Life Sciences Commons^™

Investigation Of Breeding Objectives And Indexes-In-Retrospect, Hunter F. Valasek

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

This thesis presents two projects that investigate the impacts of breeding objectives and indexes-in-retrospect within the beef cattle industry. The first project synthesized how changes due to planning horizon, breeding system, and sale endpoint in the economic breeding goal of cattle influence the relative emphasis of traits as well as the re-ranking of selection candidates. A total of three breeding systems that represent straightbred and crossbred cattle were used along with six planning horizons (2, 5, 10, 20, 30, and 50 yrs.) for both a weaning and slaughter point of sale. The combination of these different breeding objective attributes resulted …

Greenhouse Gas Emissions From Two Contrasting Beef Systems From Birth To Slaughter In Eastern Nebraska, Levi Mcphillips

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

Over the last 15 years, the increase in land use for corn and soybean has come at the expense of acres of grasslands and perennial forages employed in conventional beef-production systems. Implementing alternative cow-calf production systems into existing cropping systems may be a solution for reduced land availability and reducing total greenhouse gas emissions (GHG). Therefore, GHG from a conventional (CONV) pasture-based cattle production system with cows wintered on corn residue and summer grazing of brome pasture were compared to partial-confinement system (ALT) with cows and calves in a drylot during the summer and grazing cover crops and corn residue …

Estimation Of Breed Effects And Genetic Parameters For Age At Slaughter And Days To Finish In A Multibreed Beef Cattle Population, Lindsay Upperman

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

Cattle efficiency during the finishing phase is a crucial factor in determining profit in the beef cattle industry. Economically relevant traits associated with efficient production include age at slaughter (AAS) and days to finish (DtF). Selection to reduce the number of days an animal takes to reach a finish endpoint would ultimately reduce production costs, increase net profits, and result in a more sustainable production system. However, most harvested animals are from commercial herds, necessitating the use of indicator traits from seedstock animals for selection. Potential indicator traits include ultrasound measurements that could be genetically correlated to DtF traits. The …

Understanding Rumen Microbial Community Structure And Function Towards Decreasing Methane Emissions, Allison L. Knoell

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

Resource use is continually being limited due to this growth, therefore, production of high-quality animal protein sources, such as meat and milk, are challenged. The rumen microbiome is extensive and serves to provide several metabolic requirements for the animal for growth. Recently, a significant amount of research is being driven towards understanding the rumen microbiome due to its large effect on metabolic requirements.

A study was conducted to replace alfalfa with nonforage fiber sources in dairy cows. It was determined milk yield and intake are maintained when nonforage fibers replace forage sources, while decreasing methane levels. Water consumption decreased when …

Interaction Of Urea With Frequency And Amount Of Distillers Grains Supplementation For Growing Steers On A High Forage Diet, Haley F. Linder

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

Two studies were conducted to determine interactions of urea inclusion to a dried distillers grains plus solubles (DDGS) supplement fed at two amounts and two frequencies to steers on a high forage diet. In Exp. 1, 120 steers were fed individually for 84 d. Steers received ad libitum grass hay and 1 of 8 treatments. Supplement was fed either every day (D) or 3x/week (ALT), amount of supplement fed was 6.36 kg/week (LO) or 12.73 kg/week (HI), and contain either no urea (-U) or 1.3% urea (+U). Hay DMI and steer BW were measured. In Exp. 2, 8 ruminally cannulated …

Improving The Accuracy Of Genomic Predictions: Investigation Of Training Methods And Data Pooling, Johnna Baller

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

One of the primary factors in the response to selection is the accuracy of selection. This study focused on methodologies to predict breeding values (BV) accurately within multi- and single-step genomic evaluations. Factors including cross-validation methods, dependent variables, and genotyping strategies were assessed on the accuracy of genomic BV while using multi-step prediction in real and simulated data. In both cases, random clustering led to largest estimated accuracies compared to clusters based on k-means, k-medoids, and principle component analysis, but differences in bias were not detected. Using deregressed estimated BV (EBV) to estimate SNP effects led to larger accuracies and …

Effects Of Supplemental Whole Cottonseed On Weaned Calf Production, Zachary Debord

Mahurin Honors College Capstone Experience/Thesis Projects

This study compared the effect of supplemental whole cottonseed in a weaned calf ration on cattle productivity. Feed is the main cost for livestock production. Whole cottonseed supplementation may increase production and reduce the cost of gain for the ration. During the study, 18 beef calves were weaned and split into two groups and fed, with and without WCS, for 50 days to determine the effect of supplemental whole cottonseed. Productivity was determined by measuring average daily gains for each group and comparing cost of gain for each ration. It was determined that WCS did increase productivity of weaned calves …

Feed Efficiency And Carcass Metrics In Growing Cattle, David N. Kelly, Craig Murphy, Roy D. Sleator, Michelle M. Judge, Stephen B. Conroy, Donagh P. Berry

Department of Biological Sciences Publications

Some definitions of feed efficiency such as residual energy intake (REI) and residual gain (RG) may not truly reflect production efficiency. The energy sinks used in the derivation of the traits include metabolic live-weight; producers finishing cattle for slaughter are, however, paid on the basis of carcass weight, as opposed to live-weight. The objective of the present study was to explore alternative definitions of REI and RG which are more reflective of production efficiency, and quantify their relationship with performance, ultrasound, and carcass traits across multiple breeds and sexes of cattle. Feed intake and live-weight records were available on 5,172 …

Intermountain Beef Cow/Calf Management Calendar, C. Kim Chapman, Matthew D. Garcia, Ryan Larsen, Kerry A. Rood

All Current Publications

This calendar gives beef cow/calf management tips for nutrition, animal health, finance, and public lands information for each month of the year.

Evaluation Of Protein Utilization In Low And High Protein Forage Sources And The Economic Value Of Supplementing Field Peas (Pisum Sativum) To Growing Cattle Grazing Crested Wheatgrass Pastures, Braden C. Troyer

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

Field peas are widely grown in the panhandle of Nebraska; however, markets quickly become saturated. A two year experiment was conducted comparing field peas to dry distillers grains with solubles (DDGS) as a protein supplement. The objective was to establish a price producers could pay for field peas relative to DDGS. There was a significant difference in ADG due to type of supplement (P = 0.02). Field pea supplemented heifers had 10% lower ADG compared to DDGS supplemented heifers. Economically, this means if DDGS is priced at or $124.58/ 909 kg DM a producer could pay $2.89/ 27 kg, …

Medication Darts Are Gaining In Popularity - Do They Affect Meat Quality? Are There Risks?, David J. Wilson, Kerry A. Rood

All Current Publications

Livestock, such as beef cattle or post-weaned dairy cattle that are not yet milking, are often relatively “tame” (sometimes the term tame may not apply very well) and can be readily approached within a few feet. However, without adequate restraint facilities or enough personnel, actually treating the livestock is often difficult and can become frustrating and dangerous to people and animals. A solution to this problem, which is being rapidly and increasingly adopted, is the use of medication darts. Nevertheless, many in the cattle industry are raising some concerns. What are some of the characteristics of medication darts? Is there …

Attainment And Maintenance Of Pubertal Cyclicity May Predict High A4 Cows With Reduced Fertility, Sarah Nafziger

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

Puberty attainment was investigated in heifers. Blood samples were collected from weaning until breeding during 6 years from heifers born in 2012-2017. Plasma progesterone concentrations ≥ 1 ng/ml were used to indicate cyclicity, and heifers were categorized into one of four puberty groups using SAS: 1) Early heifers reached puberty before March 12 and cycled continuously during the sampling period, 2) Typical heifers reached puberty on or after March 12 and cycled continuously, 3) Start-Stop heifers had at least one occurrence of progesterone ≥ 1 ng/ml but discontinued cycling during the sampling period, and 4) Non-Cycling heifers had no occurrence …

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

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

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

Environmental And Animal Benefits When Beef Cattle Consume Condensed And Hydrolysable Tannins, Elizabeth K. Stewart, Juan J. Villalba, Kerry A. Rood

All Current Publications

This fact sheet describes the environmental and animal benefits when cattle consume condensed and hydrolysable tannins, and includes producer concerns.

Understanding The Contributions Of Beef Cattle To Greenhouse Gas Emissions, Elizabeth Stewart, Eric Thacker, Matthew D. Garcia, Juan J. Villalba

All Current Publications

This fact sheet describes current and projected beef consumption, methane, nitrogen, beef cattle production, and possibilities for more sustainable beef production.

Collection Of Biological Material For Commercial Genomic Testing In Beef, Matthew D. Garcia, Kevin Heaton, Linden Greenhalgh

All Current Publications

This fact sheet describes collecting biological material for commercial genomic testing of beef cattle. It includes a description of materials needed, methods of collecting including blood, ear notching, or tissue collection, and how to ship and store samples.

Weaning Strategies In Beef Cattle To Reduce Stress, Matthew Garcia, Kerry Rood, Clark Israelsen

All Current Publications

This fact sheet considers weaning strategies for beef cattle, including the advantages and disadvantages of fenceline weaning, and twostep weaning.

Understanding The Semen Evaluation Portion Of The Breeding Soundness Evaluation, C. Kim Chapman, Kerry A. Rood

All Current Publications

This fact sheet explains the semen examination section of the bull breeding soundness evaluation form. It indicates what each category on the form is, why it is important, and what the requirements are for a bull to be considered a satisfactory breeder.

On-Ranch Application Of Dna Technology, Kevin Heaton, Katelyn Christensen

All Current Publications

Genetic analysis provides producers with another tool to identify individuals in a herd which have the greatest potential to be most productive or least productive, thus improving ranch sustainability. This project reported in this fact sheet demonstrated that on each ranch there were both genetically inferior and superior livestock for the production traits analyzed. Participating ranchers are using the results to select replacements and are cautioned to avoid single trait selection. This project also created a baseline for genetic quality which individual ranches could compare with future DNA test results.

Corn Residue Stocking Rate Affects Cattle Performance But Not Subsequent Grain Yield, L. A. Stalker, H. Blanco-Canqui, Jennifer A. Gigax, A. L. Mcgee, T. M. Shaver, S. J. Van Donk

West Central Research and Extension Center, North Platte

This study investigated effects of stocking rate on cattle performance, quality and quantity of corn residue, and impact of residue removal on grain yield for 5 yr at the University of Nebraska – Lincoln West Central Water Resources Field Laboratory near Brule, NE. Four removal treatments—1) no removal (control), 2) grazing at 2.5 animal unit month (AUM)/ ha, 3) grazing at 5.0 AUM/ha, and 4) baling—were applied to a center pivot–irrigated corn field (53 ha). The field was divided into eight 6.6-ha paddocks to which replicated treatments were assigned. Samples of residue were collected in October and March (before and …

Seasonal Variation In Vitamin D Status Of Beef Cattle Reared In The Central United States, E Casas, J D. Lippolis, L A. Kuehn, T A. Reinhardt

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

The objective was to retrospectively measure seasonal sunlight-associated variation in serum concentrations of 25-hydroxyvitamin D (25OHD) in beef cattle. The concentration of 25OHD was measured in crossbred animals born from March to May in 2011 and 2012. Vitamin D status 2 to 3 mo after birth (period 1) was only available for 2012 calves and was measured in June 2012. Period 1 animals had serum 25OHD concentrations of 26.3 +- 1.5 ng/mL. The 25OHD concentrations for late summer (period 2) were 46.6 +- 1.4 and 51.0 +- 1.5 ng/mL for 2011 and 2012, respectively. Serum concentration of 25OHD in early …

Demonstrating Advancements In Biotechnology To Ranchers In Southern Utah: Genetic Testing, Kevin Heaton, Katelyn Peterson

All Current Publications

This fact sheet describes genetic testing for beef cattle to identify which animals in a herd are the most productive or least productive and make some culling decisions based on the results of the tests.

Demonstrating Advancements In Biotechnology To Ranchers In Southern Utah: Pregnancy Diagnosis, Kevin Heaton, Katelyn Peterson, Alyssa O'Toole

All Current Publications

This fact sheet describes how to identify pregnant heifers and cows within 28 days of breeding using the pregnancy associated glycoproteins (PAG) test.

Demonstrating Advancements In Biotechnology To Ranchers In Southern Utah: The Snap Bvd Test, Kevin Heaton, Katelyn Peterson, Alyssa O'Toole

All Current Publications

Bovine Viral Diarrhea is a contagious beef cattle virus. The Snap BVD Test can provide accurate results in 20 to 25 minutes. This fact sheet describes how to perform the test.

Practical Reproduction Strategies For Utah Beef Ranches, Kevin Heaton, Trent Wilde, Mark Nelson, Dale Zobell

All Current Publications

This fact sheet identifies opportunities for beef cattle producers to improve herd reproduction.

Late Gestation Supplementation Of Beef Cows Differing In Body Condition Score: Effects On Cow And Calf Performance, D. W. Bohnert, L. A. Stalker, R. R. Mills, A. Nyman, S. J. Falck, R. F. Cooke

West Central Research and Extension Center, North Platte

A 2-yr study utilizing 120 mature, crossbred (Angus × Herford) cows/year, evaluated the influence of cow BCS and dried distillers grains with solubles (DDGS) supplementation during late gestation on cow performance and productivity of subsequent offspring. Treatments were arranged as a 2 × 2 factorial in a randomized complete block design with 2 BCS and with or without DDGS supplementation. Cows were nutritionally managed to enter the last trimester of gestation with a BCS of approximately 4 (LBCS) or 6 (HBCS) and were thereafter managed in a single herd (initial BCS were 4.4 and 5.7 for LBCS and HBCS treatments, …

Salt, Which Color Is Right?, James Keyes

All Current Publications

This publication explains the different colors of salt and where each should be used.

Review: Technical Aspects For The Utilization Of Small Grain Straws As Feed Energy Sources For Ruminants: Emphasis On Beef Cattle, J. Severe, D. R. Zobell

All Current Publications

This publication defines Straw and provide information on straw composition, plant cell wall development, and treatments of straw for feed.

Beef Heifer Retention Decisions, Cody Reed, Dale Zobell

All Current Publications

This publication discusses a number of general factors that are essential to an effective decision regarding whether to retain heifers or not.

Utilization Of Heterosis In A Beef Cow Herd, D. R. Zobell, J. Severe

All Current Publications

This publication defines heterosis in cows and gives information on the fundamentals, needs, and types of heterosis.