The
“Cow Value” module in Dairy Comp 305 estimates the value of each cow in a
dairy herd relative to an average fresh heifer.
A positive Cow Value means the animal is worth more than an average
heifer in that herd. A negative Cow
Value suggests the animal is worth less than an average heifer. In addition to estimating the value of the
cow, the module also calculates the current value of a pregnancy for each
adult, to help managers decide if an open animal should be inseminated.
Dairy
Comp 305 includes a powerful tool that can help dairy herd managers decide
to breed, treat, or cull animals on a daily basis. This module is called Cow Value.
There
are two important rules to remember when using the Cow Value estimates.
1.
Keep
your dairy at capacity.
2.
Every
decision made on an animal in a commercial dairy is based on improving the
herd’s profitability. You keep an
animal because she is more profitable to keep than to replace. You breed animals because they will be more
profitable if they become pregnant. You
treat animals because they will be more valuable after a treatment than they
are before. Cow Value estimates can
help the herd manager assign a value to animals more consistently.
A
commercial dairy cow’s current value is the sum of her value for beef and
the value of the milk she is likely to produce in the future.
The
value of an animal’s future production is based on
·
The
amount of milk she is likely to produce in the future.
·
The
price of milk in the future.
·
The
value of the money you must invest in the animal.
The
amount of milk an animal is likely to produce in the future is based on
·
Age –The younger the animal,
the longer she is likely to stay in the herd and produce milk.
·
Stage of lactation - an animal that is 30 days
in milk is likely to produce more milk in the future than an animal that is 200
days in milk
·
Reproductive status - an animal that is
pregnant is likely to produce more future milk, than an animal that is
open. An animal that was just
inseminated, is more likely to be pregnant than an animal that has not been
inseminated.
·
Production level - a high producing animal
is likely to produce more milk than a low producing animal.
A)
Start
Cow Value by typing COWVAL on the command line in Dairy Comp.
·
Allow
Dairy Comp to make the two new items, CWVAL and PGVAL
·
Have
Dairy Comp estimate the values
B)
Make
lists of animals to get a feel for how it ranks and values your cows.
· Change some of your assumptions and re-run the lists. Note how the values changed.
C)
Put
the CWVAL and PGVAL on your cow cards, and perhaps your vet list.
See Appendix A.
D)
Set
the scheduler to re-calculate CWVAL and PGVAL each night so the values will
stay current. See Appendix B.
Run the Cow Value module.
Go
to the command line in Dairy Comp and type COWVAL <enter>
A menu appears with the following choices:
1) Exit -
Enter 1 to exit Cow Value
2) Edit Parameters -
Change parameters
3) Estimate Cow Value -
Calculate Cow Value
4) Calculate Parameter Estimates - Use to calculate parameters from
historical performance
Select 2 – Edit Parameters
This table appears.
Lact 1
CullRate 0.20
Lact
2 CullRate 0.30
Lact
3 CullRate 0.45
Pregnancy Rate 0.14
Lact 4 CullRate 0.55
Conception Rate 0.40
Lact 5 CullRate 0.65
Heat Detection 0.35
Lact 6 CullRate 0.70
Lact
7 CullRate 0.75
VWP 60 Lact 8 CullRate
0.80
Avg Dopn 130
Lact 9 CullRate 0.90
Heifer Cost 1200
Lact 1 305 Milk 20000
Cull Value 300
Lact 2 305 Milk 22000
Lact
3 305 Milk 24000
Milk Price/cwt 13.00
Marginal Feed 3.00
Lact 1 Persist 0.96
Maint Feed/day 1.50
Lact 2 Persist 0.94
Lact
3 Persist 0.92
Discount Rate 0.10
These parameters are discussed in more detail in Appendix C, and a descriptive text appears when the value is highlighted and the F1 key is pressed.
You can return to the Cow Value menu by pressing
the escape (ESC) key. The menu option
"Calculate Parameter Estimates" will use cow data from your cowfile
to estimate the culling rates and the 305 day milk production averages. Warning:
estimates based on past performance often do not accurately project future
performance.
Once you have reviewed the parameters press
escape and select “estimate Cow Value” from the menu.
The
first time Dairy Comp estimates Cow Value it will ask you to allow it to create
two new items, first CWVAL (to store the Cow Value estimate) and then PGVAL (to store the value of a
pregnancy). Press <enter> each
time Dairy Comp asks if you would like to create the two new items. If Dairy Comp warns you that your Item Table
is full, call the dairy management support group for help. Dial 1-800-496-3344 and press 3.
A brief summary is displayed following the
calculation of Cow Value.
Cull Milk 49 <-- Cutoff pounds of milk for DNB cows
Replacement 800 <-- Cash cost of replacement (Heifer
cost – beef value of cull)
Heifers 0 <-- Number of heifers - ignore
To Sell 65 <-- Number with negative cow value
To Keep 568 <-- Number with positive cow value
Average CWVAL 705 <-- Average value of all cows
Open 277 <-- Number of open cows
Average PGVAL 178 <-- Increased value if an average
open animal becomes pregnant
Preg 356 <-- Number of pregnant cows
Average PGVAL 662 <-- Decreased value if an average
pregnant animal aborts
After calculating Cow Value exit the Cow Value
routine by pressing the escape (ESC) key.
Make a report to look at the
values
There are many different ways you may want to
look at CWVAL and PGVAL. A simple
start is to list all adults sorted by CWVAL.
The lowest value animals will be on the top of the list. The highest value animals will be on the
bottom of the list.
There are several different “FOR” statements to
consider in your report. In this
example report, we used “FOR DIM>75”.
This narrows our cow list to those with more reliable production
estimates for this lactation. It also
excludes lactation zero animals. Once
you get to know Cow Value estimates more, you may want to limit the list to
cull candidates by using “FOR CWVAL<0”.
CWVAL and PGVAL Relative to Reproductive Status
·
If an animal is not pregnant, than the value of
getting her pregnant would be her current PGVAL. (If she became pregnant today her new CWVAL would be her current
CWVAL plus her current PGVAL).
·
If the animal is pregnant her CWVAL already
includes her PGVAL. If she were to
abort then her CWVAL would decrease by the PGVAL.
·
If the animal is open and becomes bred her CWVAL
goes up because she is more likely to be pregnant than before she was bred so
she is more likely to produce more milk into the future.
A Simple Example Cow Value List
SHOW ID LACT DIM MILK RV RPRO DSLH DCC CWVAL PGVAL BY CWVAL FOR DIM>75
ID LACT DIM MILK RV RPRO DSLH DCC CWVAL PGVAL
===== ==== ===== ==== === ======= ===== ===== ====== ======
4224
3 84 26 59 BRED 11
0 -757 -248
1430 3 85 45 70 BRED 53 0 -646 157
6848
1 125 48 72 BRED 27 0 -410
587
32
3 457 47 114 NO BRED 0 0
-330 449
993 3 209 14 85 BRED 16 0 -330 -325
Animal 4224 is the least valuable animal in this
herd. Her CWVAL is -$757 relative to an average springing
heifer in this dairy. Further, If she
were to get pregnant her value to this herd would decrease another $248 because
she may be kept another lactation rather than be replaced with a more profitable
animal. This suggests that the dairy
will make more money, beginning today, if this animal is replaced with an
average, fresh, first lactation animal.
Animal 6848 has a negative CWVAL but her PGVAL
tells us that if she turns out to be pregnant to this current breeding (27 days
ago) her value will become +$587 + (-$410) = +$147. She will become $147 more valuable than an average fresh heifer
in this herd.
Animal 32 has been coded not to breed. The CWVAL shows that she should be replaced
and the PGVAL tells us that she would have been $449 more valuable had she
gotten pregnant earlier in this lactation.
--- Middle of report deleted ----
The end of the Cow Value report
ID LACT DIM MILK RV RPRO DSLH DCC CWVAL PGVAL
===== ==== ===== ==== === ======= ===== ===== ====== ======
5413 1 484 0 120 DRY 335 274 1782 2789
2579 1 465 79 130 PREG 127 131 1791 1359
2699
1 332 0 136 DRY 246 246
1814 2821
5324
1 343 82 135 PREG 123 91
1912 1426
This report lists the most valuable animals at
the end. Animal 5324 wins. Notice that if she aborts her value will
drop from $1912 to $486 ($1912-$1426).
If 2699 aborts her value will drop from $1814 to –$1007 and she should
be sold.
Key
to the Report Headings
ID Cow ID number
LACT Lactation number
DIM Days in milk
MILK Last test day milk weight
RV Relative value (internal)
RPRO Repro code (FRESH,BRED,DRY etc)
DSLH Days since last breeding
DCC Days carried calf if pregnant
CWVAL estimate of cow
PGVAL estimate of
value of pregnancy
From
the Author, Dr. Steven Eicker, DVM
The future value of a cow is of course,
unknown. This module is based on models
that estimate the future profitability of a cow based on the parameters listed
above. But certainly, pregnant cows are
much more likely to remain in the herd, and higher producing cows are more
likely to be more profitable next lactation too. Thus, these predictions should be used as guidelines. They are
not meant to replace sound judgement, but to augment it.
The value of a cow is always relative to that of
a replacement heifer.
Thus, a cow with a negative value is a potential
cull. A cow with a
value of $150 that is diagnosed with a displaced
abomasum may be more profitable shipped than treated.
The estimated value of a pregnancy can assist a
dairy in deciding whether it is worth the effort to breed a cow. Likewise, for a pregnant cow, the pregnancy
value can help estimate the cost of an abortion. Open cows with negative pregnancy values should not be bred, as
spending money on pregnancy will lower their value!
Perhaps the most thought provoking concept
arises when an open cow has a negative cow value, and also has a negative
pregnancy value. This means she is worth less pregnant that if she remains
open. However, the software algorithm assumes that cows that are not coded DNB
are still trying to get pregnant, and that a percentage of the time they will. Thus, this cow will have a lower cow value
while she is still eligible to be breed.
Her value should INCREASE once she is flagged as a DNB. This makes sense - it is sometimes a
profitable decision to flag a cow as a DNB cow. Note that a cow flagged as DNB may still have a positive cow
value, until her milk production decreases below that cull/cutoff value.
By necessity, we are modeling the future to
predict the future production of each cow.
We make lots of assumptions, such as eventually, all cows leave the
dairy, and when they do, a replacement enters the herd. Crucial to the model is that a dairy farm
will operate to maximize profitability.
Again, DNB cows demonstrate some of the fundamental concepts.
Flagging a cow DNB means she will not freshen again. It means that she will be sold once her milk
production is "too low". What does "too low" mean? Two possibilities:
1. Her
feed cost exceeds her income, somewhere around 20 pounds.
2. Her
daily profit is less than a replacement, even including the
cost
($1/day) of the replacement, somewhere around 50 pounds.
Assuming a dairy is trying to make a profit, the
correct decision is #2. The model sells
cows once they produce less than this "Cutoff" milk. Let's say cutoff milk is 50#. A cow producing 60 pounds is profitable
until she reaches 50 pounds, about two more months. Her expected production is about 55 for 60 days, which generates
about 60 * (55-50) = 300# or $30 more than the heifer. Fine, her CWVAL will be about $30.
Appendix A
Adding CWVAL and PGVAL to your Cow Card
display
Go to an animal’s cowcards and select two spots
you would like to display the CWVAL and PGVAL estimates.
·
“Right click” on the space on the cowcard you
wish to display the Item.
·
“Left click” on add\replace an item on the page.
·
“Left click on the Item from the Item pick list
that is displayed.
Once you have placed the items on a cow card,
press ESC to exit Alter. Go to an
animal’s cow card and confirm that the items are displayed.
Appendix B
Automatically
updating Cow Value every day using the Dairy Comp Task Scheduler.
Animals’ values change daily. The calculation must be re-run each day for
the estimate to remain current.
Under the File Menu select Alter.
·
Select 6) Schedule Tasks.
·
From the Task Scheduler Menu, select 4) Add a
new task.
·
When it asks for the next date to run, select
tomorrow’s date.
·
Schedule the next time for 0100, (1:00 AM).
·
The Interval Unit will be Days.
·
The interval will be 1, meaning every 1
day.
·
The command to run is COWVAL\G.
Now the first time Dairy Comp is running idle in
the foreground after 1:00 AM tomorrow, and each successive day, it will
recalculate the Cowvalue estimates.
Appendix C
Add
CWVAL and PGVAL to your vet list
One of the best times to decide to stop breeding
an animal is when the veterinarian declares her open at a pregnancy exam. Having the value estimates on the vet list
may make it easier to make that decision more consistently.
It the items will fit into your VITEMS command,
it will be easy to add them. If they do
not fit, or you would like help putting these estimates on the vet list
Heat Detection Rate
is the ratio of heats observed to heats occurred
Conception Rate
is the ratio of conceptions to breedings
Most dairies have heat detection rates
between 0.35
and 0.75 and conception rates between 0.20
and 0.50
Pregnancy Rate is
automatically calculated as the product of heat detection and conception
rates. It can be interpreted as the
percentage of heats that result in a pregnancy.
Voluntary Wait Period
is the number of days in milk at which animals in heat will be bred.
Average Days Open
is the average days in milk at conception.
Heifer Cost is the cost to
either raise or purchase a replacement heifer.
If a significant percentage of heifers die,
consider
adding that percentage to the purchase price.
Cull Price is the average
expected income from selling a cow.
The difference between
Heifer Cost and Cull Price is the cash expense of replacing a cow.
Milk Price is the
expected milk price over the next few years per 100 units (pounds) of milk.
Marginal Feed is the
estimated cost of the incremental feed required to get this additional
milk. A quick estimate is the cost of
40 units (pounds) of dry matter.
Maintenance Cost
is the daily feed expense to feed a cow not including milk production. A quick
estimate is the daily cost to feed a dry cow, or a springing heifer.
Discount Rate is the
expected annual return a dairy should get on money invested today. It is usually slightly higher than the
current interest rate.
Cull Rate is the percent of
cows that do not reach the next lactation.
The
defaults are .20, .30, .45, .55, .65, .70, .75, .75, ...
Most dairies cull between .20 to .55 per
lactation. This number tends to
increase with age. Dairies with
excellent reproduction and low calf losses can approach .50 unless they market
springing heifers.
305 Milk is the predicted
average 305 day milk production for each lactation.
Persistency is the
estimated monthly change in milk production once a cow is past her peak
production. The default values are as
follows:
Lact 1
0.96
Lact 2
0.94
Lact 3+
0.92