The World's source for Bovine Genetics

May 2007 - Formula Changes

New Udder Composite

New UDC = [(UD x .35) + (FU x .16) + (UH x .16) + (UW x .12) + (UC x .09) + (TP x .05) - (RP* x .07)] + 0.15

Where:
    UD = Udder Depth
    UH = Rear Udder Height
    UC = Udder Cleft
    RP = Rear Teat Placement*
    FU = Fore Udder Attachment
    UW = Rear Udder Width
    TP = Front Teat Placement
* Rear Teat Position is the absolute value of the difference between the animal’s STA for Rear Teat Placement and the intermediate optimum STA of +1.00.

Eg. Animal with an STA of -2.5 would have an absolute difference of +3.5; Animal with an STA of +2.5 would have an absolute difference of +1.5

New TPI™ Formula

Current TPI Formula

[(32(PTAP)/19.4) + (18(PTAF)/23.0) + (13(PTAT)/0.7) - (2(DF)/1.0) + (10(UDC)/0.8) +
(5(FLC)/0.85) + (8(PL)/1.26) - (5(SCS)/0.13) + (5(DPR)/1.0) - (2(DCE)/1.0)]3.6 + 1548

New TPI Formula

[(28(PTAP)/19.4) + (17(PTAF)/23.0) + (13(PTAT)/0.73) - (1(DF)/1.0) + (10(UDC)/0.8) +
(5(FLC)/0.85) + (10(PL)/1.26) - (5(SCS)/0.13) + (8(DPR)/1.0) - (2(DCE)/1.0) -
(1(DSB)/0.9)] 3.7 + 1575

Note:
    New udder composite formula
    New PTATs with larger standard deviation
    Added Daughter Stillbirth
    Multiplier changed from 3.6 to 3.7
    Constant changed from 1548 to 1575


Where:
    PTAP = PTA Protein
    PTAT = PTA Type
    UDC = Udder Composite
    PL = PTA Productive Life
    DPR = PTA Daughter Pregnancy Rate
    DSB = PTA Daughter Stillbirth
    PTAF = PTA Fat
    DF = STA Dairy Form
    FLC = Feet & Legs Composite
    SCS = PTA Somatic Cell Score
    DCE = PTA Daughter Calving Ease

™TPI is a trademark of Holstein Association USA.



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