Establishment of a bovine leukemia virus-free dairy herd in Korea

다국어 초록 (Multilingual Abstract)

In view of the high prevalence rate of bovine leukemia virus (BLV) infections in cattle over the entire country, a large dairy farm in Chungnam province was chosen and‘test and segregate’ program was instituted. On July 1999, ELISA test was performed on 491 animals on the farm and only 163 cattle (139 adult cows, 18 female and 6 malecalves) were BLV-seronegative. From February 2000 through April 2004, the seronegative group was placed in barns 1,500 to 2,000 m from seropositive group andthereafter tested at 3- to 5-month intervals by ELISA. Animals seroconverted in consecutive tests were removed from the seronegative group immediately after thedetection of anti-BLV antibodies. The changes in management were aimed at preventing iatrogenic transfer of blood between cattle. Replacement heifers importedfrom other countries and calves born at the farm were repeatedly tested by ELISA, and only seronegative animals were introduced into the group. As of April 2004, there were 311 cattle in the BLV seronegative group of the farm. Twenty four cows of the initial 139 adult cows were seroconverted in 2000, and no seropositive animals were found since February 2001. Follow up of the group, from which all seropositive cattle were moved to a separate location, revealed no recurrence of BLV infection for three years. The approach in the present study might be valuable for Korean producers who would like to move toward a BLV-negative status.

참고문헌 (Reference)

1 "Veterinary Epidemiology" 37-59, 1995

2 "The epidemiology and control of bovineleukemia virus infection" 87 : 248-257, 1992

3 "Survey for antibodies to bovine leukemia virus indairy and Korean native cattle" 22 : 23-26, 1982

4 "Seroprevalence of enzootic bovineleukosis in Trakya district" 121-128, 1998

5 "Seroepizootiological study on bovine leucosis in Korea" 22 : 175-185, 1982

6 "Prevalence of anti-bovineleukemia virus antibodies in dairy and Korean native cattle" 20 : 172-176, 2003

7 "Preliminary results of a new sanitation programfor the eradication of enzootic bovine leukosis" 9 : 895-898, Vet1978

8 "Preliminary attempts to eradicate infection with bovineleukemia virus from a stock farm in Japan" 44 : 831-834, Sci1982

9 "Postnatal andprenatal transmission of the bovine leukemia virus undernatural conditions" 62 : 165-168, Inst1979

10 "Possible effect ofaltered management practices on seroprevalence of bovineleukemia virus in heifers of a dairy herd with history of highprevalence of infection" 199 : 584-588, 1991

11 "Periparturient transmission of bovine leukosis virus in dairycattle" 132 : 190-191, 1993

12 "In uterotransmission of bovine leukemia virus" 42 : 1052-1054, 1981

13 "Evaluation of a bulk-milk ELISA test for the classification ofherd-level bovine leukemia virus status" 31 : 223-230, 1997

14 "Establishment of a bovine leukosisvirus-free dairy herd" 184 : 184-185, 1984

15 "Eradicationof enzootic bovine leukosis from Finland" 59 : 43-49, Med2003

16 "Eradicationof bovine leukemia virus infection in commercial dairy herdsusing the agar gel immunodiffusion test" 50 : 221-226, 1986

17 "Eradication of enzootic bovine leukosis basedon the detection of the disease by the GP immunodiffusiontest" 9 : 885-894, 1978

18 "Differences in the serum immunoglobulinconcentrations between dairy and beef calves from birth to14 days of age" 4 : 257-260, 2003

19 "Control ofbovine leukemia virus infection in dairy herds by agar gelimmunodiffusion test and segregation of reactors" 53 : 108-110, 1989

20 "Bovine leukemiavirus:a herd-based control strategy" 3 : 339-349, 1985

21 "Bovine leukemia virus andenzootic bovine leukosis" 62 : 287-312, 1992

22 "Bovine enzootic leukosis" 10 : 129-204, 1965

23 "Appraisal of controlmeasures for bovine leukosis" 175 : 1287-1290, 1979