ABASTRACT. The objective of this study was to evaluate the plasma lipid profile and plasma fatty acids of dairy cows receiving diets supplemented with annatto. A total of 32 Holstein cows (550 kg), distributed in a completely randomized design, were allocated to individual stalls and submitted to following treatments: C0 = no annatto; C4 = inclusion of annatto at 4 g kg-1 dry matter (DM) of diet (0.07 g bixin kg-1 diet); C5 = inclusion of annatto at 5 g kg-1 DM of diet (0.09 g bixin kg-1 diet); and C7 = inclusion of annatto at 7 g kg-1 DM of diet (0.12 g bixin kg-1 diet). Blood samples were collected via epigastric vein puncture, centrifuged, and frozen for subsequent analysis. The results indicate that the inclusion (p > 0.05) of annatto does not decrease the total cholesterol or low and high density lipoproteins. However, it impacts the profile of fatty acids, evidenced by the reduction (p < 0.05) in levels of hypercholesterolemic fatty acids viz, myristic acid and palmitic acid. It also causes an increase in the levels of arachidonic acid, rumenic acid, linoleic acid, and total polyunsaturated fatty acids. Therefore, bixin included in the diets of dairy cows induces changes in the plasma fatty acid profile.

ABASTRACT. The objective of this study was to evaluate the plasma lipid profile and plasma fatty acids of dairy cows receiving diets supplemented with annatto. A total of 32 Holstein cows (550 kg), distributed in a completely randomized design, were allocated to individual stalls and submitted to following treatments: C0 = no annatto; C4 = inclusion of annatto at 4 g kg-1 dry matter (DM) of diet (0.07 g bixin kg-1 diet); C5 = inclusion of annatto at 5 g kg-1 DM of diet (0.09 g bixin kg-1 diet); and C7 = inclusion of annatto at 7 g kg-1 DM of diet (0.12 g bixin kg-1 diet). Blood samples were collected via epigastric vein puncture, centrifuged, and frozen for subsequent analysis. The results indicate that the inclusion (p > 0.05) of annatto does not decrease the total cholesterol or low and high density lipoproteins. However, it impacts the profile of fatty acids, evidenced by the reduction (p < 0.05) in levels of hypercholesterolemic fatty acids viz, myristic acid and palmitic acid. It also causes an increase in the levels of arachidonic acid, rumenic acid, linoleic acid, and total polyunsaturated fatty acids. Therefore, bixin included in the diets of dairy cows induces changes in the plasma fatty acid profile.