EN
The object of the experiment was to determine the extent to which selected electrolytes (Na, K, Ca, P) and metabolites (cholesterol, total lipids, and total proteins) changed in the blood serum during the postpartum period in ewes and their correlation to litter size. Blood was collected from the jugularis v. of 149 Slovak merino breed ewes on 1, 4, 7, 14, 17, 21, 25 and 34 postpartum days. Lower Na and K levels were recorded in ewes with twins compared to ewes with a single lamb, with the exception of day 34.When evaluating Ca levels, it was found that the group of ewes with a single lamb exhibited a range from 2.38 ± 0.16 to 2.54 ± 0.26 mmol.l-1 and the group with twins a range from 2.39 ± 0.15 to 2.51 ± 0.19 mmol.l-1 and there was no significant difference. Phosphorus levels in the group of ewes with twins were lower on all observed days than those in the group of ewes with single lambs. Lower cholesterol levels were observed from day 7 of the observed period in ewes with twins compared to ewes with a single lamb. By day 21 of the observed period total lipids exhibited lower values in ewes with twins and the total serum protein levels in ewes with single lambs tended to slightly rise during this time. From day 14 postpartum there was a mild decrease in the total protein levels in the group of ewes with twins. The discussion focused on the effect of litter size on selected biochemical parameters during the postpartum period.