Bvd query

Omallep2

What are the chances of calves being positive for bvd from first test failing second test?

greysides

Very high. I'm not sure but I think it's about 90%.

LostCovey

I wouldn't quibble with a 90% estimate Greysides - the voluntary phase of the AHI programme showed about 80% of positives remained positive on confirmatory test, but that could be higher by now with hopefully a lot less virus circulating and fewer TIs - hence more of the positives are prob PI now. The other reason that the 80% might be an underestimate is that these are the calves that were re-tested. A lot of calves that tested positive and were obviously abnormal/small/weak or that died wouldn't have been re-trested, so if you tested everything now I'd say it would not be far off 90%

LC



BVD in Ireland - key findings from the voluntary phase of the programme in 2012
• 0.61%, 0.02%, 0.44% and 98.93% of calves tested gave positive, inconclusive, empty (no tissue present) and negative results on initial testing.
• 18.1% of dairy herds and 11.6% of beef herds had one or more calves with an initial positive or inconclusive result, with the likelihood of testing positive increasing with herd size.
• 80% of calves subject to confirmatory sampling tested positive (~20% transient infection rate).
• 10% of dams tested following a positive calf result also tested positive (2-7 years old).

Omallep2

LostCovey wrote: »

I wouldn't quibble with a 90% estimate Greysides - the voluntary phase of the AHI programme showed about 80% of positives remained positive on confirmatory test, but that could be higher by now with hopefully a lot less virus circulating and fewer TIs - hence more of the positives are prob PI now. The other reason that the 80% might be an underestimate is that these are the calves that were re-tested. A lot of calves that tested positive and were obviously abnormal/small/weak or that died wouldn't have been re-trested, so if you tested everything now I'd say it would not be far off 90%

LC



BVD in Ireland - key findings from the voluntary phase of the programme in 2012
• 0.61%, 0.02%, 0.44% and 98.93% of calves tested gave positive, inconclusive, empty (no tissue present) and negative results on initial testing.
• 18.1% of dairy herds and 11.6% of beef herds had one or more calves with an initial positive or inconclusive result, with the likelihood of testing positive increasing with herd size.
• 80% of calves subject to confirmatory sampling tested positive (~20% transient infection rate).
• 10% of dams tested following a positive calf result also tested positive (2-7 years old).

Thanks lads. What % of cows with positive calves proved positive the following year?

tanko

Omallep2 wrote: »

Thanks lads. What % of cows with positive calves proved positive the following year?

If the calf is a PI, you should get the mother tested. If she tests negative I'd imagine it's extremely unlikely she will have another PI calf the following year if you keep her.

However a PI cow will always have a PI calf.

mf240

Had three pi calves in 2012 .

Cow tested non pi and have calved non pi calves since.


I was very reluctant to cull the calves, but did. Remarkable improvement in calf health since.

Omallep2

mf240 wrote: »

Had three pi calves in 2012 .

Cow tested non pi and have calved non pi calves since.


I was very reluctant to cull the calves, but did. Remarkable improvement in calf health since.

Thanks mf240. Did you vaccinate post your issue?

mf240

Omallep2 wrote: »

Thanks mf240. Did you vaccinate post your issue?

No didnt vacinate.