Browsing by Author "Engle, Terry, committee member"

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Open Access
Academic engagement: university student athletes meta-analysis
(Colorado State University. Libraries, 2020) Wightman, Lowell, author; Makela, Carole, advisor; Timpson, William, committee member; Wallner, Barbara, committee member; Engle, Terry, committee member
The purpose of this analysis was to understand the role of academic engagement for university student athletes' perceptions of how academic engagement influences their academic success. The meta-analytical process in this study focused on student athletes' awareness of the academic environment and opportunities for engagement and interpretation of how these factors influence their academic performance (e.g., comments like "Having an open study hall available every day, along my path to class and practice that includes study resources removes so many obstacles to staying focused on my class work."). From the analysis of the students' perceptions, the intent was to review academic engagement constructs and their relationships with National Collegiate Athletic Association Academic Progress Rating, U.S. Department of Education, and National Student Survey of Engagement standards for the purpose of identifying how these are similar and different. Similarities and differences inform advising/guiding students' understanding of the scholarship expectations, their interactions with faculty and staff, and their performance as students. In addition, it was important that this study inform coaches, administrators, and faculty about pedagogical strategies and environmental conditions supporting scholarship student athletes' academic engagement and academic performance. The analysis stage of this meta-analytical study systematically discovered data that answered this study's research questions in whole or part. Methodology provided guidance for discovering key findings focused on the impact of environmental settings influencing academic engagement. Examples of prosocial environment influences on academic engagement, defined by social emotional learning theory, provided findings linked to improving student athletes' academic performance. That being said, there were no concrete literature intersections, but there were literature references implying that student athletes may connect prosocial environments to academic engagement or academic performance. As the data crystallized themes and patterns emerged indicating that student athletes did not connect academic engagement or their academic performance to maintaining their scholarship or participation on their teams. In addition, this study found student athletes academically engaged in the presence of a socially and emotionally competent instructors. It was shown in the findings, pedagogical strategies used by instructors promoting social emotional constructs created an engaging and competent environment resulting in academic performance improvement.
Open Access
An evaluation of cattle handling categories in the beef quality assurance feedyard assessment, compliance of large feedyards with these guidelines, and influence of handling practices on behavior and performance of feedlot cattle
(Colorado State University. Libraries, 2015) Woiwode, Ruth, author; Grandin, Temple, advisor; Archibeque, Shawn, committee member; Engle, Terry, committee member; Kirch, Brett, committee member; Paterson, John, committee member; Rollin, Bernard, committee member
Animal husbandry and management practices were surveyed in commercial feedlots to document compliance of select feedlots with Beef Quality Assurance (BQA) guidelines for cattle handling under the premise that this data warrants inclusion in the National Beef Quality Audit (NBQA). The BQA Feedyard Assessment for cattle handling has not yet been fully validated, and this work partially substantiates the current assessment categories. The inclusion of this handling data is essential in order to continue the track record of identifying target areas where improvement is needed, and to document growth and positive performance. Collecting and reporting of survey data is part of the verification and ongoing monitoring process that characterizes an effective HACCP plan, which was the system for management that was adopted during formation of the BQA program. It has been said that producers manage what they measure, and systematic measurement of categories for cattle handling and husbandry practices in the BQA can yield valuable information to assist producers in making management decisions. The NBQA, which has been conducted in five year increments since 1991 has accomplished just that, through the identification of targets where improvement is needed, with corresponding recommendations for improvement. The growing repository of data, collected over the course of time, reflects adjustments the industry has made in an effort to continuously improve the quality and consistency of beef production, and thus increase consumer confidence. BQA is a voluntary program that allows the use of self-assessment or third party audits to ensure compliance with the guidelines of the program. The BQA Feedyard Assessment (FA) provides guidelines for cattle handling in commercial feedlots, and is a useful tool for measuring cattle handling practices. Using these guidelines, select feedlots in 3 states (Colorado, Kansas, and Nebraska) were assessed for six current BQA categories (electric prod use, falls, stumbles, jump and run, and chute operation). These states rank 5th, 3rd, and 2nd, respectively, among all states for the number of cattle on feed each year. These three states were selected based on their ranking among the top five states for number of cattle on feed, and for the high density areas of large (1000+ head) feedyards in each state, accounting for approximately 50% of all US fed cattle each year. The feedyards included in this study were all large (1000+ head capacity) yards, with a mean capacity of 34,000 head. Across 28 sites surveyed, rate of electric prod use was 3.8% vs. the 10% current BQA critical limit (CL); only 2 sites surveyed exceeded the CL with 15% and 45% respective rates; and 12 did not use an electric prod. The rate of cattle falling when exiting the squeeze chute was 0.6% vs. BQA CL 2%, and no site surveyed exceeded the CL. The rate of cattle stumbling when exiting the squeeze chute was 5.7% vs. BQA CL 10%, with 4 sites exceeding the CL and 4 sites that had no stumbles. The rate of cattle vocalizing was 1.4% vs. BQA CL 5%; for cattle that jumped or ran when exiting the squeeze chute, 52% vs. BQA CL 25%; and mean score for cattle that were improperly captured in the squeeze chute and not readjusted was 1.2%, vs. BQA CL 0%. A second study was conducted at a commercial feedlot in Kansas. The objective of this study was to investigate if a relationship exists between handling, and behavior and ADG of feedlot cattle. Upon arrival, Hereford steers (n = 496; initial BW = 304 ± 35.6 kg) of similar genetic background were sorted into four pens to determine the effects of handling on behavior and ADG. Two handling conditions prior to processing and two conditions of release from the squeeze chute were imposed. Prior to processing, handlers were required to quietly walk all steers from their home pen to the processing area (SLOW); or handlers were permitted to bring steers to the processing area in the normal fashion (FAST). Since this condition was applied to pens, pen was considered the experimental unit for the full model. Individual steers were randomly assigned to one of two conditions of release from the squeeze chute. The first was a delay no longer than 30 seconds following the completion of procedures to allow cattle to stop struggling (DELAY); the second was release immediately following the completion of procedures (NORM). Vocalization, chute temperament, exit speed and exit behavior scores were assigned to all steers during intake processing. Paired t-tests determined that cattle exiting the chute at a walk or trot vs a run tended (P=0.08) to have higher ADG. Cattle vocalizing during restraint had lower (P=0.04) ADG than those that did not vocalize. The FAST group showed a tendency to vocalize more frequently than the SLOW group. Pearson’s correlation analysis showed a significant, positive correlation between exit speed and vocalization (P= 0.0021, r= 0.14256), and a significant, negative correlation between exit speed and ADG (P= 0.0036, r= -0.13542). Using this approach, handling was correlated with behavior and ADG.
Open Access
Are you what you eat? Assessing intracellular effects of supplemental lipid within mouse (C2C12) skeletal muscle cells
(Colorado State University. Libraries, 2021) Montano, Dominique, author; Kanatous, Shane, advisor; Bell, Christopher, advisor; Engle, Terry, committee member; Florant, Gregory, committee member
The expression of myoglobin, an oxygen-binding protein, facilitates aerobically-powered dives by effectively distributing a finite oxygen supply during breath-hold dives in marine mammals (Costa 2004, Kanatous et al. 1999, Wright 2006). Multiple factors have been experimentally shown to contribute to increasing myoglobin expression, thus influencing aerobic capacity. Among the known expression pathways, the most recent and least studied involves a link between lipid supplementation and increased myoglobin expression. We are unaware of the specific conditions that drive this expression, and whether or not fatty acids play an intracellular role in upregulating myoglobin. This work elucidates the effects of lipid supplementation on the expression of myoglobin in terrestrial mammals, as well as enhances our understanding of cues that initiate the expression of factors contributing to the positive development of aerobically-based exercise in the whole animal. In order to understand these lipid influences on an aerobically-adapted animal such as a marine mammal, we focused on developing experimental designs and applications geared towards a model mammalian system of C2C12 mouse cells. Lipids possess the capacity to influence aerobic ability in mammalian models, whether through marine mammals' reliance on lipid metabolism to power aerobically-based exercise, regulating mitochondrial respiration, fatty acid metabolism that generates increased ATP from oxidative phosphorylation relative to metabolic pathways like glycolysis, lipids acting as ligands to affect genes that contribute to aerobic capacity, or lipid supplementation that increases myoglobin expression. Multiple studies from our lab have shown that lipid present in the media upregulates myoglobin in C2C12 cells, driving expression of the protein in conjunction with other elements. Although we have determined a link between lipid supplementation and myoglobin expression, the particular intracellular effects ranging from uptake, transporter protein regulation, and either storage, metabolism, or specific effects directly affecting myoglobin expression still remain to be uncovered. The factors and conditions that regulate myoglobin expression are extensive, and lipids as an avenue to myoglobin expression is a relatively new exploration that will have applications for numerous areas of physiological research. This work has applications in multiple mammalian models, including humans, and will serve to enhance our understanding of the factors that drive aerobically-based endurance exercise, as well as understanding the cues and stimuli required to increase expression of key factors that regulate aerobic capacity in mammalian systems.
Open Access
Assessment of rapid evaporative ionization mass spectrometry (REIMS) to characterize beef quality and the impact of oven temperature and relative humidity on beef
(Colorado State University. Libraries, 2018) Gredell, Devin, author; Woerner, Dale, advisor; Belk, Keith, committee member; Engle, Terry, committee member; Prenni, Jessica, committee member; Heuberger, Adam, committee member
The objective of experiment 1 was to evaluate the ability of rapid evaporative ionization mass spectrometry (REIMS) to predict beef eating quality characteristics. Striploin sections (5 cm in thickness; N = 292) from 7 beef carcass types (Select, Low Choice, Top Choice, Prime, Dark Cutter, Grass-fed, and Wagyu) were collected to achieve variation in fat content, sensory attributes, tenderness, and production background. Sections were aged for 14 d, fabricated into 2.54 cm thick steaks, and frozen until analysis. Trained descriptive panel rated tenderness, flavor, and juiciness attributes for sensory prediction models. Slice shear force (SSF) and Warner-Bratzler shear force (WBS) values were measured to predict tenderness classifications. A molecular fingerprint of each sample was collected via REIMS to build prediction models. Models were built using 80% of samples that were selected randomly for this purpose and tested for prediction accuracy using the remaining 20%. Partial least squares (PLS) discriminant analysis was used as a dimension reduction technique before building a linear discriminant analysis (LDA) model for classification. When Select and Low Choice samples, as well as Top Choice and Prime samples, were combined, balanced prediction accuracy reached 83.8%. Slice shear force and WBS tenderness classifications (tough vs tender) were predicted with 75.0% and 70.2% accuracy, respectively. Sensory models were built to assign samples into positive and negative classifications based on either all sensory attributes (i.e., tenderness, juiciness, and flavor) or only flavor attributes. Overall sensory class was predicted with 75.4% accuracy and flavor class with 70.3%. With future fine-tuning, these data suggest that REIMS produces a metabolic fingerprint to provide a method to meaningfully predict numerous beef quality attributes in an on-line application. The objective of the second study was to evaluate the roles of cooking rate and relative humidity on sensory development of beef strip steaks. Thirty USDA Choice beef strip loins were collected from a commercial packing facility. Each strip loin was cut into steaks and randomly assigned to 1 of 6 cooking methods utilizing 2 oven temperatures (80°C and 204°C) and 3 levels of relative humidity [zero (ZH), mid (MH), and high (HH)]. Cooked steaks were used to evaluate internal and external color, Warner-Bratzler and slice shear force, total collagen content, protein denaturation, and trained sensory ratings. Relative humidity greatly reduced cooking rate, especially at 80°C. Steaks cooked at 80°C-ZH had the greatest (P < 0.01) cook loss of all treatments, and cook loss was not affected (P > 0.05). Steaks cooked at 80C-ZH appeared the most (P < 0.01) well-done and had the darkest (P > 0.01) surface color. Total collagen was greatest (P < 0.01) in steaks cooked with ZH, regardless of oven temperature. Myosin denaturation was not affected (P > 0.05) by treatment. Increased (P = 0.02) sarcoplasmic protein denaturation was observed with ZH and MH, while increased (P = 0.02) actin denaturation was observed only with ZH. Oven temperature did not influence (P > 0.05) protein denaturation. Trained panelists rated steaks most tender (P < 0.01) when cooked at 80°C and with ZH and MH. Humidity did not affect (P > 0.05) juiciness at 204°C; however, MH and HH produced a juicier (P < 0.01) steak when cooked at 80°C. Humidity hindered (P < 0.01) the development of beefy/brothy and brown/grilled flavors but increased (P = 0.01) metallic/bloody intensity. Lower oven temperatures and moderate levels of humidity could be utilized to maximize tenderness, while minimally affecting flavor development.
Open Access
Authenticity and animal welfare: understanding and ameliorating the suffering of dairy cows and their calves
(Colorado State University. Libraries, 2016) Teeple, Jennifer Elyse, author; Rollin, Bernard, advisor; Engle, Terry, committee member; Wailes, William, committee member
As Bernard Rollin discusses throughout his body of work, animals have interests and unique teloi as well as the capacity to feel pain and suffer emotionally. I argue that we must confront the ways in which we contribute to the suffering of dairy cows and their calves in particular, for their lives constitute a paradigmatic denial of an animal’s telos. Martin Heidegger’s notion of everydayness and his concept of authenticity—and especially Charles B. Guignon’s interpretations of them—allow us to understand and come to terms with our own everyday contribution to the reprehensible practices surrounding dairy production. That is, Heidegger’s understanding of Being allows us to see that we are likely contributors to the perpetuation of dairy cow and calf suffering. The concept of authenticity also acts as a tool that allows us insight into describing and prescribing personal commitments that entail the amelioration of these animals’ suffering. The goal is to individually strive to improve animal welfare in the dairy industry, which entails taking responsibility for and altering our actions and choices; otherwise, to avoid doing so is culpable—a notion akin to Nancy Williams’s argument that we are affectively ignorant of our role in animal mistreatment. Finally, utilizing authenticity as a guide also allows us to look to history, idols, and exemplars for moral guidance.
Open Access
Benchmarking animal handling outcomes and analyzing impacting factors on cow-calf operations
(Colorado State University. Libraries, 2022) Calaba, Elaine, author; Edwards-Callaway, Lily, advisor; Hess, Ann, committee member; Engle, Terry, committee member; Ahola, Jason, committee member
Animal handling is an important part of the cattle industry; proper handling of animals can improve animal welfare and increase consumer confidence. One way handling is assessed on cow-calf operations is through producer education programs, such as the Beef Quality Assurance (BQA) program. A part of these producer education programs is assessing animal handling outcomes. However, there has not been much research into the occurrence and implication of cow handling outcomes. The objectives of this study were to: 1) quantify handling outcomes on cow-calf operations in the United States and 2) investigate potential factors that may influence these outcomes. An assessment was developed by refining existing BQA Cow-Calf program outcome definitions in addition to questions about animal factors, facilities, and management factors. Handling outcomes observed included: Prod Use, Miscatch, Vocalization, Jump, Slip/Stumble, Fall and Run. A total of 76 cow-calf operations were sampled in 24 states (Central, n = 17; East, n = 30; West, n = 29), with herd sizes ranging from 10 head to more than 5,000 head. Observations occurred during processing of either cows or yearling heifers through a cattle chute restraint system, regardless of procedure being performed. With herds less than 100 head, all cows or yearling heifers were observed as they moved through the single file alley, into the chute, and upon exiting the chute for a distance of three body lengths. On operations greater than 100 head, a maximum of 100 contiguous head were observed. Results indicate that most participants were BQA trained (70%) and had crossbred herds (63%) with a Docile temperament (57%) and had Daily Visual Contact with their herds (47%). The mean observations for Prod Use (18.1% ± 28.9), Miscatch (2.5% ± 5.1), and Fall (2.5% ± 4.2) exceeded the upper limit of BQA standards. The BQA threshold for Prod Use is 10%, Miscatch is 0%, and Fall is 2%. Vocalization (3.8% ± 7.6), Jump (7.5% ± 9.9), Run (7.7% ± 13.8), and Slip/Stumble (6.3% ± 9.1) were within BQA thresholds (5%, 25%, and 10% respectively). Prod Use had the greatest number of impacting factors including BQA status, Herd Size Group, Temperament, and Visual Contact while Miscatch, Vocalization, and Fall all had single impacting factors (Region, Temperament, Visual Contact, respectively). Visual Contact and Temperament had an association with the majority of outcomes. Future research should focus more in-depth on specific factors and the variety contained within and on the role of veterinarians in handling outcome frequencies.
Open Access
Capabilities of rapid evaporative ionization mass spectrometry to predict lamb flavor and overview of feeding genetically modified grain to livestock
(Colorado State University. Libraries, 2019) Gifford, Cody Lynn, author; Woerner, Dale, advisor; Belk, Keith, committee member; Engle, Terry, committee member; Prenni, Jessica, committee member; Heuberger, Adam, committee member
The objective of experiment 1 was to evaluate the ability of rapid evaporative ionization mass spectrometry (REIMS) to predict characteristics of cooked sheep meat flavor using metabolomic data from raw samples. Boneless leg samples were obtained from 150 carcasses of sheep representing three age classifications (n=50 per age classification), at three USDA inspected harvest facilities located in Colorado and California, between October 2017 to June 2018. A trained descriptive panel rated seven flavor attributes. Metabolomic data from fat, lean and ground patties from legs of sheep carcasses were captured through the REIMS platform. Principal component analysis factor scores were used in hierarchical cluster analysis to assess two-level and three-level sensory clusters. Partial least squares (PLS) was used to reduce dimensionality of data before the linear discriminant analysis (LDA) model was built. Eighty percent of the samples were randomly selected to train models and the remaining 20% were used to test prediction accuracy. Mutton carcasses were identified with 88.9% sensitivity and 80.0% precision using external fat of the leg and with 100% sensitivity and 90.9% precision using ground patties. Yearling carcasses were identified with 85.7% precision using lean and lambs were predicted with 70% precision using lean and fat tissue. Greater than 80% accuracy (overall and balanced), sensitivity and precision was achieved in models using lean and ground patties to identify production background (whether the live animal that produced the lean or ground patties was grain-finished or grass-finished). Prediction accuracies of age classification, production background and two-level flavor performance categories were 68% or higher with various machine learning algorithms coupled with data dimension reduction approaches. Further work is warranted to validate use of this technology in an on-line production setting and additional datasets could be used to further refine or create additional prediction models with better understanding of data processing characteristics. The review was conducted to assess the scientific literature for evidence of altered health effects in livestock species that have been fed genetically modified grain and any health effects discussed in reference to human consumption of meat products from those animals. Public concern still exists for feeding genetically modified (GM) or genetically engineered (GE) corn to animals that produce animal protein foods. In the U.S., 90% of all corn acres planted in 2013 were from single herbicide or insect resistance GE corn varieties. Regulation of GE crops is mandatory in the U.S. and consists of review and approval by three different Federal agencies. Substantial equivalence is a principle used in evaluating the safety of GE crops to establish that transgenic (GE or GM) varieties are nutritionally similar and as safe as non-transgenic crops. Animal feeding trials can provide further information to establish the safety of GE crops for human and animal consumption. No publications were found that had reported human metabolic effects from consuming beef cattle fed genetically modified grains. No consistent conclusions have been made that feeding GE corn to mice or rats, beef or dairy cattle, swine, or poultry causes any adverse effects to health. Parameters regarding sample size, diet treatments and specified controls exist to guide researchers in designing animal feeding trials with GE crops, but many criticisms of the scientific literature still exist. Additionally, published feeding trials conducted with transgenic corn grain and silage in beef cattle are limited.
Open Access
Carcass bruising location and bruise trim loss in finished steers, cows, and bulls at five commercial slaughter facilities
(Colorado State University. Libraries, 2018) Kline, Helen Carter, author; Grandin, Temple, advisor; Edwards-Callaway, Lily, advisor; Belk, Keith, committee member; Engle, Terry, committee member; Rollin, Bernard, committee member
Determining the location of, and investigating possible causes of, bruising in beef carcasses is critical for addressing animal well-being concerns in the livestock industry—as well as understanding losses in value that are a consequence of carcass defects. This study was conducted in five commercial slaughter facilities, located in multiple regions of the U.S., that slaughter fed steers/heifers, cows and bulls. At each plant, animals from thirty trailers, at least one animal from each utilized compartment. In total, approximately 50 animals were marked each night, providing 150 marked animals over the three days of sampling at each facility. Individual carcasses were followed through the slaughtering process and were evaluated before carcass splitting for: presence/absence and location of bruising, and the weight of bruised meat that was removed from carcasses during trimming. This study found that 28.1% of carcasses observed were visibly bruised. Regions of the carcass that had the highest bruise incidence were the round, rib, and loin beef cuts, respectively. However, some carcasses had deep tissue bruises that were not visible on the surface of the carcass, but trim loss was collected once these bruises were exposed and averaged 1.0 kg per carcass. Cattle in the top deck compartment were less likely to be bruised when compared to cattle in the belly compartment (P = 0.03). Reduction of bruising enhances animal well-being and reduction in trim loss adds economic efficiency along the entire beef supply chain.
Open Access
Chlorela sp.: lipid extracted algae utilization of algae biodiesel co-products as an alternative protein feed in animal production
(Colorado State University. Libraries, 2012) Dib, Marco, author; Archibeque, Shawn, advisor; Engle, Terry, committee member; Roman-Muniz, Noa, committee member; Van Metre, David, committee member; Wagner, John, committee member
To view the abstract, please see the full text of the document.
Open Access
Circulating micro RNA in insulin resistant horses
(Colorado State University. Libraries, 2018) da Costa Santos, Hugo F., author; Hess, Tanja, advisor; Landolt, Gabriele, committee member; Bruemmer, Jason, committee member; Coleman, Stephen, committee member; Engle, Terry, committee member
Insulin resistance is a prevalent pathophysiological disorder among domestic horses and is associated with many other conditions such as abnormal adiposity, chronic low-grade systemic inflammation, equine metabolic syndrome, and pituitary pars intermedia dysfunction. However, the processes leading to equine insulin resistance and associated conditions remain a subject of study. Studies in human and laboratory animals have shown that a class of small non-coding RNAs, known as microRNAs (miRNAs), are involved in the regulation of many biological processes and are associated with many diseases. MiRNAs have emerged as potential biomarkers in studies for the diagnosis and prognosis of many diseases, including type 2 diabetes and metabolic syndrome. Profiling circulating miRNAs allows researchers to understand further the mechanisms involved in many diseases, including type 2 diabetes mellitus and metabolic syndrome in humans, and it has excellent potential for equine medicine. In our pilot study, we hypothesized that insulin resistant horses would have a different circulating miRNA profile than those that are healthy. 6 mares were selected from an initial population to represent the most insulin-sensitive (n = 3) and insulin resistant (n = 3) states. Serum samples were collected for miRNA profiling of these animals, investigating the presence and relative amount of 340 equine miRNAs. Results showed different miRNA profiles between groups, with a total of 14 miRNAs differently expressed between insulin resistant and insulin sensitive animals. Furthermore, results of this preliminary study suggested circulating miRNA profiles as potential new tools for evaluating the mechanisms of insulin resistance in horses and the development of novel diagnosis and treatment methods for this condition in equines. The current study aimed to follow up the pilot study by increasing the number of animals undergoing miRNA profiling and including both horses and ponies for testing. It was hypothesized that insulin resistant animals (horses and ponies) would have a different circulating miRNA profile than those that are healthy. Additionally, circulating miRNA profiles of horses and ponies were also compared. Two initial populations, one of horses and one of ponies, were screened for their insulin sensitivity state using basal proxies for insulin and glucose. Selected animals, 12 non-pregnant Thoroughbred/ Thoroughbred-cross and 12 non-pregnant Welsh/Dartmoor mares were evaluated for insulin sensitivity with the frequent sampling intravenous glucose tolerance test (FSIGTT), and serum samples collected for miRNA profiling. The quantification of miRNAs was done through qRT-PCR analysis performed to investigate the presence and relative amount of 340 equine miRNAs. Confirmation by quantitative real-time polymerase chain reaction revealed that miRNA was present in the serum of all animals. After diagnosis based on the FSIGTT results, mares were divided into groups representing their insulin sensitivity state: insulin sensitive (IS, n = 13, ten horses and three ponies) or insulin resistant (IR, n = 11, two horses and nine ponies) animals, and their miRNA profile compared. Results demonstrated that from the 340 miRNAs analyzed, 13 miRNAs were differentially expressed between insulin resistant and insulin sensitive horses, 15 differently expressed between insulin resistant and insulin sensitive ponies, 17 differently expressed between horses and ponies, and 14 differently expressed between insulin resistant and insulin sensitive animals, horses and ponies combined (p<0.05), with 4 of these miRNAs already noted when comparing horses versus ponies. In the horse groups, three miRNAs were expressed in the insulin resistant group only. Finally, eight circulating miRNAs are proposed as potential regulators of equine insulin resistance. The results of this study, in addition to our preliminary investigation, suggest potential new tools that could be used to understand further the mechanisms involved in equine insulin resistance and associated conditions and for the development of new, practical and efficient diagnosis and prognosis methods for this condition in horses.
Open Access
Dietary intake in a group of old mares fed a supplement containing long chain 18:3 (n-3) fatty acid and chromium
(Colorado State University. Libraries, 2012) Otabachian-Smith, Silvia, author; Hess, Tanja, advisor; Carnevale, Elaine, committee member; Engle, Terry, committee member; Landolt, Gabriele, committee member
To view the abstract, please see the full text of the document.
Open Access
Effect of hot-iron brand size and meloxicam on behavior, health, and performance of beef calves in a pasture setting
(Colorado State University. Libraries, 2024) Keogh, Lily, author; Edwards-Callaway, Lily, advisor; Cramer, Catie, advisor; Wolfe, Barb, committee member; Engle, Terry, committee member
Animal welfare is of growing importance in beef cattle production and therefore there is heightened interest in regularly practiced, painful management practices. Hot-iron branding is a common method of permanent identification of cattle, created by intense thermal damage to the hide. The main objectives of the study were to quantify the effects of hot-iron brand size and meloxicam on pain related behaviors and health and performance parameters of 2-month-old beef calves on a commercial cow calf operation. A total of 126 calves were enrolled in the study (bulls, n=56; heifers, n=70). Calves were hot-iron branded with one of two iron sizes (small (SM), large (LG)) and administered meloxicam (MEL; dosed for a 113-kg calf at 1mg/kg of bodyweight) or a placebo (PLA)), and castrated (CAS) or not castrated (NCAS), if a heifer calf. Following the treatment application, behavioral observation (2 h periods) using instantaneous scan sampling occurred at 6 h and 24 h post branding; these observation periods (OP) represent the pharmacokinetics of oral meloxicam. A logistic regression (PROC GLIMIX) was used to assess the association between castration status, brand size, medication, observation period, as well as any interactions, on the proportional behavioral outcomes. More LG brand calves were observed standing, lying, and displaying event behaviors as compared to the SM brand calves (P = 0.003, P = 0.011, P = 0.016, respectively). OP affected the display of event and state behaviors, with standing observed more at 6 h and event behaviors displayed more at 24 h (P = 0.0028). Concurrently, CAS and SM or LG branded calves exhibited more event behaviors and standing than NCAS calves (P = 0.022). No effect of the fixed variables on average daily gain (ADG) or morbidity were observed (P > 0.05). MEL did reduce the proportion of branded heifer calves expressing event behaviors as compared to PLA, however it had less of a behavioral impact on the concurrently castrated and branded calves (P = 0.022). The results indicate that pain is present within the 24 h following branding and castration and that concurrent castration and branding elicits a greater behavioral response than only branding. This study highlighted both the feasibility of administering an oral analgesic in a commercial setting and that implementing a smaller brand size may be a strategy to reduce pain associated with hot-iron branding.
Open Access
Effects of direct-fed microbials on weight gain and gastrointestinal bacteria microbiome composition in weaned heifers
(Colorado State University. Libraries, 2019) Doubet, Curtis, author; Pond, Kevin, advisor; Engle, Terry, committee member; Holt, Tim, committee member
Weight gain and fecal analysis on 179 heifer from two breeds of cattle, Angus and Salers, were analyzed after being treated with a direct fed microbial (DFM) supplement. Heifers were split into one of three treatment groups with the control being drenched with water, a second group being drenched with 1/2oz of the DFM, and a third group being drenched with 1oz of the DFM. Heifers were monitored over a four week period and drenched on day 0 and day 28 to measure changes in weight gain and microbiome composition. Fecal samples were taken rectally from the fecal group (FG) weekly during the duration of the trial. Overall, the final model ANOVA resulted in a p-value of .9689, concluding no significant difference between the 3 treatment levels for weight gain. Time proved to be the predominant driver of gastro-intestinal microbial composition and probiotic supplementation did not lead to significant changes to the microbiome community structure. Chao1 and ACE models ran on fecal samples indicate significant impact of probiotic treatment on microbial richness and indicate that supplementation leads to greater diversity and, in turn, may mean a more robust microbiome.
Open Access
Effects of monensin sodium, plant extracts and injectable trace minerals on feedlot performance, fertility and morbidity of beef cattle
(Colorado State University. Libraries, 2015) Fischer, Mariah, author; Ahola, Jason, advisor; Peel, Kraig, advisor; Seidel, George, committee member; Engle, Terry, committee member
Two studies were conducted to evaluate the effects monensin sodium, plant extracts, and injectable trace minerals on heifer and bull fertility, and calf feedlot performance and morbidity. In the first study, Angus heifers (n = 107; 259.3 ± 21.0 d of age), blocked by weaning BW (262.7 ± 29.9 kg; d -19), were randomly assigned to treatments in a 2 x 2 factorial design, where all heifers received the same basal ration consisting of a 30% CP liquid supplement containing 200 mg/0.45 kg monensin sodium. Treatments were applied daily to the basal ration as topdressed supplements and were fed at a rate of 0.32 kg•hd-1•d-1. Treatments were as follows: 1) high level of monensin sodium (MON), where monensin sodium was topdressed at 200 mg•hd-1•d-1, 2) low level of monensin sodium plus the plant extracts cinnamaldehyde, capsicum oleoresin and eugenol (CCE), where plant extracts were topdressed at 11,000 mg•hd-1•d-1, 3) control (CON), low level of monensin sodium without topdressed supplements, or 4) high levels of monensin sodium with plant extracts (COMB), where monensin sodium was topdressed at 200 mg•hd-1•d-1 and plant extracts were topdressed at 11,000 mg•hd-1•d-1. In both studies, heifers were weighed and estrus detection patch status was recorded every 11 d. Age at puberty was determined by patch status and was recorded as the d the patch was first activated. A 14 d CIDR-PG-AI protocol was utilized to inseminate heifers, when heifers were 427.3 ± 21.0 d of age. In the 14 d CIDR-PG-AI, a controlled internal drug release device (CIDR) was inserted 33 d prior to AI and removed 14 d later. Prostaglandin was injected 16 d after CIDR removal, and heifers were inseminated 3 d later. Heifers were placed with bulls for natural service 21 d post AI. Pregnancy was determined 56 d post AI via ultrasound and 178 d post AI via rectal palpation. Calving records were used to validate ultrasound results. In the first study, there were no treatment main effects for initial or final BW (P > 0.05). There were no interactions between the main effects of monensin sodium fed at high concentrations and plant extracts for any feedlot or fertility performance variable (P > 0.05); however, there was a main effect of high levels of monensin sodium for heifer DMI from d 0 to 8 and d 8 to 15, where MON and COMB heifers had reduced DMI compared to CCE and CON heifers (P = 0.05). From d 11 to 22 and d 44 to 66, heifers that received plant extracts (CCE and COMB) had lower ADG than CON and MON heifers (P = 0.05). Feed efficiency tended (P = 0.08) to be improved in heifers fed high levels of monensin sodium (MON and COMB) compared to heifers fed low levels of monensin sodium (CCE and CON); however overall DMI, ADG, age at puberty and pregnancy rate were not affected by the main effects of high levels of monensin sodium or plant extracts (P > 0.05). In the second study, Angus bulls (n = 31, yr 1; n = 35, yr 2), heifers (n = 107) and steers (n = 105) were randomly assigned a treatment at weaning (278.6 ± 35.0 kg; 241.0 ± 19.6 d): 1) control (CON), no injection, or 2) injectable trace minerals (MIN), which included Cu, Zn, Se and Mn. The MIN treatment was administered at weaning (d 0) and again on d 64 (yr 1) and d 110 (yr 2) to bulls, and at weaning (d -19) and on d 135 to heifers. The second injections were 80 (yr 1) or 38 d (yr 2) prior to bull breeding soundness exams and 33 d prior to heifer AI. Steers received only the initial injection at weaning. Injections were administered at 1 mL/45.4 kg of BW at weaning and 1 mL/68.0 kg of BW prior to breeding soundness exams and AI, as per the product label. Bulls in both years exhibited no differences in overall ADG based on treatment (P > 0.05); however, MIN bulls had reduced ADG from d 64 to 113 (P = 0.05) versus CON. Steer and heifer ADG was not different across treatments (P > 0.05). Incidence of morbidity was not different among treatments for any class of cattle (P > 0.05). A licensed veterinarian performed the breeding soundness exams and Computer-Assisted Sperm Analysis was performed to analyze sperm motility, velocity, straightness and linearity objectively. Motility and morphology from breeding soundness exams were not effected by MIN (P > 0.05); however, in yr 2 there was a tendency for sperm from MIN bulls to have a higher percentage of secondary defects (P = 0.08). Sperm beat cross frequency was greater in CON in yr 2 (P < 0.01), and tended to be greater in CON in yr 1 (P = 0.10). Progressive velocity of sperm was greater in CON in yr 2 (P < 0.05). Neither BCS nor age at puberty in heifers was affected by treatment (P > 0.05). These results suggest there is no benefit to newly weaned calf performance or morbidity, or yearling bull or heifer fertility, when supplementing cattle with injectable trace minerals at weaning.
Open Access
Effects of two-stage weaning with nose flaps applied to calves on cow performance, calf performance, carcass quality, calf humoral immune response, and fertility
(Colorado State University. Libraries, 2015) Lippolis, Katy, author; Ahola, Jason, advisor; Engle, Terry, committee member; Callan, Rob, committee member; Swyers, Kelcey, committee member
To view the abstract, please see the full text of the document.
Open Access
Evaluation of different hair characteristics and the impact of liver abscess presence on stress related physical and physiological parameters associated with well-being in beef feedlot steers
(Colorado State University. Libraries, 2019) Baier, Faith Susan, author; Grandin, Temple, advisor; Edwards-Callaway, Lily, advisor; Engle, Terry, committee member; Rollin, Bernard, committee member
Physiological and behavioral parameters are commonly used to assess cattle welfare. The overall objective of these studies was to understand the impact of animal-based characteristics and the presence of a metabolic disease on the overall well-being of beef feedlot steers through the measurement of physical and physiological parameters. The objective of Experiment 1 was to determine the impact of hair color and length, and animal age on hair cortisol concentration in beef feedlot steers. Nineteen beef crossbred steers were used for this study. Seven of the steers (1,043 ± 6.8 kg; approx. 9 years of age) were fitted with ruminal fistulas and duodenal cannulas and classified as old steers. The other twelve steers (680 ± 4.5 kg; approx. 2.5 years of age) were fitted with only ruminal fistulas and classified as young steers. One steer was euthanized due to health problems within the first week of the study. Steers were categorized into one of three groups: old with black hair (OB, n = 3); old with white hair (OW, n = 3); young with black hair (YB, n = 12). Hair samples from the right rump region of each steer were collected throughout a period of six weeks from six different areas. Only samples collected during Week 6 were used for analyses. Older steers exhibited greater hair cortisol concentrations than younger steers (P < 0.001). The white hair of the old steers yielded higher concentrations of hair cortisol as compared to black hair from young steers (OW = 10.89 ± 2.03 pg/mg and YB = 0.98 ± 0.11 pg/mg, respectively; P < 0.001). Hair cortisol concentration was not impacted by duration of growth (P = 0.33). However, cortisol concentrations exhibited a weak, positive correlation with hair length (r = 0.33, P = 0.01). Additionally, the average hair growth per week of beef steers in the winter months was calculated to be 0.90 mm. Further research should be performed to improve our understanding of the effect of hair characteristics on hair cortisol concentrations as related to the well-being of cattle. The objective of Experiment 2 was to evaluate the relationship between liver abscess presence and stress-related parameters in beef feedlot cattle, utilizing both physiological (hair and serum cortisol, ocular temperature) and behavioral measurements (mobility scoring). The ultimate goal of the study was to establish an initial understanding of the welfare state of cattle with liver abscesses so that management practices can be maintained or changed to allow for the production of cattle to be continually practiced in an efficient and sustainable manner. Three hundred and sixty-three beef breed, Bos taurus feedlot cattle were categorized by the liver abscess score assigned during the slaughter process. The liver abscess scoring groups were: no liver abscess presence (NLA; n = 316); mild liver abscess presence (MLA; n = 21) and severe liver abscess presence (SLA; n = 24). Two animals were unable to be assigned liver abscess scores. No relationships were identified between the presence of liver abscesses and the measured parameters – ocular infrared thermography (P = 0.55), hair cortisol (P = 0.96) and serum cortisol (P = 0.21). Furthermore, hair color was not statistically significant when compared across liver abscess scores (P = 0.70). All animals exhibited normal mobility with no visual signs of lameness. The data indicate that under the conditions of this experiment, where adhesions to the body wall were not tabulated, liver abscesses did not impact measured stress-related outcomes. Additional research is necessary to understand the impact of liver abscess presence on other stress-related parameters associated with well-being in cattle. Further research should be performed to increase our understanding of feedlot cattle welfare, in relation to all associated factors – health and disease, environment, and management-related. Both studies also concluded that future research should be focused on establishing benchmark values of hair cortisol concentration for other applications and validations such as hair sampling techniques, metabolite analysis methodology, and potential health indicators.
Open Access
Evaluation of oral n-3 polyunsaturated fatty acid effect on the inflammatory response to a novel experimental model of synovitis in the horse
(Colorado State University. Libraries, 2012) Ross, Trinette Noel, author; McIlwraith, C. Wayne, advisor; Engle, Terry, committee member; Hansen, D. Karen, committee member; Hess, Tanja M., committee member; Kisiday, John D., committee member
To view the abstract, please see the full text of the document.
Open Access
Exploration of bison industry practices and mitochondrial metabolism
(Colorado State University. Libraries, 2024) Velazco, David, author; Nair, Mahesh, advisor; Edwards-Callaway, Lily, advisor; Hess, Ann, committee member; Engle, Terry, committee member
The objectives of this study were to benchmark the United States bison meat industry and to compare the mitochondrial metabolism of beef and bison. The first project evaluated bison industry stakeholder perceptions on management, animal welfare, and meat quality with in-person and online surveys. The stakeholder surveys identified animal handling, bison behavior, employee training, facility design, and transportation duration as the most critical factors that could impact animal welfare in the bison production system. The stakeholders understood that animal welfare is a crucial component of bison production and directly affects meat quality. The second project analyzed multiple live animal factors to benchmark their influence on specific meat quality attributes. Live animal production parameters of bison (n = 2,284; Bulls n = 1,101; Cows n = 199; Heifers n = 984) such as distance traveled, season, number of head bumps in the chute, sex class, and live weight were associated (P < 0.05) with differences in fat thickness, ribeye area, blood splash presence, and instrumental color of bison meat. The third experiment compared the mitochondrial metabolism of bison and beef. The left side masseter muscle of crossbred Angus steers (n = 12) and bison (n = 12) were collected within 60 minutes postmortem. The oxygen consumption rate of permeabilized muscle fibers at specific respiration states was evaluated utilizing the Oroboros O2K high-resolution respirometry system. The abundance of electron transport chain protein in bison and beef muscle was measured using gel electrophoresis. All mitochondrial data were analyzed as mixed models with species as the fixed effect, and day confounded with sex class as the random effect, using JMP Pro 16. No differences were found in oxygen consumption flux (JO2) between bison and beef under baseline, Leak respiration (LEAK; P = 0.8813), rotenone respiration (ROT; P = 0.1071), and carbonyl cyanide m-chlorophenyl hydrazone respiration (CCCP; P = 0.7502) respiration states. Bison permeabilized muscle fibers had a higher (P = 0.0016) JO2 during max OXPHOS (+D) and produced more hydrogen peroxide (P = 0.0234) during this respiration state compared to beef. Respiration control rate (RCR) did not differ (P =0.2928) between beef and bison permeabilized muscle samples. Bison muscle samples contained lower relative abundance of the electron transport chain complexes II (P = 0.0057) and III proteins (P = 0.0020) than beef. Additionally, bison and beef had similar concentrations of citrate synthase in the masseter muscle (P = 0.4650). Results from these experiments can be used as an industry reference to monitor improvements in bison animal welfare and meat quality. Additionally, information regarding mitochondrial metabolism can serve as the foundation for future research to further investigate differences in efficiency between bison and beef.
Open Access
Gene expression analysis before and after the pelvic flexure in the equine hindgut
(Colorado State University. Libraries, 2024) Moss, Cameron D., author; Coleman, Stephen J., advisor; Engle, Terry, committee member; Metcalf, Jessica, committee member; Landolt, Gabriele, committee member
The equine hindgut is the primary site of the horse's nutrient breakdown, absorption, and energy production. More than 60% of the horse's energy comes from hindgut fermentation. In this process, commensal microbes in the hindgut aid in the digestion of plant materials to create volatile fatty acids that can be used by host cells to make energy. Many severe health issues- such as colic, laminitis, or colonic impactions- often occur in the equine hindgut, making it an important site to study to provide better management, treatment, and prevention options for horses suffering from gastrointestinal disease. Although much research exists focusing on the microbiome and overall physiology of the equine hindgut, relatively little addresses the role of gene expression in maintaining a complex yet essential homeostatic balance within the gastrointestinal tract. Previous from our lab found major differences in the microbial content of gastrointestinal compartments of the equine hindgut, separated by the pelvic flexure. The pelvic flexure is a short, narrow, horseshoe-shaped loop in the equine large colon. It defines the ventral and dorsal segments of the colon and is a common site of colonic impaction in horses. Although the pelvic flexure cannot and should not act as a "barrier," something "barrier-like" may be occurring around this region as it pertains to the hindgut microbiome. The mechanism for this action is not defined. As a result, this thesis aims to investigate gene expression in the intestinal epithelial cells of the ventral colon, pelvic flexure, and dorsal colon regions of a healthy hindgut to determine what differences exist. The insight gained from this analysis will provide a baseline for comparison to understand how gene expression patterns in these tissues adapt to changes in the microbiome and external factors like diet. The results of this thesis are the first steps towards a better understanding of homeostasis in the equine hindgut.
Open Access
Genetic selection for feed intake and efficiency in beef cattle
(Colorado State University. Libraries, 2019) Culbertson, Miranda M., author; Speidel, Scott, advisor; Enns, Mark, advisor; Thomas, Milt, committee member; Engle, Terry, committee member; Frasier, Marshall, committee member
To view the abstract, please see the full text of the document.