Title: Dairy update
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00087054/00001
 Material Information
Title: Dairy update
Series Title: Dairy update
Physical Description: Serial
Language: English
Creator: Institute of Food and Agricultural Science
Publisher: University of Florida Institute of Food and Agricultural Science
Place of Publication: Gainesville, Fla.
Publication Date: Winter 2002
Subject: University of Florida.   ( lcsh )
Spatial Coverage: North America -- United States of America -- Florida
 Record Information
Bibliographic ID: UF00087054
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida


This item has the following downloads:

DairyUpdateWinter2002 ( PDF )

Full Text


FLORIDA airy Update

Institute ood ,dand Agricultural Sciences
Department of Animal Sciences

Quarterly Newsletter

Winter 2002


Professor H. H. "Jack" Van
Horn had the poor taste to retire
on January 3, 2002 after 32 years
of service to the University of
Florida. Jack joined the
Department of Dairy Science in
1970, and served as its chairman
and as a professor of dairy cattle
nutrition, giving particular
emphasis to working for the dairy
farmers of Florida on protein and
nutrient management issues. Jack
has been the point man in our
department on nutrient
management issues, especially in
sorting out phosphorous and
nitrogen mass balances for farms
as they set up their nutrient
programs. He also served for 3
years as the assistant director of
International Programs here at the
Anyone who's worked with
Jack knows well his earnest, easy
going attitude, his ready Kansan
smile, and his very direct intent of
doing research and extension
work to best serve the dairy
farmers of Florida. Dr. Van Horn
will be missed very much.
Anyone interested in sending
letters for his retirement can send

them to him at PO Box 110910,
Gainesville, FL 32611-0910.


Hi, I am the new faculty
member in what people here call
the Mike DeLorenzo position. I
want to say a few things on how I
got here and what I plan to do. I
was born in the Netherlands, grew
up on a small dairy and swine
farm. I obtained a BS and MS in
animal and dairy sciences, with a
minor in farm management, at
Wageningen University.
In March of this year I
graduated with a Ph.D. in animal
production systems from the
University of Minnesota. My
work focused on quality control
methods applied to dairy
reproduction and course work
focused on applied economics,
operations research, and statistics.
In June 2002, I joined the faculty
at UF to work on dairy systems
management and economics. My
appointment is 10% teaching,
40% extension, and 50% research.
I am especially interested in
the most economic culling and
replacement policies, dairy health
and reproduction economics, and
how to best deal with price and
production risks. All these topics
are related and aim to reduce the
cost of production.
I have been involved in the
Dairy Business Analysis Program,

which has helped me a great deal
as I learn about the dairy industry
in Florida. I am also putting
together a bio-economic computer
model of a dairy herd, which will
help to better evaluate questions
about expansion, replacement
cost, cow and cash flow, and
reproductive strategies. This
model can also mimic your herd
situation, production constraints,
and objectives in order to get the
best farm-specific information.
Other topics will come up when I
learn more about the challenges of
our dairy industry.
Feel free to contact me
with questions, comments or
suggestions you may have. at
(352) 392 7652, or


Ok, so it's a bit early in the season
for corn, but not too early to be
thinking about what to do about
corn harvest. Mark your
calendars for Thursday, June 6 for
a corn field day at the University
of Florida Dairy Research Unit in
Hague. There will be field plot
demonstrations on varieties and
weed control, discussions on
inoculants, processing, and more.
We'll be sending out an agenda
with more details in the coming



D.R. Bray, R. Giesy, R. Bucklin

A completed check-off project
is the use of thick rubber matting
in a Florida feed barn to alleviate
the stresses of concrete on cows.
These mats (J&D Manufacturing;
www.idmfg.com) were 2" thick x
4'x 6' and cost about $3.10/sq ft,
quite a bit more expensive than
rubber belting, but so much softer
to my young legs and feet.
In this experiment one half of
a feed barn was covered in the
loafing area with these mats, the
other side of the barn stayed
Equal number of cows were
on each side, all foot episodes
were recorded on PCDart for one
Total incidences of foot health
episodes totaled 98 from May
1999 thru April 2000. Note that
this is not the number of cows
treated, but rather the number of
foot episodes since some cows
had multiple episodes. Of that
total, 38 (38.8%) of incidences
were on the side with mats, while
60 (61.2%) were on the control
side, a difference of 24%.
Further, the severity of each
problem was recorded. Of cows
on the control side of the barn,
27% of cows required antibiotic
therapy, while only 21% of

episodes on the mat side received
that level of treatment.
Total cost of the foot health
episodes was calculated using Dr.
Shearer's estimated cost per
episode. Treatment costs were
$18,000 on the control side of the
barn and $11,400 on the mat side.
The $6,600 difference was felt to
be conservative given that greater
labor and medicinal cost occurred
on the control side.
According to Russ Giesy's
math, the initial cost of the mats
was $10,000. No installation or
interest costs were applied. The
payback period was estimated at
1.52 years. This rate of return is
considered desirable.
Durability of the mats was
questioned due to the much
greater price. After one year,
some deterioration was noted, but
no failure was evident. This
project will continue into the
future to test this durability issue.
The mats seemed to be preferred
by cows as the producers
perceived cows on the mat side
spent more time at rest. At the
end of the twelve month study
period, the producers placed this
mat on the control side of the
barn, feeling that the expenditure
will be a wise one if the mats last
3-4 years as they expect.
The company has changed the
composition of these mats, the
new ones seem more durable than
the old mats. This is one of
several check-off projects
working on feet and floor
covering, more exciting results
are in the future.
There is a question of where
rubber mats are needed, where
they stand to eat, or where they
walk, especially if cows have to
walk long distances to the parlor
on concrete. The force of walking
bothers me more that standing on
concrete, I think that these forces

exerted on outside claws of cows
who do not get their feet trimmed
several times a year is the biggest
What's being done in the state -

1. Belting that's been grooved
covering the entire walking
surfaces of barns, two wide
belts custom cut and installed
seem to stay in place, while
not as soft as thicker mats,
they are better than concrete
and prevent that "green
concrete" problem for new
concrete less than a year old.
2. Virgin rubber mats are going
to be used soon. I have tried
and will continue to try
different surfaces.
3. Dr. Bucklin and Dr. Shearer
are using a computerized
pressure device type mat that
will measure forces on
surfaces and how they are
distributed on surfaces.

Since I don't know where this
newsletter goes, I will not list the
names of dairies with these
surfaces, if you want to know, call
me or Russ Giesy, and we will let
you know.


K. C. Bachman

Why consider using a 40-day
dry period management strategy
on your dairy? Because a 40-day
dry period may be more profitable
than your current dry period
length. The average dry period is
approximately 68 days long,
based on DHI records processed
at the North Carolina Regional
Data Processing Center. Dairy
herds may be forfeiting 28 days of

milk income needlessly. If you
know the conception dates of
your cows, read on.
The current industry
recommendation is for a 51 to 60
day dry period length. This
standard has not changed or been
challenged with planned cow
experiments for decades. Why?
In fact, this recommendation was
never based on planned cow
experiments in which dry periods
of different lengths were assigned
to cows at random to determine
their effect on subsequent milk
production. Instead, the
recommendations came largely
from analysis of accumulated
production records. It is
important to realize that most
cows that had short dry periods
within those records were not
assigned at random to have short
dry periods. Instead, the short dry
period category is comprised
primarily of a self- selected
population of cows that freshened
earlier than expected, for
whatever reason.
Milk production subsequent to
unplanned short dry periods likely
is less than that which follows
planned short dry periods. When
it's planned, the dairy farmer
manages the cow to best prepare
her to transition into a profitable
lactation by monitoring her body
condition and providing a close-
up ration to meet her
requirements. Without planned
experiments to test short vs.
current dry periods, we don't have
a sound basis to say that the
current recommendations are best.
As we wrote in the Fall 2001
issue of Dairy Update, we have
conducted two such experiments
that used modem, high-producing
cows and current management
practices. The studies were small,
but telling. The study conducted
on a Florida dairy indicated that

15 cows that had 34-day dry
periods produced 20,077 lbs 305d
ME while their 19 herdmates with
57-day dry periods produced
19,771 lbs. Ten cows in the
UF/IFAS Dairy Research Unit
herd produced 24,268 lbs after 32
days dry while 9 herdmates with
61 days dry produced 23,212 lbs.
The short dry periods included no
special treatment or medications.
One more thing to consider if
you'd like to try 40-day dry
periods on your dairy: Based on
the evaluation of milk production
records, the negative impact of a
31 to 40 day versus a 51 to 60 day
dry period on actual 305 d
lactation production has been
estimated to be about a 4 %
decrease in subsequent milk yield.
Assuming that this 4 % value is
correct for a present-day cow and
management scenario that
supports 22,000 lbs of milk
production, the total milk
production for two consecutive
lactations would be unchanged if
cows were kept in milk for an
additional 20 days to produce the
880 lbs of saleable milk that will
be lost in the ensuing lactation as
a result of decreasing the
preceding dry period by 20 days.
Either with or without the use of
bST, this level of production in
late lactation, ie. 44 lbs/day, is
achievable by cows that produce
22,000 lbs milk during a 305 d
lactation. Therefore, when parlor
pressure does not exist, shorter
dry periods can be profitable if
milk income per day of continued
milking exceeds the difference in
the daily variable costs assigned
to a cow when she is being
managed in the lactating herd
instead of the non-lactating herd.
Again, accurate diagnosis of
pregnancy is needed to calculate
the expected calving date.


A. de Vries

The DBAP reports for 2000 have
been completed. We are currently
returning them to the participating
dairies. Our goal is to have all
reports returned before the end of
this year. We are also preparing a
summary analysis across
participating dairies. Those
results will soon appear in
Hoofprints in the Sand and as a
Florida Cooperative Extension
Publication. We think the farm
reports and the summary analysis
contain again a lot of valuable
information that will help to
improve the profitability of
participating and other dairies.
Here are some observations
from me as a relative newcomer
to DBAP. First, I hope we can
start collecting 2001 data early in
2002 and return those reports
quite a bit faster than we did this
year. Secondly, I think we can
benefit from some improvements
in the quality of the collected
data. Not that the data are wrong,
but sometimes data are just
missing without it being obvious.
To do that, we plan to make some
changes in the data collection
sheets. That should also reduce
the amount of time and expertise
needed to collect the data.
Finally, I wish we can get the
number of participating dairies up
again. That will improve the
comparisons with your peers and
allows us to do more meaningful
summary analyses. Hopefully
these changes will improve the
value of DBAP and generate
renewed enthusiasm for

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs