EN
The aim of the research was the analysis of changes in milk fat fraction content upon the use of linseeds as an additive to the rations. The research was conducted on 11 cows in the initial stage of lactation (66th day on average). The animals received an additive of whole linseeds at an amount of 200 g per cow a day. Milk samples were collected before the beginning of the experiment, and then 3, 14 and 28 days after the additive use. Components of milk fat fraction were analyzed. The results obtained indicate that the linseed additive caused a statistically significant increase of vitamin A and E content in the milk as well as the decrease of phospholipids and cholesterol in comparison to the content of these components in milk of cows that did not receive such an additive. The linseed additive did not cause changes in the content of fatty acids negatively influencing human health (C12:0, C14:0 and C16:0). A statistically significant influence of the linseed additive on the increase of the following fatty acids in milk was found: CLA (from 0.555 to 0.848 g/100 g of fat), LNA (from 0.830 to 1.071 g/100 g of fat), EPA (from 0.042 to 0.062 g/100 g of fat) and DHA (from 0.010 to 0.019 g/100 g of fat). The results confirm the possibility of modifying desired milk components by the use of a simple regimen of a linseed additive to the rations for dairy cows.