Vollmar, Kaycee, authorGrandin, Temple, advisorEdwards-Callaway, Lily, committee memberEngle, Terry, committee memberOgden, Brenda, committee memberWoerner, Dale, committee member2016-07-132016-07-132016http://hdl.handle.net/10217/173532A survey was conducted on large beef cattle feedlots in Colorado and Texas between March and July 2015, to assess the current status of conformational defects in U.S. fed steers and heifers. The objectives were to: 1) determine the prevalence of conformational defects in feedlot receiving cattle in a population across multiple regions within the United States; and 2) increase industry awareness of the structural problems found in the current cattle population to help ultimately improve a practical selection focus. Conformational traits of front and rear claw, front and rear feet angles, rear leg side view, and rear leg hind view were evaluated on a scale of 1-9 with scores 4-6 serving as the most desirable. Overall soundness was evaluated from 0-100 with 66-100 serving as optimal soundness. A new scoring tool was developed and added to assess conformational problems in cattle shoulder and hip structure. Data from 2,886 head of feedlot cattle was used to evaluate the frequency of these conformational defects. Phenotypic evaluation revealed the highest prevalence of conformational issues in the shoulder, hip, and rear leg covering multiple relationships with demographic characteristics. Of the entire sample, 49.97% had a less than ideal shoulder structure, 53.33% had a less than ideal hip structure, and 29.97% displayed a less than ideal hock structure when viewed from the side. Heavier weight cattle showed a significantly higher (P<0.0001) prevalence of front claw scissor type abnormalities (7-9) and an increase (P<0.0001) in impaired mobility scores (group 2). Northern cattle exhibited a significant (P<0.0001) increase in front claw defects of scissor claw type abnormalities (7-9). Lastly, Bos Indicus cattle displayed a higher prevalence (P<0.0001) of round hip structures (7-9) and an increase (P<0.0001) of impaired mobility scores (group 2). The remaining traits had significantly higher proportions in the desirable (normal) group, and thus, the industry has shown positive developments in rear claw set and front and rear feet angles. Additionally, 85.85% of our total sample demonstrated overall comprehensive soundness scores for sound and flexible mobility (group 3). These findings will be useful to the beef industry in creating a benchmark for the conformational status of the current cattle herd to ultimately improve skeletal structure for improved welfare and performance in feedlot cattle.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.conformationfeedlotbeef cattlesurveydefectsText