Browsing by Author "Engle, Terry E., committee member"

Now showing 1 - 20 of 23

Open Access
An in vitro system evaluation of the rumen microbiome and rumen fermentation characteristics as a result of differing feed additives
(Colorado State University. Libraries, 2019) Reyes, Arquimides A., author; Delmore, Robert J., advisor; Belk, Keith E., committee member; Engle, Terry E., committee member; Woerner, Dale R., committee member; Holt, Timothy N., committee member
To view the abstract, please see the full text of the document.
Open Access
Complete nutrient analysis of grain finished and grass finished lamb
(Colorado State University. Libraries, 2016) Gifford, Cody Lynn, author; Woerner, Dale R., advisor; Martin, Jennifer N., committee member; Engle, Terry E., committee member; Belk, Keith E., committee member; Harris, Mary A., committee member
Health conscious consumers continue to search for foods that are nutrient dense. Nutrient labeling of foods allows consumers to select foods based on nutrient composition. The objective of this study was to analyze nutrient composition of eleven raw and cooked grain-finished and grass-finished lamb cuts to update nutrient data in the USDA National Nutrient Database for Standard Reference (SR). Packages of foreshanks, whole legs, sirloin chops, whole loins, loin chops, whole frenched ribs, frenched rib chops, whole ribs, rib chops, whole shoulders, shoulder blade chops, shoulder arm chops, stew meat, and ground lamb (IMPS # 210, 234, 1245, 232A, 1232A, 204D, 1204D, 204B, 1204B, 208, 1207B, 1207A, 295 and 296) were collected in original packaging from three U.S. suppliers during all seasons. Packages were shipped to Colorado State University Meat Laboratory for retail cut dissection, cooking, and nutrient analysis. Single composites of separable lean homogenates were formed for each cut for analysis of proximates, fatty acids, vitamins and minerals. Single composited seam and external fat from each cut were analyzed for proximates, fatty acids, vitamins and minerals. Results from this study generated greater fatty acid profiles, resulted in lower fat content, established nutrient composition for grass-finished cuts and provided updated nutrient composition for inclusion into the SR.
Open Access
Consumer preferences for beef flavor
(Colorado State University. Libraries, 2014) Webb, Megan Jean, author; Woerner, Dale R., advisor; Belk, Keith E., advisor; Pendell, Dustin L., committee member; Engle, Terry E., committee member
For consumer satisfaction to occur, beef retailers and producers must continuously provide beef that contributes to desirable beef flavor. The objectives of this research was: 1) determine the consist of preference for beef flavors resulting from various production practices among beef consumers, 2) develop a true ranking of preference via best-worst (B/W) scaling, and 3) identify the proportion of preference for beef product categories resulting from various production practices. Nine consumer panels were conducted in three different geographical locations (eastern, central and western US). Consumer beef flavor preference was determined using B/W scaling, multinomial logit, and random parameter logit models in SAS® MDC. Proximate analysis and consumer ranking of attributes when making beef purchases was analyzed using an ANOVA, then means were separated using least squares means in SAS® and consumer demographic information was analyzed using PROC GLIMMIX. Overall, the four samples with the greatest percentage of lipid, F-1 Wagyu x Angus (20.2%), wet-aged upper two-thirds USDA Choice (15.6%), USDA Prime (14.7%), and dry-aged upper two-thirds USDA Choice (13.7%) resulted in a greater percentage of preference for flavor than product categories with a lower percent lipid, low USDA Choice (12.5%), USDA Select (11.9%), beef derived from domestic grass-fed cattle (6.8%); and beef derived from Uruguayan grass-fed cattle (4.5%). Results suggest the incorporation of Wagyu genetics, breeding cattle for a greater propensity of lipid, and grain finishing market beef cattle should result in a more preferred beef flavor characteristic. Results from demographic preference show females, Millennials (18 - 34 years of age), and respondents with an average or higher household income are more likely to consider beef derived from Uruguayan grass-fed cattle as their least preferred sample. Results from consumers making beef purchasing decisions show marbling level (3.8) and USDA grade of product (4.2) are moderately important and if the product was grass-fed vs. grain-fed (7.5) is the least important beef characteristic. Demographic information shows Baby Boomers (over 50 years of age) prefer beef derived from domestic grass-fed cattle (10.3%) more than both Generation X (6.0%; 35 - 50 years of age) and Millennials (7.1%; P < 0.05). Baby Boomers (18.6%) also prefer dry-aged upper two-thirds USDA Choice more than Millennials (13.6%; P < 0.05).
Open Access
Decreasing nitrogen for volatilization in beef feedlot cattle
(Colorado State University. Libraries, 2012) Kappen, Maria M., author; Archibeque, Shawn L., advisor; Engle, Terry E., committee member; Ham, Jay M., committee member
The effects of ractopamine hydrochloride (RAC) and a steroidal implant (IMP), on whole body N metabolism were evaluated in 24 Hereford x Angus steers (BW 554.4 ± 26.8 kg). The experimental design was a completely randomized block design with a 2 x 2 factorial arrangement of treatments. Factors included: 1) RAC (0.0 or 400 mg×steer-1×d-1) and 2) IMP (0.0 or 200 mg trenbolone acetate and 28 mg of estradiol benzoate). Steers were housed in individual pens and allowed ad libitum access to feed and water throughout the experiment. Steers were acclimated to the metabolism barn by bringing in, tying and currying for 12 d before the initiation of the experiment. Once cattle had been implanted for 48 d and had received RAC for 21 d, a nutrient balance study was conducted for 6 d. An IMP x RAC interaction tended (P < 0.09) to exist for DMI. Implanted steers receiving RAC tended to have lower DMI compared to non-IMP steers receiving RAC as well as IMP steers not receiving RAC. N intake (P > 0.11) and fecal N (P > 0.18) were not different due to treatment, yet numerically reflected the trend noted for DMI. Urinary N excretion was decreased by feeding RAC (P < 0.01). There tended (P < 0.08) to be an IMP x RAC interaction for urinary N excretion. Implanted steers receiving RAC tended to have less urinary N than steers receiving an implant only. Similarly, urine urea N excretion was decreased by RAC treatment (P < 0.02) and excretion tended to be decreased in steers that had also received IMP (IMP x RAC interaction; P < 0.07). Overall N retention was not affected by treatment (P > 0.14). These results indicate that urinary N excretion can be reduced by incorporating RAC according to labeled usage during the final phase of the finishing period. However, more studies will be required to elucidate the potential interactions of RAC with implant status and types of implants.
Open Access
Development of portable recycled vertical flow constructed wetlands for the sustainable treatment of domestic greywater and dairy wastewater
(Colorado State University. Libraries, 2011) Roberts, Bronte Marie, author; Goodridge, Lawrence D., advisor; Engle, Terry E., committee member; Sharvelle, Sybil E., committee member; Wickramasinghe, Sumith Ranil, committee member
To view the abstract, please see the full text of the document.
Open Access
Discovering ground beef performance through "premium grind" concepts
(Colorado State University. Libraries, 2013) McHenry, Jordan Helaine, author; Woerner, Dale R., advisor; Belk, Keith E., committee member; Tatum, J. Daryl, committee member; Engle, Terry E., committee member; Frasier, W. Marshall, committee member
Four independent experiments were conducted to evaluate performance of ground beef from various sources and production techniques. Flavor and texture of 7 different beef products and the effects of dry-aging were evaluated and quantified by descriptive sensory analysis, fatty acid composition, and volatile compound composition. Beef products evaluated included chuck shoulder clods (NAMP 114), chuck boneless short ribs (NAMP 130), whole briskets (NAMP 120), loin tenderloin tips (NAMP 1190C), loin top sirloin caps (NAMP 184D), round sirloin tip knuckles (NAMP 167), and 81/19 chuck sourced trimmings. Fresh (100% un-aged), 100% dry-aged, and 50% fresh/50% dry-aged trimmings were used to evaluate the effects of dry-aging on ground beef performance. Furthermore, the effects of grinder plate size, blend time, and patty-forming technique were evaluated and quantified by descriptive sensory analysis and objective instrument measurement. Additional treatments compared common grocery store practices of grinding bench trimmings versus re-grinding previously ground chubs. Trained panelists evaluated ground beef patties from each treatment for 10 different flavor notes, including beefy/brothy, browned/grilled, buttery/beef fat, bloody/metallic, gamey, earthy/mushroom, nutty/roasted nut, livery, sour/acidic, and bitter, as well as 7 different texture characteristics, including hardness, cohesiveness, tenderness, connective tissue, particle size, moisture content, and beef fat/oily mouthfeel. In addition, samples were analyzed to determine fatty acid composition of raw products and volatile compounds formed during cooking. No single trimming source evaluated in this study outperformed patties comprised of 81/19 chuck sourced trimmings. Notably, briskets and sirloin caps were ranked comparably to 81/19 trimmings in the desirable flavor attributes of beefy/brothy, browned/grilled, and buttery/beef fat, whereas tenderloin tips were rated lowest in the same desirable flavors. Dry-aged beef samples produced the most complex flavor profile with the highest panel ratings for earthy/mushroom and nutty/roasted nut flavors, and had high scores for browned/grilled flavor. Grinder plate size and patty-forming technique affected perceived texture differences. Panelists indicated that ground beef patties produced with smaller sized grind plates were softer, more tender, and had a smaller particle size. In agreement, objective measures of texture showed lower peak loads for patties produced with smaller sized grind plates. Patties made with a Formax (Formax F6, equipped with the 2874-6 plate, Mokena, IL) were softer and more cohesive, while patties made with the vacuum stuffer (Model VF50, Handtmann, Germany) equipped with a portioning device were more crumbly but also ranked higher for moisture content and oily mouthfeel. Ground beef patties resulting from the re-ground chubs were perceived to have a greater amount of connective tissue, a larger particle size, greater moisture content, and a greater beef fat/oily mouthfeel. Additionally, objective measures of texture showed greater peak loads for patties from re-ground chubs.
Open Access
Effect of n-3 polyunsaturated fatty acid supplementation on circulating concentrations and mRNA expression of inflammatory cytokines in horses
(Colorado State University. Libraries, 2010) Schauermann, Nicolette Lee, author; Hess, Tanja, advisor; Han, Hyungchul, advisor; Hussey, Gisela, committee member; Engle, Terry E., committee member
Introduction: Studies in horses have shown an association between increased levels of the inflammatory cytokines and inflammatory conditions. Ingestion of n-3 polyunsaturated fatty acids (PUFA) can produce inflammatory mediators with the potential to down regulate the production of cytokines. Methods: Twenty one mares were blocked by age, body weight and body condition score and randomly assigned to one of three dietary treatment supplements. Treatments consisted of: 1) fish oil supplement and diet (FISH; Magnitude™); 2) flaxseed supplement and diet (FLAX; Nutra-Flax™); and 3) control diet (CON). Horses were supplemented for 12 weeks. Serum and white blood cells were collected on weeks 0, 4, 8 and 12 and assayed for TNFα protein concentrations and IL-1, IL-6, IL-10, and TNFα mRNA expression. Data was log transformed for normalization and analyzed by ANOVA. Significant differences (P<0.05) were compared by least square means analysis. Results: Statistical analysis of mRNA expression was not completed because of failure to produce consistent, reliable results from white blood cell samples. The serum analysis revealed no treatment effects, however FISH treated horses had a trend for lower TNFα than FLAX during week 4 (P=0.1202). Both the FISH and CON groups showed an increase between week 4 and 8 and a decrease between week 8 and 12 (P<0.035). The Flax group only showed a significant change between week 8 and 12 which was similar to the other treatments (P<0.040). Discussion: For more consistent results, a standard amount of whole blood should be used for mRNA expression analysis and include a RNA quality check procedure after RNA isolation. Results indicate that supplementation is not effective in altering TNFα concentrations in adult, healthy mares. The effect of n-3 PUFA may only be evident when inflammatory challenges are present as shown in previous studies of horses prone to laminitis, suffering from arthritis or stimulated with lipopolysaccharides.
Open Access
Evaluating the effectiveness of varying doses of supplemental tryptophan as a calmative in horses
(Colorado State University. Libraries, 2016) Davis, Brittany P., author; Grandin, Temple, advisor; Engle, Terry E., committee member; Ransom, Jason I., committee member; Rojas, Donald C., committee member
Tryptophan (Trp), the amino acid precursor to serotonin, is a common ingredient in many commercial equine calming supplements. However, there is little scientific research to support the efficacy of tryptophan at modifying horse behavior. The objective of this study was to examine how various doses of tryptophan supplementation impacted reactive behavior and physiological stress measurements in the horse. Eleven horses (9 geldings, 2 mares) were given four treatments—0 mg Trp/kg bodyweight (CON), 20 mg Trp/kg bodyweight (LOW), 40 mg Trp/kg bodyweight (MED), and 60 mg Trp/kg bodyweight (HIGH)—in a randomized crossover design. Each treatment lasted three days. On Days 1 and 3 of each treatment, horses underwent a behavior test to measure startle response. Heart rate measurements and the speed at which the horses fled from startling stimuli were recorded. In addition, serum glucose, lactate, and cortisol levels were analyzed both immediately before the startle test and again 15 minutes after the test. Significant sedative effects were seen at LOW Day 1 on heart rate increase during the startle test (P = 0.05) and on change in serum lactate levels (P = 0.03). At MED Day 1, sedative effects were seen on change in serum cortisol levels (P = 0.01). Some excitatory effects were seen at MED Day 3 on the time for heart rate to return to baseline after the startle test (P = 0.03). No significant effects were seen at HIGH Day 1 or Day 3. A subset of blood samples was analyzed for serum free Trp and the ratio of Trp to other large neutral amino acids, which verified treatment effect.
Open Access
Exploring animal welfare through an investigation of veterinary education and on-farm assessments of dairy calf welfare
(Colorado State University. Libraries, 2016) Shivley, Chelsey B., author; Grandin, Temple, advisor; Garry, Franklyn B., committee member; Engle, Terry E., committee member; Rollin, Bernard E., committee member; Kesel, Martha L., committee member
To view the abstract, please see the full text of the document.
Open Access
Identifying preferences for specific beef flavor characteristics
(Colorado State University. Libraries, 2012) O'Quinn, Travis Gene, author; Belk, Keith E., advisor; Tatum, J. Daryl, advisor; Woerner, Dale R., committee member; Engle, Terry E., committee member; Chapman, Phillip L., committee member
Descriptive sensory analysis of beef samples was conducted at culinary institutions in three regions of the United States to determine differences in beef flavor attributes and flavor preferences among 12 different beef product categories (treatments). Treatments were chosen specifically to permit identification and characterization of production-related beef flavor differences, including effects of USDA grade (Prime, Premium Choice, Low Choice, Select), cattle breed-type (Angus, Holstein, American Wagyu), finishing diet (grass-fed, corn-fed, barley-fed), use of growth technologies (non-implanted, implanted, implanted & fed β agonists), and postmortem aging method (wet-aged, dry-aged). Panelists (N = 307) rated ground strip loin samples from each treatment for 13 different flavor notes (beefy/brothy, browned/grilled, buttery/beef fat, nutty/roasted nut, earthy/mushroom, bloody/metallic, grassy, livery, fishy, sour, sweet, and bitter) and overall flavor desirability. Each sensory attribute was rated on a 10-cm, unstructured line scale with 0 cm verbally anchored at very low intensity for all flavors and dislike extremely for flavor desirability and 10 cm verbally anchored at very high intensity for all flavors and like extremely for flavor desirability. In addition, samples were analyzed to determine percentage chemical lipid, moisture, protein, and ash of raw products, fatty acid composition of cooked products, and quantities of volatiles produced during cooking. Of the factors analyzed, USDA Quality grade and finishing diet (grain-fed vs grass-fed) had the largest effects on beef flavor attributes. Differences in cattle-breed type (Angus vs Wagyu), grain source (corn vs barley), aging technique (dry-aged vs wet-aged), and use of growth technology (non-implanted vs implanted vs implanted & fed β agonists) had only minimal effects on flavor. Extending the wet-aging period from 14 to 46 d had a negative effect on flavor, producing samples that scored higher (P < 0.05) for sour flavor than all other treatments. Panelists preferred samples with flavors described as beefy/brothy, browned/grilled, buttery/beef fat, nutty/nutty roasted nut, and sweet, and disliked flavors identified as bloody/metallic, grassy, gamey, livery, fishy, sour, and bitter. Moreover, overall flavor desirability scores were positively correlated (P < 0.05) with the concentration of several monounsatured fatty acids including C12:1, C14:1, C16:1 c9, and C18:1 c9. Stearic acid (C18:0) concentration was negatively correlated (P < 0.05) with overall flavor desirability and positively correlated (P < 0.05) with bloody/metallic, grassy/hay like, gamey, livery, fishy, sour, and bitter flavors. The concentration of several polyunsaturated fatty acids including C18:2t (total), C18:3 n-3, and C22:5 n-3, were found highest (P < 0.05) in Organic grass-fed samples and were negatively correlated (P < 0.05) with overall flavor desirability. Overall flavor desirability was positively correlated (P < 0.05) with diacetyl (2, 3-butanedione), acetoin (3-hydroxy-2-butanone), 3-methyl butanal, and pentanal concentrations. Samples with higher concentrations of dimethyl sulfide were rated lower (P < 0.05) for overall flavor desirability. The concentrations of several volatile compounds were correlated with various beef flavors including beefy/brothy, buttery/beef fat, browned/grilled, earthy/mushroom, nutty/roasted nut, sour, bitter, and sweet.
Open Access
Influence of post-mortem aging time and method on flavor and tenderness of beef, and comparison of retail cutting yields, times, and value in thirteen beef subprimals from beef and Holstein cattle
(Colorado State University. Libraries, 2018) Foraker, Blake Austin, author; Woerner, Dale R., advisor; Belk, Keith E., committee member; Engle, Terry E., committee member; Heuberger, Adam L., committee member
The objective of this study was to identify flavor and tenderness differences in beef aged for different lengths of time and using different methods. Strip loin sections from commodity, USDA Choice beef carcasses (n = 38) were randomly assigned to 1 of 8 aging treatments: 1) 3 d wet-aged; 2) 14 d wet-aged; 3) 28 d wet-aged; 4) 35 d wet-aged; 5) 49 d wet-aged; 6) 63 d wet-aged, 7) 21 d dry-aged; and 8) 14 d wet-aged followed by 21 d dry-aged (combination). Trained sensory panelists rated the cooked product for flavor and textural attributes, and samples were evaluated for Warner-Bratzler and slice shear force, fatty acid composition, amino acid composition, and volatile flavor compounds. Wet-aging of beef up to 35 d caused no changes (P > 0.05) in flavor notes. However, beef wet-aged for 49 d or longer was rated lowest (P < 0.01) for the attribute of beef flavor ID and greatest (P ≤ 0.02) for metallic, sour, oxidized, nutty, musty/earthy, and liver-like. No differences (P > 0.05) were identified between wet-aging, dry-aging, or the combination of both for any flavor attributes. Fatty acid profiles did not differ (P > 0.05) by aging length of time or method. Concentrations of amino acids and volatile flavor compounds increased (P < 0.01) during the wet-aging period, but minimal differences in these compounds were noted between wet- and dry-aged beef. Additionally, beef that was wet-aged for 3 d was toughest (P < 0.01). Nonetheless, tenderness improvement only occurred up to 28 d of wet-aging, where no subsequent differences (P > 0.05) were noted. Results suggested that wet-aging to extreme lengths of time may have a dramatic effect on flavor profile of beef, without necessarily improving tenderness. Additionally, eating quality characteristics do not necessarily differ between wet- and dry-aged beef. Holsteins comprise approximately 20% of the U.S. fed beef slaughter, and the carcass characteristics of Holsteins tend to differ (on average) from those of traditional beef breeds. Retail cutting yields, cutting times, and resulting value were evaluated in thirteen subprimal cuts from carcasses of fed Holstein (n = 398) and beef-breed (n = 404) origin. Generally, subprimals from carcasses of beef-breeds were heavier (P < 0.05) than those derived from Holsteins. Greater (P < 0.01) saleable yields of retail cuts were noted for ribeye rolls, short loins, and inside rounds (individual muscle) from carcasses of Holsteins, and bottom round flats from carcasses of beef-breeds. Saleable yields of all other subprimal cuts did not differ (P > 0.05) between cattle types. Only the amount of time taken to cut center-cut top sirloin butts derived from beef-breeds were faster (P < 0.01) than those for cuts from carcasses of Holsteins; in all other instances, times for cutting subprimals derived from Holstein carcasses were either faster (P < 0.05) or not different (P ≥ 0.05). Retail prices among cuts from differing breed types were minimal, but true differences (P < 0.05) in cutting yields for ribeye rolls and short loins from carcasses of Holsteins may generate greater values to a steak cutter or retailer. Such advantages could be attributed to smaller, more manageable, and leaner cuts produced from carcasses of Holsteins. Therefore, further research regarding retail cutting differences between cattle types may provide insight for operations seeking maximum retail yields and profit.
Open Access
Investigating the impact of husbandry and management practices on the interaction of animal well-being and product quality in beef, swine, and dairy production systems
(Colorado State University. Libraries, 2011) Vogel, Kurt D., author; Grandin, Temple, advisor; Belk, Keith E., committee member; Engle, Terry E., committee member; Rollin, Bernard E., committee member
The impact of husbandry and management practices were investigated in a beef feedlot, a small slaughter facility, and a dairy. In the first experiment, the impact of â-adrenergic agonist supplementation and implant strategy on the physiological, metabolic, and behavioral responses of feedlot steers was evaluated. Due to the ineffectiveness of head-only electrical stunning of pigs in small slaughter establishments, a two-stage stunning method was proposed where head-only stunning for 3 s was immediately followed by application of the same stunning wand to the cardiac region of the animal for 3 s while lying in lateral recumbancy. A paired-comparison study was conducted on 89 pigs in a small slaughter facility to compare the head-only method applied for 6 s to the head/heart method. Head/heart stunning eliminated rhythmic breathing, natural blinking, eye tracking to moving objects, and righting reflex, which were all observed in head-only stunned pigs. Blood lactate was not different (P > 0.05) between stunning methods (head only: 8.8 ± .7 mmol/l, head/heart: 7.8 ± .7 mmol/l). Stun to bleed time did not differ (P > 0.05) (head only: 32 ± 1 s, head/heart: 33 ± 1 s). No heartbeat was observed with the head/heart method. Longissimus thoracis pH, color, and drip loss were not different (P > 0.05) between stunning methods. This study determined that the head/heart electrical stunning method reduced the incidence of signs of return to sensibility without significant effects on meat quality, plant operation speed, or blood lactate concentration. As concern toward the care afforded to animals on U.S. dairy farms increases, benchmark data and means of assessing the welfare status of the dairy industry are necessary to dovetail with existing National Animal Health Monitoring System and National Cattlemens' Beef Association National Non-fed Beef Quality Audits. The 3rd study was developed to explore the framework of a potential study to dovetail with these two programs and identify variables of relevance to such an analysis. A single Northern Colorado Dairy Herd enrolled in the Cooperatives Working Together (CWT) Dairy Herd Retirement program was selected for this pilot study. Overall, data suggested that risk factors for herd health issues exist based on lactation number, days in milk, daily milk production, and previous lactation 305 d milk. Our analysis showed that muscling and finish scores are potentially valuable tools for assessing body condition score in cows post mortem. Body condition score was different between daily production levels (low: 3.08, medium: 2.70, high: 2.51) (P < 0.05). The mean percentage of broken tails in the herd was 44.1% and the occurrence of tail breaks increased as cows became more lame (P < 0.05) and as lactation number increased (P < 0.05). Overall, this study demonstrated the importance of including welfare-relevant variables in assessing on-farm animal welfare that are not strictly restricted to production. The results of these studies indicate the importance of management in maintaining acceptable animal welfare in livestock production and processing facilities.
Embargo
Investigating the ramifications of placental SLC2A3 (GLUT3) glucose transport deficiency in sheep
(Colorado State University. Libraries, 2024) Kennedy, Victoria C., author; Anthony, Russell V., advisor; Winger, Quinton A., committee member; Rozance, Paul J., committee member; Engle, Terry E., committee member
Glucose, the primary energy substrate for fetal oxidative processes and growth, is transferred from maternal to fetal circulation down a concentration gradient by placental facilitative glucose transporters. In sheep, SLC2A1 and SLC2A3 are the primary transporters available in the placental epithelium, with SLC2A3 located on the maternal-facing apical trophoblast membrane and SLC2A1 located on the fetal-facing basolateral trophoblast membrane. We have previously reported that impaired placental SLC2A3 glucose transport resulted in smaller, hypoglycemic fetuses with reduced umbilical artery insulin and glucagon concentrations, in addition to diminished pancreas weights. These findings led us to subject RNA derived from SLC2A3-RNAi (RNA interference) and NTS-RNAi (non-targeting sequence) fetal pancreases to qPCR followed by transcriptomic analysis. We identified a total of 771 differentially expressed genes (DEGs). Upregulated pathways were associated with fat digestion and absorption, particularly fatty acid transport, lipid metabolism, and cholesterol biosynthesis, suggesting a potential switch in energetic substrates due to hypoglycemia. Pathways related to molecular transport and cell signaling in addition to pathways influencing growth and metabolism of the developing pancreas were also impacted. A few genes directly related to gluconeogenesis were also differentially expressed. Our results suggest that fetal hypoglycemia during the first half of gestation impacts fetal pancreas development and function that is not limited to  cell activity. Our results at mid-gestation led us to hypothesize that the placenta could compensate for a deficiency in SLC2A3 during the second half of gestation to maintain or recover fetal growth and development. To investigate this, we repeated the same experimental paradigm by carrying out SLC2A3-RNAi pregnancies and NTS-RNAi controls to near-term. Our objective was to assess fetal growth, uterine nutrient uptake, placental utilization and transfer to the fetus, as well as assess the responsiveness of the fetal pancreas to glucose and arginine challenges in vivo to determine the long-term impact of fetal hypoglycemia during the first-half of gestation. Pregnant ewes underwent surgical catheterization followed by a metabolic study at 133 ± 2 dGA. We observed rescued fetal and pancreatic growth. There was also significantly reduced uterine glucose uptake and placental glucose utilization, along with a tendency for increased uteroplacental amino acid carbon utilization. At baseline, ewes with SLC2A3-RNAi pregnancies had significantly reduced uterine arterial IGF1 concentrations, but no differences in glucagon or insulin concentrations. During the metabolic study, umbilical artery insulin concentrations were significantly greater in the SLC2A3-RNAi pregnancies during early GSIS, tended to be greater during late GSIS, and were significantly greater again during ASIS. These data demonstrate that the global effect on pancreatic growth and development observed at 75dGA continued into late gestation as altered pancreatic glucose and arginine sensitivity, despite rescued fetal growth. Placental compensatory mechanisms appeared to also rescue fetal growth and umbilical glucose concentrations. The decrease in uteroplacental glucose utilization while increasing amino acid utilization appears to be one major compensatory mechanism aiding in recovering glucose transfer to the fetus. In conclusion, microvillous glucose uptake to the placenta appears to be rate-limiting to fetal growth and development early in gestation, but when SLC2A3-RNAi is carried out to near-term, despite rescued fetal growth, the physiology of the entire maternal-placental-fetal unit is still impacted.
Open Access
Maternal behavior before and after parturition of Red Angus beef cows and the investigation of wolf predation on livestock populations in the northern Rocky Mountains
(Colorado State University. Libraries, 2013) Flörcke, Cornelia, author; Grandin, Temple, advisor; Engle, Terry E., committee member; Seger, Carol A., committee member; Rollin, Bernard E., committee member
To view the abstract, please see the full text of the document.
Open Access
Nutrient analysis of ten raw U.S. beef variety meat items and beef flavor myology
(Colorado State University. Libraries, 2018) Kesterson, Hannah Faith, author; Woerner, Dale R., advisor; Belk, Keith E., committee member; Engle, Terry E., committee member; Bellows, Laura L., committee member
Many factors play a role in decision-making related to food and diet; these are closely linked to preferences and personal values in populations with access to a safe and affordable food supply. Many consumers value both nutrition and flavor preferences when making individual choices that ultimately comprise their overall diet pattern. Therefore, it is critical to maintain current, valid information regarding both the sensory profile and nutrient content of foods in the marketplace. Two studies were performed on edible portions of beef carcasses; the first evaluated nutritional value of beef variety meat items in order to update the United States Department of Agriculture (USDA) Food Composition Database. Nutrition information in databases maintained by the USDA is used as groundwork by various groups for several purposes, including nutrition monitoring activities, research, policy creation, and nutritional labeling. However, up-to-date nutrition information is not available for beef variety meat items. Therefore, the objective of this study was to expand availability of nutrient data for beef variety meat items. Beef heart, liver, kidney, tongue, honeycomb tripe, oxtail, marrow bones, testicles, blood, and bone broth were obtained from facilities in the United States. Standardized procedures were used to dissect and homogenize samples. Nutrient analysis occurred at USDA-Agricultural Research Service (ARS) approved laboratories using validated methods and standards. Each of the variety meat items in this study qualifies for at least one "Good Source" or "Excellent Source" labeling claim as defined by the USDA based on the proportion of separable lean component. "Good source" indicates that a product contains 10-19% of the Daily Value (DV) or Recommended Daily Intake (RDI) per Reference Amount Customarily Consumed (RACC) for that nutrient, while "Excellent Source" designates that the food contains at least 20% of the DV or RDI per RACC for that nutrient. Additionally, Vitamin K2 has been studied recently to ascertain beneficial effects on human health, and this nutrient was present in all samples analyzed. This study provides current, analytically-derived nutrient information for U.S. beef variety meat items. Results reflect that these variety meat items could be beneficial in providing essential vitamins and minerals as a component of a healthy diet. This data will be valuable for use by the meat industry, those selling variety meats, researchers, dietetic professionals, and consumers. The objective of the second experiment was to evaluate effects of quality grade, final internal temperature, and cooking method on sensory profile of five beef muscles: rectus femoris, gluteus medius, infraspinatus, triceps brachii, and teres major, in order to characterize sensory characteristics of these cuts. Two quality grades (USDA Select, Upper 2/3 Choice/Top Choice), three cooking methods (grill, pan grill, oven roast), and three final internal temperatures (58.3°C, 70°C, and 80°C) were included; each of 102 unique treatment combinations were replicated six times. Vacuum packaged beef was purchased directly from a commercial beef harvest facility, fabricated 14 days post-production, and frozen at -20°C until analysis. Each sample was rated by a trained sensory panel for flavor, tenderness, and juiciness factors. Although muscles were not compared directly, muscle differences did exist relative to treatment effects. Degree of doneness had the greatest impact across all muscles evaluated, with higher final temperatures related to greater (P < 0.05) beef ID, browned, and roasted notes in most muscles and decreased (P < 0.05) tenderness. Additionally, panelists rated samples as having greater amounts of bloody/serumy, metallic, and sour flavors (P < 0.05) when cooked to lower end-point temperatures. Cooking method affected flavor note ratings for all muscles, with oven roasting producing increased (P < 0.05) cardboardy, earthy/musty, and sour flavors, whereas pan grilling resulted in more intense bitter and burnt flavors (P < 0.05). Quality grade had a minimal impact on the muscles included in the study. Association of volatile aromatic compounds with specific treatments also varied based on muscle. Overall, the 80°C and pan grilling treatments were related to the most volatile compounds compared to other treatments; primarily pyrazines, alkanes, and alkenes. These results highlighted the importance of understanding the properties of individual cuts in order to best utilize them for a positive eating experience. In combination with previous research, these data will be used to develop a resource that characterizes sensory characteristics of lesser-utilized beef cuts to benefit the meat industry, foodservice operations, in-home cooks, and ultimately beef consumers.
Open Access
Nutrient analysis of the beef alternative merchandising cuts
(Colorado State University. Libraries, 2011) Desimone, Tonina Leslie, author; Belk, Keith Evan, 1961-, advisor; Engle, Terry E., committee member; Woerner, Dale R., committee member; Kendall, Patricia A. (Patricia Ann), 1947-, committee member
Six carcasses were selected from each of four different beef packing plants. Carcasses were a combination of USDA Yield Grade 2 (n = 12) and USDA Yield Grade 3 (n = 12), US Quality Grade Premium Choice (n = 8), Low Choice (n = 8), and Select (n = 8), and two genders (steer n = 16, heifer n = 8). The four beef packing plants were located in the Midwestern part of the United States: two in Colorado, one in Kansas, and one in Nebraska. Beef Ribeye, Beef Loin, Strip Loin, and Beef Loin, Top Sirloin Butt subprimals were collected from both sides of these carcasses. Subprimals were vacuum packaged and aged for 14 to 21 days at 0 to 4°C. Subprimals were fabricated into the Beef Alternative Merchandising (BAM) cuts, as described by the Beef Innovations Group of the National Cattlemen's Beef Association (NCBA), at Colorado State University Meat Laboratory. Cuts from both sides of the carcass were randomly designated for use in obtaining cooked and raw nutrient data. All cuts were vacuum packaged and stored at -18°C for subsequent cooking and/or dissection. Raw cuts were thawed at 0 to 4°C for 24 to 48 h and then dissected into separable lean, separable fat, and refuse (connective tissue). Cuts to be cooked were thawed for 24 to 48 h at 0 to 4°C, roasted or grilled, tempered for 24 to 48 h at 0 to 4°C, then dissected into separable lean, separable fat, and refuse. Following dissection, both raw and cooked samples were homogenized and then stored at -80°C for subsequent nutrient analysis. The BAM cuts were analyzed for moisture, crude protein, percent lipid, and ash. Of the muscles that comprise the BAM cuts, the Spinalis dorsi contained the highest percent fat and lowest percent moisture. As fat content increased, moisture content subsequently decreased. The muscles from the Top Sirloin Butt were the leanest of the muscles comprising the BAM cuts. Fatty acid composition and cholesterol content was determined using gas liquid chromatography. Of the fatty acids identified, saturated-, monounsaturated-, and polyunsaturated fatty acids represented 44.92, 46.04, and 3.04%, respectively. The Gluteus medius contained the highest percentage of polyunsaturated fats regardless of Quality Grade. Of the fatty acids detected, oleic, palmitic, and stearic acids represented 74.56% of the fatty acid profile of all BAM cuts. Trans fats totaled 6.4% of the fatty acids identified for all the BAM cuts. This study identified seven cuts from three Quality Grades that qualify for USDA Lean and one cut from two Quality Grades that qualify for USDA Extra Lean.
Open Access
Nutrient composition and sensory attributes of beef from grain-finished steers and heifers
(Colorado State University. Libraries, 2013) Acheson, Rebecca Jean, author; Woerner, Dale R., advisor; Tatum, J. Daryl, committee member; Engle, Terry E., committee member; Belk, Keith E., committee member; Bunning, Marisa L., committee member
Over the past decade, nutrient composition of beef became an increasingly important topic both domestically and internationally for the beef industry and its consumers. Beef is an important source of protein, monounsaturated fatty acids, conjugated linoleic acid, vitamins and minerals. Due to evolutionary changes in production practices and fabrication techniques the current nutrient data in the USDA National Nutrient Database for Standard Reference has become outdated. The objectives of these studies were to determine the nutrient composition of ten beef loin and round retail cuts to update the USDA National Nutrient Database for Standard Reference (SR). Seventy-two carcasses representing a national consist of yield grade, quality grade, and genetic type were identified from six regions across the U.S. Beef short loins, strip loins, tenderloins, inside rounds, and eye of rounds (IMPS # 173, 175, 190A, 169A, and 171C) were collected from the selected carcasses and shipped to three university meat laboratories for storage, retail fabrication, and raw/cooked analysis of nutrients. Sample homogenates from each animal were analyzed for proximate composition, as well as fatty acid, cholesterol, vitamin, and mineral content. Data from this study were intended to update SR information regarding the nutrient status of beef and to determine the influence Quality Grade, Yield Grade, and sex classification have on proximate composition. This study identified four Upper Choice, seven Low Choice, and eight Select cuts that qualify for the lean nutrient claim based on cooked separable lean values. Results from the cooked beef loin samples indicate that beef is a good source of iron, vitamin B2, and phosphorus, and an excellent source of selenium, zinc, and vitamins B3, B6, and B12. The nutrient data provided will be utilized to help update nutritional labels of beef products and to help design future dietary interventions that include beef as a protein source.
Open Access
Replacing dietary carbohydrate with calcium salts of fatty acids and the effects to finishing lamb feedlot performance and carcass characteristics
(Colorado State University. Libraries, 2010) Seabrook, Jill L., author; Peel, R. Kraig, advisor; Callan, Robert J., committee member; Engle, Terry E., committee member
The objective of this study was to investigate the performance and physiological effects imposed on finishing lamb (n = 60, BW x= 41.6 ± 1.4 kg) feedlot performance and carcass characteristics by replacing dietary carbohydrate with calcium salts of fatty acids (CSF A). Upon arrival, lambs were weighed on 2 consecutive d and randomly assigned to 1 of 4 dietary concentrations of CSF A. Treatments included 1) 0% CSF A (Control); 2) 4% CFSA; 3) 7% CSFA and 4) 11% CSFA on a DM basis. Diets were formulated to be isoenergetic (TDN basis) and isonitrogenous (DIP and UIP) and consisted of 75% concentrate, and 25% roughage ( com silage). Ration TDN was kept similar between treatments; rations with less com had a higher concentration of CSF A-pellet. Intake was controlled to balance TDN per kilogram of BW across treatments; all treatments met 2006 NRC requirements for growing lambs [18]. Lambs were weighed and bled every 14 ± 2 d. Blood samples were analyzed for glucose, lactate and insulin concentrations. On d 61, lambs were transported and slaughtered at a commercial abattoir. Hot carcass weight (HCW) was determined at the time of slaughter, and longissimus muscle (LM), liver and subcutaneous adipose tissue samples were collected at slaughter and snap-frozen for later analysis of FA composition. Longissimus muscle area (LMA) and back fat (BF) carcass measurements were determined after 48 h storage at 0°C chill. There was a treatment by time interaction for overall ADG (P = 0.01). Lambs receiving 11 % CSFA had lower ADG, lighter HCW (P < 0.001) and smaller LMA (P < 0.01) than all other treatments. Control lambs had greater (P < 0.05) BF than lambs receiving 11 % CSF A, but had similar BF to lambs receiving 4 and 7% CSF A. There was no treatment effect on dressing percentage. There was a treatment by time interaction observed for blood glucose (P = 0.02); lambs fed the control diet had a tendency to have higher blood glucose concentrations. Blood insulin values were not different (P = 0.36) between treatments, and insulin to glucose ratios were similar among treatments. Overall blood lactate levels had a tendency to be lower as dietary CSF A concentration increased, although not significantly (P = 0.11). Fatty acid profiles for LM, liver and subcutaneous adipose were similar across treatments. Overall, the data suggest that CSF A can be used to replace a carbohydrate source such as com; at rates up to 7% DMI before performance is negatively affected.
Open Access
Special-fed veal: separable components, proximate composition, and nutrient analysis of selected raw and cooked, wholesale and retail cuts
(Colorado State University. Libraries, 2014) Perham, Carlie Claire, author; Woerner, Dale R., advisor; Belk, Keith E., advisor; Engle, Terry E., committee member; Delmore, Robert J., committee member; Foster, Michelle T., committee member
Nutritional qualities of consumer foods are of great importance in improving health. The American obesity epidemic and resulting government recommendations for the decrease in the consumption of foods with high fat and sodium content resulted in an increase in consumer awareness of nutrition. In 2010, the Food Safety Inspection Service published the final rule "Nutrition Labeling of Single-Ingredient Products and Ground or Chopped Meat and Poultry Products" (75 FR 82148) requiring nutrient facts for individual retail cuts be labeled, effective January 1, 2012, under revisions to the Code of Federal Regulations (CFR) for "Nutrition labeling of meat and meat food products" (9 CFR 317.300). Veal products are included in the section regarding the "Identification of major cuts of meat products", which specifies cuts required to have a nutrition label, including veal (9 CFR 317.344). In order to supply veal producers and retailers with nutritional label information, and therefore provide consumers with accurate nutritional information, it is necessary to analyze modern and prevalent veal retail cuts for nutrient content. Ten raw and cooked special-fed veal cuts from six different suppliers of United States-sourced veal were analyzed for nutrient contents. Veal has improved in many aspects of nutrient composition compared to values used in the current United States Department of Agriculture (USDA)-Agriculture Research Service (ARS) Nutrient Database Standard Reference 26 (SR-26). According to USDA federal regulations (9 CFR 317.362), leg cutlets, loin chops, and shank cross-cuts (osso buco) can be labeled under the USDA classification of "Extra Lean" with less than 5g total fat, 2.5g or less of saturated fat, and less than 95mg of cholesterol. Additionally, shoulder blade chops were considered "Lean", having less than 10g fat, less than 5 g of saturated fat, and less than 95 mg of cholesterol per 100 g. The American Heart Association "Heart Check" requirements are met by leg cutlets, loin chops, and shank cross-cuts. Compared to SR-26 data, cholesterol levels declined by 30%. Veal provides an "excellent" source of: Vitamins B2, B3, B6, B12; selenium, zinc, phosphorus, and copper. Additionally, veal is a "good" source of Vitamin D, iron, and potassium. These results provide nutrition facts for consumers to use in conjunction with common cookery methods like grilling- which currently is not an option for veal when searching for foods on the current SR. Additionally, values for choline and Vitamin D are now available for veal. Vitamin D levels in veal from these data showed that raw and cooked ground veal fulfill the requirements to be labeled as a "good source" of this anti-carcinogenic nutrient, containing more Vitamin D than fortified milk and having close to the same levels of eggs and fish. Veal is a lean, complete protein choice for consumers, providing "excellent" and "good" amounts of protein, vitamins, and minerals.
Open Access
The effect of crude protein withdrawal and the use of β-agonists on feedlot performance, carcass merit, and theoretical nitrogen retention and excretion for heavy yearling steers
(Colorado State University. Libraries, 2011) Peterson, Ryan Kenneth, author; Wagner, John Joseph, 1958-, advisor; Engle, Terry E., committee member; Callan, Robert J., committee member
Eight hundred and sixty-four crossbred yearling steers were used in a 3 x 4 factorial experiment to study the effects of β - agonist (BA) administration and crude protein (CP) withdrawal during the last 28 d on feed. Three BA treatments were evaluated: no BA, 200 mg Optaflexx (OPT) per head daily for 28 d, and 75 mg Zilmax (ZIL; 7.56 g/ton DM basis) per head daily for 20 d. The 4 CP withdrawal treatments included: 1) 13.5% CP, 3.5% crude protein equivalent (CPE) from non-protein nitrogen (NPN) from d 0 through slaughter (13.5/3.5); 2) 13.5/3.5 until 28 d remained on feed followed by 12.5% CP, 3.5% CPE from NPN (12.5/3.5); 3) 13.5/3.5 until 28 d remained on feed followed by 12.5% CP, 2.5% CPE from NPN (12.5/2.5); and 4) 13.5/3.5 until 28 d remained on feed followed by 11.5% CP, 1.5% CPE from NPN (11.5/1.5). There were no interactions (P > 0.32) between BA and CP withdrawal treatment; therefore, only main effects are discussed. Average slaughter weights and ADG were greater (P < 0.01) for steers treated with BA as compared with control steers. There were no differences between the slaughter weights and ADG for the OPT versus the ZIL steers. Beta-agonist treatment had no effect on daily dry matter intake. Feed-to-gain ratio was improved by 25% for steers fed BA during the final 28 d as compared with controls. More than a 35% improvement (P < 0.001) in gain-to-feed ratio (G:F) for the final 28 d was observed for steers fed BA as compared with controls. Differences between OPT and ZIL were not significant. Net energy recovery was increased 19% during the final 28 d on feed for steers fed BA as compared with controls. Least squares means for HCW, adjusted for live weight at treatment initiation, was 9.21 kg heavier (P < 0.01) for ZIL steers as compared with controls. The advantage (P < 0.05) in HCW for ZIL as compared with OPT was 5.81 kg. Although not statistically significant, the numerical advantage in HCW for OPT as compared with controls was 3.4 kg. Dressing percentage was increased for steers fed ZIL versus control (64.4 versus 63.4%, P < 0.001) and OPT (P < 0.01) but not increased for OPT versus control (63.2 versus 63.4%; P = 0.67). No BA treatment differences were observed for fat depth measured at the 12th rib. Ribeye area for control carcasses (avg = 32.87 cm2) was lower (P < 0.06) than OPT (avg = 33.53 cm2) which was in turn lower (P < 0.01) than ZIL (avg = 34.59 cm2). Kidney, pelvic, and heart fat was lower for ZIL as compared with control (P < 0.05) or OPT (P < 0.10). Yield grades calculated from carcass measurements were similar for OPT and ZIL (3.01 versus 2.97), and both were reduced (P < 0.05) as compared with control (avg = 3.12). Carcasses from OPT and ZIL treatments were more likely (P < 0.05) to qualify for the USDA Yield Grade 1 and 2 categories and less likely (P < 0.05) to qualify for the USDA Yield Grade 3 category as compared with control. There were no differences in the distribution of USDA Yield Grade 4 and 5 carcasses among control, OPT, and ZIL treatments. Marbling score was similar for OPT and ZIL carcasses averaging Small11 and Small09, respectively. Marbling score for the control carcasses was significantly higher (P < 0.01) than for BA treatment and averaged a Small32. The likelihood of an individual carcass within a pen of grading low Choice and above was reduced (P < 0.01) for the OPT (avg = 53.9%) and ZIL (avg = 49.7%) treatments as compared with controls (avg = 61.8%). Slaughter weight, ADG during the final 28 d, and ADG d 1 through slaughter was lower for the 12.5/3.5 treatments as compared with the 12.5/2.5 (P < 0.05) and 11.5/1.5 (P < 0.10) treatments. Crude protein withdrawal treatment had no effect on HCW and all other carcass variables evaluated. Lower slaughter weight by the 12.5/3.5 treatment and the effect of this reduced weight on ADG were likely a function of reduced gut fill due to a reduction in DMI by steers fed the 12.5/3.5 diets during the final 28 d on feed as compared with the 13.5/3.5 (P < 0.05), 12.5/2.5 (P < 0.0.01), and 11.5/1.5 (P < 0.10) treatments. Nitrogen retention was 5.54, 5.43, 6.97, and 6.90% of N intake for the 13.5/3.5, 12.5/3.5, 12.5/2.5, and 11.5/1.5 CP treatments, respectively. Nitrogen excretion was 5,282; 4,654; 4,875; and 4,391 g/hd for the 13.5/3.5, 12.5/3.5, 12.5/2.5, and 11.5/1.5 CP treatments, respectively. Nitrogen excretion was greatest (P < 0.001) for the 13.5/3.5 CP treatment as compared with the remaining treatments. Differences between the 12.5/3.5 versus 12.5/2.5 (P < 0.05) and between the 12.5/2.5 versus 11.5/1.5 (P < 0.0001) treatments were also significant. Using the 12.5/2.5 or 11.5/1.5 CP treatment diets as compared with the 13.5/3.5 CP diet did not reduce feedlot performance, HCW, or USDA Quality and Yield Grade during the final 28 d. Considering the source and cost of non-protein nitrogen, significant savings could be obtained from using the 12.5/2.5 diet or the 11.5/1.5 diet as compared with using the 13.5/3.5 diet during the last 28d on feed.