Effective Cooling Systems for Improving Fertility
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Aug. 22, 2002
With Jim Spain, Associate Professor of Animal Science,
University of Missouri, Columbia
Jim, we’ve been talking about what we can do to help facilitate
the heat loss that cows are generating, and an effective cooling
system benefits milk production and feed intake during the period
of heat stress, but it also has a very positive effect on fertility
and conception rates. Tell us about it.
Fans and sprinklers are going to be the key component of the system.
We need to look to see if we can’t strategically operate those to
maximize the heat transfer. For one example, we certainly encourage
producers in their holding pen, which is under cover and shaded so
that we reduce the exposure of the cows to sun while they’re crowded
in the holding pen before milking that we use sprinklers, that we use
fans to try and minimize the effects of the crowding on thermal balance
so that those cows don’t come into the parlor after having gained heat
in the holding pen. But when they return to the barn, we need those
fans strategically placed so that we’ve got maximum air movement over
the skin of the cows. We like to see the fans over the free stalls
because that’s where we want those cows spending their time laying
down in clean, dry, comfortable free stalls. We like the sprinklers
over the feed line if we can manage the water and we’re not having
problems with the sprinkled water getting over into the feed or over
into the bedding and into the stalls. Some folks use misters, some
use sprinklers, some use foggers. That water needs to be used in a
manner that’s best for the housing environment that each one of the
producers is using on their individual farm. One of the places that
we often overlook our opportunity is when it cools off at night. Many
of our cooling systems have been designed to where they’re hooked into
a thermostat. That when it cools off at night it turns those fans off,
and that’s really we think as a missed opportunity, that we can use
that cooler night air, turn the sprinklers off because we’re not going
to be using evaporative cooling now, we’re going to use convective
cooling, where we’re pushing cool night air across the skin of the cows
and helping them lose the body heat. So instead of setting the thermostat
at 70 or 72 degrees Fahrenheit, we’re dropping the thermostat on the fan
control down to that 60 to 65 degree range, so that those fans run a
little longer at night and cool those cows a little more and help those
cows get back down to thermal balance. That costs us a little extra
electricity, and we recognize that, but we think the benefit is that in
keeping those cows cooler we can undo some of the adverse seasonal effects
on fertility. That cow is going to eat a little better, and because she
eats a little better, she is going to stay in a little better body condition.
Because she stays in a little better body condition, we know that’s going
to have a positive effect on fertility, especially for the cows that are
calving in August, September, and in some parts of the country, October.
Cooling cows in that early lactation is critical to their stand on a high
plane of nutrition and their ability to achieve high fertility and high
first service conception rates when we start breeding those cows back in
late October through early November. An effective cooling system will
have a benefit on the milk production and on feed intake during the period
of heat stress. It’s also going to have a very positive effect on fertility
and conception rates when those cows are reaching that end of that volunteer
waiting period and entering into the breeding herd on the dairy.
Copyright 1996-2002 Select Sires Inc. Last updated 28-Aug-2002.
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