Comparative study of the effects of testing laboratory, counting method, storage and shipment on somatic cell counts in goat milk.

摘要

Milk samples were collected monthly from 10 goats at Langston University, USA, from April-September 1996. Somatic cell counts (SCC) were determined at 4 laboratories (I, II, III and IV) using the pyronin Y-methyl green (PYMG) direct microscopic method and/or Fossomatic machines calibrated with goat (1 machine) or cow (3 machines) milk standards. The effects of sample transport and storage on SCC were also determined. The PYMG microscopic method and the Fossomatic machine calibrated with goat milk standards gave similar estimates of SCC in goat milk. However, the Fossomatic machines calibrated with cow milk standards estimated SCC of goat milk to be 24.5% higher than a machine calibrated with goat milk standards (P<0.05). No significant differencein SCC of goat milk was found between the 2 laboratories using the PYMG microscopic method. Transporting milk samples in an ice box (3 days) and storing in a refrigerator (3 days) did not affect SCC results.