You have been contacted by Farmer Elsie de Koo about a mastitis problem
that she has in her herd. She has a 100-cow Jersey herd in central Ohio.
There has been a gradual increase in the bulk tank somatic cell count
from approximately 320,000 cells/ml six months ago to almost 700,000 cells/ml
now in October. There has been no obvious increase in clinical mastitis
cases during this time (two or three cases each month). Her cows are milked
twice a day in a double-4 Herringbone parlor. The parlor has a low-pipeline
system without automatic take-offs. The cows are housed in two freestall
barns with access to partially-shaded concrete lots. They are fed grain
in the parlor and from a computerized feeder. Silage and hay is offered
in bunks in the exercise lots.
Elsie is particlularly concerned about the problem because she
has lost some premium payments for her milk because of this elevated somatic