Dynamics of some biochemical parameters in the blood serum of sheep in theperiod of synchronization treatment and on the days of observation after insemination

10 ewes aged 3-5 years were included in the experiment, Their weight ranged from 40 to 50 kg. Feedstuffs contained hay, straw, silage and turnip. Wate r and salt were given ad libitum. Mating lasted from 14 to 24 September 199 5. Blood was sampled from v. jugularis before synchronisation (day 0) and o n days 4, 7, and 14 during the treatment with Agelin vaginal tampons (20 mg chlorsuperlutin). After the tampon removal, ewes were applied PMSG (pregna nt mare serum gonadotropin) i.m. and during rutting season were inseminated . Sampling continued on insemination day and on days 7, 13, 17 and 34 after insemination. Concentrations of Na and K were determined from blood serum using the method of absorbent spectrophotometry and the machine Atom Spek f y Rang-Higler. Concentrations of Ca, P, total lipids and cholesterol were d etermined by help of BIO-Lachema tests (Lachema, Brno). No significant chan ges in concentrations of Na were observed during the treatment with Agelin vaginal tampons (144.82 +/- 3.05-153.50 +/- 4.72 mmol.l(-1)). A statistical ly significant decrease was found on insemination day (P < 0.01) and contin ued to the end of the experiment (P < 0.001). Similarly, the values of K di d not change essentially during synchronisation and ranged from 5.34 +/- 0. 41 to 5.92 +/- 0.3 mmol.l(-1). In the remaining days their values tended to decrease and were statistically significant (P < 0.01) on insemination day and on the following days after insemination 7, 13, 17, and 36 (P < 0.001) . Mean values of Ca (2.63 +/- 0.21-2.91 +/- 0.26 mmol.l(-1)) and P (1.71 +/ - 0.17-1.95 +/- 0.30 mmol.l(-1)) were not statistically significant while t he vaginal tampons were inserted. Concentrations of Ca tended to decrease a nd were statistically significant (P < 0.05, P < 0.01, P < 0.001, P < 0.001 ) during observed days. A significant decrease (P < 0.05) in concentrations of P was found since day 7 after insemination. Statistically significant d ifferences in cholesterol concentrations were not reported. Mean values ran ged from 1.62 +/- 0.41 to 1.75 +/- 0.34 mmol.l(-1). Mean concentrations of total lipids significantly decreased on insemination day (P < 0.05) and wer e within reference range. Their values ranged from 1.96 +/- 0.42 to 2.05 +/ - 0.46 g.l(-1) during the Agelin tampon treatment. Starting on day 7 after insemination to the end of experiment their concentrations ranged from 1.69 +/- 0.51 to 1.85 +/- 0.47 g.l(-1). Dynamics of observed parameters indicat es their importance when maintaining homeostasis in animals during observed period.