Effects of Duration of Storage and Storage Temperature on Cell Counts of Bovine Blood Samples as Determined by an Automated Haematology Analyser

Analysis of blood cells is an important part of many scientific investigations in the field of cattle herd health. Over the last 30 years, automated blood analysis has all but replaced manual counting of blood cells using counting chambers. The present study investigated the effects of prolonged storage and storage temperatures on cell counts as determined by a haematology analyser. Blood samples from 20 clinically healthy cows were repeatedly analysed with a Cell-Dyn 3500 (Abbott Diagnostika, Delkenheim), within 24 hours after collection and after storage at either 4° C or 20° C. The counts of most blood cells were more stable in samples stored at 20° C than those stored at 4° C. For at least 8 h, the counts of all analysed cell types, with the exception of lymphocytes, remained within ±3 standard deviations that were calculated for fresh samples, provided that the blood was stored at 20° C. Correspondence and offprint requests to: Dr Ulrich Bleul, Klinik für Fortpflanzungskunde, Universit?t Zürich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.