132 Carcass merit, primal cutout, and retail yield of Holstein and Holstein x SimAngus finished calves

Abstract Dairy-beef has increased in popularity, altering the U.S fed beef supply. The objective of this study was to evaluate the effect of Holstein x SimAngus breeding on carcass composition, carcass performance, and primal cutout. Calves were sourced (n = 10 Holstein steers, n = 13 Holstein x SimAngus (Hol x SimAngus) steers and n = 12 Hol x SimAngus heifers) from University of Missouri Foremost Dairy. At 190 kg calves were randomly assigned to one of two treatments, Fast = fed to achieve 1.13 kg gain/d or Slow = fed to achieve 0.57 kg gain/d. Calves were individually fed for 147 d, then moved to group feedlot housing. Cattle were humanely slaughtered under USDA inspection, immediately following slaughter hot carcass weight (HCW) was recorded. Following slaughter, carcass length, body width, backfat thickness and area of the longissimus muscle (LM) was recorded. One side of the carcass was fabricated to various cuts following the Institutional Meat Purchasing Specifications. Round were knife separated into fat, bone, and lean. Area of the LM was measured for the entirety of the Ribeye Roll and Strip Loin in 2.54 cm sections. Warner Bratzler Shear Force (WBSF) and Slice Shear Force (SSF) tests were analyzed on strip steaks. Data were analyzed as a linear mixed model as a 2 by 2 + 1 factorial design with the fixed effect factors of breed and diet nested relative to Holstein steers using PROC MIXED of SAS 9.4 (SAS Institute, Cary, NC). The Satterthwaite method for degrees of freedom was used to analyze data under the assumption of unequal variance between treatments. Significance was denoted at P ≤ 0.05. Treatment diet did not impact carcass composition or fresh meat parameters (P 0.05). Hol x SimAngus carcasses exhibited shorter carcass length (P 0.01) and body lengths (P = 0.002) compared with Holstein carcasses. Body width was narrower for Hol x SimAngus carcasses (P 0.01). Hol x SimAngus carcasses had heavier hot carcass weights compared with Holstein carcasses (P = 0.0159). Dressing percentage was greater for Hol x SimAngus carcasses (P = 0.0001). Holstein carcasses had less backfat (P = 0.0003). LM area was larger for Hol x SimAngus carcasses (P 0.01). Hol x SimAngus carcasses had heavier Rib, Full Loin and Round primals (P 0.05). Ribeye Roll and Strip Loin weight was heavier in Hol x SimAngus carcasses (P 0.01). Holstein carcasses displayed heavier round (P = 0.0002), directly related to an increase in bone weight of the round (P 0.01) No differences were observed for WBSF (P = 0.427) or SSF (P = 0.264). Hol x SimAngus LM area for all sections of the Ribeye Roll and Strip Loin were larger than Holsteins (P 0.05). Carcass composition, primal cutouts, and retail yield suggest that Holstein x SimAngus carcasses had improved yield production compared with Holsteins without a loss in quality.