Cell content of goat milk: California mastitis test, Coulter counter , and fossomatic for predicting half infection.

The mean cell count of goat milk collected in early and midlactation from udder halves free of infection was 1404 X 10(3) cells/ml and 614 X 10(3) cells/ml estimated by Coulter Counter and Fossomatic. Arithmetic means of cell count by Fossomatic method for samples within California Mastitis Test scores were similar to results from cow milk. Results by the three methods were closely correlated .7. Means of cell counts were 2858 X 10(3) cells/ml and 1293 X 10(3) cells/ml by Coulter Counter and Fossomatic methods for udder halves harboring coagulase-negative staphylococci and 8946 X 10(3) cells/ml and 4804 X 10(3) cells/ml for halves infected by major pathogens. Of the thresholds examined, 1000 X 10(3) cells/ml was most satisfactory for both Coulter Counter and Fossomatic methods, because it detected about 80% of major infections and gave an acceptable proportion of errors.