Institute of Food and Agricultural Sciences (IFAS)
Department of Animal Sciences
Quarterly Newsletter Vol. 8 No. 4 Fall 2008
Russ Giesy Retired from UF Dairy Extension
Multi-county dairy extension agent Russ Giesy retired in
August from UF/IFAS Extension after 21 years of service.
Russ served the dairy industry in any way he could with
a focus on farm business financial
"' analyses (DBAP) and cost-benefit
analyses of nutrient management
He was recognized for his service
to the Florida dairy industry by
industry leaders at the Florida Dairy
Business Conference in Ocala on September 8.
Russ has accepted a position as classifier with the
Brown Swiss Association. He and his wife Joan plan to
stay in Leesburg, Florida.
Dr. Joan Dusky, associate dean for Extension, said
that the University of Florida plans to fill the now vacant
position. UF will work with the Florida dairy industry to
define the job description and the location of the new
dairy agent. We wish Russ good luck in his new
Business Plan for Dairy Digesters
A $78,658 grant funded by the USDA Rural
Development Agency will provide a feasibility study for
methane digesters on dairies in Florida, from farm to
the consumer. The end-product of the grant is a
business plan that can be used by producers to apply for
funding to site digesters and a solid marketing plan for
energy and other co-products of digesters. The project
is led by Frankie Hall at Florida Farm Bureau and
collaborators include the UF Department of Animal
Sciences, Southeast Milk Inc, Sunbelt Milk Producers,
Florida Environmental Defense, Farm Credit (North and
South Florida), Florida Electric Cooperatives, the
Association of Florida Conservation Districts, the Hardee
and Hillsborough County Farm Bureaus, and the
Okeechobee Area Ag-Council. Look for meetings in early
2009 to report the outcomes of the study. For more
information contact Frankie Hall (Frankie.Hall@ffbf.org)
or Geoff Dahl (email@example.com).
Check presentation ceremony (9/29/08) at the UF Dairy Unit
for the USDA Rural Development Value Added Producer Grant
awarded to the Florida Farm Bureau for a feasibility study of
anaerobic digesters. L-R: USDA Rural Development State
Director Ronald Whitfield, Rural Development Business
Programs Director Joe Mueller, Geoffrey E. Dahl of UF, Adele
Griffin representing FL Senator Mel Martinez, and Frankie Hall
of Florida Farm Bureau.
What I Did On My Summer Vacation
David R. Bray
I went to cow Disneyland Barns in South Dakota; lots of
animals in one place. The new thing in dairy housing in
the Midwest is Low Profile Cross Ventilated housing
Characteristics of LPCV Barns
The low profile results from the roof slope being
lowered from a 4:12 pitch like in our open free stall
barns to a 0.5:12 pitch. The barn height is determined
by the heights of the feed trucks.
These buildings are more like big box warehouse
structures. The shell of the building can be erected by
any contractor. This may reduce the cost of the building
because the cost of these LPCV barns per cow maybe
less than our present tunnel barns, but obviously not
less than our traditional open free stall barns in Florida.
These LPCV barns have a smaller land space
requirement than a naturally ventilated free stall barn
because a double eight row LPCV barn does not have
the 100' open space requirement needed by two 4 row
barns needed to house the same number of cows in
naturally ventilated barns as shown in Figure 1.
Figure 2 illustrates the end view of the open LPCV
building with the evaporative cooling pad system
located along one side of the building and fans are
placed on the opposite side. More space is available for
fan placement and the cooling system parallel to the
ridge rather than perpendicular because the equipment
doors are located in the end walls.
/ 200 Cows
- 0 Bottom of Baffle 8' above alley floor (6'4" opening) Baffle
Er trance Doors 200 Cows
Baffle 200 Feedspaces
200 Cows 20' Cross Alley (2 8' Water Troulhs
184 Freestalls per Pen (46" stall wdth)
84 51" fans located along west side
A layout of eight row LPCV buildings with tail to tail
free stalls is shown in Figure 3. Notice the baffles
located 8' above the alleys. They deflect the air down
on the cows for more efficient cooling of the cows. Also
the air flow hits the cow in the front or back so both
sides of the cow are cooled in the free stalls and at the
feed lane, unlike in a natural ventilated free stall barn or
a tunnel ventilated barns where the air flow is to one
side of the cows. Air speed is usually less than eight
mph in the summer and low as 2 mph in the winter.
Cooling in LPCV barns is usually done by cooling
pads. These fiber honeycomb pads are usually 8" thick
and water trickles down the pads from the top to the
bottom and un-evaporated water is re-circulated the
large fans on the other side of the barn draw air from
the outside through the pads and pickup water in the
air, cooling the air which raises the humidity and is
exhausted out through the fans air exchange is usually
about once every 2 minutes.
Cooling can also be done via high pressure foggers
(1500 psi) mounted from the ceiling which also
evaporative cools the air and raises the humidity. Air is
exhausted on the other side of the barn, but in this case
Roof Slope -
Baffle (Bottom 8 ft above alley)
the system provides a open sidewall with a curtain
controlled inlet that operates from September to May.
It also allows some natural light into the barn which
may impact the orientation of the LPCV.
10' Evaporative Pad
If it Works in South Dakota, Will it Work in South
This seems like a great solution for the Midwest
where winter is a much bigger problem than summer.
In cold weather the pads are covered with a curtain and
air inlets above them can be opened to produce fresh
air and many of the fans are turned off and everything
is great. Manure does not freeze on the floor, people
are happy and the cows are happy.
The reason this cools in the summer is that it is not
always hot and humid. This works great on a 900 day
with low humidity. Once the humidity rises, it is like
here; you must add water to the cow's back and have
fans to dry the cows off and take the heat with it. Most
of the hot weather there is hot but not humid for great
lengths of time.
In the Southeast you would have to add feed line
sprinklers to cool the cows both night and day. Air flow
is usually about eight mph in LPCV which is probably not
high enough to dry the water off the cows back. This
not to say that larger fans could not be used to increase
air flow to evaporate sprinkler water off the cows and
cool the cows.
As with everything, it's what you like. How much
money you wish to spend determines what you build.
These LPCV barns may be less expensive to build than
our tunnel barns; both need high priced roof insulation.
The LPCV barns do not need side curtains because side
walls are either fans or pads, and we would not need
the 5' roof overhand to protect the fans shrouds from
falling ice and snow off the roof.
If you wish to recycle sand, it can be done. One
dairy we visited in southern Minnesota scraped manure
into a water plume in the middle of the barn which
removed it and sand was separated in a long lane like
we do. Some go to a screw sand separator by the plume
system or just screws moving the manure to the
separator where water is added to remove the sand.
Other Good Things About LPCV Barns in the Midwest
1. The cooling system adds no water to the floors or
the waste management system; you would have to
do it here.
2. You can use time-controlled lighting in these barns.
The cooling pads reduce sunlight and the fans block
sunlight. The ends are solid, not curtains. If properly
installed this can increase milk production. There
are many people out there that have a timed light
scheme and many are wrong. If this interests you in
whatever type of barn you have, contact us here at
the Department of Animal Sciences and we will give
you the proper specifications.
3. While I hate enclosed places, these barns with
proper lighting and being wide give the feel of not
being in a mushroom growing barn.
4. Because the climate is somewhat controlled,
dairymen who have them say they have had better
feed intake, higher milk production and
reproductive success over their previous facilities.
1. This is a gate nightmare. It seems like a 100 gates
everywhere; cattle guards seem like a nice idea to
2. Because walking time is shorter in these facilities,
the time cows are out of their pens may be less
than traditional barns, which means all bedding and
alley scraping must be done quickly.
3. I guess alley scrapers have not been perfected yet,
but it seems like a better idea than skids steer
4. They will soon have skid steer Olympics in the
Midwest. These guys are amazing, their spins and
backups are great and when they go too far those
air baffles keep score of the mishaps.
5. Lots of garage doors are needed to feed and bed
cows. This leads to different barn designs to
eliminate doors and still feed and bed cows. Every
time a garage door is open the cooling system quits
because air is entering through open doors, not the
6. The first thing taught on a LPCV dairy is what to do
when the power goes off, then lighting hits the
generator. An emergency evacuation plan for cows
and people is needed. In less than an hour
everything inside will be dead if the fans go off.
Some have kept lots of doors just for that reason.
7. The ingeniousness of dairymen never ceases to
Facing Cow Management Decisions with the New Cost
of Production on Southeast Dairy Farms
Albert De Vries
The 2008 Florida Dairy Business Conference was held
September 8 in Ocala and attracted over 70 participants
from among dairy producers, allied industry, and
educators. One theme of the conference was the
increased cost of production in the Southeast and how
that might affect your cow management decisions.
Estimates from USDA show that the cost to produce one
cwt of milk in FL and GA has increased by about $4 in
the last year and a half (Figure 1). The annual swings are
a result of lower milk production in the summer.
2004 2005 2006 2007 2008
Figure. Total cost of milk production/cwt milk.
I put together a simple spreadsheet to evaluate how
increased feed cost would affect feed cost per cwt of
milk produced by days after calving (Figure 2). Figure 2
uses an equation from the book Nutrient Requirements
of Dairy Cattle, a standard reference, to predict dry
matter intake as a function of milk production, body
weight, and days after calving. It is clear that early in
lactation feed cost per Ib of milk produced is lower than
later in lactation. A simple explanation is that dry
matter intake for maintenance is relatively independent
of days after calving. So there is always a fixed feed cost
just to keep the cow alive that does not yet support milk
Figure 2 shows that higher cost of dry matter
($14/cwt dry matter) increase feed cost/cwt of milk
later in lactation more than lower cost of dry matter do.
This means that it becomes relatively more expensive to
milk cows later in lactation. Consequently, it becomes a
little bit more important to have a fresh herd. For
example, it becomes a bit more important to get cows
pregnant early in lactation when feed costs are higher.
The effect is quite small, however.
1 51 101 151 2)1 251 301 351 401 451
Diys after caing
Figure 2. Feed cost/cwt milk by days after calving.
Increased feed costs have a greater effect on break-
even milk yield to pay for feed cost. Figure 3 shows
break-even milk yields for a cow that consumes 42 Ibs
of dry matter per day. Dry matter cost varies from $8 to
$14 per cwt and milk price varies from $19 to $25.
Complete slides from this presentation and other
slides and handouts from the 2008 Dairy Business
Conference are posted at the Florida Dairy Extension
website at http://dairy.ifas.ufl.edu.
8 10 12 14
Dry matter cost, $1100 Ibs
Figure 3. Break-even milk yield.
Upcoming Dairy Meetings
* November 12-13, 2008: Southeast Dairy Herd
Management Conference in Macon, Georgia.
* February 10-11, 2009: 20th Florida Ruminant
Nutrition Symposium in Gainesville, Florida.
* April 28, 2009: 46th Florida Dairy Production
Conference in Gainesville, Florida.
For more information, visit http://dairy.ifas.ufl.edu or
contact Albert De Vries, firstname.lastname@example.org.
Dairy Update is published quarterly by the Department of Animal Sciences, University of Florida, as an educational and informational service. Please address any
questions or comments to Albert De Vries, Editor, Dairy Update, PO Box 110910, Gainesville, FL 32611-0910. Phone: (352) 392-5594. E-mail: email@example.com. Past
issues are posted on the UF/IFAS Florida Dairy Extension website at http://dairy.ifas.ufl.edu. This issue was published on October 6, 2008.