Browsing by Author "Nair, Mahesh, committee member"
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Item Open Access Benchmarking and analysis of current pre-slaughter management factors and their influence on welfare and meat quality outcomes in fed beef cattle(Colorado State University. Libraries, 2023) Davis, Melissa, author; Edwards-Callaway, Lily, advisor; Nair, Mahesh, committee member; Hess, Ann, committee member; Mooney, Daniel, committee memberSeveral factors related to pre-slaughter management of fed beef cattle and their impacts on welfare and meat quality have been identified and discussed thoroughly in previous literature. However, a full catalog of these factors and indicators used to evaluate their impacts on cattle welfare is missing. Additionally, benchmarked data for these factors and welfare and meat quality outcomes, and an analysis of their relationships on a large scale is underrepresented in current literature. The objectives of the first chapter of this dissertation were to catalog pre-slaughter management factors, identify indicators used to evaluate their impacts, and ultimately gain a further understanding of the relationships between pre-slaughter management factors and cattle welfare. This review included an in-depth analysis of 69 studies from across the globe that identified factors related to transportation and handling using behavioral and physiological indicators to measure welfare that were the most researched throughout the studies. The discussion of this review also identified pre-slaughter factors that require benchmarking and/or more research on their potential impacts on cattle welfare. Thus, the objectives of the second chapter in this dissertation was to benchmark pre-slaughter management factors at a collection of commercial fed cattle processing facilities. This data collection took place at five commercial processing facilities in the West, Midwest, and Southwest regions of the United States from March 2021 to July 2022. Data were collected on a total of n = 637 slaughter lots representing n = 87,220 head of cattle. Transportation factors such as distance travelled and the time cattle waited on the truck to unload after arriving at the facility, space allowance in lairage for cattle, lairage duration and cattle mobility was recorded. Environmental factors were later recorded from an online weather service, and cattle characteristics and several meat quality factors including bruising, quality grading, carcass weight and dark cutting were obtained from plant records. Descriptive statistics were calculated for both the lot and individual animal level depending on the variable. Cattle travelled on average, 155.8 ± 209.6 km (Mean ± SD) to the processing facility from the feedlot, waited 30.3 ± 39.7 minutes to unload at the plant and were held in lairage for 200.7 ± 195.0 minutes. The mean lairage density was 3.1 ± 2.0 m2/animal, and a majority of cattle (91.8%, n = 77,645) were scored as having normal mobility. Carcass bruising prevalence was 69.7% (n = 57,099), and of those that were bruised, 65.2% (n = 39,856) had multiple bruises. Having this baseline benchmarking data outlines not only areas that need further improvement, but also areas in this sector that the industry has already improved upon. This benchmarking data also identified the need for additional analysis on the relationships between these factors and outcomes. Therefore, the objective in the final chapter of this dissertation was to assess the effects of these factors on select welfare and meat quality outcomes in fed beef cattle. Using the same data set and methods as in the second chapter, any slaughter lots with no response variables or < 75% of predictor variables present were excluded. A total of n = 619 slaughter lots representing 84,508 head of cattle were used for further analysis. Descriptive statistics for this subset of data and linear and logistic regression models were performed to assess relationships. Statistical significance was determined at P < 0.05. Predictor variables of interest included plant, breed, sex class, operation shift at the plant, distance travelled, truck waiting time to unload, lairage duration and space allowance, THI, and wind speed. Outcome variables of interest included mobility, bruising, dark cutting, quality grades, and hot carcass weights. All outcomes of interest were associated with several pre-slaughter factors of interest, particularly plant and cattle breed. Increased odds of impaired mobility were associated with increased distance travelled (1.001, 1.000 – 1.001; OR, CI) and truck waiting time (1.003, 1.001 – 1.004; OR, CI). Increased odds of carcass bruising were associated with decreases in distance travelled (0.997, 0.996 – 0.998; OR, CI), but increases in space allowance in lairage (1.035; 1.017 – 1.053; OR, CI). Cattle that experienced increases in lairage duration were associated with decreased hot carcass weights (P < 0.0367) and increased odds of cark cutting (1.034, 1.001 – 1.068; OR, CI). Additionally, cattle that were slaughtered during the first shift of operation at the plant were associated with decreased odds of being bruised (0.806, 0.772 – 0.842; OR, CI), being classified as a dark cutter (0.416, 0.336 - 0.514; OR, CI), and having a poorer quality grade (0.777, 0.657 - 0.920; OR, CI). Results from these studies identify areas where further and more detailed research is needed to fill knowledge gaps and fully understand these relationships. This research also has the potential to aid in informed decision-making regarding cattle management during the pre-slaughter period and further educate the industry on sustainable management practices.Item Open Access Edible mealworms: can fermentation improve consumer acceptability and nutritional value?(Colorado State University. Libraries, 2023) Wilson, John W., author; Weir, Tiffany, advisor; Bunning, Marisa, committee member; Stull, Valerie, committee member; Nair, Mahesh, committee memberAs the global population increases, the demand for animal-based protein is also on the rise. To meet this demand, it is important to identify sustainable sources of animal protein that have a smaller environmental impact than conventional animal protein production. One potential solution to this challenge is the development of consumer-acceptable insect-based protein products utilizing the larva and pupae of Tenebrio molitor, a type of darkling beetle whose larval and pupal states are edible. These beetles can be reared in small spaces, do not require direct sources of fresh water, and convert feed into protein more efficiently than conventional meat production. In addition, their waste (frass) is dry, making it easier to contain than waste from conventional animal rearing operations, reducing the risk of contaminating the surrounding environment. In addition, the larvae and pupae can be eaten in their entirety, eliminating potential waste streams of byproducts associated with conventional meat processing. With less space, less water usage, more efficient feed conversion ratios, and nearly zero waste, the development of an edible mealworm industry in the global West would help relieve some of the pressures on the current animal protein systems and improve global food security. To accomplish this, it is necessary to generate a consistent demand in the global West for insect protein. Currently, in the United States, edible insects are largely relegated to ground powders designed to "hide" the insects or are placed in novelty products like chocolates and lollipops to confront people's notion of disgust. To introduce mealworm protein into the mainstream, it must be in a form that is accessible to the average American consumer, be safe to eat, and have comparable nutritional attributes as other protein-based products on the market. Tempeh fermentation techniques may be an appropriate approach to accomplish these goals. Tempeh fermentation uses Rhizopus oligosporus mycelium to knit together legumes into a solid cohesive substrate. The product can then be utilized in a variety of ways that are familiar to American consumers including stir frys, burgers, nuggets, and crumbles. This project seeks to utilize tempeh fermentation techniques to develop an insect-based product that is both consumer-friendly but also capitalizes on the known and emerging nutritional and environmental benefits of edible insects. In Chapter 1, I examine the safety of tempeh produced with various life stages of the Tenebrio molitor beetle. Samples were assessed for water activity (aw), and pH to determine the shelf stability of the products. Pathogenic risk was assessed through testing for coliforms, Salmonella and Listeria, and samples were analyzed for heavy meatal content via utilized Inductively Coupled Plasma and Mass Spectrometry (ICP-MS). This exploration allows us to determine best storing and cooking methods and helps identify critical control points in production to help minimize the risk to the consumer. In this chapter, I was able to demonstrate that tempeh made with Tenebrio molitor was just as safe as conventional soy-based tempeh and requires similar storage and cooking precautions to minimize the risks of consumption. In Chapter 2 we conducted a nutritional analysis of the insect-based tempeh products in comparison to traditional soy-based tempeh. We utilized ICP-MS to quantify the presence of micronutrients within each example. Samples were also analyzed for vitamins, macronutrients, and amino acid profile. We then calculated the protein digestibility using the Protein Digestibility-Corrected Amino Acid Score (PDCAAS). Comparison of results with traditional soy-tempeh products helps us to determine if the products provide comparable nutrition to products already on the market. It also helps to determine if the novel products will fill the nutritional space of more conventional sources of protein. This chapter found that the tempeh products made with the Tenebrio molitor had nutritional attributes comparable to conventional soy tempeh. Chapter 3 examines the bioavailability of iron within the sample set and compare the results to conventional bee samples, current on-the-market plant-based meat alternatives, and traditional soy-based tempeh. ICP-MS was utilized to quantify the amounts of iron present in each chemically digested sample. Then, digestates were added to Caco-2 human colonic cells to allow absorption of available iron. Iron absorption rates were then determined by using a human ferritin Eliza kit. This assessment helps us determine if the presence of insect protein improves the bioavailability of iron in a traditionally plant-based food and allows us to compare the availability of the iron in the novel products to conventional beef and current plant-based meat products. The bioavailability of iron in the novel products exceeded that of the conventional beef and the plant-based meat alternative. In Chapter 4, we conducted a consumer acceptability study to analyze the potential for consumer acceptance of a tempeh product made with 50% mealworms and 50% soybeans when compared to a commercial soy-based tempeh. An online survey was conducted to assess the public's attitudes to entomophagy, their current level of exposure to the practice, and the willingness to consume insects. Next, the mealworm soybean tempeh was evaluated by a trained sensory panel to develop a lexicon that describes the organoleptic attributes of the product. Finally, a blind in-person sensory evaluation was conducted to assess the overall acceptability of the product. During the in-person evaluation, participants were provided with different prompts to determine if details around the environmental impact of insect eating versus conventional meat production would affect the favorability of the product. Participants in this study rated the flavor equal to that of the commercial soy tempeh and majority of participants indicated they were equally or more likely to consume insect-based products again. The final chapter explores the need for research around branding and availability on insect-based food products to increase acceptance of entomophagy in Western society. This dissertation aims to determine the safety of utilizing edible insects in tempeh fermentation, examine the nutritional attributes of tempeh products made with various life stages of the Tenebrio molitor beetle, determine how effective these products are in filling their intended nutritional niches, and assess the potential for consumer acceptance of insect-based tempeh products. This dissertation provides a strong foundation for the understanding of the safety, nutrition, and acceptability of utilizing T. molitor-based tempeh as an alternative source of protein.Item Open Access In vivo and in vitro attributes of copper, zinc, and manganese sources in beef cattle nutrition(Colorado State University. Libraries, 2023) Guimaraes, Octavio, author; Engle, Terry T., advisor; Wagner, John, committee member; Geornaras, Gina, committee member; Nair, Mahesh, committee member; Holt, Tim, committee memberTrace minerals are not just vital components in the diets of domestic livestock species; they are also essential for ensuring optimal performance, health, reproduction, and a robust immune system. In today's volatile markets, producers and nutritionists face the challenge of meeting predefined goals and targets. They must employ strategies that can maximize production and efficiency. The intricate mechanisms governing the digestion, absorption, and storage of copper (Cu), zinc (Zn), and manganese (Mn) are influenced by various factors, including diet type, breed, life stage, among many others. Research has uncovered intriguing opportunities to enhance the utilization of trace minerals (TM) in ruminant nutrition. To further our comprehension of the digestion, absorption, and retention of modern trace mineral forms, this study conducted 3 experiments aimed at investigating the in vivo and in vitro characteristics of hydroxy trace minerals (HTM), organic chelated trace minerals (CTM), and sulfate trace minerals (STM) forms of Cu, Zn, and Mn. This dissertation is the continuation of a Master Thesis submitted by Guimaraes et al., 2021. In the current series of experiments the influence of TM source on digestibility and ruminal solubility was investigated. The objectives of experiment 1 were to determine the effects of TM source on 1) nutrient digestibility and ruminal fermentation, 2) concentrations of soluble Cu, Zn, and Mn in the rumen following a pulse dose of TM, and 3) Cu, Zn, and Mn binding strength on ruminal digesta using dialysis against a chelating agent in steers fed a diet formulated to meet the requirements of a high producing dairy cow. Twelve Angus steers fitted with ruminal cannulae were adapted to a diet balanced with nutrient concentrations similar to a diet for a high producing lactating dairy cow for 21 d. Steers were then randomly assigned to dietary treatments consisting of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either sulfate (STM), hydroxychloride (HTM) or complexed trace minerals (CTM). The experimental design did not include a negative control (no supplemental Cu, Mn, or Zn) because the basal diet did not meet the NRC (Nutrient Requirement for Beef Cattle) requirement for Cu and Zn. Copper, Mn, and Zn are also generally supplemented to lactating dairy cow diets at concentrations approximating those supplied in the present study. Following a 14-d adaptation period, total fecal output was collected for 5-d. Following the fecal collection period, rumen fluid was collected for VFA parameters. On the following day, the same diet was provided for 14 d, without supplemental Cu, Zn, and Mn. This period served as a wash-out period. A pulse dose of 100, 400, and 600 mg of Cu, Zn, Mn, respectively, from either STM, HTM, or CTM, was administered via ruminal cannulae to the steers on day 15. Over a 24-h period ruminal samples were obtained every 2-h. Following centrifugation, the supernatant was analyzed for Cu, Mn, and Zn. Ruminal solid digesta samples from times 0, 12, and 24 hours after bolus dosing were exposed to dialysis against Tris-EDTA. The digestibility of NDF and ADF were lesser in STM vs. HTM and vs. CTM supplemented steers. Steers receiving HTM and CTM had greater total VFA concentrations than STM, and molar proportions of individual VFA were not affected by treatment. Ruminal soluble Cu and Zn concentrations were greater post dosing in STM and CTM supplemented steers at 2, 4, and 6 h for Cu and 4, 6, 8, 10 and 12 h for Zn when compared to HTM supplemented steers. The release of Cu and Zn from ruminal solid digesta following dialysis against Tris-EDTA at 12 and 24 h post-dosing was greater for steers receiving HTM compared to those receiving STM or CTM. Results indicate trace mineral source impacts: 1) how tightly bound Cu and Zn are to ruminal solid digesta; 2) fiber digestion; 3) and ruminal total VFA concentrations. The objective of experiment 2 was to evaluate the effects of sources of STM and HTM fed at the same levels on 1) nutrient digestibility and fermentation characteristics, 2) ruminal solubility of Cu, Zn, and Mn following a pulse dose of trace mineral I, and 3) binding strength of Cu, Zn, and Mn on ruminal solid digesta upon dialysis against a chelating agent. Minor dietary changes can have a direct impact on ruminal pH, temperature, microbial population, and redox potential, which will influence fermentation, and ultimately affect nutrient digestibility. These changes can influence or be influenced by the solubility of certain TM in the rumen. Rumen soluble TMs can alter nutrient digestibility, fermentation, and increase chances of antagonistic interaction. Twelve ruminally cannulated Angus steers (BW 587.6 ± 23.1 kg) were adapted to a diet balanced to meet requirements of finishing steers for 21 d. Steers were then randomly assigned to dietary treatments consisting of Cu, Mn, and Zn supplemented at 18, 40, and 90 mg/kg DM, respectively, from STM or HTM sources (n = 6 steers/treatment; experimental unit = steer). Following the 14 days treatment adaptation period total fecal output was collected for 5 d. Digestibility of DM, CP, Starch, NDF, and ADF was not affected (P > 0.15) by TM source. On d 6, rumen fluid was collected at 0, 2, and 4 h post feeding for VFA analysis. There were no treatment x time interactions for any VFA measured. However, HTM steers had greater (P < 0.05) ruminal molar proportions of propionate and tended (P < 0.07) to have greater molar proportions of valerate compared to STM steers. Steers fed STM had greater (P < 0.05) molar proportions of butyrate compared to HTM steers. Steers were then fed the same high concentrate diet without supplemental Cu, Zn, or Mn for 14 d. On d 15 steers received a pulse dose (via rumen cannulae) from either STM or HTM. Ruminal samples were obtained at 2 h intervals starting at -4 and ending at 24 h relative to dosing. There was a treatment x time interaction (P < 0.05) for ruminal soluble Cu concentrations. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, and 16 h post dosing in STM compared to HTM supplemented steers. There was no treatment x time interaction for ruminal soluble Zn or Mn concentrations. The release of Cu, Zn, and Mn from ruminal solid digesta following dialysis against Tris-EDTA at 12 and 24 h post-dosing was greater (P < 0.01) for steers receiving HTM compared to those receiving STM. Results of this experiment indicate that trace mineral source affects how tightly bound Cu, Zn, and Mn are to ruminal solid digesta, and that ruminal solubility of Cu differs between STM and HTM sources and may impact rumen fermentation characteristics. Experiment 3: This study analyzed samples from experiments investigating TM source effects on nutrient digestibility, short-chain fatty acid production, Cu, Zn, and Mn ruminal solubility, and binding strength in rumen insoluble digesta. Twelve Angus steers (5+ years old) participated in three studies: Study 1 (Guimaraes et al., 2020, 2021; medium quality forage diet), Study 2 (Guimaraes et al., 2022; dairy type diet), and Study 3 (unpublished, Chapter 3 of this dissertation; high concentrate diet). Due to impacts on digestibility, fermentation, mineral solubility, and binding in all studies, microbiome analysis was conducted to assess potential bacterial and protozoa population shifts from all studies. In Study 1 (medium quality forage diet), Papillibacter was the predominant species in the rumen. Rumen samples showed a significant time point impact on Shannon's PD (P < 0.05). Beta diversity analysis using unweighted UniFrac revealed notable differences in community diversity between rumen and fecal samples (q < 0.001). Rumen microbiota clustered at multiple time points. No beta diversity differences between STM and HTM were observed at baseline (Time A, q = 0.23), but differences emerged after adaptation (Time C, q < 0.03) and during total collection (Time F, q < 0.01). ANCOM analysis revealed higher abundance of Papillibacter, Ruminoccoccaceae, and Prevotellaceae in rumen samples, regardless of TM source. No significant differences were found in fecal samples. ANCOM analysis did not detect measurable differential abundance between trace mineral sources in fecal or rumen samples following Alpha and Beta diversity results. In Study 2 (dairy diet), Moraxellaceae was the most prevalent species within the rumen. Rumen samples showed a significant time point effect on Shannon's PD (P < 0.001), with noteworthy differences between several time points. However, TM source had no impact on Shannon's PD (P = 0.15). Fecal samples showed no differences in time points or TM sources. Beta diversity analysis using unweighted UniFrac revealed a significant distinction between microbial community diversity in rumen and fecal samples (q < 0.001). Rumen microbiota clustered differently at various time points. Trace mineral source did not affect Beta diversity, but there was a tendency toward greater diversity with HTM supplementation (q = 0.07). ANCOM analysis found higher abundance of ASVs Moraxellaceae, Planococcaceae, Ruminoccoccaceae, and Prevotellaceae in the rumen environment, regardless of TM source. No significant differential abundance was detected between TM sources in rumen samples, consistent with Shannon's PD diversity analysis. In Study 3 (high concentrate diet), Moraxellaceae and Planococcaceae were the most abundant in rumen samples. Rumen samples showed a significant impact of collection time point on Shannon’s PD (P < 0.001), with significant differences between several time points. However, TM source had no effect on Shannon’s Diversity (P = 0.19). Interestingly, Shannon’s Diversity in feces showed significant differences between TM sources (P < 0.03), with STM having lesser diversity than HTM. There was no effect of time point in fecal samples (P = 0.38). Beta diversity analysis using unweighted UniFrac revealed clear differences between microbial diversity in rumen and fecal samples (q < 0.001). ANCOM analysis found higher abundance of ASVs Moraxellaceae, Prevotellaceae, Planococcaceae, and Ruminoccoccaceae in the rumen environment, regardless of TM source. In conclusion, this study provides valuable insights into the complex interplay between TM sources, the rumen microbiome, and various aspects of rumen health and function. While TM sources did not significantly alter the rumen microbiome composition, time points demonstrated substantial effects on microbial communities. These findings contribute to our understanding of how dietary factors can influence rumen ecology and function, with potential implications for livestock nutrition and management strategies. In conclusion, while experiment 1 showed that HTM and CTM sources positively impacted fiber digestibility and ruminal VFA concentrations compared to STM, experiment 2 indicated that the diet type could influence these effects. However, ruminal soluble mineral concentrations remained greater in STM-supplemented steers. Experiment 3 further highlighted the differences in rumen and fecal microbiota diversity between TM sources. These findings underscore the importance of selecting the appropriate TM source based on specific dietary and production requirements. The interactions between TMs, diet type, and the rumen microbiome are complex and require further investigation to optimize ruminant nutrition and overall well-being. This research builds upon previous studies and contributes valuable insights into the utilization of TMs in ruminant nutrition, paving the way for more informed decision-making in livestock production practices.