35 pp. / The dependency of Arizona ranchers on federal lands has been well documented. Mayes and Archer (1982) estimated that public and state grazing lands outside of the Indian reservations account for 85% of the total grazing land in Arizona. The partnership between private ranchers, state lands, and the federal government comes with many complex factors that influence the cost of doing business both in terms of variable and fixed costs. Not only are the regulations, fees, and enforcement of regulations a challenge for managing mixed land ownership, but additional costs from vandalism, theft, and daily disruptions of operations add to the normal operating expenses (Ruyle et al., 2000). Ownership and maintenance of range improvements, such as wells, spring development, and dirt tanks, etc., is also complicated by the rangeland ownership mix. This study is designed to examine the cost of ranching for different geographic areas in Arizona and show how different production costs exist throughout the state.

Since adoption is a dynamic process that involves learning about new technologies, static adoption models fail to adequately explore the effects of changes in farmers’ perception and attitudes over time. This study analyzed the influences of farmers’ learning and risk on the likelihood and intensity of adoption of improved tef and wheat technologies in Northern and Western Shewa zones of Ethiopia. The study employed Xtprobit and Xttobit and random effect models and panel data of the same farmers from 1997 to 2001. Separate samples were selected for wheat and tef and the study covers the same farmers from 1997-2001. Panel data are better suited to study dynamic changes and the random effect models control for unobserved variability and potential endogeniety. Comparison of the main features of tef and wheat farmers revealed that wheat farmers are slightly younger, more educated, have slightly higher family size and significantly higher family labour than tef farmers. While average farm size is similar for tef and wheat farmers, farmers cultivated 60% and 30% of their land to tef and wheat, respectively. However, tef farmers allocated only 20% of their tef area to improved varieties due to shortage of desirable varieties whereas wheat farmers allocated 90% of their land to improved varieties from 1997 to 2001. Only three improved varieties were demonstrated and limited quantities of improved seeds were distributed to tef farmers whereas six improved wheat varieties were demonstrated and relatively sufficient quantities of improved seeds were distributed to wheat farmers during the study. Besides, similar levels of fertilizers and herbicide were used on tef and wheat. Wheat and tef were mainly grown for own consumption as less than half of the produce (48% of all wheat and 46% of all tef) was sold in the market. The study provided evidence of the importance of learning in the adoption decision and area allocation to improved varieties. As farmer’s gained more experience from growing the new varieties in previous years, they continued adoption and increased areas under these varieties. The study also revealed that adopters of wheat and tef technologies have increased their production by 20% and 39%, respectively, than non-adopters. Results of the analyses indicate that awareness, availability and profitability of the new improved tef and wheat varieties enhanced farmer’s learning and farmer’s experience had positive influence on the likelihood and intensity of improved seed adoption. Improved tef and wheat varieties were found more risky than the local varieties. The study further revealed that younger age of farmer, farmers’ learning from previous experience, availability of family labour and credit are key determinants of the likelihood and intensity of adoption of improved seed. Policies and strategies that contribute to timely availability of improved inputs and provision of credit enhance farmers learning from their own experience on adoption. Policies and strategies that focus on farmers’ education and provision of insurance for crop failure to reduce risk would help the new extension program (NEP) achieve its objectives which give emphasis to raising smallholders’ production and productivity. / Thesis (PhD (Agricultural Economics))--University of Pretoria, 2008. / Agricultural Economics, Extension and Rural Development / unrestricted

Methods for engineering mice to express polyclonal repertoires of human antibodies are well established and their use to produce human monoclonal antibodies of predefined specificity has been widely demonstrated (Ishida, et al., 2002; Lonberg, et al., 1994; Mendez, et al., 1997; Nicholson, et al., 1999). Although such engineered mice do expresses diverse repertoires of human antibodies and are immunophysiologically similar to humans; due to their small size, they are not suitable for the production of significant quantities of human polyclonal antibodies (hPAbs). Currently, hPAbs are in wide clinical use for prophylaxis and therapy in immunocompetent and immunodeficient patients [Keller, et al., 2000). Because these antibodies are obtained from human sources their supply is limited and their titers are often low because immunization protocols to raise pathogen-specific antibodies in donors are optimized for safety rather than for magnitude and duration of antibody response. Given these limitations, a technology for the production of antigen-specific hPAbs in large nonhuman hosts is novel and has significant biomedical and biodefense interest. Considering the differences in the mechanisms and strategies used by bovines and humans to diversify their antibody repertoires (Butler, 1998; Flajnik, 2002; Reynaud, et al., 1991; Meyer, et al. , 1997), questions arise about the capacity of HACs to sponsor the generation of functional human Ig repertoires. This prompted the following critical questions to be addressed: Can a large and viable population of human Ig-producing cloned HAC-Tc cattle be produced? Does human Ig synthesis persist as the animals mature? Is any portion of the human Ig assembled as fully human antibodies free of bovine heavy or light chains? Do rearranged human heavy chain loci undergo class switching in bovine cells? Does the HAC construct encode a broad diversity of human immunoglobulins in cattle? Most importantly, does immunization induce any fully human, antigen-specific polyclonal antibodies in cloned, HAC-Tc cattle, and effect protective functions? Resolving these questions is necessary to determine if the immunological divergence of bovines and humans prevent the use of HAC-bovines as suitable bioreactors for production of human antibodies for therapy. The availability of cloned HAC-Tc cattle that are imrnunologically mature has enabled the conduct of studies to address these questions, and the following results have been obtained. Biochemical and serological studies determine that fully human Ig isolated from HAC-Tc cattle is polyclonal and is comprised of both human μ and γ isotypes, demonstrating that the HAC-borne human IgH locus undergoes class switching within bovine cells. (Abstract shortened by UMI.)

Understanding the demographic profile and previous knowledge base of students enrolled in the introduction to animal science course is critical for developing curriculum to enhance student learning. During the fall 2019 semester, students (n=414 of 519) enrolled in the introduction to animal science course at three universities in the Midwest region were evaluated with the objectives of identifying demographic variables and their relation to pre-course and post-course animal agriculture and livestock perceptions. The findings showed that 68% of respondents were female, 58% were animal science majors, and 55% were from hometowns with less than 20,000 people in the population. Forty-eight percent and 36% indicated to have previous agriculture exposure and involvement through FFA and 4-H, while 43% and 55% had no previous involvement in FFA and 4-H, respectively. Companion animals (e.g. dogs and cats) and beef cattle were nearly 50% of students’ species of interest. Additionally, 34% of students felt they had extensive knowledge of companion animals, while 19% indicated they had extensive knowledge in beef cattle and 17% in equine. Students indicated to have the least amount of knowledge in sheep and exotic animals. In addition to species, students indicated their degree of previous knowledge in animal science disciplines. Students (20%) perceived to have extensive knowledge in welfare and well-being but lacked in breeding and genetics. Majority of students recognized animal agriculture as an important industry in their state and were supportive of the growth and expansion of the livestock industry. When asked to respond to statements pertaining to livestock operations, students (49%) strongly agree the use of captive bolt to stun beef and dairy cattle prior to slaughter is acceptable and it is save for livestock producers to perform castration using banding or surgical procedures. Overall, there were pre-course findings that were statistically significant among the demographic profiles of students and their perceptions of livestock operations in the United States, but few post-course findings demonstrated statistical significance. This research suggests the importance of developing curriculum that meets the desires and needs of current students enrolled in an introduction to animal science course.

Thesis (M.Sc. (Agricultural Economics)) -- University of Limpopo, 2019 / Livestock production is the most important sub-sector in agriculture in South Africa. It contributes a very large proportion to the agricultural gross domestic product. It has been identified as the sub-sector that has potential in improving food security and livelihoods of the rural people. The current study analyses the determinants of market participation and profitability of IDC Nguni smallholder farmers in the Limpopo Province, South Africa. The aim of the study was to contribute to the body of knowledge that exist in the study area, particularly of Limpopo Province livestock marketing by analysing determinants of market participation and profitability. The primary data were collected using structured questionnaires. All IDC Nguni Project beneficiaries (62 famers)were included in the survey. Descriptive data were analysed using Version 23 of SPSS. The logistic regression was used to analyse market participation data, multiple regression was used for profitability data and livelihood model for assessing the contribution of the project to livelihoods. The models were analysed using Stata 14. The results revealed that 59% of the respondents participated in the market and 41% of respondents did not participate. The study revealed that 54% of the respondents indicate that market access was easy and only 38% of respondents indicated that market access was not easy and 8% of respondents revealed that they do not know how the market access was because they were not yet selling. Seventy percent of the farmers perceived their livelihoods being improved after joining IDC Nguni Cattle Project whereas 23% of the farmers perceived their livelihood not improve after joining IDC Nguni Cattle Project. Gross margin computation showed that 52% of the farmers made gross margins ranging between R2 000 and R481 200 during the 2015 production/marketing season. The overall gross margins showed that 46% of the farmers made loss ranging from R7 300 to R170 500 during the 2015 marketing season, and 2% of the smallholder farmers were operating break-even point. The average gross margin for Community Property Associations was R6 031 while for individual farmers it was R16 082. The decision making process, for example to sell vii livestock, may be complex in the CPAs and hence a higher gross margin results for individual farmers than for CPAs. Thirty-six percent of CPAs made a loss, while 49% of individual farmers also made loss during 2015. The results of logistic regression showed that marital status, education level, loan repayment, price of an animal and household income were all significant factors (at various probability levels and with different signs), influencing market participation in the study area. A multiple regression model revealed that empirically the herd size, farm size and distance travelled to the market were significant at various probability levels and with different signs influencing profitability in the study area. Livelihood model results revealed that recent increase in farm income and farm size were all significant at different probability levels and with different signs influencing smallholder farmers' livelihood improvement in the Limpopo Province. The study identified some challenges faced by smallholder farmers in Limpopo Province. The major ones were inadequate access of market information, high transactional costs, poor conditions of the animals and poor access to markets. Policy makers should come up with policies that support the smallholder farmers with formal training, seminars and workshops to improve profitability of the farmers. Basic training of production and marketing may enable the smallholder farmer to increase profits. Other recommendations were formation of farmers' organisations, access to financial resources and private-public collaboration to establish central selling points. / Department of Science and Technology-National Research Foundation (DST-NRF) Centre of Excellence (CoE) in Food Security and National Agricultural Marketing Council (NAMC)

The purpose of this research was to implement a stratifying sampling system in the communities of La Inmaculada, Tunshi San Miguel, and Ela Guano, part of the Chambo-Guano irrigation system. The domesticated animal population in these communities consisted of cattle, sheep, swine, guinea pigs, and poultry. The animal feed used in these communities included alfalfa, grass, corn stalks, banana, weeds, kitchen residue, hulk, hard and soft corn, barley, wheat and other feed preparations. In general, animal management in these communities is technically deficient and most animals exhibited diseases that are controllable by veterinarians. Study recommendations to improve conditions for rural populations include implementing an integrated production project with technical assistance programs and other changes to improve animal genetics.

Stockholm Exergi provide district heating in Stockholm and plan to integrate their district heating system with the production of biochar, by building a plant that produces 100MW district heating and 100 000 tonnes biochar per year, in order to reduce greenhouse gas emissions. Biochar may mitigate climate change, but the added benefits of biochar, beyond the benefits of carbon sequestration, lack quantification. This report aims to review, quantify and document the cumulative benefits, with respect to climate, health, and resource consumption, of biochar application to Swedish agriculture, as a livestock feed additive. A life cycle of biochar as a livestock feed additive is illustrated, where the biochar is ingested by livestock and retrieved in manure. The manure is thereafter co-composted with the biochar, and finally, returned to soil. Each step proceeding the initial application carries important benefits to climate, health or resource consumption. Providing all livestock in Sweden with biochar requires 100 000 tonnes per year and may potentially reduce greenhouse gas emissions from livestock by up to 450 000 tonnes of carbon dioxide equivalents (CO2-e) per year. Distributing the biochar to farms across Sweden results in around 10 000 tonnes of CO2-e emissions per year. Hence, the potential net annual reduction in greenhouse gas emissions is approximately 440 000 tonnes of CO2-e in Sweden. This is equivalent to -590g CO2-e/kWh for a biochar plant that produces 100MW district heating. Research also suggests a reduction in greenhouse gas emissions from biochar co-composting and biochar soil application. However, the concentration of biochar retained in manure subsequent to feeding is too low to draw a conclusion regarding its effect on emissions. Health benefits of biochar as a livestock feed additive include reduced (or even eliminated) need for antibiotics, fewer cases of illness amongst livestock, fewer deaths, and higher quality cow milk. The biochar also eliminates manure odour, improving work environment for farmers. Biochar co-composting may reduce ammonia emissions and improves nutrient retention. Applying the co-compost to soils eliminates soil pathogens, detoxifies allelochemicals, increases the growth rate of beneficial microbes, and reduces fertilizer need. Crops will thus become more resistant to mould and biotic stresses. / Stockholm Exergi producerar och levererar fjärrvärme till Stockholmsregionen och planerar att bygga en anläggning som producerar 100 MW fjärrrvärme i samband med 100 000 ton biokol per år, för att minska koldioxidutsläppen. Biokol framställs genom pyrolys av biomassa och binder fast kolatomer i sin struktur, vilket leder till minskade koldioxidutsläpp om biokolet hindras från att oxideras genom någon form av lagring. Denna rapport undersöker genom en litteraturstudie de adderade nyttorna med biokol som råvara i djurfoder med avseende på klimat, hälsa och resursanvändning. De adderade nyttorna uppskattades genom att följa biokolets livscykel från råvara i djurfoder till gödsel. I första steget intas biokolet av djur, sedan hamnar biokolet i djurens avföring som därefter komposteras och används i växtodling. Det totala biokolbehovet för att mata alla produktionsdjur i Sverige uppskattades till 100 000 ton per år och beräknades minska växthusgasutsläppen med 450 000 ton koldioxidekvivalenter (CO2-e) per år. Dock måste biokolet transporteras långa sträckor över hela landet och utsläpp från transporter uppskattades till 10 000 ton CO2-e. Detta innebär en utsläppsminskning med 440 000 ton CO2-e per år, vilket motsvarar -590 g CO2-e/kWh för en biokolanläggning som producerar 100 MW fjärrvärme. Resultaten visade också att biokol förbättrar djurens allmänna hälsa, minskar dödligheten samt leder till ett minskat behov av antibiotika. Dessutom minskar lukten från gödsel, vilket förbättrar arbetsmiljön inom jordbruk. Vid kompostering kan biokol minska utsläpp av ammoniak (en giftig kemikalie) och öka koncentrationen av näringsämnen i gödseln. När det sedan används vid odling kan det leda till en ökad tillväxt av nyttiga mikroorganismer, samtidigt som patogener elimineras, vilket leder till att växter får en ökad resistans mot biotisk stress och mögel. Dessutom minskar behovet av konstgödsel.

Ruminants play an essential role in supplying nutrients to the global population. Despite notable advancements in the livestock industry, there is a rising demand for animal protein products and a pressing need for sustainable practices. Consequently, it is imperative to focus on improving efficiency and sustainability across the environmental, economic, and social dimensions of the livestock system. Precision livestock farming (PLF) technologies have emerged as a potential solution to enhance sustainability by integrating individual animal monitoring and automated control over animal productivity, environmental impacts, health, and welfare parameters. Although PLF holds promise for improving livestock management practices, its widespread adoption is hindered by challenges including the high costs associated with implementation, data ownership, and implementation across different environments. he overarching aim of this research was to investigate and propose solutions to the challenges that limit the extensive implementation of wearable technologies in livestock systems. The primary objective of the first study was to develop and assess the utility of an open-source, low-cost research wearable technology equipped with Bluetooth for monitoring ruminants in a confined setting. The study successfully demonstrated the functionality and cost-effectiveness of this technology and its potential for monitoring ruminants' behavior in research and practical applications. Building upon the success of the technology in intensive systems, the subsequent study focused on updating the wearable sensor for deployment in extensive systems. This was achieved by incorporating LoRa data transmission and enabling real-time monitoring of livestock location. The study effectively demonstrated the feasibility of the updated technology for real-time monitoring of livestock in extensive grazing systems. In continuation of testing the feasibility of sensors, the subsequent experiment aimed to assess the accuracy and precision of a low-cost wearable sensor photoplethysmography (PPG) sensor in monitoring heart-rate (HR) of sheep housed under high-temperature conditions. The results revealed poor accuracy and precision in detecting HR changes using the PPG sensor. Future studies should explore alternative sensor deployment methods and data analytics techniques to improve the accuracy of a PPG sensor in detecting HR in livestock animals. The follow-up study focuses on evaluating the suitability of a continuous glucose monitor (CGM) designed for humans in measuring interstitial glucose concentrations in sheep, as a potential replacement for traditional blood glucose measurements. The findings demonstrated great potential of CGM in detecting changes in glucose concentrations in sheep. However, the study`s limitations such as the small sample size, warranting further investigation with a larger sample size and potential standardization with laboratory analysis bore implementing CGMs as a replacement for traditional glucose measurement methods in research. The limited expansion of technology application in extensive livestock systems, in contrast to confined operations, can be attributed to challenges such as limited battery life and data transmission. To overcome these limitations, edge processing techniques which involve performing data processing, analytics, and decision-making closer to the data source, have been proposed as cost-effective strategy for enhancing the usability of inertial measurement unit systems (IMU) in monitoring grazing animal behavior. Therefore, the objective of the fifth study was to explore different classification techniques suitable for edge processing using an open-source IMU. Analysis of variances, logistic regression, support vector machine, and random forest were evaluated for classifying grazing, walking, standing, and lying behaviors. The random forest model achieved the highest accuracy (93%) in classifying grazing using 1-minute interval. Moreover, the algorithms were compared considering a periodic snapshot of data with intervals of 3 or 5 seconds, and interesting revealed no significant impact on algorithm accuracy on differentiating behavior of grazing cows using IMU systems. Heat stress has negative impacts on animal behavior, welfare, and productivity. While IMU systems have been used to detect behavioral changes in thermoneutral conditions, their effectiveness on heat-stressed animals remains unclear. The objective of the last study was to investigate changes in sheep behavior using a low-cost IMU and the influence of ambient temperature in the algorithms ability to classify behaviors. Eating, lying, standing and ruminating while standing and lying were classified during exposure to different ambient temperature patterns. The algorithm demonstrated acceptable accuracies in differentiating behaviors under thermoneutral conditions, but its performance was impaired when tested outside the thermal range. Future research should focus on developing algorithms that account for different environmental conditions to improve the accuracy of IMU in classifying animal behavior. Collectively, these investigations contribute to enhancing the applicability of technologies in livestock systems. / Doctor of Philosophy / The global population relies on ruminant animals, such as cattle and sheep, for essential nutrient. However, with the increasing demand for animal protein products, there is a growing need for sustainable practices in the livestock industry. Precision livestock farming (PLF) technologies have emerged as a potential solution to enhance sustainability by enabling individual animal monitoring. However, challenges such as data ownership and accessibility and high costs, impair its adoption. To overcome these challenges and enhance the applicability of wearable sensors in livestock systems, this research aimed to explore potential solutions. The objective of the first study was to develop and evaluate an open-source, low-cost wearable technology equipped with Bluetooth for monitoring ruminants in confined settings. The study successfully demonstrated the functionality and cost-effectiveness of this technology for monitoring ruminant behavior. Building up the success of the technology in intensive systems, the subsequent study focused on updating the wearable sensor for deployment in extensive systems. This was achieved by incorporating LoRa data transmission, enabling real-time monitoring of livestock. The study effectively demonstrated the feasibility of and potential of the updated technology for real-time monitoring in extensive livestock systems. Continuing with the feasibility testing of technologies, the next experiment aimed to assess the accuracy and precision of a low-cost photoplethysmography (PPG) sensor in monitoring heart rate (HR) in sheep housed under high-temperature conditions. Unfortunately, the results indicated poor accuracy and precision in detecting HR changes using the PPG sensor. Future studies should explore alternative sensor deployment methods and data analysis techniques to improve the accuracy of PPG sensors for HR monitoring in livestock animals. The followed study focused on evaluating the suitability of a continuous glucose monitors (CGM) designed for humans to measure interstitial glucose concentrations in sheep and potentially replacing traditional blood glucose measurements. The findings demonstrated the potential of CGMs to detect changes in glucose but limitations such as the small sample size suggest the need for further investigations with a larger sample size and potential standardization with laboratory analysis before implementing CGM as a replacement for traditional glucose measurement methods in research. In extensive systems, where technology adoption has been slower compared to confined operations, edge processing techniques are proposed as a cost-effective strategy to monitor grazing animal behavior using inertial measurement unit systems (IMU). In the fifth study, different classification techniques were explored using an open-source IMU, including analysis of variances, logistic regression, support vector machine, and random forest. The random forest model achieved high accuracy (93%) in classifying grazing behavior with a 1-minute interval. Surprisingly, algorithm accuracy was not affected when snapshot in time was performed. The final study focused on using a low-cost IMU to investigate sheep behavior under varying ambient temperature conditions. While algorithm performed well under thermoneutral conditions, its accuracy decreased outside the thermal range. Future research should focus on algorithms that account for different environmental conditions to improve IMU accuracy in classifying behavior. These investigations contribute to enhancing technology's applicability to in livestock systems by addressing challenges and developing practical solutions to improve livestock management and animal well-being.

This dissertation challenges Charles W. Ramsdell's needless war theory, which argued that profitable slavery would not have existed west of the 98th meridian and that slavery would have died a natural death. It uses statistical information that is mined from the county tax records to show how slave-owners on the northwestern frontier of Texas raised livestock rather than market crops, before and during the Civil War. This enterprise was so strong that it not only continued to expand throughout this period, but it also became the foundation for the recovery of the Texas economy after the war.

Increased volatility of agricultural commodity prices as well as market linkages between the agricultural and energy markets expose producers to different types of systematic price risk. Producers that operate on margins involving both input and output price uncertainty are perhaps the most adversely affected by these volatility changes. The beef cattle feeding industry is one such example. This research focuses on how expected margins in the beef cattle backgrounding and finishing stages are affected by output and input price uncertainty.