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A major portion of dairy-influenced fed beef slaughter in the United States has shifted away from straightbred dairy cattle – namely Holsteins – because of growing popularity in crossbreeding beef sires to dairy cows, commonly termed “beef on dairy.” Many industry stakeholders have expressed concerns about considerable visual variation in crossbred beef × dairy cattle, even in contemporary groups. Influence of dairy breeding often carries negative implications in the beef industry, such that most USDA certified programs explicitly exclude animals with phenotypic evidence of dairy influence. These anecdotal claims of increased visual variation and negative associations of dairy influence have resulted in questions about the appropriate economic value of beef × dairy crossbreds, and no substantiative data exists to support or refute these claims. Visual variation in crossbred beef × dairy cattle may suggest inconsistency in expected performance of their end-product, such that dairy-like appearing crossbreds might perform differently from beef-like appearing crossbreds. This study evaluated the influence of visual breed character in crossbred beef × dairy cattle on carcass performance and eating quality of beef.
A panel of 3 expert evaluators assessed a total of 615 crossbred (Angus or Simmental × Angus sires mated to Holstein cows) beef × dairy calves for muscling and frame size on their date of harvest. Visual assessments were used to subset each pen and categorize cattle (n = 82 to 84 per group) into 4 phenotype groups (Group 1 = most dairy-like, Group 4 = most beef-like). Grade information, carcass length, and round conformation score was collected for each carcass. Strip loin sections were collected from selected carcasses and aged 14 d postmortem. Steaks were fabricated for analysis of shear force (slice and Warner-Bratzler), trained sensory evaluation (tenderness, juiciness, and flavor notes), and retail color display (visual and instrumental assessments). Images of steaks were measured to understand total area, length, and width. Fatty acid composition was determined using gas chromatography. Muscle fibers in each sample were measured for cross-sectional area and characterized by myosin heavy chain (MHC) isoforms. Data analyses accounted for pen effects (block) and tested for the fixed effect of phenotype group.
By design, live muscling and frame size scores were different between each phenotype group, demonstrating that – on average – cattle from each phenotype group were visually different in their appearance. While crossbred beef × dairy cattle expressed divergent visual appearances (beef-like versus dairy-like), these different phenotypes generally translated to minimal differences in carcass traits and even fewer differences in eating quality. Carcasses of crossbred beef × dairy cattle with divergent phenotypes were not different in hot carcass weight, dressing percentage, ribeye area, USDA Yield Grade, or mean marbling score. At similar carcass weights, a difference may exist in distribution of muscularity between crossbred beef × dairy cattle, which needs to be better understood through carcass yield testing. Concerns by retailers and foodservice distributors of triangular strip loin steaks from dairy influenced cattle seems to be mitigated with the influence of beef genetics in beef × dairy crossbreds, and steak shape was not different between different phenotype groups. Trained sensory panelists were not able to differentiate differences sensory attributes – including tenderness, juiciness, and flavor notes – between phenotype groups. Likewise, Warner-Bratzler and slice shear force values were not different between phenotype groups. Steaks in retail display did not demonstrate meaningful differences between phenotype groups. Moreover, fatty acid composition was not meaningfully different between phenotype groups, supportive of sensory findings. Crossbred beef × dairy cattle that were more dairy-like in appearance (Group 1) exhibited a greater proportion of fibers that were intermediate (between glycolytic and oxidative; MHC IIA) in their metabolism than crossbreds that were more beef-like (Group 3) in appearance. This difference in muscle fiber type composition between phenotype groups might suggest an opportunity for more aggressive use of growth technologies – namely beta-agonists – in beef × dairy crossbreds that are dairy-like in appearance.
This study demonstrated that expression of dairy character – or beef character – in crossbred beef × dairy cattle does not meaningfully contribute to differences in carcass performance or eating quality. Efforts to exploit complementarity of genetics from beef breeds in the terminal beef × dairy crossbreeding system will not negate the positive influence of dairy breeding on tenderness and flavor in the end-product. Marketing programs founded on the production of consistent and premium products – like branded programs – may be able to capitalize on these qualities of beef from crossbred beef × dairy cattle.