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 …

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

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 …

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 …

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 …

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). …

The Effects Of Hmtba (2-Hydroxy-4-Methylthio-Butanoic Acid) Supplementation On Ruminal Microbial Crude Protein Synthesis And Community Structure In Dairy Cattle, Chad J. R. 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 Sorting Prior To Feeding Zilpaterol Hydrochloride And Effects Of Different Implant Strategies On Feedlot Performance And Carcass Characteristics Of Steers And Heifers, Fred H. Hilscher Jr

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

Two experiments evaluated the effects of sorting and feeding Zilpaterol hydrochloride (ZH) to steers on feedlot performance and carcass characteristics. In Exp. 1, treatments compared unsorted cattle either fed ZH or not, and three treatments utilizing 1 sort at the beginning, middle or end of the finishing period. In Exp. 2, treatments compared unsorted cattle fed ZH, and two treatments that utilized 1 sort based on initial BW or 4 sorts at the end of the finishing period. Feeding ZH increased BW, HCW and percentage of overweight carcasses; however, sorting decreased carcass weight standard deviations, and percent overweight carcasses. Feeding …

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 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 …

Energy Content Of Reduced-Fat Dried Distillers Grains And Solubles For Lactating Dairy Cows And Effects On Energy And Nitrogen Balance, Alison J. Foth

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

Eight Holstein and 8 Jersey multiparous, lactating cows were used to complete 56 energy balances to determine the energy content of reduced-fat distillers grains and solubles (RFDDGS). A repeated switchback design was used to compare treatments with and without RFDDGS. Diets consisted of 24.2 % corn silage, 18.4 % alfalfa hay, 6.94 % brome hay with either 22.9 % rolled corn and 14.8 % soybean meal (Control), or 8.95 % rolled corn, 28.8 % RFDDGS, and 0 % soybean meal (Co-P; DM basis). The inclusion of RFDDGS did not affect (P = 0.86) DMI averaging 21.4 ± 0.53 kg …

Feeding Condensed Distillers Solubles To Feedlot Finishing Steers And The Effects Of Feed Additives In Adaptation Diets, Marie E. 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. …

Estimation Of Breed-Specific Heterosis Effects For Birth, Weaning And Yearling Weight In Cattle, Lauren N. Schiermiester

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

Genetic selection decisions are important components of improved beef production efficiency. Exploiting heterosis and breed complementarity can improve economically relevant traits and system efficiency. The objective of the current study was to estimate breed-specific heterosis for the seven largest beef breeds (according to registrations) for birth, weaning and yearling weight.

Birth, weaning and yearling weights were recorded for steers, heifers and bulls (n= 6,834) from Cycle VII and advanced generations of the Germ Plasm Evaluation project of the U.S. Meat Animal Research Center. Breeds represented in these data included: Angus, Hereford, Red Angus, Charolais, Gelbvieh, Simmental, Limousin and composite MARC …

Feeding Alkaline Treated And Processed Crop Residue To Feedlot Cattle, Sarah J. Peterson

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

Chemical treatment and decreased particle size are methods used to improve digestibility and utilization of the available nutrients in low quality forages. Previous research has indicated that chemically treated corn residue can take the place of corn when included in finishing rations containing distillers grains. Also, decreasing particle size utilizing methods such as pelleting has been shown to improve DMI and ADG. However, limited research has been completed on use of chemical treatment and pelleting in growing and receiving rations. Also, an ideal distillers inclusion has not yet been identified when including alkaline treated stalks in finishing rations. Therefore, a …

Determining Forage Intake Of Nursing Calves Grazing Native Sandhills Rangeland, Jennifer A. Walker

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

Effective management of grazing lands is important for longevity and productivity. Accurate calculations of stocking rates per animal unit will aid in long term sustainability. Calculating stocking rates for cattle can prove challenging for cows and nursing calves. Limited research has been conducted to determine forage intake of the nursing calf pre-weaning. The objective of Trial 1 was to determine nursing calf forage intake over time until weaning. Trial 1 used 8 crossbred cow-calf pairs in experiment 1 and 12 pairs in experiment 2. Pairs were separated into two groups rotating between grazing upland range or housed in individual pens …

Comparison Of Wet Or Dry Distillers Grains Plus Solubles To Corn As An Energy Source In Forage Based Diets And In Vitro Forage Standard Development Based On In Vivo Digestibilities Utilizing Brome Hay, Prairie Hay And Meadow Hay., Nerissa Ann Ahern

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

Four growing experiments were conducted to evaluate the use of dry rolled corn (DRC) and either dry (DDGS) or wet distillers grains plus solubles (WDGS) as energy sources in high forage diets. In Exp. 1, steers were fed a blend of sorghum silage and alfalfa hay and supplemented 1 of 4 inclusions of WDGS, DDGS or a MIX (67% WDGS: 33% Straw). In Exp. 2, Exp. 3 and Exp. 4, steers were fed diets including WDGS, DDGS or DRC at different inclusions, replacing sorghum silage and grass hay. In Exp. 1, WDGS, DDGS and MIX produced greater ending BW, ADG …

Lifecycle Efficiency Of Mice Divergently Selected For Heat Loss, Adrienne Bhatnagar

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

Divergent selection for heat loss as an indication of maintenance energy requirements in mice resulted in a low (ML) and high maintenance line (MH), and an intermediate control line (MC). Improved feed efficiency has been observed in ML mice, which would be economically beneficial in livestock species. However, previous work showed evidence of unfavorable correlated responses to selection in ML mice compared to MH mice. Therefore, the objective of this study was to model a lifecycle similar to a livestock production system using these lines and determine if these correlated responses diminish the benefit of improved feed efficiency by calculating …

The Effects Of Feed Additives, Housing Systems, And Stress On Salmonella Shedding In Single Comb White And Brown Laying Hens, Dana L. Hahn

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

A series of studies were conducted examining feed additives, housing systems and stress on Salmonella shedding. Alternative feed additives such as prebiotics, probiotics and essential oils have been shown to reduce pathogenic bacteria colonization. Furthermore, stressors such as movement have been shown to increase Salmonella shedding. The goal of the studies was to examine if alternative ingredients reduce Salmonella shedding in alternative housing systems and through movement stress. Study 1 examined cage and cage-free housing with mannan oligosaccharide (MOS) supplementation. Treatments were arranged in a 2x2 factorial design: cage or cage free; MOS (0% or 0.08%). There was no effect …

Genomic Predictions For Age At Puberty And Reproductive Longevity In Sows Using Bayesian Methods, Katherine L. Lucot

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

Including marker-assisted selection in breeding programs is potentially more efficient than traditional selection for improving traits that are expensive or difficult to measure. One of the challenges of genomics is the lack of robustness of marker effects across populations and over time (generations) and the cost to commercial producers of high-density arrays. The objective of this study was to analyze differences in the proportion of phenotypic variation explained by different fractions of major 1 Mb windows and SNPs. Using a population of Nebraska Index Line and commercial Large White x Landrace females (n = 1,234) generated in 11 batches, we …

Effects Of Distillers Grains Plus Solubles And Monensin Supplementation On Yearlings Grazing Smooth Bromegrass, Tyler L. Hasenauer

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

Supplementing cattle on grass is an effective way of increasing animal efficiency and grass utilization. Distiller grains plus solubles (DGS) supplementation has been repeatedly proven as an effective supplement by providing ruminally undegradable protein (RUP), fat, and highly digestible fiber. The effects of monensin supplementation on grazing cattle are variable. Although some research has shown a decrease in forage organic matter intake (FOMI), the popular belief is monensin increases ADG while maintaining DMI in a grazing situation. Two experiments were designed to observe the effects of DGS and monensin supplementation on cattle grazing smooth bromegrass. In the first study, ADG …

Use Of Distiller Grains In Alternative Beef Heifer Systems, Jared M. Mracek

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

Every year, producers select replacement heifers with the intention that these heifers are the future of their cow herd. Producers normally select replacement heifers at weaning based on weight and structure. When selecting heifers at weaning, producers risk not selecting heifers that would be productive cows based on their criteria. By delaying the selection of replacements, it will allow producers to increase the opportunity to thoroughly evaluate replacement prospects. The corn dry-milling industry produces byproducts that can be economical supplements to growing cattle on forage. An experiment evaluated an alternative heifer system utilizing distiller grains as an energy source to …

Effects Of Conventional And Alternative Curing Methods On Processed Turkey Quality Traits, Amy Lynn Redfield

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

This study compared physicochemical and sensory qualities of deli-style turkey breast produced pre-converted celery juice powder (CP; for alternative curing) or sodium nitrite (SN; for conventional curing). Formulas were designed to include 0, 50, 100, 150, and 200 ppm ingoing sodium nitrite or the equivalent from CP or SN, and 3 replicates of products were manufactured. Turkey and curing brines were tumbled, stuffed, and cooked to an internal temperature of 73.9^oC. Products were stabilized and sliced into 12 mm slices (physicochemical trait analysis) and 2 mm slices (sensory trait analysis). Physicochemical traits measured only on d 0 were …

Genome-Wide Analysis Of The Variation In Host Genetics In Response To Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle

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

Porcine circovirus is the primary causative 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 lead to mortality. The variation in host genetics plays a role in the ability to initiate an effective immune response. The objective of this research was to identify major genetic variants and genes that influence immune response and PCVAD susceptibility. Commercial crossbred pigs (n=974) were experimentally infected with a PCV2b strain to analyze genetic sources of variation in PCVAD susceptibility. The strain used for experimental infection was …

Model Development For The Prediction Of Intake And Carcass Measures To Be Used As Economic Marketing Determinants For Calf-Fed Steers, Mallorie F. Wilken

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

Accurate prediction of intake and carcass characteristics can assist in projecting input costs and potential premiums when cattle are sold at optimum finishing so net profit/loss can be anticipated. Currently published DMI prediction equations and dietary NE values are based off of data collected over 50 years ago and have been shown to inaccurately predict intake compared to a prediction equation based of off performance data. Calculating dietary NE values from performance data increased precision and accuracy of prediction. Additionally, prediction accuracy was increased for diets containing ethanol byproducts. Since ethanol byproducts have been shown to have 110 to 140% …

The Role Of Sirtuin 1 And Ceramide In T10C12 Conjugated Linoleic Acid Induced Delipidation In 3t3-L1 Adipocytes, Wei Wang

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

Project 1: Trans-10, cis-12 conjugated linoleic acid (t10c12 CLA) reduces triglyceride (TG) levels in adipocytes through multiple pathways, with AMP-activated protein kinase (AMPK) generally facilitating, and peroxisome proliferator-activated receptor γ (PPARγ) generally opposing these reductions. Sirtuin 1 (SIRT1), a histone/protein deacetylase that affects energy homeostasis, often functions coordinately with AMPK, and is capable of binding to PPARγ, thereby inhibiting its activity. This study investigated the role of SIRT1 in the response of 3T3-L1 adipocytes to t10c12 CLA by testing the following hypotheses: 1) SIRT1 is functionally required for robust TG reduction; …