1. Evaluating Fat and Muscle in Livestock Developed by: Celina Johnson University of Florida

2. Why is it Important to Evaluate Fat and Muscle? Meat Animals - we sell muscle All gender classes - important –Intact males, market animals and replacement females. Johnson, 1997

3. How Do Animals Get Fat? Top to Bottom Front to Rear Johnson, 1997

4. Growth Curve Time Wt. 1 2 3 4 1.Prenatal 2.Rapid Growth 3.Fat deposit begins 4.Fat puberty market Johnson, 1997

5. Effects of Sex Female usually deposits fat earlier than castrates or intact males. Cattle:Heifers market at lighter wts. Exception: Swine boargilt barrow leanfat Johnson, 1997

6. Effects of Frame Size Small Framed animals: Greater deposit of fat at lighter weights At the same body composition, small animals will be lighter. Johnson, 1997

7. At Equal Body Composition: Weights:Lg > Med > Small Efficiency:Equal, same point on growth curve At Equal Weight: Efficiency:Lg > Med > Small why?Composition Johnson, 1997

8. Effects of Frame Size Age Influences Weight Age Large Medium Small Johnson, 1997

9. Weight Age Effects of Frame Size Weight Influences Large Medium Small Johnson, 1997

10. Fat Deposition Sites Brisket (cattle), Jowl (hogs), Breast (lambs) Ribs Loin Edge Twist Area Flank Tailhead area Johnson, 1997

11. Fat Deposition Sites Johnson, 1997

12. Muscle Evaluation Sites Hindquarter (round - cattle; leg - lamb; ham - hog) Stifle Forearm Over Top - loin and rump Width of Base Johnson, 1997

13. Muscle Evaluation Sites Johnson, 1997

14. Muscle Evaluation Sites Johnson, 1997

15. Body Shapes DesirableUndesirable The widest part of the animal should be at the stifle, indicating lean, not fat Johnson, 1997

16. Lean Hog Johnson, 1997

17. Over Finished Hog Johnson, 1997

18. Under Finished Beef Johnson, 1997

19. Over Finished Beef Johnson, 1997