1. Developed by: Celina Johnson University of Florida
Swine Evaluation
Developed by:
Celina Johnson
University of Florida

2. What’s Evaluated?? Last Rib BackFat (LRBF) 10th Rib Backfat
Visual Evaluation
10th Rib Backfat
Adjustment from LRBF
USDA Muscle Score (MS)
Grade = (4 * LRBF) - MS
Johnson, 1997

3. What’s Evaluated?? Loin Eye Area (LEA) % Muscle
Estimate using live weight
% Muscle
Calculation using:
Live weight
10th rib backfat
LEA
Johnson, 1997

4. Evaluating for Fat Where to evaluate? Jowl Forerib Shoulder Blade
Elbow Pocket
Loin Edge
Flank
Tailhead
Seam of Ham
Johnson, 1997

5. Evaluating for Fat
Johnson, 1997

6. Evaluating for Muscle Where to Evaluate? Shoulder Forearm Loin Stifle
Ham
Johnson, 1997

7. Evaluating for Muscle
Johnson, 1997

8. Converting LRBF to 10th RBF
IF… < 1.0” THEN…
Leave the same
IF… 1.0 to 1.1” THEN…
add 0.1”
IF… > 1.1” THEN…
add 0.2 to 0.4”
IF… light muscled THEN…
add more
IF… heavy muscled THEN…
add less
Johnson, 1997

9. Estimating LEA using Live Weight
Average Muscled Hogs
225# = 5.0 in2
250# = 5.5 in2
275# = 6.0 in2
Adjust 0.1 in2 for every 5# live weight
Adjust as needed using visual evaluation
Johnson, 1997

10. % Muscle Calculation Base Percent = 50.0 Three Factors Weight 10th RBF
LEA
Johnson, 1997

11. % Muscle Calculation Weight Base = 240 # Adjust +/- 1% for every 5#
Above 240#…decreases %
Below 240#… increases %
Johnson, 1997

12. % Muscle Calculation LEA Base = 5.0 in2
Adjust +/- 0.2% for every 0.1 in2
Above 5.0 in2… increases %
Below 5.0 in2… decreases %
Johnson, 1997

13. % Muscle Calculation 10th RBF Base = 0.8 in.
Adjust +/- 1% for every 0.1 in.
Above 0.8 in… decreases %
Below 0.8 in… increases %
Johnson, 1997

14. % Muscle Problem: Live Weight = 260 lbs. 10th RBF = 0.9 in.
LEA = 5.9 in2
Johnson, 1997

15. % Muscle Problem: Live Weight = 260 lbs. Base = 240 Difference = 20 #
Adjust down 4%
= 46.0%
Johnson, 1997

16. % Muscle Problem: 10th RBF = 0.9 in. Base = 0.8 in.
Difference = 0.1in.
Adjust down 1%
= 45.0%
Johnson, 1997

17. % Muscle Problem: LEA = 5.9 in2 Base = 5.0 in2 Difference = 0.9in2
Adjust up 1.8%
= 46.8%
Johnson, 1997