Effects of flaxseed diets on fattening response of Hanwoo cattle: 2. Fatty acid composition of serum and adipose tissues

Two separate trials were designed to determine effects of dietary level of whole flaxseed (WFS) on fatty acid composition of serum, and subcutaneous, perirenal, intermuscular, and intramuscular adipose tissues of Korean Hanwoo cattle. Twenty-one bulls (trial 1) and 15 cows (trial 2) were assigned to diets containing 0, 10 or 15% WFS. Relative treatment effects were similar between bulls and cows. The proportion of C18:3 in serum and to a lesser extent in adipose tissues were increased by-dietary inclusion of WFS, reflecting supplemented lipid composition of WFS that escaped ruminal biohydrogenation. Animals fed WFS had a lower proportion of saturated fatty acids in serum and adipose tissues than animals fed diets without WFS, while the opposite trend was observed in unsaturated fatty acids with little differences between two WFS groups. WFS-fed animals had higher proportions of C 18: 1, 18:2, 18:3, 20:3, and 22:3 and lower proportions of C12:0, 14:0, 16:0 and 18:0 in intramuscular fat than animals fed diets without WFS. Furthermore, feeding WTS increased proportions of both omega-3 and omega-6 fatty acids but decreased the ratio of omega-6/omega-3 substantially. In conclusion, feeding WFS can be an effective method of increasing absorption of unsaturated fatty acids, and subsequent deposition in adipose tissues.