Effect of Centrifugal Force on Packed Cell Volume and Trapped Plasma in Avian Blood

INTRODUCTION PACKED cell volume (PCV) of human and other mammalian blood is generally determined by the hematocrit method using standard centrifugal conditions as suggested by Wintrobe (1961) or Gregersen (1951). Widely different centrifugal conditions, however, have been used for avian blood (Aramaki and Weiss, 1961; Atwall et al., 1964; Bell, 1957; Bierer et al., 1964; Gilbert, 1965; Heller and Paul, 1933; Kaplan, 1954; Newell and Shaffner, 1950; Saha and Ghosh, 1965; Tapper and Kare, 1956. Due to the shape and size of the erythrocytes, centrifugal forces employed and other factors, a certain amount of plasma will remain trapped (TP) between the cells after centrifuging. The amount trapped can be determined and a correction factor calculated for estimating the “true” or corrected PCV. Because the shape and size of avian erythrocytes is not the same as that of human or other mammals, the usually accepted correction factor may not necessarily apply.…