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Department of Animal Science: Faculty Publications

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Full-Text Articles in Animal Sciences

Estimates Of Genetic Parameters For Holstein Cows For Test-Day Yield Traits With A Random Regression Cubic Spline Model, B.J. Degroot, Jeffrey F. Keown, L. Dale Van Vleck, Stephen D. Kachman Jun 2007

Estimates Of Genetic Parameters For Holstein Cows For Test-Day Yield Traits With A Random Regression Cubic Spline Model, B.J. Degroot, Jeffrey F. Keown, L. Dale Van Vleck, Stephen D. Kachman

Department of Animal Science: Faculty Publications

Genetic parameters were estimated with restricted maximum likelihood for individual test-day milk, fat and protein yields and somatic cell scores with a random regression cubic spline model. Test-day records of Holstein cows that calved from 1994 through early 1999 were obtained from Dairy Records Management Systems in Raleigh, North Carolina, for the analysis. Estimates of heritability for individual test-days and estimates of genetic and phenotypic correlations between test-days were obtained from estimates of variances and covariances from the cubic spline analysis. Estimates were calculated of genetic parameters for the averages of the test days within each of the ten 30-day …

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Effect Of Competition On Gain In Feedlot Bulls From Hereford Selection Lines, L. Dale Van Vleck, L. V. Cundiff, R. M. Koch Jun 2007

Effect Of Competition On Gain In Feedlot Bulls From Hereford Selection Lines, L. Dale Van Vleck, L. V. Cundiff, R. M. Koch

Department of Animal Science: Faculty Publications

This study examined competition effects on ADG in the feedlot of 1,882 Hereford bulls representing 8 birth years from a selection experiment. Each year, 8 feedlot pens were used to feed bulls in groups, with 2 pens nested within each of the 4 selection lines. Gains were recorded for up to 8 periods of 28 d. Models for analyses included pen effects (fixed or random), fixed effects such as year and line, and random direct genetic, competition genetic (and in some analyses competition environmental), and environmental effects. Each pen mate as a competitor affected the records of all others in …

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Across-Breed Adjustment Factors For Expected Progeny Differences For Carcass Traits, L. Dale Van Vleck, L. V. Cundiff, T. L. Wheeler, S. D. Shackelford, M. Koohmaraie Apr 2007

Across-Breed Adjustment Factors For Expected Progeny Differences For Carcass Traits, L. Dale Van Vleck, L. V. Cundiff, T. L. Wheeler, S. D. Shackelford, M. Koohmaraie

Department of Animal Science: Faculty Publications

Adjustment factors to allow comparison of EPD from several breed associations for birth, weaning, and yearling weights have been available for more than 10 yr. This paper describes steps to calculate adjustment factors for EPD for 4 carcass traits: marbling score, fat thickness, ribeye area, and retail product percentage. The required information is the same as for the weight traits: 1) breed of sire solutions based on measurements on progeny at the US Meat Animal Research Center (USMARC) that have sires with breed association EPD, 2) mean EPD of sires weighted by number of progeny at USMARC (USMARC progeny not …

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Impact Of Bovine Somatotropin On Ranking For Genetic Value Of Dairy Sires For Milk Yield Traits And Somatic Cell Score, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck Mar 2007

Impact Of Bovine Somatotropin On Ranking For Genetic Value Of Dairy Sires For Milk Yield Traits And Somatic Cell Score, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Records of Holstein cows were used to examine how different models account for the effect of bovine somatotropin (bST) treatment on genetic evaluation of dairy sires for yield traits and somatic cell score. Data set 1 included 65, 720 first-lactation records. Set 2 included 50,644 second-lactation records. Set 3 included 45,505 records for lactations three, four, and five. Estimated breeding values (EBV) of sires were with three different animal models. With Model 1, bST administration was ignored. With Model 2, bST administration was used as a fixed effect. With Model 3, administration of bST was used to define the contemporary …

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Estimates Of Correlations Among Yield Traits And Somatic Cell Score With Different Models To Adjust For Bovine Somatotropin Effects On Holstein Dairy Cows, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck Mar 2007

Estimates Of Correlations Among Yield Traits And Somatic Cell Score With Different Models To Adjust For Bovine Somatotropin Effects On Holstein Dairy Cows, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Records of Holstein cows from the Dairy Records Processing Center at Raleigh, NC were edited to obtain three data sets: 65,720 first, 50,694 second, and 65,445 later lactations. Correlations among yield traits and somatic cell score were estimated with three different models: 1) bovine somatotropin (bST) administration ignored, 2) bST administration as a fixed effect and 3) administration of bST as part of the contemporary group (herd-year-month-bST). Heritability estimates ranged from 0.13 to 0.17 for milk, 0.12 to 0.20 for fat, 0.14 to 0.16 for protein yields, and 0.08 to 0.09 for somatic cell score. Estimates were less for later …

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Technical Note: Use Of Marker-Based Relationships With Multiple-Trait Derivative-Free Restricted Maximal Likelihood, Z. Zhang, E. S. Buckler, L. Dale Van Vleck Mar 2007

Technical Note: Use Of Marker-Based Relationships With Multiple-Trait Derivative-Free Restricted Maximal Likelihood, Z. Zhang, E. S. Buckler, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The widespread use of the set of multiple- trait derivative-free REML programs for prediction of breeding values and estimation of variance components has led to significant improvement in traits of economic importance. The initial version of this software package, however, was generally limited to pedigree- based relationships. With continued advances in genomic research and the increased availability of genotyping, relationships based on molecular markers are obtainable and desirable. The addition of a new program to the set of multiple-trait derivative-free REML programs is described that allows users the flexibility to calculate relationships using standard pedigree files or an arbitrary relationship …

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Localization Of Period 1 Mrna In The Ruminant Oocyte And Investigations Of Its Role In Ovarian Function, R. A. Cushman, M.F. Allan, S.A. Jones, Gary P. Rupp, S.E. Echternkamp Feb 2007

Localization Of Period 1 Mrna In The Ruminant Oocyte And Investigations Of Its Role In Ovarian Function, R. A. Cushman, M.F. Allan, S.A. Jones, Gary P. Rupp, S.E. Echternkamp

Department of Animal Science: Faculty Publications

The clock gene Period 1 (Per1) may be a prolificacy gene, because it localized to the mouse oocyte and Per1-null drosophila shed fewer eggs. Because Per1 mapped to a region of mouse chromosome 11 syntenic to bovine chromosome 19 where a quantitative trait loci (QTL) for ovulation rate existed, we hypothesized that Per1 influenced folliculogenesis and ovulation rate in ruminants. Ovarian cortex was collected at slaughter on days 5, 12, 15, 17, and 20 after estrus for real-time RT-PCR evaluation of Per1 mRNA expression in Dorset (n = 18), Romanov (n = 10), Romanov/Dorset (n = 21), …

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Estimation Of The Proportion Of Feed Protein Digested In The Small Intestine Of Cattle Consuming Wet Corn Gluten Feed, Paul J. Kononoff, S. K. Ivan, Terry J. Klopfenstein Jan 2007

Estimation Of The Proportion Of Feed Protein Digested In The Small Intestine Of Cattle Consuming Wet Corn Gluten Feed, Paul J. Kononoff, S. K. Ivan, Terry J. Klopfenstein

Department of Animal Science: Faculty Publications

The objectives of this study were to expand the database and determine the intestinal digestibility of rumen undegradable protein (dRUP) of common dairy feeds and to determine the effects of feeding 37.9% wet corn gluten feed on these estimates. Two ruminally and duodenally fistulated steers were assigned randomly to a crossover design with 4-wk periods. The mobile bag technique was used to determine rumen undegradable protein (RUP), dRUP, total tract digestible protein, and total tract digestible dry matter of alfalfa hay, brome hay, alfalfa haylage, corn silage, whole cottonseed, soybean meal, soyhulls, ground corn, nonenzymatically browned soybean meal, and dried …

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Characterizing Linkage Disequilibrium In Pig Populations, Feng-Xing Du, Archie C. Clutter, Michael M. Lohuis Jan 2007

Characterizing Linkage Disequilibrium In Pig Populations, Feng-Xing Du, Archie C. Clutter, Michael M. Lohuis

Department of Animal Science: Faculty Publications

Knowledge of the extent and range of linkage disequilibrium (LD), defined as non-random association of alleles at two or more loci, in animal populations is extremely valuable in localizing genes affecting quantitative traits, identifying chromosomal regions under selection, studying population history, and characterizing/managing genetic resources and diversity. Two commonly used LD measures, r2 and D’, and their permutation based adjustments, were evaluated using genotypes of more than 6,000 pigs from six commercial lines (two terminal sire lines and four maternal lines) at ~4,500 autosomal SNPs (single nucleotide polymorphisms). The results indicated that permutation only partially removed the dependency of …

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Effect Of A Vaccine Product Containing Type Ill Secreted Proteins On The Probability Of Escherichia Coli 01 57:H7 Fecal Shedding And Mucosal Colonization In Feedlot Cattle, R. E. Peterson, Terry J. Klopfenstein, Rodney A. Moxley, Galen E. Erickson, S. Hinkley, G. Bretschneider, E. Berberov, D. Rogan, David R. Smith Jan 2007

Effect Of A Vaccine Product Containing Type Ill Secreted Proteins On The Probability Of Escherichia Coli 01 57:H7 Fecal Shedding And Mucosal Colonization In Feedlot Cattle, R. E. Peterson, Terry J. Klopfenstein, Rodney A. Moxley, Galen E. Erickson, S. Hinkley, G. Bretschneider, E. Berberov, D. Rogan, David R. Smith

Department of Animal Science: Faculty Publications

Preharvest intervention strategies to reduce Escherichia coli 0157:H7 in cattle have been sought as a means to reduce human foodborne illness. A blinded clinical trial was conducted to test the effect of a vaccine product on the probability that feedlot steers, under conditions of natural exposure, shed E. coli 0157:H7 in feces, are colonized by this organism in the terminal rectum, or develop a humoral response to the respective antigens. Steers (n = 288) were assigned randomly to 36 pens (eight head per pen), and pens were randomized to vaccination treatment in a balanced fashion within six dietary treatments of …

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Effects Of Dried Distillers Grains And Equivalent Undegradable Intake Protein Or Ether Extract On Performance And Forage Intake Of Heifers Grazing Smooth Bromegrass Pastures, J. C. Macdonald, Terry J. Klopfenstein, Galen E. Erickson, W. A. Griffin Jan 2007

Effects Of Dried Distillers Grains And Equivalent Undegradable Intake Protein Or Ether Extract On Performance And Forage Intake Of Heifers Grazing Smooth Bromegrass Pastures, J. C. Macdonald, Terry J. Klopfenstein, Galen E. Erickson, W. A. Griffin

Department of Animal Science: Faculty Publications

Crossbred heifers (n = 120; BW = 368 kg, SD = 39 kg) were used to determine effects of dried distillers grains (DDG) and relative contributions of undegradable intake protein (UIP) and fat (ether extract, EE) in DDG on ADG and forage intake (FI). Heifers rotationally grazed six 3.5-ha, smooth bromegrass paddocks (IVDMD = 65.7%, CP = 20.8%, UIP = 2.17%, DM basis). Heifers were blocked by previous ADG and allotted to treatments in a 3 × 3 + 1 factorial design. Factors were source and level of supplementation. Supplements were as follows: 1) DDG (UIP = 15.8%, EE = …

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Renewed Selection For Heat Loss In Mice: Direct Responses And Correlated Responses In Feed Intake, Body Weight, Litter Size, And Conception Rate, J. M. Mcdonald, Merlyn K. Nielsen Jan 2007

Renewed Selection For Heat Loss In Mice: Direct Responses And Correlated Responses In Feed Intake, Body Weight, Litter Size, And Conception Rate, J. M. Mcdonald, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Divergent selection in mice was renewed in 3 independent replicates for high (MH) and low (ML) heat loss. An unselected control (MC) was maintained in all replicates. Heat loss was measured for individual male mice for 15 h, overnight in direct calorimeters. After 16 initial generations of selection followed by 26 generations of relaxed selection, divergent selection resumed for 9 generations. The realized selection applied was very close to the maximum possible selection according to the criteria and protocol. Selection differentials were greater for high than for low selection due to greater variation in the MH line. When corrected for …

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Effect Of Lactobacillus Acidophilus Strain N P51 On Escherichia Coli 0157:H7 Fecal Shedding And Finishing Performance In Beef Feedlot Cattle, R. Peterson, Terry J. Klopfenstein, Galen E. Erickson, J. Folmer, S. Hinkley, Rodney A. Moxley, David R. Smith Jan 2007

Effect Of Lactobacillus Acidophilus Strain N P51 On Escherichia Coli 0157:H7 Fecal Shedding And Finishing Performance In Beef Feedlot Cattle, R. Peterson, Terry J. Klopfenstein, Galen E. Erickson, J. Folmer, S. Hinkley, Rodney A. Moxley, David R. Smith

Department of Animal Science: Faculty Publications

A 2-year study was conducted during the summer months (May to September) to test the effectiveness of feeding Lactobacillus acidophilus strain NP51 on the proportion of cattle shedding Escherichia coli 0157:H7 in the feces and evaluate the effect of the treatment on finishing performance. Steers (n = 448) were assigned randomly to pens, and pens of cattle were assigned randomly to NP5 1 supplementation or no supplementation (control). NP5 1 products were mixed with water and applied as the feed was mixed daily in treatment-designated trucks at the rate of l09 CFU per steer. Fecal samples were collected (n …

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Efficacy Of Dose Regimen And Observation Of Herd Immunity From A Vaccine Against Escherichia Coli 01 57:H7 For Feedlot Cattle, R. E. Peterson, Terry Klopfenstein, Rodney A. Moxley, Galen E. Erickson, S. Hinkley, D. Rogan, David R. Smith Jan 2007

Efficacy Of Dose Regimen And Observation Of Herd Immunity From A Vaccine Against Escherichia Coli 01 57:H7 For Feedlot Cattle, R. E. Peterson, Terry Klopfenstein, Rodney A. Moxley, Galen E. Erickson, S. Hinkley, D. Rogan, David R. Smith

Department of Animal Science: Faculty Publications

A clinical trial was conducted to test the effect of a vaccine product containing type I11 secreted proteins of Escherichia coli 0157:H7 on the probability that feedlot steers shed E. coli 0157:H7 in feces. Six hundred eight same-source steers were utilized. Of these, 480 steers were assigned randomly to 60 pens (eight head per pen) and to one of four vaccination treatments (120 cattle per treatment, two head per treatment per pen). The four treatments were (i) no vaccination; (ii) one dose, vaccinated once at reimplant (day 42); (iii) two doses, vaccinated on arrival (day 0) and again at reimplant …

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Comparison Of Performance And Economics Of A Long-Yearling And Calf-Fed System, W. A. Griffin, T. J. Klopfenstein, G. E. Erickson, D. M. Feuz, James C. Macdonald, D. J. Jordon Jan 2007

Comparison Of Performance And Economics Of A Long-Yearling And Calf-Fed System, W. A. Griffin, T. J. Klopfenstein, G. E. Erickson, D. M. Feuz, James C. Macdonald, D. J. Jordon

Department of Animal Science: Faculty Publications

Performance and economics of calf feeding and feeding long-yearlings was compared from University of Nebraska research conducted from 1996 to 2004. All calves in these studies were spring born and purchased the subsequent fall. The heaviest calves (292 ± 5 kg) were placed into the feedlot and fed an average of 168 d (calf-feds), whereas the lighter calves (239 ± 5 kg) were placed into a long-yearling system consisting of corn residue grazing followed by summer grazing before entering the feedlot for finishing. Long-yearlings were fed in the feedlot for an average of 90 d. At the beginning of the …

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Managing The Risk Of Comparing Estimated Breeding Values Across Flocks Or Herds Through Connectedness: A Review And Application, L. A. Kuehn, Ronald M. Lewis, D. R. Notter Jan 2007

Managing The Risk Of Comparing Estimated Breeding Values Across Flocks Or Herds Through Connectedness: A Review And Application, L. A. Kuehn, Ronald M. Lewis, D. R. Notter

Department of Animal Science: Faculty Publications

Comparing predicted breeding values (BV) among animals in different management units (e.g. flocks, herds) is challenging if units have different genetic means. Unbiased estimates of differences in BV may be obtained by assigning base animals to genetic groups according to their unit of origin, but units must be connected to estimate group effects. If many small groups exist, error of BV prediction may be increased. Alternatively, genetic groups can be excluded from the statistical model, which may bias BV predictions. If adequate genetic connections exist among units, bias is reduced. Several measures of connectedness have been proposed, but their relationships …

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Genetic Parameters For Yield Traits Of Cows Treated Or Not Treated With Bovine Somatotropin, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck Jan 2007

Genetic Parameters For Yield Traits Of Cows Treated Or Not Treated With Bovine Somatotropin, A. Al-Seaf, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The objective of this study was to estimate genetic correlations between yield traits of cows treated with bovine somatotropin (bST) and the same yield traits of untreated cows. Lactation records from registered Holstein cows were divided by parity into 3 data sets: 1, 2, and 3 through 5. Approximately 10% of the records in each data set were from cows treated with bST. The numbers of records of treated and untreated cows in the data sets were 4,337 and 48,765; 3,730 and 37,796; and 3,645 and 33,957. Two-trait animal models (records for cows treated or not treated) were used to …

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Utilization Of Corn Co-Products In The Beef Industry: Feeding Of Corn Milling Co-Products To Beef Cattle, Galen E. Erickson, Virgil R. Bremer, Terry J. Klopfenstein, Leslie Aaron Stalker, Richard J. Rasby Jan 2007

Utilization Of Corn Co-Products In The Beef Industry: Feeding Of Corn Milling Co-Products To Beef Cattle, Galen E. Erickson, Virgil R. Bremer, Terry J. Klopfenstein, Leslie Aaron Stalker, Richard J. Rasby

Department of Animal Science: Faculty Publications

Corn milling co-products are expected to increase dramatically in supply as the ethanol industry expands. Distillers grains, corn gluten feed, or a combination of both co-products offer many feeding options when included in pasture and feedlot diets. These co-product feeds may effectively improve cattle performance and operation profitability. When these co-products are fed in feedlot diets, adjustments to grain processing method and roughage level may improve cattle performance. Innovative storage methods for wet co-products and the use of dried co-products offer small operations flexibility when utilizing co-products. As new co-products are developed by ethanol plants, they should be evaluated with …

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Carcass Traits And M. Longissimus Lumborum Palatability Attributes Of Calf- And Yearling-Finished Steers, P. S. Brewer, J. M. James, Chris R. Calkins, Richard J. Rasby, Terry J. Klopfenstein, R. V. Anderson Jan 2007

Carcass Traits And M. Longissimus Lumborum Palatability Attributes Of Calf- And Yearling-Finished Steers, P. S. Brewer, J. M. James, Chris R. Calkins, Richard J. Rasby, Terry J. Klopfenstein, R. V. Anderson

Department of Animal Science: Faculty Publications

A 2-yr experiment was conducted to compare carcass characteristics and meat palatability attributes of steers (³⁄₄ British, ¹⁄₄ Continental) finished postweaning as calves or yearlings. Calves and yearlings of the same contemporary group were designated to a finishing system at weaning. Calves (n = 73) were finished in the feedlot (191 d) on a high-concentrate diet. Yearlings (n = 84) grazed crop residues after weaning, followed by spring and summer pasture grazing, and concluded with a short finishing period (91 d) in the feedlot. All steers were fed to a constant, fat thickness endpoint of 1 cm. The M. longissimus …

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Technical Note: Use Of Marker-Based Relationships With Multiple-Trait Derivative-Free Restricted Maximal Likelihood, Z. Zhang, R. J. Todhunter, E. S. Buckler, L. Dale Van Vleck Jan 2007

Technical Note: Use Of Marker-Based Relationships With Multiple-Trait Derivative-Free Restricted Maximal Likelihood, Z. Zhang, R. J. Todhunter, E. S. Buckler, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The widespread use of the set of multiple- trait derivative-free REML programs for prediction of breeding values and estimation of variance components has led to significant improvement in traits of economic importance. The initial version of this software package, however, was generally limited to pedigree- based relationships. With continued advances in genomic research and the increased availability of genotyping, relationships based on molecular markers are obtainable and desirable. The addition of a new program to the set of multiple-trait derivative-free REML programs is described that allows users the flexibility to calculate relationships using standard pedigree files or an arbitrary relationship …

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Unsaturated Fatty Acids And Sodium Affect The Liver-Like Off-Flavor In Cooked Beef, B. E. Jenschke, J. M. Hodgen, J. L. Meisinger, A. E. Hamling, D. Moss, M. Lundesjo Ahnstrom, Kent M. Eskridge, Chris R. Calkins Jan 2007

Unsaturated Fatty Acids And Sodium Affect The Liver-Like Off-Flavor In Cooked Beef, B. E. Jenschke, J. M. Hodgen, J. L. Meisinger, A. E. Hamling, D. Moss, M. Lundesjo Ahnstrom, Kent M. Eskridge, Chris R. Calkins

Department of Animal Science: Faculty Publications

Beef knuckles (n = 60) were chosen from a population of 328 knuckles to test a selection procedure and determine the potential causes of liver-like off-flavor. In phase I, 2 independent panelists were allowed to smell the aromas or smell and taste samples of cooked beef to determine the presence or absence of the liver-like off-flavor and off-flavor intensity. The panelists tested knuckles from 5 feedlots, but only identified 29 as having an off-flavor. A kappa statistic was generated to assess the level of agreement of the 2 panelists that indicated the panelists moderately or substantially agreed when judgments were …

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Effect Of Increasing Levels Of Corn Bran On Milk Yield And Composition, B. N. Janicek, Paul J. Kononoff, A. M. Gehman, K. Karges, M. L. Gibson Jan 2007

Effect Of Increasing Levels Of Corn Bran On Milk Yield And Composition, B. N. Janicek, Paul J. Kononoff, A. M. Gehman, K. Karges, M. L. Gibson

Department of Animal Science: Faculty Publications

Thirty-nine lactating Holstein cows (23 multiparous and 16 primiparous) were randomly assigned to 1 of 3 dietary treatments in a crossover design. Dietary treatments differed by the proportion of corn bran [10, 17.5, and 25% dry matter (DM); designated as low, medium, and high] replacing corn silage and alfalfa. The corn bran coproduct contained 8.2% moisture and 12.9% crude protein, 30.4% neutral detergent fiber (NDF), and 45.0% nonfiber carbohydrate, 9.9% ether extract, and 0.70% P (DM basis). The low treatment consisted of 15.8% NDF from forage (fNDF) and 33.1% total NDF; the medium treatment consisted of 12.9% fNDF and 32.5% …

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Effect Of Incremental Urea Supplementation Of A Conventional Corn Silage-Based Diet On Ruminal Ammonia Concentration And Synthesis Of Microbial Protein, S. E. Boucher, R. S. Ordway, N. L. Whitehouse, F. P. Lundy, Paul J. Kononoff, C. G. Schwab Jan 2007

Effect Of Incremental Urea Supplementation Of A Conventional Corn Silage-Based Diet On Ruminal Ammonia Concentration And Synthesis Of Microbial Protein, S. E. Boucher, R. S. Ordway, N. L. Whitehouse, F. P. Lundy, Paul J. Kononoff, C. G. Schwab

Department of Animal Science: Faculty Publications

One primiparous and 3 multiparous lactating Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design to determine the efficacy of adding urea to a corn silage-based diet on ruminal fermentation and microbial protein synthesis. Dietary treatments were 0, 0.3, 0.6, and 0.9% urea in diet dry matter (DM); urea was manually top dressed and incorporated into the ration. The basal diet contained (DM basis) 52% forage (with 61% of forage provided as corn silage) and 48% concentrate ingredients. The basal diet was formulated to meet National Research Council (NRC, 2001) requirements …

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Selection And Dietary Quality Of Beef Cattle Grazing Smooth Bromegrass, Switchgrass, And Big Bluestem, B. H. Kirch, L. E. Moser, S. S. Waller, T. J. Klopfenstein, G. E. Aiken, J. R. Strickland Jan 2007

Selection And Dietary Quality Of Beef Cattle Grazing Smooth Bromegrass, Switchgrass, And Big Bluestem, B. H. Kirch, L. E. Moser, S. S. Waller, T. J. Klopfenstein, G. E. Aiken, J. R. Strickland

Department of Animal Science: Faculty Publications

The ability of grazing animals to enhance quality of diet by selection is important in production. The study determined the effects of selection on dietary quality of cattle grazing monocultures of smooth bromegrass (Bromus inermis Leyss; SB), switchgrass (Panicum virgatum L.; SG), and big bluestem (Andropogon gerardii Vitman; BB) as influenced by plant maturity. Three ruminally-fistulated steers (295 kg) strip-grazed SB, SG, and BB at vegetative, elongation, early reproductive, and a regrowth stage of development. Selection was maximized by providing cattle access to 40 kg of DM/d per head. Clipped samples were compared with dietary samples accumulated during 45 min …

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Urea Inclusion In Distillers Dried Grains Supplements, L. A. Stalker, D. C. Adams, T. J. Klopfenstein Jan 2007

Urea Inclusion In Distillers Dried Grains Supplements, L. A. Stalker, D. C. Adams, T. J. Klopfenstein

Department of Animal Science: Faculty Publications

Two experiments evaluated the inclusion of urea in distillers dried grains supplements. In Exp. 1, 60 Angus heifers (278 ± 16 kg) were individually fed diets consisting of 58% ground corn cobs, 12% sorghum silage, and 30% distillers dried grains (DM basis) in Calan electronic gates. Urea replaced distillers dried grains at 0, 0.4, 0.8, 1.2, or 1.6% of diet DM. In Exp. 2, 48 crossbred heifers were fed meadow hay ad libitum and 1.4 kg (DM) distillers dried grains to which was added either 0 or 45 g urea/ heifer daily. In both experiments, no response in animal weight …

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Production And Economic Comparisons Of Two Calving Dates For Beef Cows In The Nebraska Sandhills, M. C. Stockton, D. C. Adams, R. K. Wilson, T. J. Klopfenstein, R. T. Clark, G. L. Carriker Jan 2007

Production And Economic Comparisons Of Two Calving Dates For Beef Cows In The Nebraska Sandhills, M. C. Stockton, D. C. Adams, R. K. Wilson, T. J. Klopfenstein, R. T. Clark, G. L. Carriker

Department of Animal Science: Faculty Publications

Calving date for 120 cows in the Nebraska Sandhills was changed from the traditional calving season beginning March 15 (d 75) to one beginning June 15 (d 167) to match increased nutrient needs for lactating cows to immature grazed forages that are high in protein and energy. The hypotheses being tested were that 1) less hay and purchased feeds would be required, 2) production costs would be reduced, and 3) net returns would be greater for June-calving cows compared with their March-calving counterparts. All steer calves from 75 March-calving cows were moved to a feedlot within 60 d of weaning …

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A General Review Of Competition Genetic Effects With An Emphasis On Swine Breeding, C. Y. Chen, Rodger K. Morota, S. Newman, L. D. Van Vleck Jan 2007

A General Review Of Competition Genetic Effects With An Emphasis On Swine Breeding, C. Y. Chen, Rodger K. Morota, S. Newman, L. D. Van Vleck

Department of Animal Science: Faculty Publications

A review of previous studies is presented on estimates of genetic parameters and responses to selection with traditional breeding approaches, on correlations between agonistic behavior and growth performance, and on theoretical frameworks for selection incorporating interactions among individuals and on practical methods for incorporating competition effects in breeding programs.

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Effects Of Distillers Grains Or Corn Supplementation Frequency On Forage Intake And Digestibility, T. W. Loy, J. C. Macdonald, Terry Klopfenstein, Galen E. Erickson Jan 2007

Effects Of Distillers Grains Or Corn Supplementation Frequency On Forage Intake And Digestibility, T. W. Loy, J. C. Macdonald, Terry Klopfenstein, Galen E. Erickson

Department of Animal Science: Faculty Publications

Ten ruminally cannulated heifers (BW = 416 kg; SD = 24) were used to test the effect of the form and frequency of supplemental energy on forage DMI and digestibility. Five treatments were arranged in a replicated, 5 × 4 Latin rectangle (n = 8), and included no supplement (control), dry-rolled corn (DRC) fed daily, DRC fed on alternate days (DRC-A), dried distillers grains plus solubles (DDGS) fed daily, and DDGS fed on alternate days (DDGS-A). Supplements fed daily were fed at 0.40% of BW, whereas alternate day-fed supplements were fed at 0.80% of BW every other day. Chopped grass …

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Comparison Of Heat Tolerance Of Feedlot Heifers Of Different Breeds, Tami M. Brown-Brandl, John A. Nienaber, Roger A. Eigenberg, Terry L. Mader, J.L. Morrow, J.W. Dailey Oct 2006

Comparison Of Heat Tolerance Of Feedlot Heifers Of Different Breeds, Tami M. Brown-Brandl, John A. Nienaber, Roger A. Eigenberg, Terry L. Mader, J.L. Morrow, J.W. Dailey

Department of Animal Science: Faculty Publications

Heat stress in cattle causes decreases in feed intake and feed efficiency; in extreme cases, it can cause death. These losses amount to millions of dollars each year. A study was designed to determine severity of heat stress among four breeds of cattle. Throughout two summers, 256 feedlot heifers of four different breeds were observed. Respiration rates, panting scores, and surface temperatures were taken twice each day on 10 animals/breed for several weeks during the summers of 2002 and 2003. Twenty-four-hour behavior measurements were recorded for four heat-stress and four thermoneutral days. Results showed during the afternoon, Angus cattle (black) …

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Microarray Profiling Of Skeletal Muscle Sarcoplasmic Reticulum Proteins, Jospeh S. Schulz, Nathan Palmer, Jon Steckelberg, Steven J. Jones, Michael G. Zeece Sep 2006

Microarray Profiling Of Skeletal Muscle Sarcoplasmic Reticulum Proteins, Jospeh S. Schulz, Nathan Palmer, Jon Steckelberg, Steven J. Jones, Michael G. Zeece

Department of Animal Science: Faculty Publications

Microarrays were developed to profile the level of proteins associated with calcium regulation in sarcoplasmic reticulum (SR) isolated from porcine Longissimus muscle. The microarrays consisted of SR preparations printed onto to glass slides and probed with monoclonal antibodies to 7 target proteins. Proteins investigated included: ryanodine receptor, (RyR), dihydropyridine receptor, (DHPR), triadin (TRI), calsequestrin (CSQ), 90 kDa junctional protein (JSR90), and fast-twitch and slow-twitch SR calcium ATPases (SERCA1 and SERCA2). Signal from a fluorescentlylabeled detection antibody was measured and quantitated using a slide reader. The microarray developed was also employed to profile Longissimus muscle SR proteins from halothane genotyped animals. …

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