An experimental comparison of methods for somatic cell count determination in milk of various species of mammals

Abstract

Somatic cell count (SCC) is important foodstuff, hygienic and health indicator of milk and animal mammary gland. The goal of this paper was to evaluate an ability of chosen methods to reach the SCC reliable results in various biological kinds (species) of milk. The various methods of SCC determination were compared in cow (CM), goat (GM), sheep (SM) and human (HM) milk: direct microscopy (DM); fluoro-opto-electronic (Fossomatic 90; Foss); fluorescent (DCC; De Laval). Used methods had cow milk calibration basically. The DM, Foss and DCC result relations about SCC were very close, mostly > 0.92 (P < 0.001) for CM, GM and SM. In CM the regression equations between methods were near ideal form y = 1x + 0. The mean differences SCC data sets between mentioned methods were small for CM, larger for SM and HM and the largest for GM. It is possible to convert all DCC results in SM, HM and GM to DM or Foss method. The conversion equations were stated from DCC: to DM in cow milk y = 1.1293x − 5.5029; to Foss in goat milk y = 3.603x − 3171.4; to Foss in sheep milk y = 1.3805x − 18.149; to Foss in human milk y = 2.6246x + 158.63. Assesment of conversion equations should be individual laboratory event. Results had relatively good correspondence among DM, Foss and DCC for SCC determination in CM, GM, SM and HM for milk quality control. DCC had lower results in small ruminants as compared to Foss calibrated on CM using DM. DCC in HM had lower results as Foss adjusted by CM at good correlation (0.84; P < 0.001).