The effect of feeding fat supplement powder containing an additive (lecithin or bile powder) with the physical form of flaked or granulated on the apparent digestibility of nutrients and some blood parameters in Holstein dairy cows

The particle size and physical form of fat supplements are effective factors in the digestibility of nutrients, fatty acids, and some blood parameters in dairy cows. This research aims to investigate the effect of a feeding fat supplement containing an additive (lecithin or bile powder) with the physical form of flake or granule on the apparent digestibility of nutrients and some blood parameters in Holstein dairy cows. 48 lactating cows were used during two experimental periods in a 2x3x2 completely randomized factorial design and randomly grouped into 6 experimental treatments: 1. Control diet + 2.5% granulated fat supplement, 2. Control diet + 2.5% granulated fat supplement containing 5% lecithin 3. Control diet + 2.5% granulated fat supplement containing 5% bile powder 4. Control diet + 2.5% Flaked fat supplement 5. Control diet + 2.5% Flaked fat supplement containing 5% lecithin and 6. Control diet + 2.5% Flaked fat supplement containing 5% bile powder. All the experimental diets were balanced according to the recommendations of the National Research Association. All data were analyzed by statistical software. The digestibility of the ether extract, total fatty acids, 16 and 18-carbon fatty acids, as well as the plasma concentration of NEFA, triglycerides, cholesterol, HDL, and VLDL were increased in the treatments containing the additives (P ≥ 0.05). The addition of emulsifying ingredients to the fat supplement of the high-production dairy cow diet may have positive effects on the digestibility of some nutrients and lipid metabolism.