Experience with clearing herds for BVDV infections

Practitioner Jørgen Katholm

Vivild

Denmark

Herds with PI

1988-1994

Herds with PI

1988-1994

Herds with PI

1988-1994

Herds with PI

1988-1994

Herds with PI

1988-1994

Herds with PI

1988-1994

Herds with PI

1988-1994

(2 beef herds)

Herd symptoms months from birth of PI calv-9 - -6 Recycling-9 - -6 Diarrea, cows, reduced milk

Dead cows -6 - -4 reduced immunity, severe coliform mastitis, ringworm,

pyogenes infections. High Bulk milk cell count

-6 - -1 Abortion storm-6 - -2 week calves born, calf diarrea, (Seropositive calves) -7 - 0 Growth retarded calves-1 - 0 malformated calves, blind-1 - 0 Stillbirth 0 - 2 PI calves-1 - 2 Retaind placenta 0 - 3 Week calves, diarrea 1 - 4 Lunginfections 2 - ? Sudden death of PI calves Mucosal Disease

BVD Eradication

Individual marking: Ear tags (database)

Trade restrictions Biosecurity (status of BVD)

Blood testing Relaibel tests PRICE

Education of vets. Brownlie, Alenius, KalisPractising Vets

Education of farmers Vets from farmer organisationsLocal vets

Trend setting Farmers Free of infectionInfected - Time scale of disease

All Herds infected and clean

1994 Trend setters

Free 5-10 years

First eradication 1990-91

BVD Eradication plan1990 Test all cattle for antibodies (PRICE – Holland 1/3)

Test all negative for virus by virusculture

Herd status antibody in 5 bloodsamples

1994 Test all cattle > 3 month for virus (ELISA)

Until 1 year after last PI

no antibod testing (PRICE)

Farmers organisation started volontary BVD-Status

Milk: 4 times/year Beef 3 blood for antibodies/year

Infection stops to spread

BUT 3 farms bought seropositive heifers calving with PI

All Herds infected and clean

1994

Beef Herds Infected 1996

Beef Herds in VivildTotal infected 10herds 8 with PI

0

20

40

60

80

100

120

140

160

1996 1997 1998 1999 2000 2001 2002 2003

infected Beef herds herd size

Beef Herds Infected 1999

Last PI Beef herd killed 8 dec 1999

Milking Herds infected

and clean

1994

Milking Herds Infected 1995

Milking Herds in Vivildtotal 54 infected 40 with PI

0102030405060708090

100

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

infected milking herds herd size

Milking Herds Infected 1999

Milking Herds Infected

2000

Last PI killed 16 jan 2001

All Herds 2003 Free

Normal calves negative 8 month

1 HF calv positive 10 months negativ 14 months

1 beef calv positive 12 months negativ 13 months

Maternel antibodies

BVD antibodies in Charolais young stock939 930938 925937 931920 915934 919929 916911 926921 923912 933 935 922913 924936 917910 927918 27832-892940928914

BVD antibodies in Charolais young stock

22/12 1998 7 calves dehorned + 1 BVD antibodies939 930938 925937 931920 915934 919929 916911 926921 923912 933 935 922913 924936 917 negativ910 927918 27832-892940928914

BVD antibodies in Charolais young stock

5/3 1999 3 BVD blodsamples for status

939 930938 925937 931920 915934 919929 916911 926921 923 positive912 933 positive935 922 positive913 924936 917 910 927918 27832-892940928914

BVD antibodies in Charolais young stock

18/3 1999 5 BVD blodsamples

939 930938 925937 931920 915934 919929 916911 926921 923 positive912 933 positive935 922 positive913 924936 917 positiv910 927918 27832-892 negative940928914

BVD antibodies in Charolais young stock

27/4 1999 BVD blodsamples all herd

939 negative 930 negative938 negative 925 negative937 negative 931 negative920 negative 915 negative934 negative 919 negative929 negative 916 negative911 negative 926 negative921 negative 923 positive912 negative 933 positive935 negative 922 positive913 negative 924 negative936 negative 917 positiv910 negative 927 negative918 positiv 27832-892 negative940 negative928 negative914 negative

Conclusions

• Happy farmers will spread the news• Biosecurity - stops the infection • Eradication - straight forwad

When going for the virus and the tests are reliable

• Big herds maybe prolonged eradicationseperated flocks selling of young calves

• No spread from Bull stations by semen• Injections with infected medicine can cause acute

infection

Thank you

For BVD eradication