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Development of Genetic Evaluations and Decision Support to improve

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Development of Genetic Evaluations and Decision Support to improve Powered By Docstoc
					    Genetic Evaluations
    & Decision Support
to Improve Feed Efficiency
         Dorian Garrick
  Department of Animal Sciences
    Colorado State University
           Knee-Jerk Logic
• Natural to think we should strive to
  become more efficient producers
• We have been indoctrinated into using
  EPDs as tools to aid selection
  – Use WWD EPDs to increase weaning weight
  – CED EPDs to increase ease of calving
• Therefore natural to want efficiency EPDs
  to become more efficient
       Animal Breeding

Goal          Breeding
              Objective Selection Criteria

  Economic
   Analysis                 Breeding Scheme
                                Design


       Mating Plan Dissemination
                      System
                          Goal
• Cow-Calf
  – (Future) profit from sale of weanlings produced from
    grazed (otherwise low-value) forage while enhancing
    wildlife and environmental factors
  – Ranch is the unit of interest
• Feedlot
  – (Future) profit from finishing a pen or line of weanlings
     • considering food safety, environment, human health
  – Pen is the unit of interest
 What do you do with the Goal?
• Define the breeding or selection objective

  – List of traits that (directly) influence the goal

  – The relative emphasis of each trait in the list
               List of Traits
• Most producers can define this list more
  easily than the goal
• Suppose our list includes:
  – Outputs (eg total sale weight)
  – Inputs (eg purchased feed)
  – Efficiency (eg lbs net sale weight/lbs feed)
• This list dictates the EPDs we desire
            Index Approach
• Simultaneously consider the EPDs for
  each trait in the list in terms of their
  contribution to our goal (profit)

  $INDEX = r1EPDwt - r2EPDfeed + r3EPDeffic
      Relative Trait Emphasis
• Relative Economic Value (REV)

• Value of a unit change in that trait, all
  other traits in the list held constant
  – Separately calculate this value for sale
    weight, feed requirements, and efficiency
        REV for Sale Weight
• What is the “value” (increased profit) from
  a unit change in sale weight, with no
  changes in the other traits in our objective
  (ie feed requirements or feed efficiency)?
        REV for Sale Weight
• What is the “value” (increased profit) from
  a unit change in sale weight, with no
  changes in the other traits in our objective
  (ie feed requirements or feed efficiency)?

  – The answer is the sale price
         Index Approach


$INDEX = (beef price) EPDwt
           - r2EPDfeed + r3EPDeffic
          REV Feed Intake
• What is the “value” (increased profit) from
  a unit change in feed requirements, with
  no changes in the other traits in our
  objective
  (ie sale weight or feed efficiency)?
           REV Feed Intake
• What is the “value” (increased profit) from
  a unit change in feed requirements, with
  no changes in the other traits in our
  objective
  (ie sale weight or feed efficiency)?

  – The answer is the feed price
         Index Approach


$INDEX = (beef price) EPDwt
      - (feed cost) EPDfeed + r3EPDeffic
            REV Efficiency
• What is the “value” (increased profit) from
  a unit change in efficiency, with no
  changes in the other traits in our objective
  (ie sale weight or feed costs)?
             REV Efficiency
• What is the “value” (increased profit) from
  a unit change in efficiency, with no
  changes in the other traits in our objective
  (ie sale weight or feed costs)?

  – The answer is there is no change in profit
             Index Value
• $INDEX = r1EPDwt - r2EPDfeed +r3EPDeffic


• $INDEX = (beef price) EPDwt
                   – (feed cost) EPDfeed


• We don’t need an EPD for efficiency
              REV Efficiency
• Efficiency is therefore not an economically
  relevant trait (ERT) provided sale weight
  and feed intake are included in our
  objective
  – Efficiency is not a “line item” in our financial
    statements
     • Sale revenue and feed costs are line items
  – Efficiency is however a useful fundamental or
    key performance indicator (KPI)
Graphical Consideration
       of Issue
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)




                                       600

                                       500

                                       400

                                       300
                                                                          Points form an ellipse
                                       200
                                                                          Shape of ellipse depends
                                                                          upon genetic correlation
                                       100

                                         0
                                             0   2000              4000                6000        8000
                                                        Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600

                                       500

                                       400

                                       300                                                      Average
                                                                                              Performance
                                       200

                                       100

                                         0
                                             0   2000              4000                6000         8000
                                                        Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600

                                       500

                                       400

                                       300                                                       Average
                                                                                               Performance
                                       200                                                    650 lb / 4000 lb
                                                                                                  0.1625
                                       100

                                         0
                                             0   2000              4000                6000            8000
                                                        Feed Sold on Feedlot (lb DM)
             Feed Efficiency
• Efficiency typically measures
                output divided by input
  – Big numbers are “desirable”
  – Lbs gain per lbs feed (eg 1/6 =0.16 lb/lb)
• Alternative is feed conversion rate
  – input over output
  – Small numbers are “desirable”
  – Lbs feed per lb gain (eg 6 lb/lb)
• Rankings are “equivalent”
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600

                                       500

                                       400

                                       300                   488 lb / 3000 lb                    Average
                                                                 0.1625                        Performance
                                       200                                                    650 lb / 4000 lb
                                                                                                  0.1625
                                       100

                                         0
                                             0   2000              4000                6000            8000
                                                        Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600
                                                                                                814 lb / 5000 lb
                                       500                                                          0.1625

                                       400

                                       300                   488 lb / 3000 lb                    Average
                                                                 0.1625                        Performance
                                       200                                                    650 lb / 4000 lb
                                                                                                  0.1625
                                       100

                                         0
                                             0   2000              4000                6000            8000
                                                        Feed Sold on Feedlot (lb DM)
                                                                                         Iso-efficiency Line
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600
                                                                                                814 lb / 5000 lb
                                       500                                                          0.1625

                                       400

                                       300                   488 lb / 3000 lb                    Average
                                                                 0.1625                        Performance
                                       200                                                    650 lb / 4000 lb
                                                                                                  0.1625
                                       100

                                         0
                                             0   2000              4000                6000            8000
                                                        Feed Sold on Feedlot (lb DM)
              Iso-efficiency
• All animals on the line have the same
  efficiency
  – If efficiency was your goal, you would be
    equally happy with any of those animals
                                       900

                                       800
                                                  Most
                                                 Efficient
                                       700
Gain Sold on Feedlot (lb liveweight)




                                       600
                                                                                                  Least
                                                                                                 Efficient
                                       500
                                                   Increasing
                                                        Efficiency
                                       400

                                       300

                                       200

                                       100

                                         0
                                             0           2000              4000                6000          8000
                                                                Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600

                                       500

                                       400

                                       300                                                      Average
                                                                                              Performance
                                       200

                                                 Where do you want to move the average ?
                                       100

                                         0
                                             0   2000              4000                6000         8000
                                                        Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                             O
                                       600

                                       500
                                                   Increased
                                                  Sale weight
                                       400
                                                   Increases
                                                    Revenue
                                                 $0.86/lb BWT
                                       300                                                              Average
                                                  $100/116 lb
                                                                                                      Performance
                                       200

                                       100

                                         0
                                             0           2000              4000                6000         8000
                                                                Feed Sold on Feedlot (lb DM)
                                       900                                                            Decreased feed costs
                                                                                                      $5.70 per 100 lb DM
                                       800                                                            1750 lb costs $100

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                             O
                                       600

                                       500
                                                   Increased
                                                  Sale weight
                                       400
                                                   Increases
                                                    Revenue
                                                 $0.86/lb BWT
                                       300
                                                  $100/116 lb
                                       200

                                                          Where do you want to move the average ?
                                       100

                                         0
                                             0           2000              4000                6000       8000
                                                                Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                     O
                                       600

                                       500

                                       400

                                       300

                                       200

                                       100

                                         0
                                             0   2000              4000                6000   8000
                                                        Feed Sold on Feedlot (lb DM)
                                       900

                                       800

                                       700
Gain Sold on Feedlot (lb liveweight)


                                                                        O
                                       600

                                       500

                                       400       Iso-income line

                                       300

                                       200

                                       100

                                         0
                                             0      2000              4000                6000   8000
                                                           Feed Sold on Feedlot (lb DM)
                                       900
                                                                       Most
                                       800                           Profitable


                                       700       Increasing
Gain Sold on Feedlot (lb liveweight)


                                                    Profit
                                       600

                                       500
                                                                                           Least
                                                                                         Profitable
                                       400

                                       300

                                       200

                                       100

                                         0
                                             0                2000                4000                6000   8000
                                                               Feed Sold on Feedlot (lb dry matter)
                                       900                               Most
                                                                       Profitable
                                       800

                                       700        Most
                                                                                                           Least
Gain Sold on Feedlot (lb liveweight)


                                                 Efficient
                                                                                                          Efficient
                                       600

                                       500                                                  Least
                                                                                          Profitable
                                       400

                                       300

                                       200
                                                         Do you want efficiency or profitability ?
                                       100

                                         0
                                             0               2000              4000                6000       8000
                                                                    Feed Sold on Feedlot (lb DM)
            Summary so far
• We need good EPDs
  – For outputs (Sale weight & Value)
  – For inputs (Feed intake, Health, Labor)
• Selection on overall value that rewards
  output and penalizes inputs will increase
  efficiency
  – We don’t need an efficiency (or conversion)
    EPD
     Determining Feed Intake
• Feed requirements are determined by:
  – Maintenance requirements
     • Metabolic body weight, condition score, milk
       potential
  – Activity & Climate (if not thermo-neutral)
  – Production
     • Gain, pregnancy, lactation, (replacements)
  – Unique (unknown) factors that differ from one
    animal to another (eg proton leak) (ie RFI)
       Predicting Feed Intake
• Could measure feed intake
  – Easier in a feedlot than extensive grazing
  – Subject to measurement & other errors
• Could predict expected feed intake from
  knowledge of productivity
  – Will account for most of the variation in feed
    requirements
  – Will not account for variation in “efficiency”
    known as “residual feed intake” or RFI
              Index Value
• $INDEX = (beef price) EPDwt
                   – (feed cost) EPDfeed

• $INDEX = (beef price) EPDwt
        – (feed cost) EPDpredicted feed
        – (feed cost) EPDRFI
                 Index Value

• If we don’t have intake observations all
  animals will have the same EPD for RFI
  – Cannot predict it from correlated characters,
    as if we could, we can come up with a better
    “predicted feed”
     • RFI is the part of feed intake we cannot explain
         National Perspective
• With or without individual feed intake
  – Predict feed intake from “performance”
  – Don’t need feed intake EPD per se
     • Depends upon for eg rate of gain
     • Account for the cost of predicted feed in decision
       support using performance (& repro) EPDs
• With individual feed intake
  – Predict an EPD for residual feed intake
     • Account for the cost/saving of RFI along with
       predicted feed in decision support
       Feed Intake Milestone
• Before we get individual feed intakes
  – Use predicted requirements
  – For cow-calf
     • Need mature weights & CS
     • Need heifer pregnancy & stayability
  – Need Total Herd Recording (THR)
• After we get individual feed intakes
  – Only change will be EPDs for RFI
         Getting Feed Intake
• No standards/guidelines for calculating
  feed intake
  – Role for BIF
• No existing infrastructure for collecting
  feed intake
  – Role for Breed Association
                   Summary
• Selection for profit requires measures of outputs
  and inputs
  – Don’t need an EPD for efficiency or intake
  – Predict inputs from knowledge of production
• Better estimates of cow-calf inputs require THR
  – Immediate opportunity to improve existing cow-calf
    recording practices and more fully account for
    expected feed requirements
• Future opportunity to collect actual feed intake –
  outcome will be RFI
      Alternative List of Traits
• Suppose our list of traits had only
  included:
  – Sale weight
  – Feed Efficiency
          Economic Values
• What is the value of a unit change in sale
  weight with no change in feed efficiency?

  – The answer is no longer the sale price
    Sale Wt Economic Values
• What is the value of a unit change in sale
  weight with no change in feed efficiency?

  – The answer is no longer the sale price
     • If sale weight increases, and efficiency of gain is
       unchanged, more feed will be required
  – The answer is the sale price less the cost of
    the feed required for the extra gain
     • But marginal and average efficiency may differ
  Feed Effic Economic Values
• What is the value of a unit change in feed
  efficiency with no change in sale weight?

  – The answer is not straightforward – it
    depends upon the feed cost and the amount
    of feed consumed
  – We cant put a value on feed efficiency without
    considering feed intake

				
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