usda genetic evaluations for type traits

2006

George R. WiggansGeorge R. WiggansAnimal Improvement Programs LaboratoryAgricultural Research Service, USDA, Beltsville, [email protected]

USDA Genetic Evaluations for USDA Genetic Evaluations for Type TraitsType Traits

ADGA 2006 (2) G.R. Wiggans200

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Type TraitsType Traits

Describe physical characteristics of animal

Final Score (overall assessment) Scored 50-99

Linear traits (13 traits) Scored 1-50


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History of Type EvaluationsHistory of Type Evaluations

1986 – Sire model for final score

1988 – Collection of linear traits

1989 – Sire model for linear traits

1995 – Multi-trait animal model

2000 – Base change

2005 – Base change


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Numbers of Appraisals of DoesNumbers of Appraisals of Does2000 2001 2002 2003 2004 2005 2006

Alpine 888 1,141 892 1,368 1,061 1,254 1,185

Nubian 1,099 1,059 916 1,345 1,161 1,173 1,330

Toggenburg 404 579 408 546 453 520 687

LaMancha 581 546 524 714 758 584 885

Saanen 326 552 422 436 439 541 539

Oberhasli 204 268 246 328 284 299 312

Experimental 190 263 204 244 238 182 262

Sable - - - - - 40 38

Total 3,692 4,408 3,612 4,981 4,394 4,593 5,238


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Appraisals for Does in 2005Appraisals for Does in 2005(n=4,593)(n=4,593)

Trait Mean SD Min MaxFinal score 85.8 4.0 55 93Stature 24.8 7.5 1 50Strength 27.0 5.3 3 48Dairyness 33.2 3.7 12 45Teat diameter 20.4 7.2 2 50Rear legs 27.7 3.5 3 42Rump angle 30.5 6.0 5 46Rump width 28.2 5.2 4 50Fore udder attachment 33.7 5.5 1 50Rear udder height 36.7 6.6 5 50Rear udder arch 24.1 6.2 5 48Udder depth 33.2 7.1 5 50Suspensory ligament 25.4 4.7 13 45Teat placement 17.5 5.8 2 50


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Evaluation model Evaluation model

An equation that indicates what factors contribute to an observation

Separates the genetic component from other factors

Solutions used to predict the genetic potential of progeny


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Type Evaluation ModelType Evaluation Model

MODEL: y = h + a + p + ey = Adjusted type recordh = Herd appraisal datea = Animal genetic effect (breeding value)p = Permanent environment

Non-genetic effect common to all a doe's appraisals

e = Unexplained residual


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Multi-trait ModelMulti-trait Model

Scores from one trait affect the evaluation of other traits through the genetic correlations


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Genetic Correlations Genetic Correlations

Final Score Strength Dairyness

Fore Udder Attachment

Final Score 1.00 .30 -.15 .66

Strength 1.00 -.51 .15

Dairyness 1.00 -.16

F. Udder Att. 1.00


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Genetic ParametersGenetic Parameters

Heritability – Portion of variation due to genetics

Repeatability – Similarity of repeated records, includes genetic and permanent environmental effects


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Heritability and RepeatabilityHeritability and Repeatability

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Rear udder arch

Rear legs

Dairyness

Fore udder attachment

Rear udder height

Udder depth

Final score

Rump width

Strength

Rump angle

Suspensory ligament

Teat placement

Teat diameter

Stature

Heritability

Repeatability


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Genetic Change per year from does Genetic Change per year from does born 1990 born 1990 –– 2003 2003

Trait Trend R2

Rear legs -0.060 0.979Rear udder height -0.058 0.931Udder depth -0.028 0.675Fore udder attachment -0.009 0.699Rear udder arch 0.005 0.098Final score 0.033 0.927Dairyness 0.053 0.965Rump width 0.059 0.829Teat diameter 0.067 0.859Strength 0.107 0.968Suspensory ligament 0.119 0.970Teat placement 0.195 0.983Rump angle 0.240 0.987Stature 0.389 0.957


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Breeding value trend for typeBreeding value trend for type

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

19901991

19921993

19941995

19961997

19981999

2000Year

Tre

nd

(B

V)

Final Score

Stature

Fore Udder Attachment


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Herds for Bucks Born 1999 – 2003Herds for Bucks Born 1999 – 2003(n=2,451)(n=2,451)

0

300

600

900

1200

1500

1800

1 2 3 4 5 6 7 8 9 10

Herds

Bu

ck

s


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Daughters for Bucks Born 1999 – 2003Daughters for Bucks Born 1999 – 2003(n=2,451)(n=2,451)

0

150

300

450

600

750

900

1050

1 4 7 10 13 16 19 22 25 28

Daughters

Bu

cks


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Distribution of Reliability for Final Distribution of Reliability for Final ScoreScore

0

50

100

150

200

250

300

350

400

450

500

00.

050.

100.

150.

200.

250.

300.

350.

400.

450.

500.

550.

600.

650.

700.

75

Reliability of Final Score

Fre

qu

en

cy

of

Re

liab

ility


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Methods of Expressing evaluationsMethods of Expressing evaluations

Estimated breeding value (EBV) Animal’s own genetic value

Predicted transmitting ability (PTA) ½ EBV Expected contribution to progeny


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Combining type and productionCombining type and production

Production-Type index (PTI) Combines yield and type evaluations

into a single value There are 2 versions:

PTI 2:1, weights 2 production : 1 type PTI 1:2, weights 2 type : 1 production


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AIPL web servicesAIPL web serviceshttp://aipl.arsusda.gov/query/public/tdb.shtml#GoatsTBLQueries provide display of:

Pedigree information Yield records Herd test characteristics Genetic evaluations of does & bucks

Yield Type

Access information using: ID number Animal name Herd code


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19181918


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19471947


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19771977


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20032003


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SummarySummary

Type data contributes to genetic evaluations of Final Score and 13 linear traits

Multi-trait Animal Model combines information from all relatives and traits

Few bucks have many daughters in many herds so reliability is low

Production-type index combines evaluations

Substantial genetic progress is occurring in several traits

usda genetic evaluations for type traits

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