Browsing by Author "Ahola, Jason K., committee member"
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Item Open Access Benchmark of lamb quality in U.S. retail and foodservice markets(Colorado State University. Libraries, 2015) Hoffman, Travis William, author; Belk, Keith E., advisor; Woerner, Dale R., committee member; Ahola, Jason K., committee member; Pendell, Dustin L., committee member; Holt, Timothy N., committee memberQuality is an accumulation of attributes that satisfy customer preferences and expectations. Lamb quality is a moving target that means different things to the supply chain and sheep/lamb industry stakeholders. The objectives of this research were to determine the rank, definition, relative preference, and willingness to pay (WTP) for seven quality attributes and quantify product attributes of lamb at U.S. retail markets. Structured interviews of retail and foodservice respondents were conducted from May 2014 to March 2015 via face-to-face or telephone with lamb/protein purchaser representatives of retail (n = 60), foodservice (n = 45), and purveyor (n = 15) marketing sectors. Shares of preference (relative percentage of preference) in best/worst evaluation for all interviews indicated that eating satisfaction (38.9%) was the most important attribute. Shares of preference for all seven specified quality attributes were statistically different from each other (P < 0.05). Credence attributes of origin (17.2%) and sheep raising practices (13.6%) ranked second and third overall, respectively. Physical product characteristic traits of product appearance/composition (10.5%) and weight/size (8.5%) were ranked fourth and fifth in shares of preference, respectively. Nutrition/wholesomeness (7.1%) ranked sixth and product convenience/form (4.2%) ranked seventh in the overall ranking across all sectors of retailer, foodservice, and purveyor interview respondents. In WTP analyses, origin (25.8%) and sheep raising practices (20.0%) had the greatest likelihood of being a non-negotiable requirement for lamb purchasers. Eating satisfaction was the trait most likely to receive a premium (71.7%) from buyers, and product assurance of eating satisfaction generated the greatest average WTP premium (18.6%). This research indicated, across all sectors, eating satisfaction, defined as lamb flavor/taste, was the most important quality trait to those who purchase lamb. In-store evaluations of retail lamb labels showed that lamb shoulder and loin chops originating from the U.S. garnered the greatest price premiums compared to either New Zealand or Australian lamb (P < 0.05). Lamb was merchandised to American consumers at specialty type stores at an increased price per kg premium than either locally owned or national grocery chains (P < 0.05). Lamb shoulder prices at retail were merchandised with the greatest premium for product of U.S. origin from a specialty store packaged in modified atmosphere packaging and labeled with local (+ $5.42/kg) and natural (+ $5.40/kg) claims (P < 0.05). Lamb loin prices at retail were merchandised with the greatest premium for product of U.S. origin from a specialty store merchandised in a full service case or modified atmosphere packaged and labeled with a source verified and branded (+ $7.21/kg) label claim (P < 0.05). Shoulder and loin chop prices analyzed via hedonic modeling were not different for store location (East, Central, and West) nor USDA process verified Never-Ever 3 claim (P > 0.05). Additionally, this research indicated that lamb loin and rib chops purchased at U.S. retail markets originating from U.S. lamb were the most muscular. Loin eye area of loin chops from U.S. origin were greater (19.55 cm2) than Australian chops (16.77 cm2), and chops from New Zealand (14.52 cm2) were the least muscular (P < 0.05). Also, Australian lamb (0.64 cm) had a trimness advantage of external fat of loin chops compared to lamb originating from either the U.S (0.84 cm) or New Zealand (0.86 cm; P < 0.05). Lamb producers should strive to place a strategic emphasis on quality attributes identified in this research to ensure eating satisfaction and lamb flavor are optimized for American Lamb, and to produce lamb with product authenticity attributes requested by retail and foodservice sectors, and inevitably American lamb consumers. An important application of the research included the development of an American lamb quality mission to: improve the consistency of quality, cutability, and marketability of American lamb with a consumer driven focus. The final phase of this project was a sheep/lamb industry strategy workshop that identified goals to: 1) Address factors contributing to lamb flavor, their impact on consumer satisfaction, and align flavor characteristics with target markets; 2) Improve lamb management to hit market-ready targets for product size, composition, and eating satisfaction while reducing production costs; and 3) Identify and capitalize on market opportunities for American lamb. A continuous improvement mentality is essential to lamb quality management throughout the supply chain in order to maintain (and increase) market share and demand for American lamb.Item Open Access Dairy cow management and welfare: practices on dairy operations in the United States that may impact dairy cow welfare, lameness, and beef quality assurance(Colorado State University. Libraries, 2015) Adams, Ashley E., author; Román-Muñiz, Ivette N., advisor; Olea-Popelka, Francisco J., committee member; Lombard, Jaosn E., committee member; Ahola, Jason K., committee member; Edwards-Callaway, Lily, committee memberTo view the abstract, please see the full text of the document.Item Open Access Molybdenum exposure in drinking water vs feed affects copper apparent absorption differently in beef cattle consuming a high forage diet(Colorado State University. Libraries, 2020) Thorndyke, Meghan, author; Engle, Terry, advisor; Ahola, Jason K., committee member; Ippolito, Jim, committee memberTwelve Angus steers were utilized to investigate the influence of molybdenum (Mo) in drinking water or feed on apparent absorption and retention of copper (Cu) and Mo. Steers were fed a low-quality grass hay diet for 14 days. Steers were then housed in individual metabolism stalls for 5 days to determine dry matter intake (DMI). Steers were then blocked by body weight and DMI and randomly assigned within block to one of three treatments. Treatments consisted of: 1) control (no supplemental Mo); 2) 5.0 mg Mo/kg DM from sodium molybdate dihydrate (Mo-diet), and 3) 1.5 mg Mo/L from sodium molybdate dihydrate delivered in the drinking water (Mo-water). After the 5 day DMI determination period, total fecal and urine output was collected for 5 days. Dry matter intake, Cu and water intake, and DM digestibility were similar across treatments. As expected, Mo intake was greater (P < 0.05) in Mo-water and Mo-diet steers when compared to controls but similar between Mo-water and Mo-diet steers. Apparent absorption and retention of Cu (% of Cu intake) was greater (P < 0.05) in controls when compared to Mo-diet supplemented steers. Apparent absorption and retention of Cu (% of Cu intake) in steers in the Mo-water treatment did not differ from controls or those receiving the Mo-diet. Molybdenum-diet and Mo-water supplemented steers had similar apparent absorption and retention of Cu. Apparent absorption and retention of Mo (% of Mo intake) was greater in controls when compared to Mo supplemented steers. These data indicate that Mo consumed in water may impact Cu absorption and retention to a lesser extent than Mo supplemented in the diet.Item Open Access Perceptions of the national dairy farmers assuring responsible management (FARM) animal care program(Colorado State University. Libraries, 2018) Rink, Kayla A., author; Román-Muñiz, Ivette N., advisor; Archibeque-Engle, Shannon, committee member; Turk, Phillp, committee member; Ahola, Jason K., committee member; Hadrich, Joleen C., committee memberThe National Dairy Farmers Assuring Responsible Management (FARM) Animal Care program provides guidelines for farms producing 98% of the U.S. milk supply. Producers who sell milk to co-ops or processors participating in FARM must follow animal care standards defined by the program's technical writing group. Objectives of this study were to assess producers' perceptions about knowledge, experience, value, and reasons for considering FARM important, and to determine if perceptions differ based on producer demographics. Quantitative and qualitative data were collected from a 30-question survey instrument. Quantitative questions aimed to address project objectives, and qualitative data were provided through one open-ended survey question that asked participants what they thought the main goal of the FARM program was. Additional feedback was offered by participants through providing text in comment boxes, writing on the back of the survey, or writing a separate letter and returning it with their survey. Quantitative data were analyzed using principal components analysis and qualitative were analyzed through thematic analysis. Themes for the qualitative data were constructed through a set of initial codes which were developed from patterns found in the data. The use of triangulation, debriefing, clarification of researcher positionality, and audit trails were used to enhance trustworthiness of the study. Dairy producers from collaborating dairy co-ops and processors were recruited via electronic and postal mail. A total of 487 respondents from 40 states completed the survey. Of the survey participants, n = 414 (85%) answered the open-ended question, and n = 190 (39%) provided additional qualitative feedback. Thematic analysis revealed five main themes: producers on the defense, distrust of program, return on investment, anger, and nostalgia. Of respondents, 50.0% identified dairy co-ops or processors as the main source of information about FARM, and 73.6% reported being knowledgeable about FARM. More formal education and larger herd size were correlated with greater producer knowledge (P < 0.01 and P = 0.04, respectively). More producer input in the revisions of FARM was identified as a need by 83.3% of respondents. While 89.3% of respondents reported positive experiences with evaluations and relationships with evaluators, 45.6% did not think that FARM has value overall. Females had a neutral impression of the value of the FARM program and males had a negative impression (P = 0.02). Greater respondent age was predictive of greater perceived value of FARM (P < 0.01). Age was significant in determining the reasons for considering FARM important (P < 0.01). Odds that respondents described FARM as important because it improved animal health and wellbeing over describing FARM as not important increased 7.2% (OR = 1.072; 95% OR CI: 1.024, 1.122) with each year of age. As age increased, respondents were more likely to describe FARM as important because it unified the dairy industry on animal welfare over describing FARM as not important (OR = 1.095; 95% OR CI: 1.029, 1.164). Results indicate to increase buy-in and positive perceptions of producers, future versions of FARM should solicit producer input and target specific producer demographics for training and program promotion. The FARM program should address communication deficits, program inequalities, and provide more opportunities for producer input by fostering collaboration with producers to co-produce program standards. Findings from this study can be utilized to inform communication strategies and increase producer buy-in in future versions of the FARM program.Item Open Access Pre-weaning performance in lambs after nutrient specific restriction in gestation and training cognitive skills to improve integration and application of knowledge in animal physiology(Colorado State University. Libraries, 2024) Stucke, Rachael, author; Cadaret, Caitlin N., advisor; Ahola, Jason K., committee member; Winger, Quinton A., committee memberDue to seasonal availability and quality of range forage, extensively managed ewes often experience nutrient restriction during gestation. Neonatal lamb performance after severe experimental nutrient restriction during gestation has been well studied; however, there is a gap in understanding of how practical nutrient restriction experienced over the course of a production cycle impacts lamb success. Therefore, the objective of the first study was to investigate early life performance in lambs from ewes fed a diet from 30-125 days of gestation (dGA) that simulates winter forage or one that meets all nutritional requirements for gestation. Maternal BCS and weight losses were evident prior to the standard supplementation period suggesting impacts on the fetus could be happening due to nutrient restriction earlier in gestation. Lambs from dams who received the lower quality diet did not differ by bodyweight but were not able to thermoregulate as well as lambs whose dams had their requirements met during the first week and on specific weeks thereafter. Beginning at six weeks of life through weaning lambs from restricted dams had lower body weights compared to lambs from fully nourished dams. This data demonstrates that nutrient challenge during gestation, even when re-alimented in late gestation, decreases performance. The lamb data showed that while there are no apparent differences in growth during the first week of life, NR animals start to diverge later in life even when provided high quality nutrition. This coupled with reduced thermoregulatory ability suggests tissue specific differences may underlie animal variation and warrants further investigation. Case-based learning immerses students in real-world scenarios, prompting observation, action, and reflection to enhance cognitive skills. The open-ended nature of such learning can challenge students to reach higher levels of critical thinking, however, we have noticed that without guidance, students often do not know how to approach these types of questions. Therefore, the objective of study 2 was to investigate how two low-input interventions strategies may help train cognitive skills and improve student performance. Three semesters of an undergraduate physiology course employed a case-based assessment strategy. Semester 1 (S1) represented no intervention, Semester 2 (S2) included two dedicated class periods of instructor-led guidance on approaching case studies, and Semester 3 (S3) utilized an online peer evaluation platform, where students evaluated and provided feedback to each other. In S2 and S3 pre-surveys were administered to understand changes in students' perceptions of their own cognitive skills. The average grade on case studies after intervention was the highest in S3 where peer intervention was employed. When comparing changes in perceptions, student confidence in their cognitive skills generally increased in S2 and S3. Interestingly, while peer evaluation improved student performance, free response questions indicated that students did not enjoy peer evaluation and felt that it was not beneficial to their learning. Peer evaluation provides a unique opportunity for students to actively engage in the learning process and to practice cognitive skills. This process holds dual benefit as reviewing peers requires students to reflect, analyze, and evaluate, which are cognitive skills also needed to solve the case studies.Item Open Access Preimplantation genetic diagnosis of equine embryos(Colorado State University. Libraries, 2010) Cullingford, Erika L., author; Seidel, George Jr., advisor; McCue, Patrick, advisor; Ahola, Jason K., committee member; Bouma, Gerrit, committee memberIn horses, determination of certain genetic traits/alleles in embryos before embryo transfer would be advantageous due to the costs of resulting pregnancies. An attractive option is preimplantation genetic diagnosis (PGD), but to date few biopsied equine embryos have resulted in pregnancies. In the current experiment, 37 embryos ranging from 160 - 575 μm in diameter were biopsied. To obtain embryos, donor mares were monitored using transrectal ultrasonography. When a follicle > 35 mm in diameter was observed, 2,500 IU hCG or 1.5 mg deslorelin acetate was administered, and mares were inseminated daily until ovulation was detected. Embryos were recovered nonsurgically on days 6.5 – 7 (day 0 = ovulation). Trophoblast biopsies were collected in a 30 μl droplet of Syngro Holding Medium (Bioniche, Belleville, ON) using a piezo drill and beveled injection pipette. After removal of the embryo, the droplet containing the biopsied cells was moved into an Eppendorf tube and centrifuged. Supernatant was removed leaving ~5 μl sample, which was snap frozen for later genetic testing. Fifteen biopsied embryos were immediately transferred nonsurgically into uteri of synchronized recipients. Day 16 pregnancy rate for embryos ≤ 300 μm was 75.0% (6 of 8; 175 – 240 μm), which was not significantly different from control embryos of the same size (77.3%; 17 of 22). For embryos > 300 μm, day 16 pregnancy rate was 28.6% (2 of 7; 320 and 400 μm), which was not significantly different from control embryos of the same size (62.5%; 10 of 16). Additionally, 22 embryos (150 - 440 μm) were vitrified by standard procedures after biopsying and later warmed and transferred directly. No embryos > 300 μm (n = 3) became pregnancies after vitrification. Day 16 pregnancy rate for ≤ 300 μm was 47.4% (9 of 19; 150 – 225 μm), which was significantly different (p < 0.05) from direct transfer and control embryos of the same size (75.0% and 77.3%, respectively). Three of these pregnancies (150 - 200 μm) resulted in the formation of empty trophoblastic vesicles by 25 d. All pregnancies were terminated on or after 25 d to collect embryos for further genetic testing. For preimplantation genetic testing, a duplex nested polymerase chain reaction (PCR) was developed for amplification of the DNA from the biopsied cells using primers for sex chromosome-linked zinc finger protein genes (ZFx/ZFy; 445 bp), and 2 pairs of primers for equine-specific sex-determining region on the Y-chromosome (SRY; 217 bp, 121 bp). Experiments on XX and XY genomic DNA from white blood cells revealed accurate genetic testing on as little as ~9 pg DNA, which equals ~1 cell. Sex determination on biopsied material occurred for 30% of samples, one of which was confirmed from a placental sample. Low PGD results indicate either lack of sensitivity of the test, or more likely the loss of cells during the steps of transfering the biopsied cells to Eppendorf tubes. We concluded that biopsy collection, preimplantation genetic diagnosis, and direct transfer can be performed on equine embryos without compromising pregnancy rates when performed on embryos ≤ 300 μm. Vitrification lowered pregnancy rates of biopsied embryos (p < 0.05). Continued effort in improving genetic tests and in vitrifying equine embryos, especially those > 300 μm, is warranted.Item Open Access Vitrification of in vitro- and in vivo-produced bovine embryos for direct transfer(Colorado State University. Libraries, 2012) Kruse, Shantille, author; Seidel, George E., Jr., advisor; Ahola, Jason K., committee member; Bruemmer, Jason E., committee memberThe overall objective of my thesis research was to improve procedures for vitrifying bovine blastocysts so as to enable direct embryo transfer to the uterus. Blastocysts were produced using standard in vitro procedures in Experiments 1, 2, and 3. Procedures were done at room temperature, 22 ± 2 °C. Unless otherwise mentioned, all media were made in SynGro®. In Experiment 1, base media contained either 1) normal concentrations of sodium (120 mM) and calcium (2 mM);(CON) or 2) 60 mM sodium + 60 mM choline chloride and 0.5 mM calcium (LOW). Blastocysts were exposed to 5 M ethylene glycol (V1) for 3 min and moved to 6.5 M ethylene glycol + 0.5 M galactose + 18% Ficoll (V2). Straws (0.25 mL) were loaded with a column of 120 μl 1 M galactose followed by an air bubble, then V2 containing embryos followed by an air bubble, and 60 μl 1 M galactose followed by sealing with a plastic plug. After 35 s, embryos were vitrified by either 1) standard cooling in liquid nitrogen cooled air (AIR) for 1 min or 2) cooling via contact of straw walls with columns drilled into an aluminum block immersed in liquid nitrogen (BLK) for 2 min and then directly plunged into liquid nitrogen. These combinations resulted in 4 treatments (AIR x CON; n = 61, AIR x LOW; n = 58, BLK x CON; n = 73, BLK x LOW; n = 54). BLK Embryos were warmed by holding straws in air for 10 s, placing them in a water bath at 37 °C for 20 s, mixing embryos with galactose diluent in the straw for 2 min and expelling. Embryos were recovered, rinsed through holding medium, and cultured in chemically defined medium (similar to synthetic oviduct fluid (SOF)) for 24 h before being evaluated for survival. Post warming survival did not differ (P > 0.10) between treatments (AIR x CON = 42.0%; AIR x LOW = 26.8%; BLK x CON = 21.8%, BLK x LOW = 24.5%). Despite lack of statistical significance, we recommend use of LOW base media because both sodium and calcium levels are reduced. Use of this media should therefore have less chance of sodium and calcium toxicity, and could deter apoptosis. The BLK vitrification method is both easier to use and more consistent. In Experiment 2, we sought to identify the most efficacious cryopreservation method for in vitro-produced bovine blastocysts that would enable direct embryo transfer from 0.25 mL straws used as containers for cryopreservation. Although not a method for direct transfer, Cryotops were chosen to serve as positive controls (CON), as they are the industry standard for vitrification of human embryos. Embryos were cryopreserved by vitrification with a Cryotop (CON; n = 118), using an aluminum block (BLK; n = 128), or by slow freezing (SLF; n = 131). Vitrification procedures were as described above for BLK with the exception that CON embryos were placed in < 1 μl V2 onto Cryotops, and after 35 s, vitrified by plunging directly into liquid nitrogen. Embryos cryopreserved via SLF were exposed to 1.36 M glycerol in modified Dulbecco's PBS + 0.4% BSA (PBS) for 10 min, loaded into 0.25 mL straws, and placed into a freezing machine. Straws were cooled to -6 °C at 4 °C per min, held at -6 °C for 5 min, seeded, held at -6 °C for an additional 10 min, and then cooled to -30 °C at 0.5 °C per min and plunged into liquid nitrogen. After storage for at least 24 h in liquid nitrogen, embryos were warmed/thawed. Embryos cryopreserved via CON were removed from Cryotops by direct placement into a 200 μl drop of 1 M galactose for 2 min, whereas BLK/SLF embryos were warmed/thawed as described above with the exception that glycerol was removed in three 6 min steps from SLF embryos: 0.8 M glycerol + 0.3 M sucrose; 0.4 M glycerol + 0.3 M sucrose; and 0.3 M sucrose followed by PBS for 2 min. After recovery, embryos were rinsed through holding medium and cultured as described above. Post warming survival was greater (P < 0.01) for CON than BLK (85.9% and 70.6%, respectively); BLK was greater (P < 0.01) than SLF (56.1%). Although BLK resulted in lower post-warming survival than CON, it may be an acceptable method for direct transfer, which yielded greater post-warming survival than SLF, the current method used for cryopreservation of bovine embryos. In Experiments 3 and 4, the objective was to compare pregnancy rates of recipients of in vitro-(Exp 3) or in vivo-produced bovine blastocysts (Exp 4) cryopreserved via VIT versus SLF. In vitro-produced embryos were produced by standard procedures. In vivo-produced embryos were recovered 7 d post estrus from crossbred, nonlactating superovulated beef cows. Embryos were cryopreserved via BLK vitrification (VIT; Exp 3, n = 78; Exp 4, n = 46 ) or slow freezing (SLF; Exp 3, n = 78; Exp 4, n = 44). Embryos were cryopreserved and warmed/thawed as described above followed by nonsurgical transfer into non-pregnant cows culled for unknown reasons, but with normal-appearing reproductive tracts. Recipients were d 7 ± 0.5 of the estrous cycle, and each received 2 embryos into the uterine horn ipsilateral to the corpus luteum. Pregnancy diagnosis was performed at d 37 ± 2 via ultrasonography. Survival rate per embryo (normal fetus with heartbeat) did not differ (P > 0.10) between methods (Exp 3, VIT = 14.1%; SLF = 16.7%; 9 of 15 pregnant cows carried twins; Exp 4, VIT = 45.7%; SLF = 38.6%; 17 of the 21 pregnant cows carried twins). Therefore, VIT was similarly efficacious to SLF for cryopreservation of bovine embryos, and simpler, requiring less equipment, time, and expense.