Researchers in Iowa analyzed data on more than 21,000 cattle in 18 southwest Iowa feedlots from 2002 to 2006 as part of the Tri-County Steer Carcass Futurity. They reported the following relationships in the Journal of Animal Science.

  • Disposition score More excitable cattle had lighter initial and final weights, higher average daily gains, lower numerical yield grade, higher marbling and quality grade and greater death loss.
  • Respiratory sickness Higher sickness was related to lower weights, ADG, numerical yield
  • grade and marbling.
  • Initial weight Cattle that started heavier had higher final and carcass weights and less sickness.
  • Initial Body-Condition Score Cattle that started in higher body condition were heavier at the start but lighter at slaughter.
  • Respiratory disease treatment Higher number of treatments related to lower ADG, higher death loss and more lung lesions.
  • Breed type Continental-type cattle had heavier final and carcass weights, lower yield grade and lower marbling.
  • Muscling score Cattle with lower score had lighter carcass weight, smaller ribeye, higher numerical yield grade, lower marbling and lower quality grade.