Genetic Base and Trait Definition Update

Paul VanRadenAnimal Improvement Programs LaboratoryBeltsville, MD, [email protected]

2004

2004

2004

Genetic Base and Trait Definition Update

ADSA-ASAS JOINT MEETING 2004 (2) P.M. VanRaden200

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Previous USA Base Changes

1965

Predicted Difference (subtract mean yield)

1974

Modified Contemporary Comparison

1984

Red & White and Holstein bases separated

1989

Red & White and Holstein bases merged, Animal Model

1995

Age-Parity adjustments (changed trend)

2000

Lifetime Net Merit, true protein (SD change)


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2005 Trait and Model Changes

Adjust for past inbreeding and expected future inbreeding (EFI)

Adjust for differing parity SD

Yield PTA expressed to average age instead of mature equivalent

Use cow instead of bull base for DPR

Convert PTA SCS to Udder Health?


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Genetic Gain 1995-2000(birth year)

BV HO JE BS GU AY MS

Prot (kgs)

17 15 15 11 7 5

Fat (kgs) 16 15 18 15 8 8

Milk (kgs)

535 407 436 387 235 212

Prod Life .5 .7 .7 .5 .5 1.1

SCS .02 .01 -.08 .03 -.01 .03

DPR (%) -.1 -.2 -.4 -.4 .0 .1


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Daughter Pregnancy Rate Bases

PTA DPRHO JE BS GU AY MS

1995 cow mean

.4 .2 .6 -.3 -.1 .5

progress -.1

-.1 -.2 -.2 .0 .0

Base change -.3

-.1 -.4 +.5 +.1 -.5


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Inbreeding AdjustmentsVanRaden and Smith 1999 JDS 82:2771

Past inbreeding (F) and future (EFI) Regression on F in animal model (PTA0) PTAEFI = PTA0 + EFI * byield.F Publish PTAEFI , use PTA0 in mating program

Helps pass Interbull trend tests 2 and 3 Corr (current PTA, PTAEFI) = .9976 PTAEFI trend 6% lower, PTA0 trend 3% higher Corr (USA, other countries) decline by .01


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Parity SD Adjustments

Multiplicative age factors Means are adjusted to mature yield Variances are not quite equal

Deviations will be multiplied by [1.07 1.00 .95 .90 .85] (parities 1-5)

Helps pass Interbull trend test 1 Corr (official, adjusted PTA) = .9998

for Holstein bulls born since 1995


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Adjust Yield PTA to Average Age

Average age vs. mature offsets base SD

Base SD has not been updated since 1995 Change would multiply PTA by 1.11 (Hol) Reduced age (36 mo) divides by 1.10 PTA lb / EBV kg = 2.2 / 2 = 1.10

Proposed by USDA (M. Schutz) in 1994 Recommended by Holstein GAC, Oct 1994 Vetoed by Council “to allow the industry

time to consider the nature and effect of such a change.”


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Somatic Cell Count Measured with same standard metric

unit (cells / ml) in every country

Transformed by log 2, log 10, or log e

Reversed scales in 9 of 19 countries

Added means of 100, 3, 4, etc.

Changed SD to report EBV, PTA, or STA

Different choice in almost every country!


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International Udder Health Scales

Ctry Unit

Mean

SD Dir Ctry Unit

Mean

SD Dir

USA PTA 3.1 .22

- NLD RBV

100 4 +

CAN PTA 3.0 .25

- DNK RBV

100 5 +

BEL EBV 3.0 .47

- SWE RBV

100 7 +

JPN EBV 2.4 .42

- DEU RBV

100 12 +

AUS EBV 0 .11

- ITA STA 4 1 +

GBR PTA 0 13 - FRA STA 0 1 +

HUN STA 0 1 - ESP STA 0 1 +


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SCS vs. Udder Health

PTA UH = -5 (PTA SCS – breed avg.)

Reversed scale with mean 0, SD 1 Interpreted like linear trait STAs Positive numbers would be favorable Range would be similar to DPR, PL +1 PTA UH would equal a reduction in

SCC of 13%

Udder Health is an Interbull term


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SCS Breed Means

SCS HO JE BS GU AY MS

1995 3.10 3.31

3.09 3.21

2.93

3.03

2000 3.09 3.34

2.94 3.31

2.97

3.07

Difference

-0.01

0.03

-0.15

0.10

0.04

0.04

Instead use: 3.00

3.00 3.00

3.00

3.00

3.00


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Summary

Genetic progress in most recent 5 years similar to previous 5 years

Adjustments for inbreeding and for differing parity SD will be introduced

PTA SCS will not change to udder health

February 2005 changes must be sent to Interbull by September 1, 2004

Genetic Base and Trait Definition Update

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