Total and differential cell count by direct microscopic method on ewe milk.

Abstract

On 700 milk samples from single half udders of Comisana ewes, somatic cell count (SCC) and differential cell count (DCC) were determined, using a Fossomatic 90 cell counter (Foss Electric, Denmark) (SCCF) and milk smears stained with May Grünwald-Giemsa (DCCS). SCC and DCC were also determined with modified KOVAH SYSTEM (Hicor Biomedical Inc. Irvine, CA, USA) (SCCK and DCCK, respectively). Out of 665 milk samples from half udders without clinical signs of mastitis, 640 (Class I) were sterile, while 25 (Class II) were bacteriologically positive. Out of 35 milk samples (Class III) from half udders with clinical signs of mastitis, 25 were bacteriologically positive. Mean results (after logarithmic transformation of cells/ml/10(3)) of SCCF and SCCK for all the 700 milk samples were 1.89 +/- 0.58 and 1.86 +/- 0.60 with linear correlation coefficient (r) of 0.960, while least squares means for Class I, II and III were 1.78, 2.23 and 3.73 respectively and 1.75, 2.19 and 3.74 with r of 0.894, 0.979 and 0.987. Mean results of DCCS and DCCK were 38.1 +/- 23.3, 34.9, 52.1, and 82.2 PMNL% and 41.8 +/- 21.7, 38.6, 60.2, and 87.3 PMNL% with r of 0.855, 0.812, 0.697 and 0.805. The results showed high correlation coefficients and a good reliability between SCCK and SCCF and high correlation coefficients for DCC methods. In conclusion, it could be suggested that the possibility of routine use of the KOVAH SYSTEM method is particularly useful in detecting if an abnormal SCC is due to a polymorphonuclear neutrophil leukocytes increase.