engleski

Blood lipids and proportion of fatty acids, especially CLA in milk of Simmental cows fed with unprotected sunflower oil

The main objective of our research was to determine an effect of unrifined and unprotected sunflower oil on the fatty acid composition and blood lipid profile in Simmental cows. Ten Simmental cows in mid-lactation were appointed for changeover feeding trial over the 35-d period. Cows were allocated to basal diet (BD) ; 41% concentrate, 33% perennial ryegrass haylage, 26% corn silage in dry matter, or basal diet supplemented with 200g of unprotected sunflower oil (SO) per cow daily. The total blood cholesterol concentration increased significantly in SO diet (5.58 mmol/L vs. 4.58 mmol/L) and triacilglycerol concentration did not change between the treatments. The SO diet significantly and rapidly elevate ratio of cis-9, trans-11 CLA (1.25% vs. 0.80%) and linoleic acid (3.56% vs. 2.75%) in milk, and simultaneously significantly decrease palmitic acid ratio (25.14% vs. 29.99%). High individual variations in blood cholesterol concentration and milk CLA proportions were determined, especially after the introduction of sunflower oil in the diet. Highly positive correlation between the linoleic acid and CLA proportions were determined (r = 0.80), and negative correlation between the total blood cholesterol concentration and milk fat content, during the SO treatment, were observed. In conclusion, relative small quantity of unprotected high linoleic sunflower oil in the diet significantly modified the fatty acid composition of Simmental cows’ milk, with the individual differences in the response to the diet changes.

fatty acids; lipid profile; milk; cows; vegetable oil

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