Ninety-three multiparous Holstein cows
averaging 130 days in milk (DIM) were
utilized to evaluate three cooling treatments
installed in separate pens of a four-row freestall
barn in northeast Kansas during the
summer of 1999. Treatments were: 1) a
double row of 36-inch fans spaced at 24-ft
intervals over the freestalls; 2) a single row of
36-inch fans spaced at 24-ft intervals over the
freestalls and over the cow feed line; and 3) a
double row of 36-inch fans spaced at 24-ft
intervals over the freestalls and a single row
over the feed line. Each pen was equipped
with identical sprinkler systems over the cow
feed line. The 85-day study evaluated milk
production, body condition score, respiration
rate, and feed intake of cows cooled with the
systems. Cows cooled with fans over the
freestalls and feed line produced more (P<
.05) milk (98.8 vs 93.9 lb/cow/day) than
those cooled with fans only over the freestalls.
Milk production was similar for cows
cooled with fans over the freestalls and feed
line, and doubling the number of fans over the
freestalls had no apparent advantage. Cows
in all treatments consumed similar amounts of
feed, and those cooled only by fans over the
freestalls tended to gain more body condition
than cows in the other two treatments. Estimated
increase in net income realized from
using these cooling systems ranged from
$3,500-6,100/year/pen.
