Institute of Food and Agricultural Sciences (IFAS)
Department of Animal Sciences
airy Upda t
Quarterly Newsletter Vol. 8 No. 3 Summer 2008
Can You Spit Into the Wind?
David R. Bray
We are now in the peak of hot, humid weather here
in the Southeast. Is your cow cooling system up to the
task of keeping your cows cool? There are many
components to cooling cows; the first is spraying water
on the cows' backs and the second most important
component is air movement to evaporate the water off
the cow to cool her.
Here is a Test
For proper air flow, stand halfway
back from your fans and spit at the fan.
If the spit hits the fan you don't have
enough air flow. If it blew the chew out
of your mouth you have enough air flow.
When we design a cooling system for an open barn,
it is usually done by "rule of thumb." A fan blows ten
times its diameter or a 36" fan blows 30 feet. A 48" fan
blows every 40 feet etc. This means that in most cases,
you should have enough air flow to dry the cow off and
take the heat with it. Fans need to be placed over the
feed face. You also need fans over the free stalls to
provide air movement and they will help dry the beds
out. If your barn is not at least 16 feet at the eaves, has a
4:12 roof pitch and a 3 foot wide ridge opening, it may
need more fans to ventilate the hot air out of the barn
and evaporate the water off the cows' backs. Many tall
barns can get by with one fan over the free stalls. Not so
tall barns need two fans over the free stalls.
Should I be Green?
Being green can be good or bad. You can be "green
with envy" or green like "Kermit the Frog." Or just be
smart about what you do.
Fans are rated for air flow at different static
pressures. As a general rule, the least expensive fan will
be the least efficient. Some of the old 36" fans we have
used are very inefficient but some are very efficient.
There several tests that are done for efficiency. The
secret is to make sure the testing was done by an
independent testing service. Fan manufacturers may do
their own testing but the results may be biased.
CFM/watt is a good standard to judge a fan because
it standardizes any size fan. The higher the CFM/watt
rating, the more efficient the fan, so you can compare
36" fans to 48" fans for efficiency.
Fans can lose 40% of their efficiency by being dirty.
Belt driven fans can lose up to 40% of their efficiency
because the belts are not tightened properly. Along with
the losses of being dirty you'll have bigger losses. Fans
with plastic shutters are more often efficient because
metal shutters may have linkages that corrode and not
Effectiveness of most fans varies by a factor of two.
The annual cost of operating most 36" fans for 240 days
at $0.10 per kilowatt electricity rate is about $300 for the
most efficient fans and about $600 for the most
In a 600-foot long open four row free stall barn, with
36" fans spaced 30 feet down the barn and fans over
each row of free stalls and each feed face, you would
need 120 fans for the 600 cows. The inefficient fans will
cost $72,000 per year to operate; the efficient fans will
cost $36,000 per year to operate. This is a savings of
$36,000 per year for this 600 cow barn! If you have 3 of
these barns for a total of 1800 cows this would be a
savings of $108,000 per year for 1800 cows. If you had
to pay $200 more for an efficient fan this would be
$28,000 for the 120 fans in each barn or you could pay
for the fans in less than a year and have $8,000 left to
take your wife to Hawaii.
Keep your fans clean, belts tight and as fan die,
replace them with more efficient fans. Look for
CFM/watt as a guide, no matter what size fan you decide
on. To learn more about fans, contact Dave Bray at
drbrav(,ufl.edu or call (352) 392-5594.
UF Dairy Faculty and Student Win National Awards
UF dairy faculty Charlie Staples, Geoff Dahl, and
Albert De Vries, as well as graduate student Bruno do
Amaral, won national awards this year at the joint annual
meeting of the American Dairy Science Association and
the American Society of Animal Science held in
Indianapolis, IN, on July 7-11. Dr. Charlie Staples
received the American Feed Industry Association Award
for his work in dairy cattle nutrition. Dr. Geoff Dahl was
the recipient of the Pfizer Animal Health Physiology
Award for recent work in dairy cattle physiology. Dr.
Albert De Vries received the ADSA Foundation Scholar
Award in Production which recognizes young scholars.
Graduate student Bruno do Amaral received the Omega
Protein Innovation Research Award for his work with
feeding fish products to dairy cows. Bruno is advised by
Drs. Charlie Staples and GeoffDahl.
What is DAIReXNET?
Albert De Vries
DAIReXNET is a national, extension-driven web
resource designed to meet the educational and decision-
making needs of dairy producers, allied industry
partners, extension educators and consumers. Through
collaboration amongst dairy professionals, relevant,
cutting-edge information and learning opportunities are
provided which are science-based and peer-reviewed in
an accessible, 24/7 format.
DAIReXNET was launched in
October 2007 at the World Dairy
Expo in Madison, WI. Current
informational resources on the site
include: searchable state and
regional extension newsletters,
answers to frequently asked
questions, access to cutting-edge
content in 13 subject areas, consumer links about the
dairy industry and its products, news and a calendar of
upcoming extension events.
DAIReXNET dairy subject areas are:
* Business Management and Farm Labor
* Calf and Heifer Management
* Materiales en espafiol
* Food Safety
* Health and Diseases
* Mastitis and Milking Management
* Milk Marketing
* Nutrient Management for Dairies
* Nutrition of Milking and Dry Cows
* Organic Dairy Production
Leadership for this community of practice is
provided by 10 dairy extension professionals from
across the United States. Additionally, the subject areas
are led by 13 dairy experts from across the country. Two
hundred and seven dairy professionals representing 35
universities, including UF, and allied industries and
including the top 25 dairy states are currently
participating in DAIReXNET. Visit DAIReXNET at:
* Or through the Florida Dairy extension site at
Program 2008 Florida Dairy Business Conference
Date: September 8, 2008
Place: Marion County Extension Office
2232 NE Jacksonville Road, Ocala, Florida
Preliminary program as of July 14, 2008:
Registration See registration details below.
Welcome Russ Giesy
The UF commitment to teaching, research,
and extension in a new era Dr. Joan Dusky,
UF Associate Dean for Extension
10:30 Crossbreeding opportunities Dr. Chad
Dechow, Dept. of Animal and Dairy Science,
Penn State University, University Park, PA
11:00 Squeezing the most milk out of your feed
dollars Randy Cragoe, Cragoe Consulting, Inc.,
11:30 Learning Chinese for fun and profit Jerry
Dryer, Editor, Dairy & Food Market Analyst.
Lunch sponsored by our sponsors
Presentation of the 2008 Dairy Community
1:00 DBAP report: effect of type of feeding system
on costs of southeast dairy farms Dr. Mary
Sowerby, UF Extension Dairy Science
1:20 Feeding your cows cheaper: perennial vs.
annual forages Dr. Yoana Newman, Forage
Specialist, UF Agronomy Department.
1:40 Milk quality is more than SCC and SPC, now
it is shelf life Dave Bray, UF Animal Sciences.
2:00 Facing cow management decisions with the
new cost of production on southeast dairy
farms Dr. Albert De Vries, UF Animal
2:20 Break sponsored by our sponsors
2:45 Opportunities to enhance reproduction, cow
health and herd life within breed Dr. Chad
Dechow, Dept. of Animal and Dairy Science,
Penn State University, Univerity Park, PA
3:15 Redefining dairy herd efficiency in our new
economic climate Randy Cragoe, Cragoe
Consulting, Inc., Brookings, SD
3:45 DBAP report: now in its 14th year, can DBAP
historical data suggest future economic
viability? Russ Giesy, UF Extension Dairy
4:00 Dairy producer panel: controlling costs in
today's new economy; how we plan to remain
competitive participants TBA
5:00 Program evaluation & adjourn
Lunch is free for those that call Jeanne at (352) 793-
2728 before noon Friday, 9/05/08. After that time or on
the day of the program, lunch will be $15.00.
For more information, contact Russ Giesy, by email
rgiesv@(ufl.edu, or call (352) 793-2728 (office).
2008 Florida Dairy Production Conference
Proceedings Now Online
Albert De Vries
The 45th Annual Florida Dairy Production
Conference was held April 29, 2008 in Gainesville. Over
one hundred dairy producers, allied industry people,
folks affiliated with UF and others attended the
conference. The program was again rated as quite good.
The 2008 proceedings papers are available at
http://dairy.ifas.ufl.edu. Also included on the site are
pictures of the Conference and summaries of Southeast
Milk Inc. Dairy Check-off grants. An archive of past
conference proceedings is also available. The 2008
papers now posted are:
* Feed Efficiency Opportunities with 2008 Feed Cost -
Michael Hutjens, University of Illinois
* A.I. Technology is Changing Rapidly!! (Molecular
Genetics and Sexed Semen) David Thorbahn,
* Florida Dairy Youth Program Update Brent
Broaddus, University of Florida
* Feeding Management to Reduce the Environmental
Impact of Dairy Farms Robert James et al.,
* Development of a High Fertility Timed Insemination
Program for Dairy Heifers William W. Thatcher et
al., University of Florida
* Is Testing Cows for Disease Resistance a Practical
Tool for Managing Health in Dairy cows? Jason
De La Plaz et al., University of Florida
* Effect of Rust Infestation on Silage Quality -
Adegbola Adesogan et al., University of Florida
* Direct Comparison of Natural Service vs. Timed AI:
Reproductive Efficiency and Economics Fabio
Lima et al., University of Florida
* Sexed Semen Economics Albert De Vries,
University of Florida.
2008 Florida and Georgia Dairy Road Show
Proceedings of the 4th Florida and Georgia Dairy
Road Show held in March 2008 are now posted on the
Florida Dairy Extension website at
http://dairy.ifas.ufl.edu. Papers available are:
* What is New in Dairy Reproduction? Carlos Risco
* Housing and Management in the Dry Period Geoff
* Feeding Management: Do's and Don'ts John
* Manure to Money??? Carbon and Renewable Energy
Credits Mary Sowerby
BIOENERGY 2008 Farm to Fuel Summit
Ann C. Wilkie
In 2006, the Florida Farm
to Fuel Initiative was
statutorily created to enhance
the market for and promote
the production and U
distribution of renewable
energy from Florida-grown
crops, agricultural wastes and
residues, and other biomass,
and to enhance the value of agricultural products and
expand agribusiness in the State. Since then, the Florida
Department of Agriculture and Consumer Services has
hosted two "Farm to Fuel Summits" in Orlando (2006)
and St. Petersburg (2007), each of which attracted
several hundred participants.
The third Florida Farm to Fuel Summit is scheduled
for July 30th August 1st at the Rosen Shingle Creek
Resort in Orlando. The 2008 Summit will provide
further opportunities for industry leaders to discuss
Florida's energy future and join in shaping the future of
biofuels and renewable energy in the State of Florida.
This high-profile event will feature speakers and
panelists representing international, national and state
perspectives on issues of research, production and
distribution of biofuels, including biodiesel, bioethanol
For the 2008 Summit agenda and registration
information visit the Farm to Fuel website:
For questions or issues about bioenergy, contact: Dr.
Ann C. Wilkie at acwilkiekgufl.edu or (352) 392-8699.
Ann Wilkie is in the Department of Soil and Water
DHIA has Tools for Management of Somatic Cells
Daniel W. Webb
Dairy herd managers are concerned about the level
of somatic cells in their milk for several reasons. The
somatic cell count as measured in milk provides an
indication of udder health of lactating cows and also
indicates milk quality and potential shelf life. Milk
processors insist on lower average somatic cell counts,
thus dairy farmers make every effort to keep counts low
to protect and enhance the marketability of milk as it
leaves the farm.
DHIA lab analysis of milk samples from individual
cows collected on test day provides a unique insight into
a herd's milk quality. Monthly DHIA reports contain
somatic cell numbers expressed as somatic cell count
(scc) and somatic cell count score (sccs). The score is a
logarithmic conversion aimed at making interpretation
clearer. The following table shows the relationship of
scc and sccs:
Level Somatic Cell Somatic Cell
Count Count Score
Negligible 25,000 1.0
Very Low 50,000 2.0
Low 100,000 3.0
Medium 200,000 4.0
Medium High 400,000 5.0
High 800,000 6.0
Very High 1,600,000 7.0
We took a look at DHIA data from 126 herds in
Florida and Georgia that sampled for somatic cells in
June of this year (table below). Herds included ranged
from 30 to 3800 cows per herd. Average milk
production was 56.8 pounds, ranging from 30.6 to 82.1
pounds per cow per day. Thirty-four herds had an
average SCC score < 3.0.
Average SCC (weighted by milk lbs.) 387,000
Average SCC Score 3.2
SCC Score for 1st Lact Cows 2.9
SCC Score for 2nd Lact Cows 3.1
SCC Score for 3rd+ Lact Cows 3.7
SCC Score for Cows in Milk 41-99 Days 2.9
% of Cows with SCCS less than 3.0 57.0
% of Fresh Cows with SCCS 4.0 & greater 41.4
% 1st lact Cows with SCCS less than 3.0 62.9
% 2nd lact Cows with SCCS less than 3.0 60.0
% 3rd lact Cows with SCCS less than 3.0 48.0
DHIA herds have a number of tools to choose from
for managing somatic cell information:
* The first is to ask your DHIA technician to collect a
milk sample from each cow and submit it for sec
analysis. Reviewing these numbers for the herd and
for cows in high risk categories can be a helpful
resource in keeping control of the udder health in a
herd. The monthly DHI-202 Herd Summary
provides a look at the herd sec situation.
* The somatic cell count profile, special option DHI-
520 can be selected. This report summarizes the scc
data for a single test day and provides a listing that
identifies cows with specific sec problems. It also
tells how much the herd average sec count would
decrease with this cow diverted from the milk tank.
As an example, one recent report identified 7 cows
in a herd of 3200 that were responsible for 12% of
the herd's bulk scc total. This profile also gives a 6-
month scc history for each cow, the average sec
score for the current lactation, the number of tests
over 3.9 and each cow's contribution to the bulk
tank scc total.
* Twice each year, a Herd Management Comparison
DHI-530 allows comparison of the herd's current
performance to that of 1 year earlier and to the state
breed average. Included in this comparison are sec
* The SCC Hot Sheet provides a timely overview of
the herd sec results from test-day. This report can be
faxed or mailed direct from the lab. It has unique
value since milk production is combined with scc to
allow for quick decisions of cows to divert from the
Monitoring the sec situation for each cow and for the
herd allows herds to reduce the herd's somatic cell count
and provide enhanced milk quality for the market!
For more information, contact Dan Webb at
email@example.com or call (352) 392-5592.
UPCOMING DAIRY MEETINGS
* The annual Florida Dairy Business
Conference is planned for Monday
September 8, 2008. Location will be the Marion
County Extension Office in Ocala. For more
information, contact Russ Giesy, rgiesvyiufl.edu,
(352) 793-2728 (office).
For registration information, agendas and other
meeting details, visit the Florida Dairy Extension site at
http://dairy.ifas.ufl.edu or contact Albert De Vries,
devries(@ufl.edu, (352) 392-5594.
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: devries(tufl.edu.
Past issues are posted on the UF/IFAS Florida Dairy Extension website at http://dairv.ifas.ufl.edu. This issue was published on July 16, 2008.