Abstract

This investigation was done to research the effects of vegetable oils on UFA content in milk fat and performances of high-yielding lactating cows. Sixteen lactating Holstein cows in early lactation were used in a complete randomized design. Experimental diets included: 1) Control (without oil, CON); 2) Diet with 2% soybean oil (SBO); 3) Diet with 2% sunflower oil (SFO); and 4) Diet with 2% canola oil (CLO). Supplementation with vegetable oils tended to decrease DMI, resulting in reduced milk production. Lowest milk production obtained by SBO treatment with 26.44 kg/day compared with CON diet (32.85 kg/day). The cows whose feed had SBO and SFO added, produced milk with the highest content of UFA, as C18:1 content was 26.82 g/100 g milk fat by SFO compared with CON (20.86). Content of C18:2 obtained 3.53 g/100 g milk fat by SFO that was highest compared to other treatments. These results were observed for C18:3 isomers, too. All observations for C18 UFA were significant (P<0.05). Despite, obtained results about CLO was unintelligible. In general, supplementation of dairy cow diets with vegetable oils tended to enrich UFA content in milk fat significantly. Sunflower oil seemed to be the optimal source to increase UFA production.

Key words: Vegetable oil, fatty acid, dairy cow.