Nutrient digestion, ruminal fermentation and plasma lipids in steers fed combinations of hydrogenated fat and lecithin.

Commercial soybean lecithin replaced hydrogenated fat in steer diets to determine if phospholipids enhance fatty acid digestion and microbial fermentation in ruminants. Four diets were fed in a 4 x 4 Latin square to four Angus steers with ruminal cannula. One diet contained no added fat (control) and three contained hydrogenated fat and lecithin in weight ratios of 100:0, 86:14, and 72:28. All diets with added fat had lower fatty acid digestibilities compared with the control diet with no difference due to level of lecithin. Ruminal acetate and acetate:propionate ratios were reduced by all fat supplements but reduced less for the supplements containing lecithin. Plasma triglyceride and cholesterol concentrations were increased from dietary fat but not increased as much if lecithin were present in the diet. Feeding lecithin to ruminants does not improve digestibility of hydrogenated fats that are highly saturated.