PPR Formula

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PROGRESSIVE PERFORMANCE RANKING (2007)

(Comparison 12/2020 to last revised 12/2017)

The Brown Swiss Progressive Performance Ranking (PPR) is the ranking system for sire and cow genetic evaluations.  The formula has weights which add to 100 and, thus, are comparable to the percentage weight for each variable. 

 

PPR Formula Ranking Weights (Percentage)

 

 

Protein

Fat

PL

UDC

MO

DPR

LIV

SCS

2020 PPR 30 22 8 10 6 16 4 4

2017 PPR

34

28

6

10

6

12

4

 

 

The PPR Formula

D2020    [30(PTAprotein/SDprotein) + 22(PTAfat/SDfat) + 8(PTAPL/SDPL) + 10(PTAUDC/SDUDC)

                  + 6(PTAMO/SDMO) + 16(PTADPR/SDDPR) + 4(PTALIV/SDLIV) - 4(PTASCS-3.06/SDSCS) ]


D2017    [34(PTAprotein/SDprotein) + 28(PTAfat/SDfat) + 6(PTAPL/SDPL) + 10(PTAUDC/SDUDC)

+ 6(PTAMO/SDMO) + 12(PTADPR/SDDPR) + 4(PTALIV/SDLIV) ]

where:    

PL = Productive Life

UDC = Udder Composite (See Formula below)

MO = Mobility

DPR = Daughter Pregnancy Rating

LIV = Livability

SD = Standard Deviation of corresponding traits follow:

Trait                             Standard Deviation

Protein                                     15.90

Fat                                           22.10

PL                                             2.10

UDC                                           0.65

MO                                            0.68

DPR                                           1.40

LIV                                            1.40 

SCS                                            0.12

 

Since the weights sum to 100, the divisor is (100/100) or 1.

 

Udder Composite

(UDC) = .22(PTAFUA/SDFUA) + .18(PTARUH/SDRUH) + .22(PTARUW/SDRUW) +

.18(PTAUC/SDUC) + .10(PTAUD/SDUD) + .10(PTATP/SDTP

    
  Corresponding Standard Deviations

 Trait Standard Deviations
Revised 4-2020
Fore Udder Attachment (FUA) 1.0
Rear Udder Height (RUH) 0.9
Rear Udder Width (RUW) 0.8
Udder Cleft (UC) 0.8
Udder Depth (UD) 0.9
Teat Placement (TP) 1.0