[Cell count and differential cell count in goat milk--variability and influencing factors]

In a total of 413 dairy goats of different breeds from five herds (milk performance 550-1000 kg) somatic cell counts and cell types were investigated in fore milk samples from udder halves, in composed udder and bulk milk samples. Cytoplasmatic particles in the milk were not counted. Three herds were investigated monthly during two years. At every sampling a clinical examination of the mammary gland (fore milk, teats, gland tissue, lymphatic nodes of the udders) and a bacteriological examination of the milk samples were carried out. In all herds the clinical health status of the udders was good. Independent of the sample type the mean SCC was about 1000 x 10(3)/ml with a wide range between several millions and < 100,000/ml. A seasonal influence on the monthly minima and maxima of the bulk milk SCC was evident, the lower SCC being recorded mainly during April to October. Increasing lactation numbers and months are connected with increasing SCC. Goats with high milk SCC at the begin of the lactation tended to maintain their high SCC levels as the lactation progressed. Limit values for SCC in goat milk should take into account the influence of the kidding season of the herds upon the dynamics of the bulk milk SCC. Polymorphonuclear leukocytes were the main cell type in goat milk (around 40%), their number tended to increase as total SCC increased, in particular in samples with cell counts above one million. Likewise, the differences between SCC in the milk of corresponding udder halves increased significantly as one of the halves showed more than one million somatic cells. Defining limit values for SCC in goat milk this should be taken into account.