Abstract

The contagious pathogens causing mastitis were evaluated by multiplex polymerase chain reaction (M-PCR) in 4 quarters of the first, third, and fifth parities in industrial, semi-industrial, and traditional dairy cattle farms in Isfahan province, Iran. Prevalence of sub-clinical mastitis caused by contagious pathogens in industrial, semi-industrial and traditional farms was 13.4, 38.2 and 44.2%, respectively, Staphylococcus aureus (S. aureus) was more prevalent than Streptococcus agalactiae (S. agalactia) in all the dairy farms. However, prevalence of S. agalactiae was more in industrial farms as compared to traditional farms. The mean somatic cell count (SCC) did not differ significantly in different farm types. S. aureus was more prevalent than S. agalactiae in each parity number. Mean SCC between M-PCR^- and M-PCR⁺¹ status had no significant difference within the first parity. The mean SCC differed significantly with increasing parity number. In M-PCR^-status parity number had non-significant effect on mean SCC. Therefore, mean SCC was affected not only by pathogen type and diversity but also by parity number.

Key words: Multiplex polymerase chain reaction (M-PCR), somatic cell count,Staphylococcus aureus, Streptococcus agalactiae, contagious pathogen.

Abbreviation

SCC, Somatic cell count; M-PCR, multiplex-polymerase chain reaction;S. aureus, Staphylococcus aureus; S. agalactiae, Streptococcus agalactiae.