1. American Simmental Association’s Economic Selection Indexes
Wade Shafer
American Simmental Association
Bozeman, MT

2. Which Sire Should I Use? Lot 1: Pretty Boy
Comments: this is a wonderful bull
Performance Data:
BW:95
ABW:98
BWR:103 WW:670 AWW:690 WWR:112 YW:1240 AYW:1300 YWR:110
SC:32
ASC:36
HH:54
FS: 6.5
BF: .2
ABF: .15
BFR: 103
REA: 15
AREA:14.5
REAR: 104
IMF: 2.7
AIMF: 2.5
IMFR: 94
PA: 140
APA: 150
PAR: 92
EPDs:
REA:.3
BKF:.01
MBL:.2
YG:.2
MW:25
MHH:.5
WBSF:-.01
STAY:18
CE:2
BW:4
WW:35
YW:68
MCE:4
MLK:10
TM:27
CW:20
REA:3

3. Using EPDs Without Selection Indexes . . .

4. Economic Selection Indexes
All-Purpose Index (API)a
Bred to all-aged females
Retain replacements
Terminal Index (TI)a
Bred to mature cows
No replacements retained
aGeneral Assumptions
Sires mated to Angus cows
Integrated system selling on end product
Prices/costs based on CattleFax 5-yr average

5. Top TI Sires Tend to Excel in:
Growth
MRB CE DC BW WW YW MC ML ST CW YG MB 6 4 54
119 -2 19 30
.15
.37

6. Top API Sires Tend to Excel in:
STAY
DCE, MCE MW
MRB DC WW YW MW MC ML ST CW YG MB 12 23 25
-55 6 4 28
-44
-.33
.11

7. $ Difference Over Life of Sire
$56 TI
$76
Exposed to 30 cow/yr for 5 years
$3,000

8. $ Difference Over Life of Sire
$88
$124
API
Exposed to 30 cow/yr for 5 years
$5,400

9. Predictions
All seedstock for beef production will eventually be bred through the use of indexes
Commercial cattle producers will drive index use
Why?
It works
It’s SIMPLE!