Transcript Reproduction of the cow herd

Update on the NBCEC
Decision Support System
R. Mark Enns
Department of Animal Sciences
Colorado State University
What is Decision Support?

For many traits there are optimum
levels of EPDs that are not the highest
or lowest, but somewhere in between.
The most valuable animal often
represents a balance of EPDs for
various traits.
Richard M. Bourdon
Understanding Animal Breeding
Current Modeling Approach
Simulated Situation
Current
Cow
Herd
(EPD)
Base
Current
(equilibrium)
Cow
X
Herd
(EPD
&
Performance)
Like
Merit
Bulls
Base Cow-calf outputs & inputs
Bulls
Selected
X
From
Sire Summary
Daughter
(equilibrium)
Cow
Herd
X
(EPD
& base mean
Performance)
Like
Merit
Bulls
Simulated Cow-calf outputs & inputs
Decision Support Model
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Goals

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User friendly and simple while remaining as
accurate and powerful as possible
Alternative to Indexes

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B. Brigham
Allows producers to customize to fit their own
production system
‘Selection by Simulation’
Automated with online sire summaries
Include only traits which economically effect
production
Current Model Assumptions

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Developed for cow/calf production
Calves are sold at weaning
Cow herd reaches equilibrium

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Simulates a herd of daughters
No breed effects

Eliminated with MBE
Other Considerations

The system should not be used to
compare bulls of differing breed
compositions

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Does not currently account for heterosis
Must be cognizant of the differences in
EPD produced by each breed

Stayability

Ramifications of having/not having
How important is reproductive
ability?

The largest contributor to profitability of
the cow/calf operation.

Ponzoni and Newman, 1989; Melton, 1995
Change in net income ($) per 1000
base cow herd -- stayability
Net Income
Herd Stayability
Stayability EPD
Change in number of mature
cows– stayability
ERT’s used in the DSS

Sale weight

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Weaning weight
direct
Weaning weight
maternal
Cow weight

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Sale of cull cows
Yearling weight
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Maintenance energy
req.
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Number of cows
Feed costs
Heifer pregnancy and
stayability
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Age structure
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Sale of open heifers
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WW of calves
number of animals for
sale/replacements
ERT’s used in the model and
their influence

Calving Ease
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Direct and Maternal
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Number of calves
Costs of assistance
Additional

Birth weight (part of growth curve—feed
req.)
Red Angus Example:
Next release (beta)
Most complete set of EPD for the
Economically Relevant Traits
Scenario #2

Keep cow numbers constant
Scenario #3

Herd only experiences 10% calving difficulty

All else constant
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EPD
Costs
Prices received
Rank of bulls under different
scenarios
Bull
Scenario
1
Scenario 2
(holds cow #
constant)
Scenario 3
(# 2 except 10% calving diff.)
Chateau 744
7
2
3
Grandcanyon 1244G
4
1
1
Cherokee Cnyn 4912
2
5
5
Vacation H7106
3
7
7
Make Mimi 7249
5
4
4
Cheyenne B221L
6
3
2
Romeo L081
1
6
6
Outcomes
Customized selections for these
particular management scenarios
based on economics of those decisions
Ert.agsci.colostate.edu
Future additions
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Price slide (only interface remaining)
Discounted gene flow
Post-weaning model (prototype done)
Heterosis effects/MBE EPD
Streamlining input of EPD
Risk analysis that accounts for differences in
accuracy of EPD
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Yearling vs proven sires
Questions?