Fatty acid profiles of milk and Minas frescal cheese from lactating grazed cows supplemented with peanut cake

Abstract

Milk and Minas frescal cheese were evaluated from crossbred Holstein × Gir cows that were fed diets enriched with 0, 33, 66 and 100% inclusion levels of palm kernel cake in a concentrated supplement in replace of soybean meal. Eight crossbred lactating cows were distributed (four animals × four treatments × four periods) in the experimental design of double 4 × 4 Latin squares. The capric (C : 10, P = 0·0270), undecylic (C : 11, P = 0·0134), and lauric (C : 12, P = 0·0342) saturated fatty acid concentrations and CLA (C18 : 2c9t11, P = 0·0164) of the milk fat decreased linearly with an increasing percentage of peanut cake in the diet. The increased peanut cake content (100%) in the diet was associated with a linear decrease in C : 10 (P = 0·0447), C : 12 (P = 0·0002), mirystic (C : 14, P < 0·0001) and palmitic (C : 16, P < 0·0001) saturated fatty acid concentrations and an increase in arachidic, lignoceric, palmitoleic and elaidic acid levels in the Minas frescal cheese fat made from the milk. Both the milk and the Minas frescal cheese showed a linear decrease in the concentration of monosaturated fatty acids (P < 0·0001), atherogenicity index, and thrombogenicity index (P < 0·05), while the hypocholesterolaemic: hypercholesterolaemic and omega 6: omega 3 (P > 0·05) ratios were not influenced by the different peanut cake levels. The inclusion of up to 100% peanut cake as a substitution for soybean meal in the concentrate of grazing lactating cows resulted in changes in the nutritional quality of their milk products, as indicated by the increase in polyunsaturated fatty acids and the decrease of saturated fatty acids (lauric, myristic, and palmitic).