The importance of staphylococci and threshold value of somatic cell count for diagnosis of sub-clinical mastitis in Pirlak sheep at mid-lactation

Reprod Domest Anim. 2011 Dec;46(6):970-4. doi: 10.1111/j.1439-0531.2011.01768.x. Epub 2011 Mar 3.

Abstract

This study investigated the bacterial agents causing sub-clinical mastitis and the mean somatic cell counts (SCC) of milk in Pirlak sheep at mid-lactation. The percentage of infected udder halves was 11.4% (53/464). The most frequently isolated species were coagulase-negative staphylococci (CNS) (64.2%), followed by Staphylococcus aureus (24.5%) and Escherichia coli (11.3%). Among the CNS, the most common species was Staphylococcus epidermidis (38.2%). The other species isolated from milk samples were Staphylococcus xylosus (17.7%), Staphylococcus chromogenes (14.7%), Staphylococcus simulans (8.8%) and Staphylococcus hyicus (8.8%). The mean SCC for culture positive and negative samples was 1742×10(3) and 161×10(3) cells/ml, respectively. A significant difference (p<0.05) was determined between with and without microbial growth groups in terms of the SCC values. Threshold limit for SCC was 374×10(3) cells/ml for Pirlak sheep. In conclusion, it was considered that SCC is an important predictor of sub-clinical mastitis in Pirlak sheep. This is the first study to describe the bacterial agents causing sub-clinical mastitis and threshold limit for SCC in Pirlak sheep in Turkey.

MeSH terms

  • Animals
  • Female
  • Lactation / physiology
  • Mastitis / diagnosis
  • Mastitis / veterinary*
  • Milk / cytology*
  • Milk / microbiology*
  • Sheep
  • Sheep Diseases / diagnosis*
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / veterinary
  • Staphylococcus / isolation & purification*