Objective—To evaluate the effect of frequent milkout
(FMO) on the outcome of experimentally induced
Escherichia coli mastitis in cows.
Design—Randomized complete block study.
Animals—16 Holstein dairy cows.
Procedure—Cows were randomly assigned to 1 of 4
groups and were either not infected and not treated
(NI-NT), experimentally infected with E coli and not
treated (EC-NT), not infected and FMO (NI-FMO), or
experimentally infected with E coli and FMO (EC-FMO).
The infected quarter in cows in FMO groups
was milked out every 4 hours from 16 to 36 hours and
every 6 hours from 36 to 84 hours after challenge,
with the aid of oxytocin administration. Somatic cell
counts (SCC); times to bacterial, clinical, and systemic
cures; and serum concentrations of α-lactalbumin
Results—Use of FMO did not appear to affect SCC.
For EC-NT and EC-FMO groups, mean bacterial cure
times were 203 and 159 hours, clinical cure times
were 276 and 360 hours, and systemic cure times
were 144 and 159 hours, respectively; these times
were not significantly different. Concentrations of
α-lactalbumin were significantly increased in the EC-NT
group at 12 hours and in the NI-FMO group at 36
and 60 hours after challenge, compared with values
of cows in other treatment groups.
Conclusions and Clinical Relevance—Compared
with results in control cows, FMO does not appear to
be an efficacious treatment for experimentally
induced moderate to severe E coli mastitis. (J Am Vet
Med Assoc 2003;222:63–66)