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Animal Sciences

Beef Research Report, 2003

Animal Science

Publication Year

Articles 1 - 17 of 17

Full-Text Articles in Life Sciences

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 ...


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 ...


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 ...


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 ...


Effect Of Ghrelin Injection On Blood And Body Composition In Rats, Michelle M. Bohan, Travis J. Knight, Aimee Wertz, Allen H. Trenkle, Donald C. Beitz Jan 2003

Effect Of Ghrelin Injection On Blood And Body Composition In Rats, Michelle M. Bohan, Travis J. Knight, Aimee Wertz, Allen H. Trenkle, Donald C. Beitz

Beef Research Report, 2003

Ghrelin has been reported to cause hyperglycemia in humans and adiposity in rodents. The objective of trial one was to test the effects of ghrelin on blood and body composition in rats. The objective of trial two was to evaluate the effect of two doses of ghrelin on blood and body composition. Trial One: Adult male Sprague Dawley rats were administered 1 μg/rat ghrelin in 0.15 M NaCl or vehicle (0.15 M NaCl) every morning for 30 days. The terminal blood sample was analyzed for glucose, urea nitrogen, and nonesterified fatty acids concentrations. The carcasses were analyzed ...


Effects Of Grazing Management On Sediment And Phosphorus Losses In Run-Off (A Progress Report), Mathew M. Haan, James R. Russell, Wendy J. Powers, Steven K. Mickelson, Syed I. Ahmed, John L. Kovar, Richard C. Schultz Jan 2003

Effects Of Grazing Management On Sediment And Phosphorus Losses In Run-Off (A Progress Report), Mathew M. Haan, James R. Russell, Wendy J. Powers, Steven K. Mickelson, Syed I. Ahmed, John L. Kovar, Richard C. Schultz

Beef Research Report, 2003

In 2001 and 2002, pastures at the ISU Rhodes Research and Demonstration Farm were grazed to determine the effects of stocking treatment on nutrient and sediment loss from pastureland. Treatments included an ungrazed control (UG), summer hay harvest with winter stockpiled grazing (HS), continuous stocking to a residual height of 2 inches (2C), rotational stocking to a residual height of 2 inches (2R), and rotational stocking to a residual height of 4 inches (4R). At three times in 2001 (late spring, mid-summer, and fall) and four times in 2002 (early spring, late spring, mid-summer, and fall), rainfall simulations were conducted ...


Use Of 25-Hydroxyvitamin D3 To Improve Beef Tenderness, Aimee Wertz, Donald C. Beitz, Allen H. Trenkle, Travis J. Knight, Ronald L. Horst, Elisabeth J. Huff-Lonergan, Frederick C. Parrish Jr. Jan 2003

Use Of 25-Hydroxyvitamin D3 To Improve Beef Tenderness, Aimee Wertz, Donald C. Beitz, Allen H. Trenkle, Travis J. Knight, Ronald L. Horst, Elisabeth J. Huff-Lonergan, Frederick C. Parrish Jr.

Beef Research Report, 2003

Feeding the 25-hydroxyvitamin D3 (25-OH D3) metabolite of vitamin D3 has been reported to improve beef tenderness and result in lower vitamin D3 metabolite concentrations in meat. Because 25-OH D3 remains elevated in plasma for at least 8 d subsequent to feeding, we believe that 25-OH D3 can be fed as a one-time oral bolus and allow a flexible time frame for harvest with the same improvement in postmortem calcium-dependent proteolysis and beef tenderness. To test this hypothesis, 108 crossbred steers were allotted, six steers per pen to 18 pens and treatments were assigned randomly to pen. Treatments were 25-OH ...


Effects Of Dietary Energy Density On Diet And Nutrient Digestibility In Beef Cattle Diets, Claudio C. Ribeiro-Filho, Allen H. Trenkle, Daniel D. Loy Jan 2003

Effects Of Dietary Energy Density On Diet And Nutrient Digestibility In Beef Cattle Diets, Claudio C. Ribeiro-Filho, Allen H. Trenkle, Daniel D. Loy

Beef Research Report, 2003

Steers were fed diets containing energy concentrations of 2.4, 2.7, or 3.0 Mcal of ME/kg of DM to evaluate nutrient and diet digestibility and to determine the existence of associative effects when feeding diets with varying forage and concentrate ratios. The steers were placed in metabolism crates for total fecal collection. Dry matter digestibility was higher for diets with greater energy density. The 2.7 Mcal/kg diet showed a small negative associative effect on digestibility and the non-fiber carbohydrate fraction was the nutrient that had an inhibition on digestion. The results indicated that diets varying ...


Use Of Molecular Markers To Determine Parentage In Multiple Sire Pastures, Artur J.M. Rosa, Emilie Schafhouser, Abebe T. Hassen, Gene H. Rouse, Doyle E. Wilson, James M. Reecy Jan 2003

Use Of Molecular Markers To Determine Parentage In Multiple Sire Pastures, Artur J.M. Rosa, Emilie Schafhouser, Abebe T. Hassen, Gene H. Rouse, Doyle E. Wilson, James M. Reecy

Beef Research Report, 2003

The purpose of this research was to determine the parentage of animals generated by multiple sire technique. Test of paternity was performed on 63 Angus animals, belonging to 29 families within the Rhodes breeding project, using multiplexed microsatellites. Paternity was determined for 23 families. One of the two possible sires was excluded with multiple markers for 19 families and with a single marker for four families. One of the possible sires was excluded for two families but DNA was not available for the other possible sire. Thus it wasn’t possible to confirm paternity. Four families had both possible sires ...


Effects Of Grazing Management On Pasture Production And Phosphorus Content Of Forage (A Progress Report), Mathew M. Haan, James R. Russell, Wendy J. Powers, Steven K. Mickelson, Syed I. Ahmed, John L. Kovar, Richard C. Schultz Jan 2003

Effects Of Grazing Management On Pasture Production And Phosphorus Content Of Forage (A Progress Report), Mathew M. Haan, James R. Russell, Wendy J. Powers, Steven K. Mickelson, Syed I. Ahmed, John L. Kovar, Richard C. Schultz

Beef Research Report, 2003

In spring 2001, pastures were grazed at the ISU Rhodes Research and Demonstration Farm to determine the effects of grazing management on pasture productivity and phosphorus (P) content of forage. Treatments included an ungrazed control, summer hay harvest with winter stockpiled grazing, continuous stocking to a residual height of 2 inches, rotational stocking to a residual height of 2 inches, and rotational stocking to a residual height of 4 inches. Forage production was greatest in June and July, decreased in August, and had a slight rebound in September and October before going dormant in November. Phosphorus concentration of forage was ...


The Effects Of Direct-Fed Microbials On Feedlot Performance And Carcass Characteristics Of Finishing Steers Fed Wet Corn Gluten Feed, Allen H. Trenkle Jan 2003

The Effects Of Direct-Fed Microbials On Feedlot Performance And Carcass Characteristics Of Finishing Steers Fed Wet Corn Gluten Feed, Allen H. Trenkle

Beef Research Report, 2003

This experiment was conducted to evaluate the efficacy of daily feeding a live microbial preparation containing live organisms fed to finishing cattle. Additions of live organisms to the rumen are thought to improve the fermentation and overall digestion. Three strains of a lactobacillus and a propionibacterium were studied in this experiment. The study was conducted with Angus steers with an average initial weight of 625 lbs and fed a finishing diet containing on a dry basis 30% wet corn gluten feed, 60% rolled corn, 8% chopped hay and 2% supplement for 174 days. Feeding the microbial product being marketed for ...


Effects Of Corn Crop Residue Grazing On Soil Physical Properties And Subsequent Soybean Production In A Corn–Soybean Crop Rotation, Justin Clark, James R. Russell, Douglas Karlen, W. Darrell Busby, Brian Peterson, Larry Pellack, Dallas L. Maxwell Jan 2003

Effects Of Corn Crop Residue Grazing On Soil Physical Properties And Subsequent Soybean Production In A Corn–Soybean Crop Rotation, Justin Clark, James R. Russell, Douglas Karlen, W. Darrell Busby, Brian Peterson, Larry Pellack, Dallas L. Maxwell

Beef Research Report, 2003

For three years beginning in 1999, a 96-acre field near Atlantic, Iowa was used to study the effects of corn residue grazing by beef cows on soil characteristics and soybean yields in subsequent years. Each winter, cows were allowed to graze corn crop residues inside selected paddocks in four sub-fields over five monthly periods. To compare the effects of grazing, one paddock was left as an ungrazed control. At the end of grazing in the spring, soil bulk density, moisture content, and penetration resistance were measured inside and 15 ft outside twelve grazing exclosures in each paddock. Soil surface roughness ...


Effects Of Dietary Energy Density And Frame Size On Performance And Body Composition Of Feedlot Steers, Claudio C. Ribeiro-Filho, Allen H. Trenkle, Daniel D. Loy Jan 2003

Effects Of Dietary Energy Density And Frame Size On Performance And Body Composition Of Feedlot Steers, Claudio C. Ribeiro-Filho, Allen H. Trenkle, Daniel D. Loy

Beef Research Report, 2003

Thirty-six steers were sorted by frame size and individually fed diets containing 2.4, 2.7, or 3.0 Mcal of ME/kg of DM to evaluate the effects of dietary energy density and animal frame size on performance and body composition. Frame size did not have an effect on performance or body composition. Steers fed the 2.4 or 2.7 Mcal/kg diet had a higher feed intake than those fed the 3.0 Mcal/kg diet, but they were less efficient. The results indicated that steers fed the diet with higher energy concentration deposited more fat earlier ...


Evaluation Of Individual Feed Intake, Body Composition, And Performance Of Performance-Tested Angus Bulls During A 14-Year Period, Claudio C. Ribeiro-Filho, Daniel D. Loy, Allen H. Trenkle, W. Darrell Busby Jan 2003

Evaluation Of Individual Feed Intake, Body Composition, And Performance Of Performance-Tested Angus Bulls During A 14-Year Period, Claudio C. Ribeiro-Filho, Daniel D. Loy, Allen H. Trenkle, W. Darrell Busby

Beef Research Report, 2003

Two hundred fifty-five purebred Angus bulls had their performance tested by the Wardens Farm in Council Bluffs, Iowa over a 14-year period. The bulls feed intake was recorded individually, and performance and ultrasound measurements were determined. Performance and body composition data were used to estimate required feed intake by Perry and Fox (1997) model, and estimated and observed DMI were compared. Average estimated DMI was 25.84 lbs/day and average observed Dry Matter Intake (DMI) was 24.93 lbs/day. The results indicated that the model is promising in estimating feed intake of purebred Angus bulls, but a few ...


Feedlot Performance Of Cattle Program Fed Supplemental Protein, Allen H. Trenkle, K. Barrett Jan 2003

Feedlot Performance Of Cattle Program Fed Supplemental Protein, Allen H. Trenkle, K. Barrett

Beef Research Report, 2003

One hundred sixty eight 12 to 13 month-old steers weighing 740 lbs were allotted to 28 pens. Seven pens were allotted to each of four programs for providing supplemental protein. The programs were I: Continuous supplementation with soybean meal (12.4% crude protein), II: Continuous supplementation with urea (11.7% crude protein), III: Feeding supplemental soybean meal (12.4% crude protein) and changing to urea supplementation (11.7% crude protein) at 42 days and IV: Feeding supplemental soybean meal (12.4% crude protein), changing to urea (11.7% crude protein) at 42 days followed by decreasing the concentration of supplemental ...