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

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Articles 181 - 210 of 299

Full-Text Articles in Animal Sciences

Evaluation Of The Metabolic Response, Blood Chemistry Profile, And Cardiac Morphology Of Beef Heifers Supplemented With Zilpaterol Hydrochloride Followed By An Endocrine Induced Stress Challenge, Joe O. Buntyn Aug 2016

Evaluation Of The Metabolic Response, Blood Chemistry Profile, And Cardiac Morphology Of Beef Heifers Supplemented With Zilpaterol Hydrochloride Followed By An Endocrine Induced Stress Challenge, Joe O. Buntyn

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

The objective of this study was to determine the metabolic, stress, hematology, organ weights, histology and cardiac anatomical features of beef heifers supplemented with zilpaterol hydrochloride (ZH) when exposed to a corticotropin-releasing hormone (CRH) and arginine vasopressin (VP) challenge. Crossbred heifers (n = 20; 556 ± 7 kg BW) were randomized into two treatment groups: 1) Control (CON): no ZH, and 2) Zilpaterol (ZIL): supplemented with ZH at 8.33 mg / kg (DM basis). The ZIL group was supplemented ZH for 20 d, with a 3-d withdrawal period. On d 24, heifers received an intravenous bolus of CRH (0.3 µg …


Effects Of Salt And Nitrite Concentration On The Shelf Life Of Deli-Style Ham, Regan Elise Stanley Aug 2016

Effects Of Salt And Nitrite Concentration On The Shelf Life Of Deli-Style Ham, Regan Elise Stanley

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

Deli-style hams were manufactured to measure the effects of salt and nitrite concentration on shelf life and physicochemical characteristics. Three replications of deli-style ham treatments were manufactured in a 3 x 4 factorial arrangement of salt concentration (0.7%, 1.4%, or 2.1%, meat block basis) and nitrite concentration and source (0 ppm, 100 ppm or 200 ppm sodium nitrite, SN, or 100 ppm sodium nitrite equivalent from pre-converted celery juice powder, CP; Veg Stable 506, Florida Food Products). Salt concentration, water activity, cook yield, and texture profile analysis (TPA) were measured on w 0. Color, pH, residual nitrite, and aerobic and …


Development Of Terminal And Maternal Economic Selection Indices In Beefmaster Cattle, Kathleen Pearl Ochsner Aug 2016

Development Of Terminal And Maternal Economic Selection Indices In Beefmaster Cattle, Kathleen Pearl 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 …


Impact Of Finishing Diets With De-Oiled Distillers Grains Or Antioxidant Containing Supplement On Beef Shelf Life, Katherine I. Domenech-Pérez Aug 2016

Impact Of Finishing Diets With De-Oiled Distillers Grains Or Antioxidant Containing Supplement On Beef Shelf Life, Katherine I. Domenech-Pérez

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

In its entirety this dissertation intended to address the impact of feeding several forms of de-oiled corn distillers grains plus solubles and the effect of supplementing OmniGen-AF as a potential antioxidant source for extending beef shelf life. In study one we learned that despite the de-oiling process, greater inclusion levels (65%, DM basis) of de-oiled wet distillers grains plus solubles (WDGS) causes an increase in polyunsaturated fatty acids (PUFA) similar to the levels obtained with full-fat WDGS. Lower inclusion levels (35 and 50%, DM basis) of de-oiled WDGS have intermediate PUFA content in comparison to 65% de-oiled WDGS, full-fat WDGS …


Validating Laboratory Techniques That Influence Estimates Of Intake And Performance In Beef Cattle, Hannah C. Hamilton Aug 2016

Validating Laboratory Techniques That Influence Estimates Of Intake And Performance In Beef Cattle, Hannah C. Hamilton

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

Two experiments were conducted to evaluate effects of inoculum source on in vitro and in situ digestion procedures performed on grass hay and corn residue samples. Steers were fed 70% brome or 70% corn residue. Inoculum from each steer was used to perform in vitro procedures to determine IVDMD, organic matter digestibility (OMD), and neutral detergent fiber (NDF) digestibility and for in situ procedures to determine NDF digestibility. There were no interactions for inoculum source and IVDMD, OMD, or NDF digestibility.

Three cattle digestion studies were used to evaluate the relationship between TDN and digested OM (DIGOM). Total tract collection …


The Effect Of Salt Reduction On The Microbial Composition And Quality Characteristics Of Sliced Roast Beef And Turkey, Chad Gary Bower May 2016

The Effect Of Salt Reduction On The Microbial Composition And Quality Characteristics Of Sliced Roast Beef And Turkey, Chad Gary Bower

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

This study analyzed the effects of salt reduction on microbiological composition and quality characteristics of deli-style turkey breast and roast beef. Turkey breast and roast beef were manufactured with four different salt concentrations: 1.0%, 1.5%, 2.0%, and 2.5% on a meat block basis in addition to sugar, phosphate, and water. Samples were cooked, chilled overnight, sliced, and packaged. On the day of slicing, samples were evaluated for water activity, cooking yield, proximate composition and percent salt. Samples were evaluated throughout 18w of refrigerated storage for pH, texture profile analysis, aerobic plate count (APC), and anaerobic plate count. Bacterial communities were …


Genetic Parameters For Docility, Weaning Weight, Yearling Weight And Intramuscular Fat Percentage In Hereford Cattle, José A. Torres-Vazquez May 2016

Genetic Parameters For Docility, Weaning Weight, Yearling Weight And Intramuscular Fat Percentage In Hereford Cattle, José 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 …


Beef Systems Management Strategies: Calving Date Selection, Estrus Synchronization, And Post-Weaning Management, Benjamin T. Tibbitts Apr 2016

Beef Systems Management Strategies: Calving Date Selection, Estrus Synchronization, And Post-Weaning Management, Benjamin T. Tibbitts

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

The objective of an invited review and four experiments was to evaluate production implications and economic efficiencies of beef systems strategies involving calving date selection, utilization of reproductive technology, and post-weaning management of heifers and steers. The invited review in chapter II considers factors that influence a producer’s decision on when to calve beef females. The calving date decision impacts the entire beef production cycle and must take into account any environmental conditions, available resources, and cite specific advantages and/or disadvantages. Understanding the importance of varying physiological state and nutrient demands associated with lactation and gestation is critical to optimizing …


The Effect Of Diet On The Bovine Rumen Microbial Community Structure And Composition And Its Effects On Methane Production In Growing And Finishing Cattle, Allison L. Knoell Apr 2016

The Effect Of Diet On The Bovine Rumen Microbial Community Structure And Composition And Its Effects On Methane Production In Growing And Finishing Cattle, Allison L. Knoell

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

Methane is a potent greenhouse gas (GHG) that contributes to global warming. A natural by-product of ruminant fermentation is the production and eructation of methane. Methane is produced by a small unique group of microorganism’s called methanogens that belong to the domain Archaea. Enteric methane represents 2-12% energy loss in ruminants. It is well established that diet affects the microbial community structure and composition. Fermentative products of the mixed microbial population (bacteria, fungi, and protozoa) become the substrates for methanogens. These substrates influence which microorganisms will thrive. However, the effect of diet on the microbial community while simultaneously calculating …


Production And Economic Efficiencies Of Intensified Cow–Calf Production Management Systems, Jason M. Warner Dec 2015

Production And Economic Efficiencies Of Intensified Cow–Calf Production Management Systems, Jason M. Warner

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

The objective of four experiments conducted was to evaluate production and economic efficiencies of intensified cow-calf production management systems. The first experiment tested the effect of calf age at weaning on cow and calf performance and feed utilization at 2 locations. Body weight change from early to conventional weaning time was greater for early-weaned cows. Cow BCS and conception rates were not impacted by weaning. Calf BW at conventional weaning time was greater for conventionally-weaned calves than early-weaned calves at ARDC, but greater for early-weaned than conventionally-weaned calves at PHREC. Calf ADG per unit of total feed energy intake was …


Efficiency Of Energy Utilization And Fecal Mineral Excretion In Holstein And Jersey Dairy Cows, Gabriel Garcia Gomez Dec 2015

Efficiency Of Energy Utilization And Fecal Mineral Excretion In Holstein And Jersey Dairy Cows, Gabriel Garcia Gomez

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

Eight multiparous Holstein and 8 Jersey dairy cows were used to complete energy balance trials designed to determine the effect of breed on the production and energy efficiency of milk, and energy partitioning. A repeated switchback design was used to compare the effect of cow breed. Diets consisted of 24.5% corn silage, 18.4% alfalfa hay, 6.9% grass hay, with either 22.9% rolled corn and 14.8% soybean meal (CON) or 8.95% rolled corn and 28.8% reduced fat distillers grains (RFDDGS) DM-basis. Diets were offered ad libitum for a 28 d adaptation period and 95% ad libitum for a 4 d collection …


Performance, Body Temperature And Blood Metabolites Of Feedlot Steers As Influenced By Environmental Conditions And Supplementation Of Zilpaterol Hydrochloride, Bradley M. Boyd Dec 2015

Performance, Body Temperature And Blood Metabolites Of Feedlot Steers As Influenced By Environmental Conditions And Supplementation Of Zilpaterol Hydrochloride, Bradley M. Boyd

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

Trial one was conducted at the United States Meat Animal Research Center (MARC) near clay center, NE during the summer of 2014. The objective of this trial was to measure the effects of supplementing zilpaterol hydrochloride (ZH) for the final 21 days of the finishing period, and shade, on performance, body temperature, respiration rate, and mobility of finishing beef steers. Feeding ZH increased hot carcass weight, dressing percent, longissimus muscle area, and reduce USDA yield grade. Shade did not affect steer performance and did not reduce body temperature. Zilpaterol hydrochloride increased respiration rate when compared to control cattle and had …


Genomic Analysis Of Sow Reproductive Traits: Identification Of Selective Sweeps, Major Genes, And Genotype By Diet Interactions, Melanie D. Trenhaile Dec 2015

Genomic Analysis Of Sow Reproductive Traits: Identification Of Selective Sweeps, Major Genes, And Genotype By Diet Interactions, Melanie D. Trenhaile

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

Reproductive traits, such as litter size and reproductive longevity, are economically important. However, selection for these traits is difficult due to low heritability, polygenic nature, sex-limited expression, and expression late in life. Marker-assisted selection may provide an alternative to increase genetic progress.

Nebraska Index Line (NIL) has been selected for litter size related traits since 1981. It is one of the main contributing lines to the UNL reproductive longevity resource population (n > 1,500), which was genotyped for 60,000 SNPs, phenotyped for age at puberty (AP), lifetime number of parities (LTNP), litter size traits, and other reproductive traits, and fed …


Beef Cattle Management Systems For Estrus Synchronization And Heifer Development, Hazy Rae Nielson Aug 2015

Beef Cattle Management Systems For Estrus Synchronization And Heifer Development, Hazy Rae Nielson

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

Four experiments were conducted to evaluate estrus synchronization and heifer development systems. In the first experiment delaying AI 19 h following GnRH administration in a hybrid estrus detection and time AI protocol was evaluated. Final pregnancy rate was not different among heifers detected in estrus, AI at the time GnRH administration, or delayed AI. The second study compared the effect of melengestrol acetate (MGA) -PG and 14-d controlled internal drug release (CIDR) -PG estrus synchronization protocols on estrus response and pregnancy rates of 311 d old heifers. Final pregnancy rate was similar between CIDR and MGA treatment groups. The objective …


Dietary Strategies For Mitigation Of Methane Production By Growing And Finishing Cattle, Anna C. Pesta Aug 2015

Dietary Strategies For Mitigation Of Methane Production By Growing And Finishing Cattle, Anna C. Pesta

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

Interest in reducing methane (CH4) emissions by cattle has increased recently. Loss of feed energy as CH4 represents both an environmental concern and an energetic loss to the animal. Manipulation of dietary composition has proven to be an effective mitigation strategy. Experiments were conducted to evaluate the effect of several dietary characteristics on CH4 production in growing and finishing cattle, and to develop a novel, non-invasive method for quantifying emissions from animals in a production setting. Short-term gaseous emissions of CH4 and carbon dioxide (CO2) were measured and the CH4:CO2 …


Effect Of A Trace Mineral Injection On Beef Cattle Performance, Carmen J. Brasche May 2015

Effect Of A Trace Mineral Injection On Beef Cattle Performance, Carmen J. Brasche

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

Adequate trace mineral status is important in beef cow/calf and replacement heifer systems because trace minerals play vital roles in reproduction, immunity and growth. Many experiments have investigated the use of a trace mineral injection containing Cu, Mn, Se and Zn (TMI) on growth and immunity of beef cattle. However, very few have investigated TMI use on reproductive performance. Therefore, five experiments, a two year cow/calf experiment, and four replacement heifer experiments were designed to investigate the use of a TMI on reproductive performance of cows and heifers, calf growth and trace mineral status of cows, heifers, and calves. The …


Corn Plant Maturity Effect On Yield And Nutritional Quality: Corn Silage Inoculation On Performance Of Cattle Fed Silage With Or Without Live Yeast Added, Cassandra A. Row May 2015

Corn Plant Maturity Effect On Yield And Nutritional Quality: Corn Silage Inoculation On Performance Of Cattle Fed Silage With Or Without Live Yeast Added, Cassandra A. Row

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

Corn plots were serially harvested over two years to evaluate nutrient, digestibility, and yield change as plants matured from half-milk line through black layer. In yr 1 (2013), two corn plots were used, one short season (102 d), and one normal season (111 d). Year two used two Pioneer hybrids (111 d; 112 d). Silage yield and silage DM increased quadratically as maturity increased (P ≤ 0.01). Percent NDF increased quadratically (P = 0.01), and NDF-digestibility decreased linearly (P < 0.01) as maturity increased. This study suggests there is a delicate balance between plant maturity, nutrient content, and silage yield. A finishing study using 320 yearling steers (initial BW = 417 ± 22.7 kg) evaluated the effect of using a silage inoculant or not on performance and carcass characteristics. Treatments were designed as a 2×2×2 factorial arrangement with factors being no inoculant (CON) or use of inoculant (Buchnerii spp.; B500) at silage harvest, silage fed at 15 or 40% of diet DM, and presence (LEV) or absence (noLEV) of Levucell SC yeast product fed at 14.2 g/hd/d. Performance data were analyzed with pen as the experimental unit, with 5 pens/treatment. There was a three-way interaction for final live BW, HCW, ADG, and G:F (P < 0.05). Feeding corn silage at 40% inclusion instead of 15% inclusion increased DMI and decreased G:F. At 15% silage inclusion, the B500 LEV treatment had the lowest ADG. At 40% silage inclusion all treatments were similar for ADG (P ≥ 0.06). When including silage at 15%, using B500 inoculant, the addition of LEV did not …


Impact Of Wet Distillers' Grains Plus Solubles And Antioxidants On A Basic Mechanism Of Beef Tenderization, Michael D. Chao May 2015

Impact Of Wet Distillers' Grains Plus Solubles And Antioxidants On A Basic Mechanism Of Beef Tenderization, Michael D. Chao

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

Feeding high levels of wet distillers grains plus solubles (WDGS) increases polyunsaturated fatty acid (PUFA) levels in beef. Perhaps, WDGS in feedlot diets increases PUFA concentration in the SR membrane, thereby altering membrane integrity, resulting in more rapid calcium leakage and improved tenderness. Feeding antioxidants may mitigate such effects. In the first study, effects of feeding 50 % WDGS on SR membrane composition, free calcium concentration and tenderness were studied. The SR membrane from steers fed WDGS were more tender, had higher free calcium concentration, had more PUFA, more phosphatidylcholine (PC), less phosphatidylethanolamine (PE) and less total phospholipids when compared …


Effects Of Feeding Distillers Grains Throughout Different Phases Of Production On Shelf Life Of Ground Beef, Brandy D. Cleveland May 2015

Effects Of Feeding Distillers Grains Throughout Different Phases Of Production On Shelf Life Of Ground Beef, Brandy D. Cleveland

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

These studies analyzed the effects of feeding distillers grains on the shelf life of cooked and raw ground beef, and how the addition of postmortem or dietary antioxidants impact shelf life.

For study one, cattle were assigned to backgrounding diets containing low or high concentrations of wet distillers grains (WDGS) and either corn gluten feed or modified wet distillers grains (MDGS) during finishing. For study two, cattle were fed one of five finishing diets; corn, wet distillers grains (WDGS), WDGS + vitamin E, WDGS + Ethoxyquin/TBHQ, or WDGS + vitamin E + Ethoxyquin/TBHQ.

Shoulder clods from each dietary treatment were …


New Approaches To Corn Silage Use In Beef Cattle Finishing Diets, Dirk B. Burken Dec 2014

New Approaches To Corn Silage Use In Beef Cattle Finishing Diets, Dirk B. 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 Composition, Jared Vern Judy Dec 2014

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 Composition, Jared Vern 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 …


Genetic Parameter Estimates And Breed Effects For Calving Difficulty And Birth Weight In A Multi-Breed Population, Cashley Ahlberg Dec 2014

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 United States Meat Animal Research Center …


Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken Dec 2014

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 …


Feedlot Manure Management Considerations Including Anaerobic Digestion Potential And Mineral Retention, Andrea K. Watson Dec 2014

Feedlot Manure Management Considerations Including Anaerobic Digestion Potential And Mineral Retention, Andrea K. Watson

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

Three anaerobic digestion trials were conducted to evaluate methane production from feedlot manure. As organic matter content of manure decreased, degradation of manure and methane production also linearly decreased (P ≤ 0.02). Quality, or organic matter content of manure, had a greater impact on anaerobic digestion than diet (with and without distillers grains) fed to cattle. Minerals are concentrated in effluent removed from anaerobic digesters.

Knowing mineral retention within cattle allows for more accurate calculation of mineral excretion in manure. Three serial slaughter trials measured mineral retention in growing and finishing cattle. During a growing phase, beef cattle gaining …


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 Dec 2014

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 …


The Effects Of Limestone Particle Size On Bone Health And Performance Of Pullets And Hens In Conventional Cage And Alternative Housing Systems, Pamela E. Eusebio Balcazar Dec 2014

The Effects Of Limestone Particle Size On Bone Health And Performance Of Pullets And Hens In Conventional Cage And Alternative Housing Systems, Pamela E. Eusebio Balcazar

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

One of the major welfare issues in cage-free housing systems is bone fracture. The goal of this research was to improve bone health in layers by building better pullet skeletons and to investigate limestone particle size (LPS) effects on bone health in conventional cages and cage-free housing systems. Study 1 was a preliminary study that compared conventional cages with litter floor pens in terms of performance, bone health, and eggshell quality from 33 to 47 wk of age. Caged hens had higher egg production and eggshell strength, and improved feed efficiency, but lower tibia bone mineral content compared to floor …


Energy Value Of De-Oiled Distillers’ Grains Plus Solubles In Beef Cattle Diets, Meredith L. Bremer Dec 2014

Energy Value Of De-Oiled Distillers’ Grains Plus Solubles In Beef Cattle Diets, Meredith L. Bremer

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

Ethanol plants are centrifuging off oil from the thin stillage stream as it has added market value currently. The impact of oil removal on cattle performance has been minimally researched. Thus four trials, one growing, one digestion, and two feedlot, were designed to determine the energy and feeding value of de-oiled distillers grains in beef cattle diets.

In growing cattle diets, diet concentration of modified distillers grains plus solubles (MDGS) impacted cattle performance more than oil content. Ending BW, ADG, and G:F did not differ between cattle fed de-oiled or full fat MDGS, however cattle fed de-oiled MDGS had lower …


The Effects Of Hmtba (2-Hydroxy-4-Methylthio-Butanoic Acid) Supplementation On Ruminal Microbial Crude Protein Synthesis And Community Structure In Dairy Cattle, Chad James Robert Jenkins Nov 2014

The Effects Of Hmtba (2-Hydroxy-4-Methylthio-Butanoic Acid) Supplementation On Ruminal Microbial Crude Protein Synthesis And Community Structure In Dairy Cattle, Chad James Robert Jenkins

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

Metabolizable protein (MP) is protein that reaches the small intestine and is available for absorption and utilization by the cow. Dairy rations may be limited in the supply of MP essential to meeting the demands of milk synthesis, however as much as half of the MP flowing to the small intestine may be attributed to microbial origins and is referred to as microbial CP (MCP). Experiment 1 utilized a technique in which DNA was used as a microbial marker to estimate the concentration of bacterial CP (BCP) in the solid and liquid portions of rumen digesta. Rumen digesta was sampled …


Effects Of Pubertal Status And Number Of Estrous Cycles Prior To Breeding In Beef Heifers, Average Daily Gain On Reproductive Performance And Comparison Of Two Fixed Time Ai Estrus Synchronization Protocols, Rebecca A. Vraspir Aug 2014

Effects Of Pubertal Status And Number Of Estrous Cycles Prior To Breeding In Beef Heifers, Average Daily Gain On Reproductive Performance And Comparison Of Two Fixed Time Ai Estrus Synchronization Protocols, Rebecca A. Vraspir

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

Reproductive success is the most important factor in beef cattle production and is affected by timing of pubertal onset in heifers, and reproductive biotechnologies utilized. Three studies were conducted to evaluate the effects of pubertal status, ADG, and 2 fixed time AI protocols on reproductive success in beef heifers.

In the first study, heifers that were pubertal prior to breeding had a greater AI and overall pregnancy rate; produced more calves born within the first 21 d of the calving season; and weaned older, heavier calves than non-pubertal heifers. Additionally, heifers that had ≥2 estrous cycles, prior to the first …


Feeding Condensed Distillers’ Solubles To Feedlot Finishing Steers And The Effects Of Feed Additives In Adaptation Diets, Marie Elizabeth Harris Aug 2014

Feeding Condensed Distillers’ Solubles To Feedlot Finishing Steers And The Effects Of Feed Additives In Adaptation Diets, Marie Elizabeth Harris

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

By-products from the dry-milling ethanol process can be used in cattle diets to replace corn. There is a significant interaction between corn processing methods as CCDS concentration increases in the diet. Improvements are observed for SFC in final BW, ADG, and G:F over DRC. An experiment was conducted to determine if greater concentrations of CCDS could be fed in SFC based diets and maintain or improve performance. Performance and carcass characteristics were evaluated with increasing concentrations of CCDS at 0, 9, 18, 27, or 36% in place of SFC in feedlot finishing diets. As CCDS concentration increased, DMI decreased quadratically. …