Fatty acid profile of milk from cows fed palm kernel cake

Abstract

To evaluate the fatty acid profile of milk from cows fed palm kernel cake (PKC), 12 Holstein × Zebu crossbred cows were kept in the feedlot, distributed into a triple 4 × 4 Latin square, and fed the following treatments: 1) control; 2) inclusion of 50 g PKC/kg in the total dry matter (TDM); 3) inclusion of 100 g PKC/kg in the TDM; and 4) inclusion of 150 g PKC/kg in the TDM. Milk samples from the morning and afternoon milkings were collected in the amount of 1% of the daily production of each animal; subsequently, 100-mL subsamples were frozen for analysis of the fatty acid profile. Inclusion of PKC did not change the concentration of short-chain fatty acids or myristoleic (C14:1), pentadecenoic (C15:1), palmitic (C16:0), and palmitoleic (C16:1) fatty acids. Concentrations of medium-chain and lauric (C12:0) and myristic (C14:0) fatty acids increased linearly (P < 0.05). A decreasing linear effect was observed (P < 0.05) on the concentration of the C15:0 fatty acid. No effects were observed (P > 0.05) on the long-chain fatty acids and those of the omega 6 and 3 series; on the ratio between poly-unsaturated and saturated fatty acids; or on the ratio between the fatty acids of the omega 6/omega 3 series. The concentration of conjugated linoleic acid was not influenced (P > 0.05) by inclusion of PKC in the diet. Addition of palm kernel cake to the diet of lactating cows influences the concentration of medium-chain fatty acids, and of lauric (C12:0), myristic (C14:0), and pentadecanoic (C15:0) fatty acids in their milk.