**5. Conclusions**

The results of the present study sugges<sup>t</sup> that tissue composition (fat, lean, and bone), either from primal cuts or full carcass sides, and yield percentages of LMY and RCY of mature cows can be accurately predicted by CVS or DXA technologies by applying partial least square regression statistical analysis.

Although DXA results showed higher accuracy, precision, and robustness than results from CVS technologies, DXA technology is still in development for cattle and would require further design adjustments for full implementation and integration into commercial slaughter plants with moving carcass lines.

On the contrary, CVS technologies (HCC and CCC cameras) are widely implemented in North America. In the present study, predictions using HCC variables led to similar or even better results (higher R<sup>2</sup> and lower MSPE values) than those from CCC. The implementation of HCC technology for the carcass composition estimations of mature cows has the benefit that knife ribbing of the carcasses is not required, not even for RCY (%) or LMY (%) estimations. Furthermore, the combination of both CVS technologies

led to significant improvements in the tissue predictions of primal cuts and total carcass composition, particularly for lean/fat ratios, suggesting this approach as an alternative for the enhancement of the prediction accuracy on primals and carcass composition of cull cows.

**Author Contributions:** Data curation, I.L.L.; formal analysis, J.S. and I.L.L.; funding acquisition, J.L.A.; investigation, J.S., N.P. and Ó.L.-C.; project administration, Ó.L.-C.; supervision, Ó.L.-C.; writing—original draft, J.S.; writing—review and editing, J.L.A., N.P., M.J. and Ó.L.-C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was funded by Agriculture and Agri-Food Canada (AAFC) as part of their AgriInnovation Program Stream B, gran<sup>t</sup> number AIP-P335.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the AAFC-Lacombe Research and Development Centre Animal Care committee. The code for this study was 201702.

**Acknowledgments:** The authors express their gratitude to the AAFC-Lacombe Research and Development Centre (AB, Canada) Beef Unit and Meat Centre staff for animal care and management, animal slaughter and carcass fabrication, and technical collection and compilation of the research data. José Segura Plaza gratefully acknowledges the support from the Canada Sustainable Beef and Forage Science Cluster, through funding provided by the Canadian Cattlemen's Association and Agriculture and Agri-Food Canada. The authors also sincerely and gratefully acknowledge the cooperation and assistance of the Canadian Cattlemen's Association.

**Conflicts of Interest:** The authors declare no conflict of interest.
