment 2, three fistulated dry cows were assigned in a 3×3 Latin square design and the treatments were: 1) 2:1
w/w LSO+FO; 2) 1:1 LSO+FO; and 3) 1:2 w/w LSO+FO. The treatments were fed at 3% of total feed dry matter. The results
revealed that the addition of 1:2 w/w LSO+FO significantly increased ruminal C20:5n-3 and C22:6n-3 (P<0.05). Additionally,
1:1 w/w LSO+FO significantly increased the concentration of t11-C18:1.