1. Dan Morrical Iowa State University Extension Sheep Specialist Carcass Component Growth DGM:ISU

2. Lean tissue Adipose tissue Skeletal tissue Components DGM:ISU

3. Age Weight Fat Color Firmness Muscle Carcass value DGM:ISU

4. Moderately lean Heavy muscled Carcass value DGM:ISU

5. Projected Target Market Weights

6.  Frame Size, Growth and Carcass Traits DGM:ISU Texas Rambouillet Wethers SmallMediumLarge Carcass wt.545150 Backfat.18.11.07 Ribeye2.022.051.98

8. Carcass Parameters, Constant weight 105 pounds SmallMediumLarge DOF553019 Slaughter weight105 DP51.6 c 48.7 d 47.9 d FT in0.180.110.07 REA2.22.051.98 % Choice98.998.795.9 Nicholes

9. Carcass tissue weights of mature rams of two strains of Merinos of different mature size (Data from Butterfield et al., 1983a) Weight (kg) Whole Carcass TissueLarge n=3Small n=3 Sig. of Diff. Muscle25.920.7*** Bone6.44.9** Fat26.718.8** Liveweight116.590.9***

14. Carcass tissues as % of shorn full LW of mature rams of two strains of Merinoes of different mature size (Data from Butterfield et al., 1983 Percent of LW Whole Carcass TissueLarge n=3Small n=3 Sig. of Diff. Muscle22.322.8NS Bone5.55.4NS Fat23.020.7* LW100.0

16. Fat partitions by sex Fat partition% of total body fatEwes as % of rams Rams N=18Ewes N=16 Subcutaneous*30331.1 Intermuscular***30260.87 Total carcase60590.98 Kidney**12151.25 Omental18170.94 Mesenteric771 Scrotal/Udder***320.67 Total non-carcase40411.02 Total Body100 (Adapted from Thompson 1983)

18. Which group is better

19. Dorset Down Hamp. Down Ile de France South downSuffolkTexels.e. Mean Age at slaughter (days)2182362532342492476 Carcass wt (kg)1717.718.416.419.118.80.1 Daily carcass wt gain (g)86 788084832 M. longissimus Width A-mm55.156.25755.35857.70.52 Depth B-mm26.0a25.5a27.5b25.8a26.4a27.4b0.35

20. Dorset Down Hamp. Down Ile de France South downSuffolkTexels.e. Mean Carcass conformation (15 pt scale)7.6bc7.5bc8.2c8.3c7.8c7.9c0.23 Tissue in carcass (g/kg) lean557a562ab571b559ab567ab590c3.2 separable fat267cd263bcd255bc273d252b240a3.3 Daily tissue wt gain in carcass (g) lean474543 46471 separable fat22 202221200.57

21. Ile DeFrance

22. SuffCoopDLSRomFin Slaughter wt95.592.495.593.393 Age (d.)204222239222264 BF0.150.180.160.120.20 REA1.831.652.171.671.80 Fahmy etal 1992 J. Anim Sci 70:1365 Sire Breed Impact on Growth and Carcass

23. Carcass Traits by Sire Breed HampPolypay Gain0.720.65 FE6.606.70 Backfat0.30 Bodywall0.961.00 REA2.432.29 YG2.50 No impact on individual cuts Meyer et al, 1993, SRJ 9:97

24. Effect of Sire Breed on carcass traits, adjusted for carcass weight DorTexMonFinRom Slaughter wt114113 114117 BF.25 a.29 b.24 a.31 b.29 b REA2.35 a 2.54 b 2.41 a 2.12 c 2.24 a Freking and Leymaster. 2004. J. AnSci 82:3144

25. Evaluation of Texel, Columbia and Suffolk as Terminal Sires along with Finishing System TSCBGFL DP51.152.051.0 51.7 BF0.230.20 0.25 Bodywall.99 a 1.07 b 1.14 c 1.001.12 REA2.62.4 2.62.4 Morrical IASBR, 1994.

26. Restricted feeding on Growth and Carcass Intake Level 100%85%70% ADG0.900.760.65 FE3.33.4 % Water49.651.251.5 % Protein15.115.615.4 % Fat31.129.028.2 Murphy et al 1994 J. AnSci 72:3131

27. Impact of protein content and source on performance and carcass. (prolific crosses) FMSBMCGM& BMControl 16% 13% ADG.49 a.41 b.48 a.40 b FE4.99 a 5.48 b 5.11 ab 5.76 b BF0.150.170.160.18 REA1.951.911.84 90 lb slaughter weight Fahmy et all 1992 J. AniSci

28. Impact of Protein Source and Level on Suffolk Wether Growth and Performance CPSBMSBM&F 1316 ADG0.981.000.980.97 FI4.5 4.64.4 FE4.6 4.74.6 BF0.180.17 0.16 %lean53.054.754.053.6 Ribeye Area2.632.722.662.68 Neary et al, 1995

29. Frame Size and Feeding Method SmallMediumLarge Wheat Pasture gain0.140.150.14 Feed lot gain0.600.720.73 FE7.26.65.6

30. Finishing System Impacts on Carcass CFC Carcass Wt63.157 BF0.350.3 Bodywall1.10.9 Age vs System. No effects on cuts.

31. Summary Sex has an impact Protein level Older/backgrounding improves cutability