Serum electrolyte values of cows during third trimester of pregnancy and early lactation in settled cattle herds in Zaria, Northern Nigeria

Some serum electrolyte values of 170 cows in eight settled cattle herds in Zaria, Northern Nigeria during the third trimester of pregnancy and first two weeks of lactation were determined. The cows were sampled once weekly during the third trimester of pregnancy and early lactation (first two weeks) periods for two consecutive weeks respectively. The total (overall) mean prepartum and postpartum serum electrolyte values did not differ significantly (P>0.05) except for bicarbonate, where its prepartum values were significantly (P <0.01) higher than the postpartum values. Generally, most of the serum electrolyte values were within normal range as reported in the literature while some were slightly but not significantly lower than the lowest values of the range. At the herd level, there were significant differences (p<0.05) between the prepartum and postpartum values of serum sodium, phosphorus and bicarbonate and lack of significant difference (p>0.05) for all other serum electrolytes in some herds while no significant difference (p>0.05) was found between the prepartum and postpartum serum electrolyte values in the other herds. These prepartum and postpartum serum electrolyte values were not associated with obvious clinical disease. These values may therefore represent reference values that are compatible with normal health in indigenous and crossbred cows during the period under study in the area. Key words: Serum, electrolyte, prepartum, postpartum, cows, Nigeria.