Meat Science Commons^™

Evaluation Of The Effects Of Pine-Sourced Biochar On Cattle Performance And Methane And Carbon Dioxide Production From Growing And Finishing Steers, J. L. Sperber, B. C. Troyer, Galen E. Erickson, Andrea K. Watson

Department of Animal Science: Faculty Publications

A feedlot growing (77-d) and finishing (111-d) experiment was conducted to evaluate the effects of feeding biochar on steer performance, methane and carbon dioxide emissions, and carcass characteristics. Two treatments were evaluated, a control diet without biochar and the same diet with biochar included at 0.8% of dietary DM (growing) or 1.0% of dietary DM (finishing). The growing diet consisted of 40% corn silage, 40% wheat straw, 15% modified distillers grains plus solubles, and 5% supplement, with 0.8% biochar replacing fine ground corn in supplement. The finishing diet consisted of 55% high-moisture corn (HMC), 35% Sweet Bran, 5% wheat straw, …

Evaluation Of Growth Performance, Carcass Characteristics, And Methane And Co2 Emissions Of Growing And Finishing Cattle Raised In Extensive Or Partial-Intensive Cow-Calf Production Systems, Zachary E. Carlson, Levi J. Mcphillips, Rick R. Stowell, Galen E. Erickson, Mary E. Drewnoski, Jim C. Macdonald

Department of Animal Science: Faculty Publications

An experiment was conducted over 2 yr to measure performance and greenhouse gas (GHG) emissions of weaned calves from two cow-calf production systems. Crossbred steers and heifers (n = 270, initial body weight (BW) = 207 kg, SD = 35) were used in a randomized complete block design, with treatments applied to the cow-calf system. Treatments were: 1) a traditional system consisting of April to June calving with smooth bromegrass pasture and grazed corn residue as forage resources (TRAD); 2) an alternative system consisting of July to September calving utilizing partial-drylot feeding, summer-planted oats, and corn residue grazing (ALT). …

The Effects Of Administering Different Metaphylactic Antimicrobials On Growth Performance And Health Outcomes Of High-Risk, Newly Received Feedlot Steers, Carley M. Coppin, Taylor M. Smock, Cory L. Helmuth, Jeff L. Manahan, Nathan S. Long, Ashley A. Hoffman, Jeffery A. Carroll, Paul R. Broadway, Nicole C. Burdick Sanchez, James E. Wells, Samodha C. Fernando, Kristin E. Hales

Department of Animal Science: Faculty Publications

Bovine respiratory disease (BRD) is the primary animal health concern facing feedlot producers. Many antimicrobial mitigation strategies are available, but few studies have compared feedlot performance during both the receiving and finishing periods following application of different antimicrobials used as metaphylaxis at arrival. The objective of this study was to compare antimicrobial metaphylaxis methods on clinical health and growth performance across both the receiving and finishing periods. A total of 238 multiple-sourced steers in two source blocks were used in a generalized complete block design. The four treatments included: 1) a negative control, 5 mL of sterile saline injected subcutaneously …

Genes Involved In Feed Efficiency Identified In A Meta-Analysis Of Rumen Tissue From Two Populations Of Beef Steers, Amanda K. Lindholm-Perry, Allison M. Meyer, Rebecca J. Kern-Lunbery, Hannah C. Cunningham-Hollinger, Taran H. Funk, Brittney N. Keel

Roman L. Hruska U.S. Meat Animal Research Center: Reports

In cattle, the rumen is an important site for the absorption of feed by-products released by bacterial fermentation, and variation in ruminal function plays a role in cattle feed efficiency. Studies evaluating gene expression in the rumen tissue have been performed prior to this. However, validating the expression of genes identified in additional cattle populations has been challenging. The purpose of this study was to perform a meta-analysis of the ruminal transcriptome of two unrelated populations of animals to identify genes that are involved in feed efficiency across populations. RNAseq data from animals with high and low residual feed intake …

Using Pooled Data For Genomic Prediction In A Bivariate Framework With Missing Data, Johnna L. Baller, Stephen D. Kachman, Larry A. Kuehn, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Pooling samples to derive group genotypes can enable the economically efficient use of commercial animals within genetic evaluations. To test a multivariate framework for genetic evaluations using pooled data, simulation was used to mimic a beef cattle population including two moderately heritable traits with varying genetic correlations, genotypes and pedigree data. There were 15 generations (n = 32,000; random selection and mating), and the last generation was subjected to genotyping through pooling. Missing records were induced in two ways: (a) sequential culling and (b) random missing records. Gaps in genotyping were also explored whereby genotyping occurred through generation 13 …

Interaction Of Replacing Corn Silage With Soyhulls As A Roughage Source With Or Without 3% Added Wheat Straw In The Diet: Impacts On Intake, Digestibility, And Ruminal Fermentation In Steers Fed High-Concentrate Diets, Bryan W. Neville, Wayde J. Pickinpaugh, Lea J. Mittleider, Rebecca L. Moore, Kendall C. Swanson, Joel S. Caton

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the …

Impacts Of Added Roughage On Growth Performance, Digestibility, Ruminal Fermentation, And Ruminal Ph Of Feedlot Steers Fed Wheat-Based Feedlot Diets Containing 30% Modified Distillers Grains With Solubles, Wayde J. Pickinpaugh, Bryan W. Neville, Rebecca L. Moore, Joel S. Caton

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± …

Genetic Parameters, Heterosis, And Breed Effects For Body Condition Score And Mature Cow Weight In Beef Cattle, André Mauric F. Ribeiro, Leticia P. Sanglard, Warren M. Snelling, R. Mark Thallman, Larry A. Kuehn, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Understanding the genetic relationship between mature cow weight (MWT) and body condition score (BCS) is useful to implement selection programs focused on cow efficiency. The objectives of this study were to estimate genetic parameters, heterosis, and breed effects for MWT and BCS. In total, 25,035 and 24,522 overlapping records were available for MWT and BCS on 6,138 and 6,131 cows, respectively, from the Germplasm Evaluation program, a crossbred beef population at the U.S. Meat Animal Research Center. Pedigree was available for 48,013 individuals. Univariate animal models were used to estimate heritabilities for each trait by parity. …

Interaction Of Urea With Frequency And Amount Of Distillers Grains Supplementation For Growing Steers On A High Forage Diet, Haley F. Linder, Josh E. Sebade, Zac E. Carlson, Hannah C. Wilson, Tyler J. Spore, Mary E. Drewnoski, Jim C. Macdonald

Department of Animal Science: Faculty Publications

Two studies were conducted to determine interactions of urea inclusion to a dried distillers grains plus solubles (DDGS; 29.4% crude protein, 5.48% ether extract) supplement fed at two amounts and two frequencies to steers on a high forage diet. In Exp. 1, 120 (247 kg; SD = 20) steers were fed individually for 84 d. Steers received ad libitum grass hay (6.8% crude protein) and one of eight treatments. Treatment design was a 2 × 2 × 2 factorial. Supplement was fed daily or three times per week, amount of supplement fed was 6.36 kg dry matter (DM)/week [0.37% body …

Impact Of Feeding Syngenta Enogen® Feed Corn Compared To Control Corn In Different Diet Scenarios To Finishing Beef Cattle, Stacia M. Volk, Hannah H. Wilson, Kathryn J. Hanford, James C. Macdonald, Galen E. Erickson

Department of Animal Science: Faculty Publications

The objective of this pooled statistical analysis was to evaluate Syngenta Enogen® Feed Corn (EFC) versus conventional corn (CON) when fed as either dry-rolled corn (DRC) or highmoisture corn (HMC) for effects on finishing beef cattle performance and carcass characteristics. Corns were evaluated in diets with byproduct inclusion rates of 0, 15, 18, 20, and 30% distiller grains or 25 and 35% Sweet Bran® (a commercial corn gluten feed product). Seven trials (n = 1856) consisting of 200 pen means comparing 26 diet treatments were analyzed using regression in a pooled analysis. When EFC was processed as DRC, the gain …

Breed And Heterotic Effects For Mature Weight In Beef Cattle, Madeline J. Zimmermann, Larry A. Kuehn, Matthew L. Spangler, R. M. Thallman, Warren M. Snelling, Ronald M. Lewis

Department of Animal Science: Faculty Publications

Cow mature weight (MWT) is heritable and affects the costs and efficiency of a breeding operation. Cow weight is also influenced by the environment, and the relationship between the size and profitability of a cow varies depending on production system. Producers, therefore, need tools to incorporate MWT in their selection of cattle breeds and herd replacements. The objective of this study was to estimate breed and heterotic effects for MWT using weight-age data on crossbred cows. Cow's MWT at 6 yr was predicted from the estimated parameter values-asymptotic weight and maturation constant (k)-from the fit of the Brody function to …

Genetic Parameter Estimates For Bull Prolificacy And Its Relationship With Scrotal Circumference In A Commercial Beef Cattle Population, Chad A. Russell, E John Pollak, Matthew L. Spangler

Department of Animal Science: Faculty Publications

The commercial beef cattle industry relies heavily on the use of natural service sires. When artificial insemination is deemed difficult to implement, multisire breeding pastures are used to increase reproductive rates in large breeding herds or to safe-guard against bull injury during the breeding season. Although each bull might be given an equal opportunity to produce offspring, evidence suggest that there is substantial variation in the number of calves sired by each bull in a breeding pasture. With the use of DNA-based paternity testing, correctly assigning calves to their respective sires in multisire pastures is possible and presents an opportunity …

Assessment Of Alternative Models For Genetic Analysis Of Worm And Tick Infestation In Nellore Cattle, T. L. Passafaro, F. B. Lopes, Thomas W. Murphy, B. D. Valente, R. C. Leite, G. J.M. Rosa, F. L.B. Toral

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Worms and ticks are important parasites in beef cattle, especially in tropical areas, causing significant economic and production losses. Understanding animal-to-animal variation on infestation for these parasites might guide genetic selection and improvement of management practices to attenuate its detrimental effects. Statistical models used to analyze such traits usually assume a Gaussian distribution for the observed data. However, this assumption is quite often inappropriate for counting data. Therefore, the objectives of this study were: 1) Estimate genetic parameters for worms and tick infestations in Nellore cattle, and 2) To compare the overall performance of six data analysis approaches for worm …

Genetic Changes In Beef Cow Traits Following Selection For Calving Ease, Gary L. Bennett, Richard M. Thallman, Warren M. Snelling, John W. Keele, Harvey C. Freetly, Larry A. Kuehn

Roman L. Hruska U.S. Meat Animal Research Center: Reports

One approach to reducing calving difficulty is to select heifers with higher breeding value for calving ease. Calving ease is often associated with lower birth weight and that may result in other possible effects on lifetime productivity. Females from experimental select and control calving ease lines within each of the seven populations were compared. Random samples of 720 heifers from lines selected for better calving ease breeding values and 190 heifers from control lines selected for average birth weights were followed through four parities. Select and control lines within the same population were selected to achieve similar yearling weight breeding …

Evaluation Of The Effects Of Biochar On Diet Digestibility And Methane Production From Growing And Finishing Steers, Thomas Winders, Melissa L. Jolly, Hannah C. Wilson, James C. Macdonald, Galen E. Erickson, Andrea K. Watson

Department of Animal Science: Faculty Publications

The objectives of these studies were to evaluate the effects of biochar (0%, 0.8%, or 3% of diet dry matter) on diet digestibility and methane and carbon dioxide production from cattle on growing and finishing diets. The growing diet consisted of 21% brome hay, 20% wheat straw, 30% corn silage, 22% wet distillers grains plus solubles, and 7% supplement. The finishing diet consisted of 53% dry-rolled corn, 15% corn silage, 25% wet distillers grains plus solubles, and 7% supplement. In both trials biochar replaced fine ground corn in the supplement. Six crossbred steers (initial body weight [BW] 529 kg; SD …

Comparison Of Different Functions To Describe Growth From Weaning To Maturity In Crossbred Beef Cattle, Madeline J. Zimmermann, Larry A. Kuehn, Matthew L. Spangler, R. Mark Thallman, Warren M. Snelling, Ronald M. Lewis

Department of Animal Science: Faculty Publications

Cow mature weight (MWT) has increased in the past 30 yr. Larger cows cost more to maintain, but their efficiency—and thus profitability— depends on the production environment. Incorporating MWT effectively into selection and mating decisions requires understanding of growth to maturity. The objective of this study was to describe growth to maturity in crossbred beef cattle using Brody, spline, and quadratic functions. Parameter estimates utilized data on crossbred cows from cycle VII and continuous sampling phases of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. The MWT were estimated at 6 yr from the fitted parameters obtained …

Identifying Breed Effects For Cow Mature Weight, Madeline J. Zimmermann

Department of Animal Science: Dissertations, Theses, and Student Research

Mature weight (MWT) in beef cattle has increased over the past 30 yr. In general, larger cows are costlier to maintain than smaller cows, and their profitability depends on their production environment. A wide range of beef production environments exist in the United States. There are also a variety of beef cattle breeds that can be chosen and mated to create a type of cow which will be optimally suited to excel in a given environment. However, there remains a need for tools allowing effective comparison among breeds to facilitate such decision making. Unfortunately, estimated progeny differences ( …

Evaluation Of Alpha Amylase Containing Corn On Finishing Cattle Performance And Digestibilty, Melissa L. Jolly-Breithaupt

Department of Animal Science: Dissertations, Theses, and Student Research

One digestion and four finishing trials were conducted to evaluate the effect of a new corn hybrid containing an α-amylase trait, Syngenta Enogen Feed Corn (SYT-EFC) on site and extent of digestion, ruminal fermentation parameters, and feedlot performance. Experiments utilized corn containing the enzymatic gene compared to controls, the near isoline parental corn (NEG) or commercially available corn grain (CON), processed as dry-rolled corn (DRC) or high moisture corn (HMC) in diets with dry [distillers grains plus solubles (DGS)] or wet (Sweet Bran) milling byproducts. The corn grain of the experimental diets were fed as the sole grain source, comprising …

Rumen Bacterial Community Structure Impacts Feed Efficiency In Beef Cattle, Henry A. Paz, Kristin E. Hales, James E. Wells, Larry A. Kuehn, Harvey C. Freetly, Elaine D. Berry, Michael D. Flythe, Matthew L. Spangler, Samodha C. Fernando

Department of Animal Science: Faculty Publications

The importance of the rumen microbiota on nutrient cycling to the animal is well recognized; however, our understanding of the influence of the rumen microbiome composition on feed efficiency is limited. The rumen microbiomes of two large animal cohorts (125 heifers and 122 steers) were characterized to identify specific bacterial members (operational taxonomic units [OTUs]) associated with feed efficiency traits (ADFI, ADG, and G:F) in beef cattle. The heifer and steer cohorts were fed a forage-based diet and a concentrate-based diet, respectively. A rumen sample was obtained from each animal via esophageal tubing and bacterial community composition was …

Risks Associated To Different Methods Of Increasing Pregnancy Rate Of Cows In Cow-Calf Systems, Tamara Esteves De Oliveira, Julio Otavio Jardim Barcellos, Jack Whittier, Odilene De Souza Teixeira, David Santos De Freitas, Ricardo Pedroso Oaigen, Matheus Dhein Dill, Concepta Mcmanus

Department of Animal Science: Faculty Publications

This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, …

Effects Of Syngenta Enogen Feed Corn Containing An Α-Amylase Trait On Finishing Cattle Performance And Carcass Characteristics, M. L. Jolly-Breithaupt, M. E. Harris, B. L. Nuttelman, D. B. Burken, J. C. Macdonald, M. K. Leubbe, T. K. Iragavarapu, G. E. Erickson

Department of Animal Science: Faculty Publications

Two experiments evaluated the effects of feeding a new corn hybrid, containing an α-amylase enzyme trait, Syngenta Enogen Feed Corn (SYT-EFC), on feedlot performance and carcass characteristics at two locations. Experiment 1 utilized 300 calffed steers (298.5 ± 16.3 kg of BW) at the University of Nebraska–Lincoln Eastern Nebraska Research and Extension Center Mead, NE. Treatments were designed as a 2 × 2 + 1– factorial arrangement with factors consisting of 1) corn type (SYT-EFC or conventional [CON]) and 2) byproduct type (with or without Sweet Bran [SB]), or a BLEND of STY-EFC and CON without SB. In Exp. 2, …

Economic Selection Index Development For Beefmaster Cattle I: Terminal Breeding Objective, Kathleen P. Ochsner, M. D. Macneil, Matthew L. Spangler

Department of Animal Science: Faculty Publications

The objective of this study was to develop an economic selection index for Beefmaster cattle in a terminal production system where bulls are mated to mature cows with all resulting progeny harvested. National average prices from 2010 to 2014 were used to establish income and expenses for the system. Phenotypic and genetic parameter values among the selection criteria and goal traits were obtained from literature. Economic values were estimated by simulating 100,000 animals and approximating the partial derivatives of the profit function by perturbing traits one at a time, by 1 unit, while holding the other traits constant at their …

Economic Selection Index Development For Beefmaster Cattle Ii: General-Purpose Breeding Objective, Kathleen P. Ochsner, M. D. Macneil, Ronald M. Lewis, Matthew L. Spangler

Department of Animal Science: Faculty Publications

An economic selection index was developed for Beefmaster cattle in a general-purpose production system in which bulls are mated to a combination of heifers and mature cows, with resulting progeny retained as replacements or sold at weaning. National average prices from 2010 to 2014 were used to establish income and expenses for the system. Genetic parameters were obtained from the literature. Economic values were estimated by simulating 100,000 animals and approximating the partial derivatives of the profit function by perturbing traits 1 at a time, by 1 unit, while holding the other traits constant at their respective means. Relative economic …

The Impact Of Training Strategies On The Accuracy Of Genomic Predictors In United States Red Angus Cattle, J. Lee, Stephen D. Kachman, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Genomic selection (GS) has become an integral part of genetic evaluation methodology and has been applied to all major livestock species, including beef and dairy cattle, pigs, and chickens. Significant contributions in increased accuracy of selection decisions have been clearly illustrated in dairy cattle after practical application of GS. In the majority of U.S. beef cattle breeds, similar efforts have also been made to increase the accuracy of genetic merit estimates through the inclusion of genomic information into routine genetic evaluations using a variety of methods. However, prediction accuracies can vary relative to panel density, the number of folds used …

Development Of Terminal And Maternal Economic Selection Indices In Beefmaster Cattle, Kathleen P. Ochsner

Department of Animal Science: Dissertations, Theses, and Student Research

In the design of economic selection indices, the relative importance of traits in the breeding objective is reflected by their relative economic weighting. The objective of this study was to develop two economic selection indices for Beefmaster cattle: one for a terminal production system and one for a maternal production system. The terminal index was developed assuming bulls are mated to mature cows with all resulting progeny harvested. The maternal index was developed assuming bulls are mated to a combination of heifers and mature cows, with resulting progeny retained as replacements or sold at weaning.

National average prices from 2010 …

Genetic Parameters For Docility, Weaning Weight, Yearling Weight And Intramuscular Fat Percentage In Hereford Cattle, Jose A. Torres-Vazquez

Department of Animal Science: Dissertations, Theses, and Student Research

Temperament in cattle can be described as the reactivity or fear response to human handling, and it is important to beef cattle producers not only from a human safety but also due to potential correlations with other economically traits. Before a docility selection metric can be added to a genetic evaluation, any potential antagonisms with economically relevant traits should be quantified. The objective was to estimate genetic parameters, including genetic correlations, for chute score (CS), weaning weight (WW), yearling weight (YW), and intramuscular fat percentage (IMF) in Hereford cattle. Single-trait and bivariate animal models were used to estimate heritabilities and …

Effects Of Sorghum Wet Distillers Grains Plus Solubles In Steam-Flaked Corn–Based Finishing Diets On Steer Performance, Carcass Characteristics, And Digestibility Characteristics, E. K. Buttrey, K. H. Noel, F. T. Mccollum Iii, N. A. Cole, L. O. Tedeschi, James C. Macdonald

Department of Animal Science: Faculty Publications

Two studies were conducted to evaluate the effects of sorghum wet distillers grains (SWDGS) in finishing diets on steer performance, carcass characteristics, and nutrient digestibility. In Exp. 1, 240 steers (initial BW = 379 ± 1 kg) were fed steam-flaked corn–based diets with or without 25% SWDGS and 7.5, 10.0, or 12.5% alfalfa hay. There were no effects of alfalfa hay concentration on BW, DMI, ADG, or G:F (P ≥ 0.16). Including SWDGS reduced (P ≤ 0.05) ADG and G:F. Fat thickness decreased (P = 0.03) and DP tended to decrease (P = 0.09) linearly as level of alfalfa hay …

Effects Of Fat And/Or Methionine Hydroxy Analog Added To A Molasses-Urea-Based Supplement On Ruminal And Postruminal Digestion And Duodenal Flow Of Nutrients In Beef Steers Consuming Low-Quality Lovegrass Hay, R. Lopez, G. D. Bernhard, J. E. Guerra-Liera, S. A. Soto-Navarro, L. A. Balstad, M. K. Petersen, D. V. Dhuyvetter, M. S. Brown, C. R. Krehbiel

Department of Animal Science: Faculty Publications

Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molassesurea- based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass Eragrostis curvula: 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, …

Feeding Wet Distillers Grains Plus Solubles With And Without A Direct-Fed Microbial To Determine Performance, Carcass Characteristics, And Fecal Shedding Of Escherichia Coli O157:H7 In Feedlot Heifers, B. K. Wilson, B. P. Pulsipher, D. L. Step, M. E. Jacob, D. L. Vanoverbeke, C. J. Richards, T. G. Nagaraja, C. R. Krehbiel

Department of Animal Science: Faculty Publications

The inclusion of wet distillers grains plus solubles (WDGS) in feedlot diets has become a common practice in many regions of the United States due to the expanded production of byproducts and fluctuating corn prices related to ethanol production and other factors. In addition, societal concerns over the continued use of antimicrobials in agriculture production combined with an enhanced interest in disease and pathogen prevention in the food supply have led to an increased interest in use of direct-fed microbials (DFM) in growing and finishing cattle. Direct-fed microbials have been shown to improve ADG and feed efficiency, alter ruminal fermentation, …

Genetic Parameters For Docility, Weaning Weight, Yearling Weight, And Intramuscular Fat Percentage In Hereford Cattle, J. A. Torres-Vázquez, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Cattle behavior, including measures of docility, is important to beef cattle producers not only from a human safety perspective but also due to potential correlations to economically relevant traits. Field data from the American Hereford Association was used to estimate genetic parameters for chute score (CS; n = 25,037), weaning weight (WW; n = 24,908), yearling weight (YW; n = 23,978), and intramuscular fat percentage (IMF; n = 12,566). Single-trait and bivariate animal models were used to estimate heritabilities and genetic correlations. All models included fixed effects of sex and contemporary group, defined as herd–year–season, and direct genetic and residual …