Effect of amount and source of vegetable oils in a high fibrous cattle diet on in vitro rumen fermentation, nutrient degradability and rumen cis-9, trans-11 CLA concentration

Four diets with two vegetable oils at two different levels were evaluated for their in vitro rumen fermentation pattern, nutrient degradability and cis-9, trans-11 CLA production using a rumen simulation technique (RUSITEC). Control diet (C) was having roughage to concentrate in the ratio of 65:35. Treatment diets were formed by supplementing with sunflower oil (SF) and soya bean oil (SB) at 4.5 (SF4.5, SB4.5) and 6.0% (SF6, SB6) levels and incubated in RUSITEC fermenters. After seven days of adaptation period, fermentation parameters, nutrient degradability and rumen cis-9, trans-11 concentration were assessed for the next 3 days. Cis-9, trans-11 conjugated linoleic acid (CLA) content was higher in effluent from diets supplemented with 6% oil compared to that of control and 4.5% oil. SF6 and SF4.5 were more effective in increasing rumen cis-9, trans-11 CLA compared with corresponding levels of soya bean oil. However, the degradability of dry matter, acid detergent fibre, neutral detergent fibre and hemic...