Udder health and somatic cell counts in ewes

For decades, somatic cells counts in milk are used as an important measure for the diagnosis of udder infections in cows. The objectives of our investigation, performed on three farms during an entire lactation, was to get some data about the most important bacteria causing intramammary infections in milk sheep and to evaluate whether the determination of the cell content is a suitable diagnostic aid for the diagnosis of ovine udder inflammations. For the 105 examined ewes, the prevalence of intramammary infections was 25 % for the udder halves and 35 % for the animals. However the differences between the three herds were quite large. The vast majority of the intramammary infections were caused by coagulase negative staphylococci. Staphylococcus aureus and streptococcus spp. were isolated only in individual cases. Cell counts of foremilk samples were highly correlated with the infectious status of the udder halves. The influence of non infectious, management and individual differences on somatic cell counts showed to be of a similar magnitude as for cows. As opposed to goats, the cell count in ewe’s milk is a suitable indicator for the udder health. For ewe’s milk, an objection limit of 500’000 cells per mL might be reasonable.