Kentucky
Dairy Notes
April 2010
Springtime Decisions Impact Profit for the Next Year
Donna M. Amaral-Phillips
Forages are the foundation upon which rations for dairy cows and
heifers are built. Grains, byproducts, minerals and vitamins then are
added to complement the forages being fed. Generally speaking,
55% or more of a dairy cow’s ration dry matter comes from forages.
The higher the quality of forages being fed, the more forage you can
feed, and generally the ration supports a greater milk production at a
more economical cost. With increasing feed costs coupled with lower
milk prices, the importance of incorporating high quality forages has
taken on even more importance.
Additives
Minerals &
Vitamins
Grains and byproducts to make
Concentrate Mixes
10-20 cents/lb DM
Vs.
3-11 cents/lb DM
Forages - Foundation
How can we incorporate more forage and less concentrates?
In the past, many rations have contained 50 to 60% of the dry matter coming from forages. In recent years,
these percentages have been pushed upwards to include 60 % or more of the diet coming from forages,
especially in lower producing groups of dairy cows. Increasing the amount of forages fed has been
successful when quality forages are available.
Quality forages provide more nutrients in every bite. Thus, less concentrate or grain needs to be fed to
provide dairy cows with the nutrients they need to support milk production. To determine the quality of any
forage, a representative sample must be collected, sent to a forage testing laboratory, and analyzed by that
lab for its’ nutrient content. These results are then used to balance a least cost ration for the cows in the
herd. The higher the quality of forages available, the greater the amount of forage used to balance a ration
for a particular group of cows or heifers.
How can I control the quality of forages on my farm?
The quality of forages varies from year-to-year as well as from field-to-field in the same year. Thus, the
importance of separate forage samples representing different cuttings and crops need to be analyzed.
Various factors determine the quality of forages. These include:
 Growing conditions- such as temperature, rainfall and overall fertility
 Species harvested- for example grasses versus legumes. Generally, legumes are more digestible
than grasses and are higher in crude protein.
 Variety differences
 Stage of maturity forages are harvested
Management can control fertility as needed for growth of specific crop. However, changes in environmental
temperature and rainfall are beyond our control. Varietal differences may impact the quality of forages,
especially as they relate to NDF digestibility or the leafiness of the plant. The best example of varietal
differences is related to brown midrib crops such as corn for silage or sudangrasses. The brown midrib
gene decreases the amount of lignin in the plant and increases the digestibility of the NDF component of the
plant. These varieties are generally more digestible than their non-brown midrib genetically similar corn
varieties.
The quality of forages is greatly
Stage of Maturity for Harvest in Spring
impacted by the stage of maturity
Grasses ................................ Late Boot*
at which the plants are harvested.
Alfalfa .................................. Early Flower
This factor is definitely under
Oats/Rye .............................. Late Boot*
Wheat .................................. Late Boot* and then soft dough**
management or your control. As
grass and legume plants mature,
* Late Boot- Just before the seed head emerges from the stem
the percentage of leaves in the
** Soft dough- wheat kernel is filled out and is soft when
total plant decreases while the
pinched with your thumb nail
percentage of stems increases.
As a result, the digestibility or energy value of the crop decreases with advancing stage of maturity. Thus,
the recommendation is to harvest grasses and small grains, such as wheat and rye, at the late boot stage of
maturity or just before the seed head emerges from the stem. Delaying harvest does increase yield slightly,
but, can negatively impact milk production and heifer growth and the amount of forage that can be used in
the diet because of lower levels of digestible nutrients. Remember that the hardest nutrient to get into cattle
of all ages is energy, thus forage maturity or the stage at harvest greatly impacts the amount of forage which
can be effectively used in dairy cattle diets and maintain milk production or growth.
Kentucky’s spring weather is often times an enemy when trying to harvest quality forages. Spring rains can
delay harvest. The key is to make the most of Kentucky’s unpredictable weather. Starting a few days
before the optimum stage of maturity allow you to harvest higher quality forages overall with only small
decreases in yields. These small decreases in yield result in more milk or growth per acre which greatly
affects your bottom line. Ideally, you want to be one of the first of your neighbors in the field instead of the
last. Those dairy neighbors in the field first are often times those who are able to utilize more forage in their
cows’ diets and get higher milk yield and thus more income after feed costs are accounted for.
Observing Dairy Cows in Freestalls: Stop, Watch, Listen, Think, Change.
Jeffrey Bewley
1.
2.
3.
4.
5.
STOP your normal routine for a few minutes
WATCH how your cows behave within your barn
LISTEN to what they tell you about your freestall barn
THINK (critically) about how you can correct any problems you observe
CHANGE your existing freestalls to better meet your cows needs
You’ll be amazed at how much these five steps can improve cow comfort on your dairy farm. Often, dairy
producers wonder why their cows do not spend as much time lying in their freestalls as they should. This
situation is particularly problematic when cows choose to lie in manure-covered alleys rather than in the
freestalls (Figure 1). In comfortable, well-designed freestalls, cows will spend most of their time lying or
standing straight (parallel to the length of the stall) in the stall (Figure 2). Approximately 2 hours after
milking, about 90% of the stalls should be occupied. Continuous monitoring of stall use and cow behavior
while getting into and out of stalls is essential for assessing cow comfort. By understanding what behaviors
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to look for, you can learn what minor adjustments need to be made to the standard recommendations to
best fit the needs of your cows in your facilities.
Watch the cows as they lie in the stalls. Think about how a cow gets up when she is on pasture. Her
behavior in freestalls should be similar to this. Typically, a cow will first shift to move her front knees beneath
her body. Then, she lunges her head forward transferring weight to the front of her body which also allows
her rear end to be easily lifted. Next, she shifts weight to one knee and straightens the other front leg with
the foot in front of the shoulder. Finally, she shifts her weight to the straightened leg pushing up and
straightening the other front leg to finalize her standing position.
Do the cows enter the stalls with ease and with minimal hesitation? Do they come into contact with any part
of the stall while lying down? Watch cows as they rise from a resting position. Do they come into contact
with any part of the stall while getting up? Is there adequate lunge space for their heads as they rise? Do
you see any potential for injury as the cows get into and out of stalls? Do cows spend considerable time
standing in the stall, showing hesitation, before lying down in the stall? Do they push their nose or mouth
against pipes or stall structures? Do cows stand in the freestall, swinging their heads to the left and right?
Once cows are lying, do they appear calm or restless? Restlessness, or frequent changing of positions
while lying, may be another sign of potential cow comfort shortcomings. Finally, spend some time looking at
the cows focusing on the hocks, knees, and rumps. Do you see any evidence of injury, abrasions,
abscesses, bumps, or bruises that may have resulted from getting into and out of the freestalls? If you stand
in front of the stall and drop to your knees, is it a painful process? If so, how do you think this “knee test”
reflects the cow’s experience in using the stall? All of these observations may indicate potential
improvements can be made through freestall modifications.
Once you have observed the cows, use a tape measure to assess the dimensions of your existing stalls. Be
sure to collect measurements for all types of stalls in your barns. For example, the dimensions may be
different for stalls on the outside walls or if a different type of loop is used in one row versus the others.
Once you have collected this information, compare your dimensions to the recommendations listed below
(Table 1). Select freestall dimensions for the largest cows in your herd. Varying cow sizes within a herd
should lead to varying stall sizes. A one-size-fits-all approach to freestall design is not conducive to optimal
cow comfort. When possible, first lactation cows should be provided a separate pen with smaller freestalls
to accommodate their smaller frame size.
Figure 1. When a high proportion of cows choose to lie in the freestall alleys rather than in the stalls, this
may be an indication that the freestalls do not provide a comfortable resting area.
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Figure 2. In well-designed and well-maintained freestalls, most cows will be observed resting comfortably
or standing straight in the stall. In both positions, cows should be located parallel to the length of the stall.
Table 1. Recommended freestall dimensions by cow size (Graves et al., 2005, Cow Freestall (Cubicle)
Types and Details).
Animal
Weight
(lbs)
Total
Stall
Length
Closed
Front
(in)
Total
Stall
Length
Open
Front
(in)
Length
to
Brisket
Tube or
Board
(in)
Length
to Neck
Rail
(in)
Stall
Width
Center
to
Center
(in)
Height to
Top of
Partition
(in)
Height
to
Neck
Rail
(in)
Brisket
Board or
Tube
Height
(in)
900-1100
90-96
78-82
64-66
62-64
41-43
42-44
42-44
4-6
1100-1300
96-102
80-86
66-68
64-66
43-45
44-46
44-46
4-6
1300-1500
102-108
90-96
68-70
66-68
45-48
46-48
46-48
4-6
1500-1700
108-114
96-102
70-72
68-70
48-52
48-52
48-52
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Mycoplasmal Mastitis
Michelle Bilderback
Mycoplasmal mastitis is potentially a highly contagious disease that can cause severe economic
problems in affected herds. Mycoplasma bovis has also been associated with abortion, infertility, arthritis,
pinkeye, ear infections, pneumonia and abscesses. The organism is very small, lacks a cell wall and
requires special testing in the laboratory that is usually more expensive and time consuming than other
bacterial cultures. Cows diagnosed as positive for Mycoplasma should be considered positive for life.
Cows of all ages and at any stage of lactation as well as dry cows are susceptible. In lactating cows, the
“classic” signs include:
 Severe mastitis that doesn’t respond to treatment
 More than one quarter is affected (sometimes all four)
 Marked drop in milk production
 Abnormal milk (varies from watery milk with a few clots to very thick) although some do not show
abnormal color or pus.
 Cow often continues to eat and drink normally
 Chronic cow’s milk is tan colored with “sandy” or flaky sediment
 May see lameness/swollen joints due to arthritis. Occasional pneumonia.
 Some cows go dry due to the mastitis but those that continue their lactation have less milk, high cell
counts, and can shed the Mycoplasma organism intermittently throughout her lifetime
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It is important to remember regardless of what is described in textbooks, mastitis will have a unique
presentation on each farm independent of the microorganism causing it. Therefore diagnosis cannot be
based on clinical signs alone.
Most mycoplamal infections are considered contagious and are spread from cow to cow during the
milking process. This spread can occur at milking due to faulty milking machines, teat cups, contaminated
intramammary treatments and milker’s hands. Many herd infections come from the introduction of
replacements with infected udders. Large numbers of Mycoplasma organisms may be shed in the milk
before the onset of clinical mastitis so rapid spread within the herd is possible. The organism is normally
present in the respiratory and urogenital tract of healthy cattle but stresses such as calving, extreme
temperatures, transportation, comingling, or adaptation to a new parlor may allow the organism to enter the
body then travel to the udder via the bloodstream. Mycoplasma organisms can survive in wet environments
and are less sensitive to freezing and thawing than true bacteria. For these reasons, bedding, shady areas,
and ponds can also be areas of concern as sources of infection. It is important to realize that even though a
dairy is not experiencing mycoplasmal mastitis, the organism may be present so the possibility of an
outbreak always exists.
Diagnosis is based on culturing the organism from the milk. Culture of bulk milk tank samples is
valuable for screening and surveillance although cases can be missed due to dilution and also the “hit or
miss” nature of shedding. If positive on the bulk tank then individual testing is necessary. All fresh cows
and all clinical cases of mastitis should be tested as well. Mycoplasmas are somewhat fragile so samples
for culture must be kept cool or should be frozen if a delay of more than 48 hours from cow to lab is
expected.
There is no treatment for mycoplasmal mastitis. Control is based on identification of infected animals
then isolating, segregating and culling positives. If they are kept in the herd, Mycoplasma-infected cows
must be separated from the clean herd and milked last. Bulk milk tank cultures every 1-2 weeks should be
performed to monitor the success of the control program. Vaccines have not proven effective. Other proven
measures used to control the disease include:
 The use of plastic gloves and disinfection of gloved hands between cows
 Use of individual clean towels or cloths
 Teat dipping (pre- and post) with an effective germicide
 Routine maintenance and diagnostic testing of milking equipment
 Get a negative milk culture from purchased cows before adding to the herd
 Use strict aseptic technique when administering mastitis preparations or dry cow therapy.
 Waste milk should not be fed to calves without pasteurization because it may cause pneumonia,
arthritis, and/or ear infections in calves.
Mycoplasmas are considered contagious mastitis pathogens that can cause clinical, subclinical, and
chronic mastitis. Treatment is considered ineffective so control and prevention are imperative to avoid the
consequences of this pathogen.
New 4-H Dairy Jeopardy Contest
Larissa H. Tucker
The 4-H Dairy Jeopardy Contest is a new event to Kentucky 4-H. It will be held May 19, 2010, at the
Barren County Cooperative Extension Service Office. The contest is divided into Junior and Senior
divisions. It replaced the 4-H Dairy Quiz Bowl. The Dairy Jeopardy contest gives the 4-H’ers the
opportunity to participate as individuals. It tests their knowledge of every aspect of the dairy industry from
production to manufacturing as well as judging and showing. The rounds are very similar to the popular
Jeopardy game show. The following resources are good sources of questions: the Holstein Foundation
website at www.holsteinfoundation.org/youthprograms/dairyjeopardy.html, Hoard’s Dairyman Magazine,
Dairy Resource Handbook (4-H Livestock Leader Curriculum), and Virginia 4-H Dairy Quiz Bowl Materials at
the following web address http://www2.dasc.vt.edu/youth/bowlmat.html.
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Cooperative Extension Service
PRESORTED
STANDARD
US POSTAGE PAID
University of Kentucky
Animal and Food Science Dept.
400 W. P. Garrigus Building
Lexington KY 40546-0215
PERMIT
RETURN SERVICE REQUESTED
Kentucky Grazing School
April 14-15, 2010
Princeton, KY
Springtime Decisions Impact Profit for the
Next Year
Observing Dairy Cows in Freestalls: Stop,
Watch, Listen, Think, Change
4-H Dairy Cow Camp
April 24, 2010
Taylor County
Mycoplasmal Mastitis
4-H Dairy Jeopardy
May 19, 2010
Barren County
New 4-H Dairy Jeopardy Contest
State 4-H Dairy Judging Contest
June 29, 2010
Check out the newest University of
Kentucky publication entitled:
Opportunities for Improved Cow Comfort
through Freestall Barn Renovations
PDF: 652 kb, 12 pages
Kentuckiana Exchange Trip
August 3-4, 2010
Logan County, Kentucky
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