Use of urine samples for monitoring acid-base-equilibrium in herd health management of dairy cattle herds

Subclinical load on acid-base equilibrium in high-yielding dairy cattle gets even more important. Examination of urine is a possibility for monitoring acid-base equilibrium. In nine farms respectively ten cows of five different stages of lactation (early and late dry cows, cows until 1 week p.p., and two lactating groups 3 to 5 weeks p.p. and 15 to 18 weeks p.p.) were selected for taking urine samples. The pH reacts significantly when acidogenic salts or sodium bicarbonate (NaHCO3) are fed, but the differences are very small. Feeding acidogenic salts significantly decreases the net-acid-base-excretion (NABE) and concentrations of sodium, whereas calcium excretion is significantly increased. Feeding sodium bicarbonate results in a significant decrease of chloride concentrations in urine, NABE and pH-value increase to values of an alkalosis. Since NaHCO3 produces an alkalotic urine it is impossible to detect an acidotic load.