This study investigated whether the storage temperature and mixing by repeated inversion of the container before sample inoculation for culturing affected the colony counts of specific bacteria, using milk containing E. coli, and 12 quarter milk samples from cows with clinical mastitis. The inoculation tools were also examined by comparing loops and swabs with the traditional method of using a micropipette and spreader. The colony counts given by E. Coli milk samples kept at 4℃ for 3 hours decreased significantly(p<0.05)and the colony counts of both the E. Coli milk and mastitis milk samples kept at 37℃ for 3 hours increased significantly(p<0.05)compared with the colony counts of those inoculated without storing. The inversion-mixed mastitis samples gave significantly(p<0.01)higher colony counts than the samples left standing for 3 hours. When inoculated using loops, the E. Coli milk samples gave significantly(p<0.01)higher and the mastitis milk samples gave significantly(p<0.05)lower colony counts than those inoculated by the traditional method. The colony counts of both E. Coli milk and mastitis milk samples inoculated using swabs were significantly(p<0.01)lower than those inoculated by the conventional method. Therefore, it is recommended that milk samples be kept at a low temperature and inversion-mixed before inoculation. The inadequacy of loops and swabs as inoculation tools was demonstrated.

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Bovine viral diarrhea virus(BVDV)infection occurred on a dairy farm with about 70 milking cows, in a BVDV-free region. A cow with persistent infection(PI)of BVDV, introduced from another region, was identified to be the source of the infection, through antibody and BVDV gene tests performed on all cows raised on the farm. The PI cow was sacrificed, and new PI bovines were identified among calves by virological testing and culled, which led to successful clearance of BVDV from the affected farm. The viral gene was not detected in bulked milk of 13 dairy farms located around this dairy farm. The direct damage caused to the farm was 6 abortions and the sacrifice of a total of 11 animals, namely, the introduced PI cow, which was the source of infection, and 10 newly delivered PI calves. New PI developed in calves that were of gestational age 10-98 days when the PI cow was introduced into the farm, and the incidence was 34.5%(10/29).

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A 6-month-old Japanese Black heifer showed lameness, bleeding, and extension of the tarsometatarsal joint of the right rear limb, and was diagnosed having rupture of superficial and deep digital flexor tendons. The modified double-locking loop and Bunnell methods were used for tendon suture, and a plastic limb cast was also applied. The heifer recovered 40 days after surgery.

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