Effects of pre- and post-partum injections of Se, Zn and vitamin E on the concentration of cholesterol, CLA isomers and fatty acids in ovine milk*

The study was conducted on 40 Polish Merino ewes divided into two groups: experimental (E) and control (C), each of 20 animals. Four weeks before, and then on day 1, week 3 and week 6 post lambing all ewes from group E were given intramuscularly 5 ml 0.1% Na2SeO4, 10 ml 10% ZnSO4 and 250 mg vitamin E. In milk sampled 7 weeks after lambing the concentration of conjugated linoleic acid (0.66% of the fatty acid sum) was found higher (P<0.05) while cholesterol content (10.6 mg/100ml) lower (P<0.01) in group E than in group C. In group E, over the whole experiment, the level of total cholesterol of blood plasma dropped from 3.79 mmol/L to 3.02 mmol/L while HDL fraction increased from 0.85 mmol/L to 0.98 mmol/L. It is concluded that the preand post-partum intramuscular injections of Se, Zn and vitamin E improved the lipid profile of milk.