Illinois Performance Tested Bull Sale
Sale Order Determined by Power Score
The sale order for the 2012 Bull Sale will be based on the EPD Percentile Rank for the six traits of Birth Weight, Weaning Weight, Yearling Weight, Material Milk, % IMF/Marbling, and REA. These six "EPD Percentile Ranks" will be added and divided by six to arrive at the overall "Power Score."
The EPD Rank is from the "most current" Sire Summary and utilizes the NonParent Bull EPD Percentile Breakdown Table. Except for the top 1 through 5percentile breakdown, most of these tables are divided into 5% grouping, thus one will need to interpolate where a specific EPD falls within the population. When calculating the score for the actual 2012 bull sale a computer program will break each trait into specific numerical rankings (1 through 100%) to determine the overall Power Score.
Power Score (PS). The PS equation for a bull based on "Percentile Rank" will consist of the following equation
PS = (BW% + WW% + YW% + MM% + %IMF/Marb + REA%)/ 6
The scoring system is similar to golf. LOWER SCORES mean a more genetically desirable bull.
To calculate a bull's PS for 2012 one can use the following equation:
TRAIT 
EPD 
%RANK 
Birth Weight EPD 
________ 
________ 
Weaning Wt. EPD 
________ 
________ 
Yearling Wt. EPD 
________ 
________ 
Maternal Milk EPD  ________ 
________ 
%IMF/Marbling EPD 
________ 
________ 
%RP (REA) 
________ 
________ 
Total of 6 Rank Scores 
________ 

Divide Total by 6 = PS 
________ 
PS Example. The following four Angus bulls are representative of those sold through previous IPT Bull Sales. If we are to rank these for use in a rotational system in which females will be used as replacements in the cowherd:
Bull 
BW 
WW 
YW 
MM 
Marb 
REA 
A 
0.4 
+50 
+89 
+25 
+.35 
+.30 
B 
+2.2 
+57 
+104 
+29 
+.50 
+.57 
C 
+0.8 
+56 
+97 
+30 
+.59 
+.49 
D 
+2.8 
+51 
+94 
+23 
+.34 
+.28 
To calculate the PS for the bulls above, use your breed's most current Percentile Breakdown for NonParent Bulls (Spring 2012Analysis) to determine percentile ranks for the various traits. The PS for these four Angus bulls based on the "Percentile Ranks from the Spring 2012 Sire Evaluation Report  NonParent Bulls."
Sire A: (9+37+40+30+57+50)/6 = 223/6 = 37.2
Sire B: (60+12+ 8+10+ 31+13)/6 = 134/6 = 22.3
Sire C: (35+25+ 15+ 3+18+12)/6 = 108/6 = 18.0
Sire D: (72+35+27+45+60+53)/6 = 292/6 = 48.7
Thus, the order of sale for the four bulls would be…
1st  Sire C = 18.0 3rd  Sire A = 37.2
2nd  Sire B = 22.3 4th  Sire D = 48.7
(Bull D is Ineligible  Over 55 Power Score)
Obtaining Most Current Percentile Rank. A copy of the Spring 2012 Percentile Ranks from 1 to 100 for Angus, Purebred and Composite Simmental can be found on the IPT Bull Sale Web Page at …WWW.IPTBullSale.com