5 June 1998

BVDvaccine worth £35 a cow

VACCINATING against bovine viral diarrhoea, present in more than 95% of dairy herds, could be worth £35 a cow in reduced calving interval (CI), culling rates and semen use, says vaccine manufacturer C-Vet.

The firm bases its claim on a study of 10 dairy herds with a total of 497 cows. Half the cows in each herd were vaccinated before service, after matching pairs of cows for lactation number; the other cow of each pair was not vaccinated.

Vaccinated animals showed a conception rate to first service of 68% compared with 51% for unvaccinated cows. C-Vet says the result show unvaccinated cows need 1.8 services a cow, 0.3 more than vaccinated animals. With semen costing £20 a straw the difference is worth £6 a cow, it adds.

Vaccinated cows also took 3.4 days less to conceive, saving £5.75 based on DAISY estimates that each day on the CI costs £1.69.

But the greatest benefit of vaccination was a cut of 5% in the culling rate compared with 9% for unvaccinated animals, worth £23.12 a cow using DAISY estimates that each extra cull costs £578. &#42