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Comparison Of Ultrasound And Carcass Measures To Predict Percentage Of Beef Retail Product From Four Primal Cuts—Final Report, Richard G. Tait Jr., Gene H. Rouse, Doyle E. Wilson Jan 2004

Comparison Of Ultrasound And Carcass Measures To Predict Percentage Of Beef Retail Product From Four Primal Cuts—Final Report, Richard G. Tait Jr., Gene H. Rouse, Doyle E. Wilson

Beef Research Report, 2003

The objective of this study was to determine how real-time ultrasound (RTU) measurements would compare with carcass measurements to predict the percentage of retail product from the four primals (PRP4P). Data were collected on market ready cattle (n=471). Traditional carcass measures collected were: 1) hot carcass weight (HCW), 2) 12–13th rib fat thickness (CFAT), 3) 12–13th rib ribeye area (CREA), and 4) percentage of kidney, pelvic, and heart fat (CKPH). Live animal ultrasound measures collected were: 1) scan weight (SCANWT), 2) 12–13th rib fat thickness (UFAT), 3) 12–13th rib ribeye area ...


Estimation Of Heritability And Repeatability Of Ultrasound Ribeye Area Measures Using Random Regression Models, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse Jan 2004

Estimation Of Heritability And Repeatability Of Ultrasound Ribeye Area Measures Using Random Regression Models, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse

Beef Research Report, 2003

The present study included 4,653 observations from 882 Angus bulls and heifers born during the spring of 1998 to 2001. Each year cattle were scanned four to eight times for ribeye area (UREA) and other ultrasound traits, starting at a minimum age of 27 weeks. The objective of the current study was to estimate variance components, heritability, and repeatability of UREA. Direct additive genetic variance increased from 7.11 to 19.4 cm4 as measurement age increased from 27 to 62 weeks. For the same time period direct permanent environmental variance increased from 14.7 to 26.6 cm ...


Opportunities And Challenges For Dairy Steer Production In Northwest Iowa, Beth E. Doran, Ron Orth, John D. Lawrence Jan 2004

Opportunities And Challenges For Dairy Steer Production In Northwest Iowa, Beth E. Doran, Ron Orth, John D. Lawrence

Beef Research Report, 2003

A dairy steer survey, co-sponsored by Iowa State University Extension and the Iowa Institute for Cooperatives, was mailed to 635 cattle producers in northwest Iowa to assay the potential opportunities and challenges of feeding dairy steers. Replies from 177 surveys were summarized. Thirty-seven percent cited profitability as the major reason they had fed dairy steers. In comparing beef and dairy steers, reduced feeder calf cost was cited as an advantage with dairy steers. However, market access, finished market price and feed efficiency of dairy steers rated poorer than with beef steers. The biggest challenge to dairy steer production was market ...


Body Composition Changes In Bulls From Weaning To Yearling Part I — Muscle, Waste Fat And Taste Fat Deposition, Gene H. Rouse, Doyle E. Wilson, Richard G. Tait Jr., Mike Anderson, Abebe T. Hassen Jan 2004

Body Composition Changes In Bulls From Weaning To Yearling Part I — Muscle, Waste Fat And Taste Fat Deposition, Gene H. Rouse, Doyle E. Wilson, Richard G. Tait Jr., Mike Anderson, Abebe T. Hassen

Beef Research Report, 2003

These results suggest how muscle, subcutaneous fat and intramuscular fat are deposited from weaning to yearling. How might these results be explained?

  • Tissue maturity —muscle matures earlier than fat in the growth process and has nutrient priority over fat when muscle is making maximum growth. Cattle normally make maximum growth, rate/day, when muscle is being deposited at the maximum rate. Why? Muscle has a much higher water content than fat, therefore, it requires less nutrients to deposit a pound of muscle then a pound of fat.
  • 10-1 Concept—during the fattening process, 10 pounds of waste fat (subcutaneous, seam ...


2003 Beef Research Report Summary, Iowa State University Jan 2004

2003 Beef Research Report Summary, Iowa State University

Beef Research Report, 2003

Abstracts of all articles included in the 2003 Beef Research Report.


Genetic Analysis Of The Iowa Beef Tenderness And Carcass Evaluation Project, Jennifer A. Minick, Doyle E. Wilson, Daryl R. Strohbehn Jan 2004

Genetic Analysis Of The Iowa Beef Tenderness And Carcass Evaluation Project, Jennifer A. Minick, Doyle E. Wilson, Daryl R. Strohbehn

Beef Research Report, 2003

Steers from the Iowa Beef Tenderness and Carcass Evaluation Project were harvested and carcass data, including Warner-Bratzler shear force values, were collected. The heritability estimate of Warner-Bratzler shear force in this data set was 0.45, and the genetic correlation between tenderness and marbling score was -0.40. Steers with more marbling were more tender. Heritabilities for feed consumed per pound of gain and for feed consumed per day were 0.25 and 0.26 respectively. These traits were highly correlated with gain, but had no relationship to each other. The heritability of dressing percentage was 0.52. These preliminary ...


Estimating Heritability Of Percentage Of Intramuscular Fat And Ribeye Area Measures By Scan Session In Angus Bulls And Heifers, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse Jan 2004

Estimating Heritability Of Percentage Of Intramuscular Fat And Ribeye Area Measures By Scan Session In Angus Bulls And Heifers, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse

Beef Research Report, 2003

The present study included 3,066 ultrasound-predicted percentage of intramuscular fat (UPFAT) and 4,502 ultrasound ribeye area (UREA) measures of bulls and heifers from the Iowa State University beef cattle breeding project. Data were collected over a four-year period between 1998 and 2001. The objective of the current study was to estimate variance components and heritability of UPFAT and UREA. Data were analyzed based on single- and multiple-trait animal models. Heritability of UPFAT increased from a minimum of 0.36 at a mean age of 37 weeks to a maximum of 0.54 at a mean age of 54 ...


Heritability And Repeatability Of Ultrasound Predicted Percentage Of Intramuscular Fat Measures In Angus Bulls And Heifers, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse Jan 2004

Heritability And Repeatability Of Ultrasound Predicted Percentage Of Intramuscular Fat Measures In Angus Bulls And Heifers, Abebe T. Hassen, Doyle E. Wilson, Gene H. Rouse

Beef Research Report, 2003

The present study included repeated ultrasound-predicted percentage of intramuscular fat (UPFAT) measures from 675 Angus bulls and heifers collected over a three-year period between 1998 and 2000. Each year cattle were scanned four to six times for UPFAT and other ultrasound traits, starting at a minimum age of 28 weeks. The objective of the current study was to estimate variance components, heritability, and repeatability of UPFAT in young bulls and heifers. Heritability of UPFAT ranged from 0.32 at 28 weeks of age to a maximum of 0.53 at 63 weeks. Repeatability of UPFAT increased from a minimum of ...