Beef Empire Days
Carcass Index System

The Beef Empire Days Carcass Index is calculated from a base of 100 points with bonus and penalty point adjustments for hot carcass weight (HCW), adjusted backfat, ribeye area (REA), internal kidney-pelvic-heart fat (KPH), and USDA Quality Grade (QG). Carcass traits that are closer to the desired ideal specifications will have higher indices. Bonus points awarded to carcasses having larger ribeyes, low KPH fat, and QG above low Choice will improve indices. The following is a description of the index adjustment procedures for each of the carcass traits.

Hot Carcass Weight

The optimum range for hot carcass weight is defined as 750 to 1000 lbs. for both steers and heifers. The indices of carcasses with weights outside that range are penalized according to the following table.

Hot Carcass Weight Adjustment
HCW	Points	HCW	Points	HCW	Points
500	-24.10	630	-6.55	1010	-0.19
510	-22.36	640	-5.65	1020	-0.45
520	-20.69	650	-4.82	1030	-0.77
530	-19.08	660	-4.05	1040	-1.16
540	-17.54	670	-3.34	1050	-1.61
550	-16.06	680	-2.70	1060	-2.12
560	-14.65	690	-2.12	1070	-2.70
570	-13.30	700	-1.61	1080	-3.34
580	-12.02	710	-1.16	1090	-4.05
590	-10.79	720	-0.77	1100	-4.82
600	-9.64	730	-0.45
610	-8.55	740	-0.19
620	-7.52

The following figure graphically illustrates the adjustments for heifers and steers.

Adjusted Twelfth Rib Backfat Thickness

The optimum 12th rib fat thickness is defined as 0.30 inches which corresponds to a preliminary yield grade of 2.75 for both heifers and steers. Indices are negatively affected for carcasses having less than 0.28 inches or more than 0.35 inches of backfat.

Twelfth Rib Backfat Adjustment
Fat Thickness	Points	Fat Thickness	Points
0.00 - 0.03	-48	0.44 - 0.47	-6
0.04 - 0.07	-40	0.48 - 0.51	-12
0.08 - 0.11	-32	0.52 - 0.55	-16
0.12 - 0.15	-16	0.56 - 0.59	-20
0.16 - 0.19	-8	0.60 - 0.63	-25
0.20 - 0.23	-4	0.64 - 0.67	-30
0.24 - 0.27	-2	0.68 - 0.71	-35
0.28 - 0.31	0	0.72 - 0.75	-40
0.32 - 0.35	0	0.76 - 0.79	-45
0.36 - 0.39	-1	>0.79	-50
0.40 - 0.43	-2

The following figure illustrates the adjustment for backfat thickness.

Ribeye Area

A ribeye requirement is calculated for each carcass based on hot carcass weight. The equation for both steers and heifers is: Required REA, sq. in. = HCW x .012 + 4.8. A 5 point adjustment will be made to the index for every square inch that a carcass ribeye area deviates from the required value. There is also a maximum REA of 16.0 square inches for steers and heifers. Carcasses with excessively large ribeyes will be penalized 10 points for each inch, or fraction of an inch, over the 16.0 square inch REA maximim. The relationship of actual and required REA, the maximum REA, and the associated bonus or penalty points is illustrated in the graph below.

The preceding graph demonstrates than an 850 pound carcass would have a REA requirement of 15.0 square inches. If the actual REA is 16.0 square inches, 5 points would be added to the index. However, if the actual REA is 16.5 inches there would also be a 5 point penalty because the REA exceeds the 16 inch maximum by one-half square inch. The addition of the 5 bonus and 5 penalty points results in no change to the index. This additive result is shown in the following graph that illustrates the total point adjustment for the difference of the actual and required REA for various carcass weights.

This bonus and penalty points can also be calculated mathematically. For example, an 850 pound steer carcass would have a required REA of 15.0 square inches. If the carcass REA was 16.5 inches the index adjustment calculated as follows:

16.0 in.	Maximum REA
-16.5 in.	Actual REA
-0.5 in.	times 10 equals an index adjustment of -5.0

16.0 in.	Maximum REA becomes the 'actual' REA
-15.0 in.	required REA for an 850 lb carcass
1.0 in.	Times 5 equals an index adjustment of +5.0

	-5.0 + 5.0 = 0 total index adjustment

Kidney, Pelvic and Heart Fat Adjustment

The internal kidney-pelvic-heart fat index basis is 2.5%. Carcasses with a lower KPH will receive bonus points while those with a higher KPH will be penalized as shown in the following table.

Internal Fat Adjustment
KPH	Points
0.5	2
1.0	2
1.5	2
2.0	1
2.5	0
3.0	-2
3.5	-4
4.0	-6
4.5	-8
>4.5	-10

The following graph illustrates these adjustments.

USDA Quality Grade

To be competitive in the carcass show, a carcass must grade at least low Choice. The index system severely penalizes a carcass grading Select or lower. Bonus points are given to carcasses that grade above low Choice.

Quality Grade Adjustment
Quality Grade		Points
	Low	-80
Standard	Average	-80
	High	-80
Select	Low	-40
Select	High	-20
	Low	0
Choice	Average	20
	High	20
	Low	30
Prime	Average	30
	High	30

These adjustments are illustrated in the following graph.

BED Carcass Index Examples

The following table demonstrates the bonus and penalty points for various potential carcass traits using the currently defined Beef Empire Days Carcass Index System.

	Carcass Number
	1	2	3	4	5	6
Carcass Measurements
Hot carcass weight, lbs.	750	800	850	900	700	800
Backfat, in.	0.3	0.33	0.40	0.21	0.53	0.37
Kidney-pelvic-heart fat, %	2.5	2.5	3.0	1.5	2.5	2.0
Ribeye area, sq. in.
Actual	15.5	14.4	17.0	15.2	11.0	14.7
Required	13.8	14.4	15.0	15.6	13.2	14.4
Quality grade	Ch-	Ch-	Ch+	Pr	Se-	Ch-
Point Adjustments
Hot carcass weight	0	0	0	0	-1.6	0
Backfat	0	0	-2	-4	-16	-1
Kidney-pelvic-heart fat	0	0	-2	2	1	1
Ribeye area	8.5	0	-5	-2	-11	1.5
Quality grade	0	0	20	30	-40	0
Total adjustment	8.5	0	11	26	-67.6	1.5
Index base	100	100	100	100	100	100
Index total	108.5	100	111	126	32.4	101.5

The BED Carcass Index was last updated 4/19/10.