In many countries, bulk tank milk (BTM) has been used for examining milk and analyzed as an important part of milk quality assurance programs. The objectives of this study were to investigate milk quality and the presence of major mastitis pathogens in BTM, and to compare the characteristics of BTM by dairy factory or company. A total of 1588 batches of BTM samples were collected from 396 dairy farms of seven dairy factories owned by four companies in Korea. The means of individual bacterial counts (IBC) and somatic cell count (SCC) were 3.7 × 104 cells/mL and 1.1 × 105 cells/mL, respectively, and no significant differences among dairy factories were observed. The most common pathogen was Staphylococcus spp. (60.1%), followed by E. faecalis (53.8%), E. coli (37.6%) and Streptococcus spp. (22.5%). Enterococcus spp. showed the highest resistance to tetracyclines (51.1% to 73.9%) and macrolides (46.5%). S. aureus and coagulase-negative staphylococci (CNS) showed the highest resistance to penicillin (28.4% and 40.2%, respectively), and three (3.2%) S. aureus and seven (3.3%) CNS were also methicillin-resistant. These data show the diverse prevalence and characteristics of major mastitis pathogens among factories, and support the development of strong monitoring and prevention programs of mastitis pathogens by commercial dairy operations.

The purpose of this study was to survey seroprevalence of porcine reproductive and respiratory syndrome (PRRS) virus and porcine circovirus-2 (PCV-2) in Gyeongbuk province by enzyme-linked immunosorbent assay (ELISA). A total of 966 samples collected from 21 pig farms were tested. The sero-positive rate of PRRS and PCV-2 were 77.6% (750/966) and 76.4% (738/966), respectively.

Streptococcus(S.) suis is a pathogen, causing meningitis, septicemia and sudden death in weaning piglets as well as fattening pigs. Using multiplex PCR method based S. suis capsular genes, 61 S. suis isolates was classified as serotypes 2, 7, 9 and untypable. Genotyping of S. suis isolates was analysed by PFGE pattern with treated Sma I restricted enzyme. Of the 61 S. suis, 25 (40.9%) were serotype 2, 6 (9.8%) were serotype 7, 5 (8.2%) were serotype 9, and 25 (40.9%) were untypable, respectively. Twenty four PFGE patterns were detected in this study and also PFGE patterns were classified according to serotype; serotype 2 was classified as 6 genotypes, serotype 7 was 5 genotypes, serotype 9 was 3 genotypes, and untypable was 11 genotypes, respectively.

The purpose of this study was survey of porcine reproductive and respiratory syndrome (PRRS) virus antibody in Gyeongbuk province by enzyme-linked immunosorbent assay (ELISA). Total 690 samples collected from 15 pig farms were tested. The overall seroprevalence of PRRS virus antibodies was 63.2% (436/690) and 13 farms of 15 farms had at least one pig with PRRS virus antibodies. The seroprevalence of PRRS virus antibody varied with age. Results in 1 to 30 day old, 31 to 60 day old, 61 to 90 day old, 90 to 120 day old and over 120 day old pig were 58.3%, 36.0%, 68.0%, 84.0%, 80.0% and sow were 61.9% respectively.