Prioritise Cell Counts for Cull
Somatic cell counts can be a good indication of udder infections, but are influenced by a range of other factors, so should not be solely relied upon when making culling decisions.
Andrew Bradley of the Bristol Vet School told open day visitors a useful threshold to determine infection is 200,000 cells/ml. But cell counts also tend to be higher at certain stages of lactation, in older cows, or when cows are stressed.
He, therefore, suggested prioritising cows by cell count history, stage of lactation, number of affected udder quarters, age and other factors – such as lameness. Older cattle early in lactation with more than one affected quarter should be picked as probable culls, while younger ones with less time before drying off are more easily curable.
Treatment options are to cull the cow, dry it off, dry off the affected quarter, or treat during lactation, said Dr Bradley. But cultures should be taken to identify the type of infection.
“Your first option has to be to dry the cow off.” This will cure more than 80% and using dry cow antibiotics and a teat sealant during long dry periods will decrease reoccurrence by up to half, he added.