Genetic EvaluationsGenetic Evaluations & Decision Support & Decision Support

to Improve Feed Efficiency to Improve Feed Efficiency

Dorian GarrickDorian Garrick

Department of Animal SciencesDepartment of Animal Sciences

Colorado State UniversityColorado State University

Knee-Jerk LogicKnee-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 BreedingAnimal Breeding

Breeding ObjectiveSelection Criteria

DisseminationSystem

Economic Analysis

Goal

Breeding SchemeDesign

Mating Plan

GoalGoal

• 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?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 TraitsList 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 ApproachIndex 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 EmphasisRelative 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 WeightREV 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 WeightREV 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 ApproachIndex Approach

$INDEX = (beef price) EPDwt - r2EPDfeed + r3EPDeffic

REV Feed IntakeREV 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 IntakeREV 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 ApproachIndex Approach

$INDEX = (beef price) EPDwt - (feed cost) EPDfeed + r3EPDeffic

REV EfficiencyREV 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 EfficiencyREV 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 ValueIndex Value

• $INDEX = r1EPDwt - r2EPDfeed +r3EPDeffic

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

• We don’t need an EPD for efficiency

REV EfficiencyREV 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 Graphical Consideration of Issueof Issue

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Feed Sold on Feedlot (lb DM)

Gain Sold on Feedlot (lb liveweight)

Points form an ellipse

Shape of ellipse dependsupon genetic correlation

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Feed Sold on Feedlot (lb DM)

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AveragePerformance

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Feed Sold on Feedlot (lb DM)

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AveragePerformance

650 lb / 4000 lb0.1625

Feed EfficiencyFeed Efficiency

• Efficiency typically measuresoutput 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”

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Feed Sold on Feedlot (lb DM)

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AveragePerformance

650 lb / 4000 lb0.1625

488 lb / 3000 lb0.1625

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AveragePerformance

650 lb / 4000 lb0.1625

488 lb / 3000 lb0.1625

814 lb / 5000 lb0.1625

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AveragePerformance

650 lb / 4000 lb0.1625

488 lb / 3000 lb0.1625

814 lb / 5000 lb0.1625

Iso-efficiency Line

Iso-efficiencyIso-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

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Feed Sold on Feedlot (lb DM)

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LeastEfficient

MostEfficient

Increasing Efficiency

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AveragePerformance

Where do you want to move the average ?

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AveragePerformance

IncreasedSale weightIncreasesRevenue

$0.86/lb BWT$100/116 lb

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Where do you want to move the average ?

IncreasedSale weightIncreasesRevenue

$0.86/lb BWT$100/116 lb

Decreased feed costs$5.70 per 100 lb DM1750 lb costs $100

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Iso-income line

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Feed Sold on Feedlot (lb dry matter)

Gain Sold on Feedlot (lb liveweight)

MostProfitable

LeastProfitable

Increasing Profit

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LeastProfitable

MostProfitable

LeastEfficient

MostEfficient

Do you want efficiency or profitability ?

Summary so farSummary 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 IntakeDetermining 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 IntakePredicting 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 ValueIndex Value

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

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

– (feed cost) EPDRFI

Index ValueIndex 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 PerspectiveNational 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 MilestoneFeed 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 IntakeGetting Feed Intake

• No standards/guidelines for calculating feed intake– Role for BIF

• No existing infrastructure for collecting feed intake– Role for Breed Association

SummarySummary

• 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 TraitsAlternative List of Traits

• Suppose our list of traits had only included:– Sale weight– Feed Efficiency

Economic ValuesEconomic 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 ValuesSale 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 ValuesFeed 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