Animal Sciences Commons^™

Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken

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

Corn residue is an abundant feed source in Nebraska that can be utilized as an alternative winter feed. Calves were backgrounded on corn residue in order to determine gain and estimate forage intake when supplemented with distillers grains (DGS). Calves grazing the non-irrigated field gained more (1.03 kg/calf daily) when compared to those grazing the irrigated field (0.90 kg/calf daily; P < 0.01). In year 1, a quadratic effect for intake of DGS was present (P < 0.01) while year 2 observed a linear effect for increasing level of DGS (P < 0.01). The nutritional quality of corn residue was evaluated over time in order to determine changes in blade/sheath, cob, husk/shank and stem. Minimal changes in DM of the forage components occurred was grain reached 15.5% moisture. Digestibility of the blade/sheath declined linearly over time (P < 0.01) while the husk remained constant (P = 0.40). Cob digestibility decreased quadratically (P < 0.01) throughout the sampling period with few changes once grain reached 15.5% moisture. Differences observed in the digestibility of the blade/sheath were attributed to the effects of weathering. A third set of trials was conducted to evaluate the effects of by-product supplementation of calves grazing irrigated corn residue and supplemented with DGS or continuous access to lick tubs. The DGS treatment gained more (0.62 kg/calf daily) than the lick tub treatment (0.38 kg/calf daily; P < 0.01). Calves offered DGS consumed more supplement as a percentage of BW (0.52%) when compared with calves offered lick tubs (0.36%; P < 0.01) on a DM basis. Calves supplemented with DGS had a higher supplement efficiency (46.3% to 42.9%, DM basis) although no differences were present between treatments (P = 0.49). When analyzed on an OM basis, however, calves offered lick tubs had a numerically higher supplement efficiency (50.4%) in comparison to calves …

New Approaches To Corn Silage Use In Beef Cattle Finishing Diets, Dirk Burken

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

Cattle feeders are considering alternative feedstuffs to replace expensive corn grain and decrease rations costs. Feeding corn silage allows cattle feeders to take advantage of the entire corn plant at a time of maximum quality and tonnage as well as secure substantial quantities of roughage and grain inventory. Distiller’s grains have proven to be economical and are now a commonplace ingredient in feedlot finishing diets. Experiments were conducted to determine the effects of feeding increased concentrations of corn silage in replacement of corn grain in finishing diets containing distillers grains. Feedlot gains and gain:feed ratios were reduced as corn silage …

Effects Of Stocking Rate On Forage Nutrient Composition Of Nebraska Sandhills Upland Range When Grazed In Early Summer And The Effects Of Grazing On Nebraska Sandhills Meadow Forage Nutrient Compostion, Jared V. Judy

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

The objectives of this research were to 1) evaluate the effects of stocking rate on forage nutrient quality 2) quantify the relative proportions of current vs. previous year growth being consumed in early summer upland range pastures and 3) determine how grazing effects forage nutrient quality in subirrigated meadows in the Nebraska Sandhills. Experiment 1 was a two year study conducted on the experimental upland range paddocks at Gudmundsen Sandhills Laboratory. Twelve 2-hectare paddocks were assigned one of three treatments stocked at 0 (control), 0.57 (light), and 0.85 (heavy) AUM/ha. Ten 0.25 m² quadrats were clipped per paddock during …

Effects Of Feeding Distillers Grains Throughout A Yearling Heifer Beef Production System On Meat Quality Attributes And Effects Of Omnigen – Af With Ractopamine Hydrochloride On Animal Performance And Beef Carcass Characteristics Of Feedlot Steers, Kelby M. Sudbeck

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

Heifers (n = 229; 225 kg ± 2) were used in a 2 x 2 x 2 factorial to determine the effects of longterm exposure to corn distillers grains plus solubles (DGS) on meat quality characteristics. Factors included supplementing 0.91 kg (LW) or 2.3 kg (HW) modified DGS (MDGS) while grazing corn stalks; 0.6% BW dry DGS (SS) daily or none (NS) during summer grazing; and finishing diet containing 40% wet corn gluten feed (CGF) or 40% MDGS (DGF) on a DM basis. An interaction was observed within CGF for discoloration, with SS increasing discoloration 30%; but no differences between …

Genetic Parameter Estimates And Breed Effects For Calving Difficulty And Birth Weight In A Multi-Breed Population, Cashley Ahlberg

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

There are multiple breeds of beef cattle available to utilize in breeding systems to maximize production and economics. Calving difficulty (dystocia) is a significant cost to beef production and is more prevalent in first-calf heifers. The objectives of this study were to estimate genetic parameters and breed differences for calving difficulty and birth weight as a first step towards the development of across-breed adjustment factors for calving difficulty.

Two models were employed to analyze birth weight (BWT) and calving difficulty (CD) recorded on 4,579 first parity females from the Germplasm Evaluation program at the U.S. Meat Animal Research Center (USMARC). …

Glucose Significantly Enhances Enterotoxigenic Escherichia Coli Adherence To Intestinal Epithelial Cells Through Its Effects On Heat-Labile Enterotoxin Production, Prageeth Wijemanne, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

The present study tested whether exposure of enterotoxigenic Escherichia coli (ETEC) to glucose at different concentrations in the media results in increased bacterial adherence to host cells through increased heat-labile enterotoxin (LT) production, thereby suggesting the effects are physiological. Porcine-origin ETEC strains grown in Casamino acid yeast extract medium containing different concentrations of glucose were washed and inoculated onto IPEC-J2 porcine intestinal epithelial cells to test for effects on adherence and host cell cAMP concentrations. Consistent with previous studies, all LT+ strains had higher ETEC adherence to IPEC-J2 cells than did LT2 strains. Adherence of the LT2 but not the …

Volatile Organic Compound Flux From Manure Of Cattle Fed Diets Differing In Grain Processing Method And Co-Product Inclusion, Kristin Hales, David B. Parker, N. Andy Cole

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

Odor emissions from livestock production have become increasingly important in the past decade. Odors derived from animal feeding operations are caused by odorous VOC emitted from the mixture of feces and urine, as well as feed and silage which may be experiencing microbial fermentation. Distillers grains are a by-product of corn grain fermentation used to produce fuel ethanol, and this industry has grown rapidly throughout the U.S. in past years. Therefore, the use of wet distillers grains with solubles (WDGS) in feedlot cattle diets has also increased. The objective of this research was to determine specific VOC emissions from feces …

Altered Theca And Cumulus Oocyte Complex Gene Expression, Follicular Arrest And Reduced Fertility In Cows With Dominant Follicle Follicular Fluid Androgen Excess, Adam F. Summers, William E. Pohlmeier, Kevin M. Sargent, Brizett D. Cole, Rebecca J. Vinton, Scott G. Kurz, Renee M. Mcfee, Robert A. Cushman, Andrea S. Cupp, Jennifer R. Wood

Department of Animal Science: Faculty Publications

Aspiration of bovine follicles 12–36 hours after induced corpus luteum lysis serendipitously identified two populations of cows, one with High androstenedione (A4; >40 ng/ml; mean = 102) and another with Low A4 (/ml; mean = 9) in follicular fluid. We hypothesized that the steroid excess in follicular fluid of dominant follicles in High A4 cows would result in reduced fertility through altered follicle development and oocyte maternal RNA abundance. To test this hypothesis, estrous cycles of cows were synchronized and ovariectomy was performed 36 hours later. HPLC MS/MS analysis of follicular fluid showed increased dehydroepiandrosterone (6-fold), A4 (158-fold) and testosterone …

Kernel-Based Whole-Genome Prediction Of Complex Traits: A Review, Gota Morota, Daniel Penagaricano

Department of Animal Science: Faculty Publications

Prediction of genetic values has been a focus of applied quantitative genetics since the beginning of the 20th century, with renewed interest following the advent of the era of whole genome-enabled prediction. Opportunities offered by the emergence of high-dimensional genomic data fueled by post-Sanger sequencing technologies, especially molecular markers, have driven researchers to extend Ronald Fisher and Sewall Wright’s models to confront new challenges. Inparticular, kernel methods are gaining consideration as a regression method of choice for genome-enabled prediction. Complex traits are presumably influenced by many genomic regions working in concert with others (clearly so when considering pathways), thus generating …

Genetics Of The Pig Tapeworm In Madagascar Reveal A History Of Human Dispersal And Colonization, Tetsuya Yanagida, Jean-François Carod, Yasuhito Sako, Minoru Nakao, Eric P. Hoberg, Akira Ito

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that …

2014 Nebraska Beef Cattle Report

Nebraska Beef Cattle Reports

Contents:

Cow/Calf

Effect of Pubertal Status and Number of Estrous Cycles Prior to the Breeding Season on Pregnancy Rate in Beef Heifers .5

Comparison of Long-term Progestin-based Synchronization Protocols on Fixed-time AI pregnancy Rate in Beef Heifers . 8

Androgen Excess in Beef Cows Results in Altered Theca Cell Gene Expression and Fertility 11

Follicular Vascular Endothelial Growth Factor A Expression Before and After the LH Surge . 14

Evaluation of Genomic Predictors for Red Angus Cattle . 17

Preconception Distillers Grains Supplementation Improves Mature Beef Cow Return to Estrous . 19

Impact of Supplemental Protein Source on Pregnant Heifers …

Genome Wide Association Study Of Cholesterol And Poly- And Monounsaturated Fatty Acids, Protein, And Mineral Content Of Beef From Crossbred Cattle, C. M. Ahlberg, Lauren N. Schiermiester, J. T. Howard, Chris R. Calkins, Matthew L. Spangler

Department of Animal Science: Faculty Publications

The objectives were to determine the variation explained by the BovineSNP50v2 BeadChip for cholesterol (CH), polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), protein, and minerals in beef cattle, and to identify chromosomal regions that harbor major allelic variants underlying the variation of these traits. Crossbred steers and heifers (n = 236) segregating at the inactive myostatin allele on BTA2 were harvested and steaks were sampled from the M. semitendinosus and the M. longissimus thoracis et lumborum for nutrient analysis. A Bayes C algorithm was employed in genome-wide association analysis. The resulting posterior heritability (SD) estimates ranged from 0.43 (0.10) …

Ept7 Influences Estrogen Action In The Pituitary Gland And Body Weight Of Rats, Scott G. Kurz, Kirsten L. Mcfee, Nyssa Becker Samanas, Maureen Peters Hickman, Quincy A. Eckert, Tiffany L. Walker, Andrea S. Cupp, James D. Shull

Department of Animal Science: Faculty Publications

Estrogens control many aspects of pituitary gland biology, including regulation of lactotroph homeostasis and synthesis and secretion of prolactin. In rat models, these actions are strain specific and heritable, and multiple quantitative trait loci (QTL) have been mapped that impact the responsiveness of the lactotroph to estrogens. One such QTL, Ept7, was mapped to RNO7 in female progeny generated in an intercross between BN rats, in which the lactotroph population is insensitive to estrogens, and ACI rats, which develop lactotroph hyperplasia/adenoma and associated hyperprolactinemia in response to estrogen treatment. The primary objective of this study was to confirm the …

Effects Of Il8 And Immune Cells On The Regulation Of Luteal Progesterone Secretion, Heather Talbott, Abigail Delaney, Pan Zhang, Yangsheng Yu, Robert Cushman, Andrea S. Cupp, John S. Davis

Department of Animal Science: Faculty Publications

Recent studies suggest that chemokines may mediate the luteolytic action of PGF2α (PGF). Our objective was to identify chemokines induced by PGF in vivo and to determine the effects of IL8 on specific luteal cell types in vitro. Midcycle cows were injected with saline or PGF, ovaries were removed after 0.5 - 4 h and chemokine expression was analyzed by qPCR. In vitro expression of IL8 was analyzed after PGF administration and with cell signaling inhibitors to determine the mechanism of PGF-induced chemokine expression. Purified neutrophils were analyzed for migration and activation in response to IL8 and PGF. Purified …

Use Of Robust Multivariate Linear Mixed Models For Estimation Of Genetic Parameters For Carcass Traits In Beef Cattle, S. O. Peters, K. Kizilkaya, D. J. Garrick, R. L. Fernando, E. J. Pollak, R. Mark Enns, M. De Donato, O. O. Ajayi, I. G. Imumorin

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Assumptions of normality of residuals for carcass evaluation may make inferences vulnerable to the presence of outliers, but heavy-tail densities are viable alternatives to normal distributions and provide robustness against unusual or outlying observations when used to model the densities of residual effects. We compare estimates of genetic parameters by fitting multivariate Normal (MN) or heavy-tail distributions (multivariate Student’s t and multivariate Slash, MSt and MS) for residuals in data of hot carcass weight (HCW), longissimus muscle area (REA) and 12th to 13th rib fat (FAT) traits in beef cattle using 2475 records from 2007 to 2008 from a large …

Qtls Associated With Dry Matter Intake, Metabolic Mid-Test Weight, Growth And Feed Efficiency Have Little Overlap Across 4 Beef Cattle Studies, Mahdi Saatchi, Jonathan E. Beever, Jared E. Decker, Dan B. Faulkner, Harvey C. Freetly, Stephanie L. Hansen, Helen Yampara-Iquise, Kristen A. Johnson, Stephen D. Kachman, Monty S. Kerley, Jaewoo Kim, Daniel D. Loy, Elisa Marques, Holly L. Neibergs, E. John Pollak, Robert D. Schnabel, Christopher M. Seabury, Daniel W. Shike, W. M. Snelling, Matthew L. Spangler, Robert L. Weaber, D. J. Garrick, Jeremy F. Taylor

Department of Animal Science: Faculty Publications

Background: The identification of genetic markers associated with complex traits that are expensive to record such as feed intake or feed efficiency would allow these traits to be included in selection programs. To identify large-effect QTL, we performed a series of genome-wide association studies and functional analyses using 50 K and 770 K SNP genotypes scored in 5,133 animals from 4 independent beef cattle populations (Cycle VII, Angus, Hereford and Simmental × Angus) with phenotypes for average daily gain, dry matter intake, metabolic mid-test body weight and residual feed intake.

Results: A total of 5, 6, 11 and 10 significant …

Variation In Time And Magnitude Of Immune Response And Viremia In Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle, Erin E. Jobman, Timonthy W. Moural, Autumn M. Mcknite, Justin W. Bundy, Sarah Y. Barnes, Emily H. Davis, Judith A. Galeota, Thomas E. Burkey, Graham S. Plastow, Stephen D. Kachman, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

Background: Porcine circovirus 2 is the primary agent responsible for inducing a group of associated diseases known as Porcine Circovirus Associated Diseases (PCVAD), which can have detrimental effects on production efficiency as well as causing significant mortality. The objective of this study was to evaluate variation in viral replication, immune response and growth across pigs (n = 974) from different crossbred lines. The approach used in this study was experimental infection with a PCV2b strain of pigs at an average of 43 days of age.

Results: The sequence of the PCV2b isolate used in the challenge was similar with a …

Soil Organic Matter And Root And Rhizome Responses To Management Strategies In Smooth Bromegrass Pastures, John A. Guretzky, Ana B. Nuttelman, Walter H. Schacht, Terry J. Klopfenstein, Andrea K. Watson

Department of Animal Science: Faculty Publications

Soil organic matter (SOM) is a key component of pasture production. This is study investigated how management strategies that varied amount and form of N input in a long-term experiment affected concentrations and stocks of total-soil organic C and N, particulate organic carbon (POC), particulate organic nitrogen (PON), root and rhizome mass, C and N contents in topsoil of smooth bromegrass (Bromus inermis Leyss.) pastures with silty clay loam soils in a wet (2010) and dry (2012) year. Management strategies included: (i) unfertilized pasture grazed with unsupplemented beef cattle (CONT); (ii) unfertilized pasture grazed with dried distillers grains plus …

Litter Deposition And Nitrogen Return In Rotationally Stocked Smooth Bromegrass Pastures, John A. Guretzky, Walter H. Schacht, Ana B. Wingeyer, Terry J. Klopfenstein, Andrea K. Watson

Department of Animal Science: Faculty Publications

Understanding how management systems impact nutrient cycling is important to pasture sustainability. From 2010 to 2011, we investigated how supplementation of beef cattle (Bos taurus) with corn (Zea mays L.) dried distillers grains plus solubles (DDGS) on unfertilized, rotationally stocked smooth bromegrass (Bromus inermis Leyss.) pasture (SUPP) affected the litter pool, residual herbage mass, litter deposition, and litter quality relative to unsupplemented beef cattle rotationally stocked on unfertilized control (CONT) and N-fertilized (FERT) smooth bromegrass pastures. As hypothesized based on management for greater herbage mass and animal demand during the grazing season, litter deposition was 48% …

Western Immunoblotting In Avian Shell Gland Sample Immunoblotting Methods1, K.K. Hansen, R.J. Kittok, Gautam Sarath, Mary M. Beck

Department of Animal Science: Faculty Publications

Avian shell gland tissue was subjected to Western blot analysis using anti-human estrogen receptor- α antibody H222. Initial attempts to obtain consistent, high-quality blots were unsuccessful because, as it turned out, excessive lipid in tissue preparations interfered with protein separation. Incremental additions of acetone eventually proved to be the critical step in solubilizing lipids and allowing consistent separation of bands on gels. A detailed description of the methodology is presented.

Short-Term Effects Of Lower Oil Dried Distillers Grains With Solubles In Laying Hen Rations, Sheila E. Scheideler, Kathy Hanford, Brett Kreifels

Department of Animal Science: Faculty Publications

Extraction of oil from dried distillers grains has become a common practice among US ethanol producers. The valuable oil has been diverted to markets other than poultry feed, leaving new dried distillers grains with solubles (DDGS) products higher in fiber and purportedly lower in ME. This study compared 3 DDGS products with 10.3, 7.3, or 5.2% ether extract, respectively, with a corn-soy control ration in young Bovan laying hens for a feeding period from 20 to 33 wk of age. The DDGS was fed at the rate of 20% of the ration. Lower oil content of DDGS had no effect …

Quantitative Trait Loci For Energy Balance Traits In An Advanced Intercross Line Derived From Mice Divergently Selected For Heat Loss, Larry J. Leamy, Kari Elo, Merlyn K. Nielsen, Stephanie R. Thorn, William Valdar, Daniel Pomp

Department of Animal Science: Faculty Publications

Obesity in human populations, currently a serious health concern, is considered to be the consequence of an energy imbalance in which more energy in calories is consumed than is expended. We used interval mapping techniques to investigate the genetic basis of a number of energy balance traits in an F₁₁ advanced intercross population of mice created from an original intercross of lines selected for increased and decreased heat loss. We uncovered a total of 137 quantitative trait loci (QTLs) for these traits at 41 unique sites on 18 of the 20 chromosomes in the mouse genome, with X-linked QTLs …

Effects Of Beef Production System On Animal Performance And Carcass Characteristics, C. L. Maxwell, C. R. Lopez, B. K. Wilson, B. T. Johnson, B. C. Bernhard, C. F. O'Neill, D. L. Vanoverbeke, G. G. Mafi, D. L. Step, C. J. Richards

Department of Animal Science: Faculty Publications

The objective of this study was to evaluate conventional (CONV) and natural (NAT) beef production systems from annual pasture through finishing through grazing. Beef steers (n = 180, initial BW = 250 ± 19 kg) were assigned randomly to 2 treatments in the pasture phase. Steers were implanted with 40 mg of trenbolone acetate (TBA), 8 mg estradiol, and 29 mg tylosin tartrate (CONV), or received no implant (NAT). Steers on the 2 treatments grazed wheat or cereal rye for 109 d. Conventional steers had an 18.5% improvement in ADG (1.22 vs. 1.03 kg/d, P < 0.01) and a heavier final BW (385 vs. 366 kg, P < 0.01) compared with NAT steers. Following the pasture phase, steers (n = 160 steers, 5 steers/pen, 8 pens/treatment) were assigned to a 2 × 2 factorial in the feedlot phase. Production system (NAT vs. CONV) was maintained from the pasture phase, and the second factor was 7 vs. 12% low-quality roughage (DM basis, LOW vs. HIGH). During finishing, CONV steers were given 120 mg of TBA and 24 mg estradiol at processing, fed monensin and tylosin, and fed zilpaterol hydrochloride for the last 20 d of the experiment. There were no program × roughage level interactions (P > 0.07). The CONV steers ate …

Comparative Digestibility By Cattle Versus Sheep: Effect Of Forage Quality, S. A. Soto-Navarro, R. Lancaster, C. Sankey, B. M. Capitan, B. P. Holland, L. A. Balstad, C. R. Krehbiel

Department of Animal Science: Faculty Publications

The objective was to determine the effect of forage quality on apparent total tract digestibility and ruminal fermentation in cattle versus sheep. Five yearling English crossbred (Hereford × Angus) steers (440.4 ± 35.6 kg of initial BW) and 5 yearling whiteface (Rambouillet × Columbia × Debouillet) wethers (44.4 ± 4.6 kg of initial BW), each fitted with a ruminal cannula, were randomly assigned to 1 of 3 forage sources within ruminant specie, and the study was conducted over 3 periods. For forage source, both animal and period served as the blocking factor with all forage sources represented once within each …

Nebraska Bqa: Antibiotic Use Guidelines, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen have demonstrated a commitment to animal health through vaccination programs developed carefully in cooperation with their veterinarian. When animals must be treated with an antibiotic after disease diagnosis, producers need to follow important antibiotic use guidelines established through the National Beef Quality Assurance (BQA) program.

Nebraska Bqa: Effective Cattle Handling, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen know the importance of proper cattle handling and its effect on animal health and performance. Beef Quality Assurance has been implementing effective cattle handling (low-stress) into educational programs since its establishment in the 1980s.

Handling Cattle Through High Heat Humidity Indexes, Rob Eirich

Nebraska Beef Quality Assurance Program

As cattlemen enter the summer months, they need to understand and deal with heat and humidity. Consider incorporating the following practices into management plans to help reduce additional stress.

Nebraska Bqa: Handling Compromised Animals, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattle producers have long recognized the need of proper husbandry and stewardship for the animals entrusted into their care. Best livestock production practices, based on research and sound science, help ensure the well-being, animal health and productivity of cattle.

Calf Branding/Processing Time And Beef Quality Assurance, Rob Eirich

Nebraska Beef Quality Assurance Program

It is spring and that means branding time across cattle country. As producers are finishing calving season and preparing for branding/processing, it is important to review Beef Quality Assurance (BQA) guidelines. Let's take a minute to look at the key BQA principles:

Audits And Assessments In Beef Cattle Production, Rob Eirich

Nebraska Beef Quality Assurance Program

Assessments and audits are becoming a part of doing business in beef cattle production, as we are seeing beef processors implementing third-party audits. Since beginning as the Nebraska Director of Beef Quality Assurance (BQA) in July, I have been studying and gathering information on the National Cattlemen's Beef Association (NCBA) Assessment Guides and third-party audits in the beef industry.