CONCENTRATION OF SERUM ELECTROLYTES IN HOLSTEIN COWS AT LATE PREGNANCY, PARTURITION AND POST PARTURITION PERIODS

Blood samples were obtained for 85 Holstein cows in a dairy farm durin g two months prepartum, at parturition and two months postpartum. Meas ured electrolytes were sodium, potassium, chloride, calcium, inorganic phosphorus, magnesium and iron. At parturition, the level of chloride , calcium, inorganic phosphorus and iron was lower (P<0.05) than these values at other periods, whereas, concentration of magnesium was high er. No significant change was observed in serum sodium and potassium l evels. The results indicate that the most important change in serum el ectrolytes is at parturition.