In modern life oxidative stress has a serious effect on human health; therefore, natural antioxidants play an important role in human well-being. Hen (Gallus gallus domesticus) eggs can be effectively enriched with selenium and vitamin E and can be used as a source of natural antioxidants. The objective of this study was to determine the interaction of selenium and vitamin E in eggs and egg yolk oil. Two groups of Lohman Brown-Classic breed laying hens from a real production facility were taken as an experimental object. The basal diet was the same for both groups and content 25 mg kgE-1 of vitamin E added. 0.2 mg kgE-1 of sodium selenite was used as an inorganic source of selenium in feed for one hen group and 0.3 mg kgE-1 of organic selenium in the selenized yeast form for the other group. The selenium content was determined in eggs, egg yolk, egg white and egg yolk oil samples and vitamin E content in egg yolks and egg yolk oil. The results of this study indicate that there is no difference in selenium content in eggs from inorganic and organic selenium hen diet taking into account that selenium content in feed was different. The majority of selenium is located in egg yolk, but there was no selenium detected in egg yolk oil. Vitamin E content in egg yolks was not affected by the source of selenium (p is less than 0.05). High vitamin E content in egg yolk oil effectively protects egg yolk oil from oxidation during storage.

The aim of the present study was to determine the level of cholesterol in the milk of the Latvia's cow herds, analyse differences between two different methods of cholesterol determination in milk. Milk samples were obtained from the cows of Latvian Brown and Black and White breeds. The milk fat and protein were analysed by Milkoscan 133, cholesterol content was determined colorimetricaly by Blur procedure with prior lipid extraction by Roese-Gottlieb method and by gas-chromatography method. The obtained results showed that the milk fat content was 4.48+-0.28%, protein was 3.03+-0.09%, cholesterol content in milk was 21.05+-2.01 mg 100 ml*[-1), when assayed by spectrophotometer SF 26 LOMO and 18.29+-1.73 mg 100 ml*[-1), when assayed by gas chromatography. There were no significant differences in cholesterol content between both determination methods.