Animal Sciences Commons^™

Genetic Parameters For Docility, Weaning Weight, Yearling Weight, And Intramuscular Fat Percentage In Hereford Cattle, J. A. Torres-Vázquez, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Cattle behavior, including measures of docility, is important to beef cattle producers not only from a human safety perspective but also due to potential correlations to economically relevant traits. Field data from the American Hereford Association was used to estimate genetic parameters for chute score (CS; n = 25,037), weaning weight (WW; n = 24,908), yearling weight (YW; n = 23,978), and intramuscular fat percentage (IMF; n = 12,566). Single-trait and bivariate animal models were used to estimate heritabilities and genetic correlations. All models included fixed effects of sex and contemporary group, defined as herd–year–season, and direct genetic and residual …

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 …

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 either …

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 …

Effects Of Shade And Feeding Zilpaterol Hydrochloride To Finishing Steers On Performance, Carcass Quality, Heat Stress, Mobility, And Body Temperature, Bradley M. Boyd, Steven D. Shackelford, Kristin E. Hales, Tami M. Brown-Brandl, Meredith L. Bremer, Matthew L. Spangler, T. L. Wheeler, D. A. King, Galen Erickson

Department of Animal Science: Faculty Publications

Steers (n = 480; 22% with black hides and 78% with red hides) were used to study the effects of shade and feeding zilpaterol hydrochloride (ZH) on performance, carcass quality, heat stress, mobility, and body temperature (BT). A randomized block design with a 2 × 2 factorial treatment arrangement was used with 4 replicates per treatment. Factors included housing type (open or shaded pens) and the feeding of ZH (0 or 8.33 mg/kg DM) the last 21 d on feed with a 3-d withdrawal. Cattle were blocked by BW into a heavy or light block and randomly assigned to pen …

Evaluating Equations Estimating Change In Swine Feed Intake During Heat And Cold Stress, R. R. White, P. S. Miller, M. D. Hanigan

Department of Animal Science: Faculty Publications

The objectives of this study were to evaluate heat stress feed intake models for growing swine using a data set assembled from the literature and to develop a series of new equations modeling the influence of the thermal environment and interactions between the thermal environmental and other factors on feed intake. A literature survey was conducted to identify studies assessing intake responses to temperature. The resulting data set comprised 35 studies containing 120 comparisons to thermoneutral intake. Intake as a fraction of thermoneutral intake (FFI) was the primary response variable, where a value of 1 represented no change from thermoneutral …

Vegfa: Just One Of Multiple Mechanisms For Sex-Specific Vascular Development Within The Testis?, Kevin M. Sargent, Renee M. Sargent, Renata Spuri Gomes, Andrea S. Cupp

Department of Animal Science: Faculty Publications

Testis development from an indifferent gonad is a critical step in embryogenesis. A hallmark of testis differentiation is sex-specific vascularization which occurs as endothelial cells migrate from the adjacent mesonephros into the testis to surround Sertoli-germ cell aggregates and induce seminiferous cord formation. Many in vitro experiments have demonstrated that Vascular Endothelial Growth Factor A (VEGFA) is a critical regulator of this process. Both inhibitors to VEGFA signal transduction and excess VEGFA isoforms in testis organ cultures impaired vascular development and seminiferous cord formation. However, in vivo models using mice which selectively eliminated all VEGFA isoforms: in Sertoli and germ …

Economically Relevant Traits And Selection Indices, M. L. Spangler

Range Beef Cow Symposium

Sire selection should focus on that which is economical. This requires a true accounting of the traits that generate revenue or incur a cost within a specific beef cattle enterprise. Once the drivers of profit have been identified, sire selection should focus on the suite of traits that impact profitability. The use of bio-economic selection indices can dramatically reduce the complexity of multiple trait selection and aid in sire selection towards increased profitability. It is critical to use selection indices that match the intended production system. Using a terminal index in an enterprise that retains replacement heifers would not be …

Crossbreeding Strategies: Including Terminal Vs. Maternal Crosses, R. L. Weaber

Range Beef Cow Symposium

The dramatic changes and volatility cow-calf production system input costs and calf values have many producers wondering about the value of heterosis in today’s beef industry pricing structure. Many producers are seeking ways to improve cow-calf production efficiency and profitability. Profitability may be enhanced by increasing the volume of production (i.e. the pounds of calves you market) and/or the value of products you sell (improving quality). The reduction of production costs, and thus breakeven prices, can also improve profitability. Better yet, improving the input:output ratio should enhance profit. For commercial beef producers, the implementation of technologies and breeding systems that …

Using Partial Confinement Systems For Beef Cattle Production, Karla Jenkins

Range Beef Cow Symposium

Summary

• Energy density is the key to limit feeding
• Lactation increases energy needs considerably
• Consider early weaning options
• Confined calves must be able to reach water and feed
• Limit fed cows need ample bunk space and a consistent feeding routine
• Each producer needs to evaluate their resources and system options to see what might work best
• As prices change systems should be reevaluated

Cow Supplementation: Getting The Best Bang For Your Buck, Ken Olson

Range Beef Cow Symposium

How do we get the best bang for the buck?

• 2 aspects:

1. Biology: Use the right feeds to provide the right nutrients
2. Economics: price the best feeds to provide the right nutrients

High Altitude Disease, Pap, Feedlot Hypertension, And Respiratory Issues, J. M. Neary, F. B. Garry, T. N. Holt, G. M. Krafsur, P. S. Morley, R. D. Brown, K. R. Stenmark, R. Mark Enns, M. G. Thomas

Range Beef Cow Symposium

Summary

1. BRISKET DISEASE, or congestive heart failure, IS NOT UNIQUE TO HIGH ALTITUDE
2. Congestive heart failure is becoming INCREASINGLY PROBLEMATIC
3. TAKE A CLOSER LOOK – it may not be chronic pneumonia!

Economically Relevent Traits And Selection Indcies, Matt Spangler

Range Beef Cow Symposium

Summary

• Establish production goals
• Use economic indices that fit your desired breeding objectives
• Do not make sire selection more cumbersome than it needs to be
• Know your costs
• Select on PROFIT not just revenue
• Multiple trait selection is critical and could become more cumbersome
• Economic indexes help alleviate this
• Use index values that meet your breeding objective

High Altitude Disease, Pap, Feedlot Hypertension, And Respiratory Issues, J. M. Neary, F. B. Garry, T. N. Holt, G. M. Krafsur, P. S. Morley, R. D. Brown, K. R. Stenmark, R. Mark Enns, M. G. Thomas

Range Beef Cow Symposium

Right-heart failure (RHF) due to pulmonary hypertension, more commonly known as brisket disease or high altitude disease, is a complex disease that is becomingly increasing problematic for the cattle industry–regardless of altitude. The disease became known as high altitude disease because until the mid-1960s RHF was only reported at altitudes over 7,000 ft. Today, RHF is still problematic in high altitude cow-calf operations and is occurring with increasing incidence in feedlot cattle. The clinical signs are commonly mistaken for chronic pneumonia, which complicates disease diagnosis and reporting. Moreover, cattle treated for pneumonia have 2 to 3 times greater risk of …

Crossbreeding Strategies: Terminal And Maternal Crossing, Bob Weaber

Range Beef Cow Symposium

The Power of Crossbreeding

• Heterosis

• Superiority of a crossbred animal as compared to the average of its straightbred parents
• Especially maternal heterosis
• Breed Complementarity
• Selection of breeds for core traits that fill the other breed(s) shortcomings
• Maternal crossbreds-­‐appropriate cow size/lactation for environmental fitness
• Terminal crossbreds-­‐add value to calves in market place

Feedlot And Carcass Data: Making “Cents” And Making Decisions [Presentation], Julie Walker

Range Beef Cow Symposium

Summary

• Baseline of calves
• Management decision within the cow herd impacts performance within the feedlot and carcass characteristics
• Pre- and post- weaning performance is important in making management decisions

Feedlot And Carcass Data: Making “Cents” And Making Decisions, Julie Walker

Range Beef Cow Symposium

Sixty-two percent of calves are sold within 30 days of weaning (47% at weaning; McBride and Mathews, 2011). In the last decade, marketing of finished animals has shifted to selling on value-based systems. In 2012, nearly three times more cattle were sold in a value-based system compared to a traditional cash method. However, those two marketing methods accounted for nearly equal percentages of cattle sold as recently as 2006 (Mike Kasten, RBCS 2013). Therefore, carcass merit is a larger driver of value today compared to when the majority of cattle were sold on a live weight basis. How are feeder …

Prediction Of Plant Height In Arabidopsis Thaliana Using Dna Methylation Data, Yaodong Hu, Gota Morota, Guilherme J. M. Rosa, Daniel Gianola

Department of Animal Science: Faculty Publications

Prediction of complex traits using molecular genetic information is an active area in quantitative genetics research. In the postgenomic era, many types of -omic (e.g., transcriptomic, epigenomic, methylomic, and proteomic) data are becoming increasingly available. Therefore, evaluating the utility of this massive amount of information in prediction of complex traits is of interest. DNA methylation, the covalent change of a DNA molecule without affecting its underlying sequence, is one quantifiable form of epigenetic modification. We used methylation information for predicting plant height (PH) in Arabidopsis thaliana nonparametrically, using reproducing kernel Hilbert spaces (RKHS) regression. Also, we used different criteria for …

Evaluation Of Reduced Subsets Of Single Nucleotide Polymorphisms For The Prediction Of Age At Puberty In Sows, Katherine L. Lucot, Matthew L. Spangler, Melanie D. Trenhaile, Stephen D. Kachman, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

Genomic information could be used efficiently to improve traits that are expensive to measure, sex limited or expressed late in life. This study analyzed the phenotypic variation explained by major SNPs and windows for age at puberty in gilts, an indicator of reproductive longevity. A genome-wide association study using 56,424 SNPs explained 25.2% of the phenotypic variation in age at puberty in a training set (n = 820). All SNPs from the top 10% of 1-Mb windows explained 33.5% of the phenotypic variance compared to 47.1% explained by the most informative markers (n = 261). In an evaluation population, consisting …

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:CO_{2 …}

Activity Of The Porcine Gonadotropin-Releasing Hormone Receptor Gene Promoter Is Partially Conferred By A Distal Gonadotrope Specific Element (Gse) Within An Upstream Enhancing Region, Two Proximal Gses And A Retinoid X Receptor Binding Site, Rebecca Cederberg, Jacqueline Smith, Emily A. Mcdonald, Chanho Lee, Amy R. Perkins, Brett R. White

Department of Animal Science: Faculty Publications

Background: Regulation of gonadotropin-releasing hormone (GnRH) receptor (GnRHR) numbers on gonadotropes within the anterior pituitary gland represents a critical point for control of reproductive function. Binding of GnRH to its receptor regulates follicle stimulating hormone (FSH) and luteinizing hormone (LH) release and levels of this G-protein coupled receptor on the surface of gonadotropes determines their sensitivity to GnRH pulses. While transcriptional regulation of this gene has been studied in mice, rats, humans and sheep, little is known about its regulation in the pig, an important agricultural species and human research model.

Methods: We isolated 5118 bp of 5′ flanking …

A Prototype On-Line Aotf Hyperspectral Image Acquisition System For Tenderness Assessment Of Beef Carcasses, Govindarajan Konda Naganathan, Kim Cluff, Ashok Samal, Chris Calkins, David D. Jones, Carol Lorenzen, Jeyamkondan Subbiah

Department of Food Science and Technology: Faculty Publications

A prototype on-line acousto-optic tunable filter (AOTF)-based hyperspectral image acquisition system (λ = 450– 900 nm) was developed for tenderness assessment of beef carcasses. Hyperspectral images of ribeye muscle on stationary hanging beef carcasses (n = 338) at 2-day postmortem were acquired in commercial beef slaughter or packing plants. After image acquisition, a strip steak was cut from each carcass, vacuum packaged, aged for 14 days, cooked, and slice shear force tenderness scores were collected by an independent lab. Beef hyperspectral images were mosaicked together and principal component (PC) analysis was conducted to reduce the spectral dimension. Six different textural …

The Influence Of The Bovine Fecal Microbiota On The Shedding Of Shiga Toxin-Producing Escherichia Coli (Stec) By Beef Cattle, Nirosh D. Aluthge

Department of Food Science and Technology: Dissertations, Theses, and Student Research

During the past three decades, Shiga toxin-producing E.coli (STEC) have emerged as an important food safety concern. Although initially E. coli O157 was the main focus, recent outbreaks and resulting investigations have shown that certain non-O157 STEC are as much a threat to food safety as their O157 counterparts. To the beef industry, STEC have been of particular concern due to the frequent association of beef and beef products as vehicles of STEC infection. As a result, along with E. coli O157, six non-O157 STEC serogroups (known as the ‘big six’) are now regulated as adulterants in certain raw beef …

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 …

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 …

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

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 …

Characteristics Of Trailer Thermal Environment During Commercial Swine Transport Managed Under U.S. Industry Guidelines, Y Xiong, Angela Green, Richard S. Gates

Department of Animal Science: Faculty Publications

Transport is a critical factor in modern pork production and can seriously affect swine welfare. While previous research has explored thermal conditions during transport, the impact of extreme weather conditions on the trailer thermal environment under industry practices has not been well documented; and the critical factors impacting microclimate are not well understood. To assess the trailer microclimate during transport events, an instrumentation system was designed and installed at the central ceiling level, pig level and floor-level in each of six zones inside a commercial swine trailer. Transport environmental data from 34 monitoring trips (approximately 1–4 h in duration each) …

Sphingolipids Are Required For Efficient Triacylglycerol Loss In Conjugated Linoleic Acid Treated Adipocytes, Wei Wang, Michael E. Fromm

Department of Animal Science: Faculty Publications

Conjugated linoleic acid (CLA) reduces adiposity in human and mouse adipocytes. This outcome is achieved through a variety of biological responses including increased energy expenditure and fatty acid oxidation, increased inflammation, repression of fatty acid biosynthesis, attenuated glucose transport, and apoptosis. In the current study, profiling of 261 metabolites was conducted to gain new insights into the biological pathways responding to CLA in 3T3-L1 adipocytes. Sphinganine and sphingosine levels were observed to be highly elevated in CLA treated adipocytes. Exogenous chemicals that increased endogenous ceramide levels decreased lipid levels in adipocytes, and activated AMP-activated protein kinase (AMPK) as well as …

Genome-Wide Analysis Of Tnf-Alpha Response In Pigs Challenged With Porcine Circovirus 2b, C. A. Kreikemeier, T. B., K. L. Lucot, Thomas E. Burkey, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine with a role in activating adaptive immunity to viral infections. By inhibiting the capacity of plasmacytoid dendritic cells to produce interferon-α and TNF-α, porcine circovirus 2 (PCV₂) limits the maturation of myeloid dendritic cells and impairs their ability to recognize viral and bacterial antigens. Previously, we reported QTL for viremia and immune response in PCV₂- infected pigs. In this study, we analyzed phenotypic and genetic relationships between TNFα protein levels, a potential indicator of predisposition to PCV₂ co-infection, and PCV₂ susceptibility. Following experimental challenge with …