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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Beef replacement heifer decision tool

Sachse, John January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Dustin L. Pendell / Sachse Family Angus is both a commercial and registered Angus cow-calf operation in Northeast Kansas and has been in operation since 1935. The end goal in mind is to provide quality female breeding seedstock to other beef producers with the hopes of improving their herds. Successful selection and development of beef replacement heifers have major long term effects on stayability in any herd and can even have a positive impact on the whole herd. The objective of this study is to create a decision tool to determine best heifer selection strategies. Specifically, taking a look at the cost of heifer development under a range of scenarios as it applies to more traditional heifer development. The depth of literature addressing the issue of buying or raising replacement heifers is vast, providing various degrees of analysis to help a producer make the best informed decision. Some economists would argue that no single aspect of beef production management is as complicated, or has such an economic impact as cow culling and replacement heifer decisions (Melton, 1980). Procedures and methods were created to analyze whether a producer should raise or develop their own replacement heifers. One method used in creating a decision tool is an enterprise budget. Enterprise budgeting is the systematic determination and listing of expected outputs, revenues, and costs due to the production processes required to produce one unit of an enterprise for a specified time period. To take this one step further, it is assumed a producer makes choices with respect to the combinations of productive factors and products. Partial budgets include an analysis of net returns from small changes or refinement to a ranch. It focuses on parts that change while building upon an enterprise budget. In essence, it fine tunes current operations while holding all else constant. The benefits of partial budgeting take a look at what will be the new or added revenue if a change is implemented on the ranch and what costs will be reduced or eliminated if taken place. What will be the new or added costs and what revenues will be reduced if a change takes place are also things to keep in mind. Therefore, the result will show a producer the net benefit of the change. In turn, Sachse Family Angus will use this information to build their registered and commercial replacement heifers either by developing their own or purchasing from other breeders. Overtime, this decision will be critical as it will impact their herd for years to come. In conclusion, maintaining a good sound, high functioning beef cow herd means selecting and developing quality replacement heifers to retain in the herd each year. An estimated 20% of heifers born each year at Sachse Family Angus are kept as replacement heifers. When managing home raised heifers or purchased heifers, maintaining costs and keeping them in check is crucial because they represent a large up-front investment. The bottom line of this research is to give the managers at Sachse Family Angus and other operations across the country a decision tool that can be used to analyze their current resources and the resources it will take to develop their own heifers successfully and in the most cost effective way or help them analyze if purchasing their heifers makes the most financial sense.
2

Evaluation of the Effects of Heifer Development Method on Subsequent Reproductive Performance and Progeny Growth

Cain, Amanda Jillian 12 August 2016 (has links)
The objective of the present study was to evaluate the effects of low input development protocols on Southeastern replacement beef females and their offspring. Fall and spring calving crossbred beef heifers managed through one of two heifer development programs (low input, LOW or conventionally developed, CON) were evaluated for metrics of uterine artery hemodynamics, patterns of heifer and offspring growth, postpartum reproductive performance, and economic efficiency. There were significant treatment × season (P = 0.0001) and season × day (P = 0.003) interactions on heifer body weight (BW) during gestation. There was a season × day interaction on total blood flow (TBF; P = 0.05) whereby TBF increased as gestation progressed and spring calving heifers displayed increased TBF. When adjusted for BW, an additional main effect of treatment was observed (P = 0.0007) in which LOW heifers had increased TBF compared to CON heifers. There were no significant main effects of treatment or season or interactions thereof on the proportion of females cycling at the start of the breeding season (P > 0.05). Additionally, there were main effects of treatment (P = 0.0095; P = 0.02) and season (P = 0.012; P = 0.007) on calf ADG and weaning weights, respectively whereby calves born to CON females grew faster than calves born to LOW heifers, and SPRING calves gained more rapidly than FALL calves. Partial budgeting demonstrated that LOW bred heifers were $250/hd less expensive to purchase than CON heifers due to lighter BW. Calves born to LOW females yielded $6.38 less per calf compared to CON calves. The discrepancy in reproductive efficiency coupled with the failure of LOW females to achieve BW similar to CON females resulted in a difference of $403/hd in average cull value between LOW and CON females in which CON females were worth more. Thus, CON females were $159.18 more profitable than LOW females when purchased as bred heifers and sold at the weaning of their first calf. In conclusion, though uterine artery BF was not negatively affected, low input heifer development resulted in sub-optimal heifer growth, poor first calf performance, and inadequate reproductive efficiency.
3

Desempenho e características de carcaça de cabritos em dois sistemas de terminação / Performance and carcass characteristics of goat kids in two finishing systems

Salles, Fernando Marques 15 December 2010 (has links)
Made available in DSpace on 2017-07-10T17:48:22Z (GMT). No. of bitstreams: 1 Fernando_Marques_Salles.pdf: 573549 bytes, checksum: d10b17942e2969b2ccb753810523c334 (MD5) Previous issue date: 2010-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to evaluate the performance, quantitative and qualitative characteristics of the carcass, cut yields and the variation of cost and revenue in the production of beef and feedlot goats Saanen, Saanen and 7/8 Boer - 1/8 Saanen finished in semi feedlot, assessing the influence of genetic groups and finishing systems on such characteristics of goats. Significant differences were observed (P<0.05) for the different finishing systems to evaluate the characteristics of commercial income housing; carcass compactness index, not constituents of housing, loin eye area, muscle shear force; fat, moisture and ether extract. For the genetic groups, statistical differences were observed only for loin eye area, greater thickness of fat and ash content. The finishing system has influenced (P<0.05) in performance, where the confined animals showed the best characteristics, the percentage of cuts and, consequently, revenue from the sale thereof. The finishing system has influence on carcass characteristics evaluated in this study, it is possible to conclude that the Saanen can be used for the production of meat when subjected to confinement. When evaluating the quality of housing Saanen crossbred compared to 7/8 Boer - 1/8 Saanen finished in semi confined conditions of this study, we can conclude that there are few differences between the dairy breed Saanen and crossbred Boer for traits, possibly due to production of specialty meat Boer who require an intensive system to demonstrate higher performance. Investment in power gives better weight gains, and hence best proportions of commercial cuts, resulting in a higher income system. Males Saanen can be used for finishing and slaughter, supplementing the income of dairy goat. It is necessary to complete economic analysis to examine the viability of economic systems, since the budget is only a partial indicator of possible better option / O objetivo deste estudo foi avaliar o desempenho, as características quantitativas e qualitativas da carcaça, o rendimento dos cortes e a variação do custo e da receita na produção de carne de cabritos Saanen terminados em confinamento, Saanen e 7/8 Boer 1/8 Saanen terminados em semiconfinamento, avaliando a influência dos grupos genéticos e dos sistemas de terminação de cabritos sobre tais características. Foram observadas diferenças significativas (P<0,05) para os diferentes sistemas de terminação para as características: rendimento comercial de carcaça; índice de compacidade da carcaça; não constituintes de carcaça; área de olho de lombo; força de cisalhamento; teor de gordura; de umidade e de extrato etéreo. Para os grupos genéticos, foram observadas diferenças estatísticas apenas para área de olho de lombo; espessura maior de gordura e teor de matéria mineral. O sistema de terminação exerceu influência (P<0,05) no desempenho, onde os animais confinados apresentaram melhores características; na porcentagem dos cortes e, consequentemente, na receita obtida com a venda dos mesmos. O sistema de terminação exerce influência nas características de carcaça avaliadas neste trabalho, sendo possível concluir que a raça Saanen pode ser utilizada para a produção de carne quando submetida ao confinamento. Ao se avaliar a qualidade da carcaça da raça Saanen comparada aos mestiços 7/8 Boer 1/8 Saanen terminados em semiconfinamento, nas condições deste estudo, pode-se concluir que são poucas as diferenças entre a raça leiteira Saanen e o mestiço Boer para as características avaliadas, possivelmente pela especialidade para produção de carne da raça Boer que necessitaria de um sistema intensivo para demonstrar desempenho mais elevado. O investimento na alimentação proporciona melhores ganhos de peso, e, consequentemente melhores proporções dos cortes comerciais, acarretando numa renda maior do sistema. Os machos da raça Saanen podem ser utilizados para terminação e abate, complementando a renda da caprinocultura leiteira. Faz-se necessária a análise econômica completa para verificação da viabilidade econômica dos sistemas, visto que o orçamento parcial é apenas um indicador da possível melhor opção
4

Effects of Storage Conditions of Aspergillus Growth and Aflatoxin Production in Peanuts. A Study in Ghana

Darko, Clara Bernice 13 February 2017 (has links)
Peanuts (Arachis-hypogaea) are one of the staples in Ghana, Sub-Saharan Africa, and other developing countries. This leguminous crop is frequently contaminated with aflatoxins, which are secondary metabolites of some Aspergillus fungi, mostly Aspergillus. flavus and Aspergillus parasiticus. Aflatoxins in foods are known to cause liver cancer, stunted growth in children, immune system disorders and economic losses. Aflatoxin contamination of peanuts during storage is worse in the tropics because climatic storage conditions there are almost the same as the optimum conditions for Aspergillus growth: temperature conditions of about 26-43 °C and relative humidity of 62-99%. This study investigated the growth of Aspergillus and the production of aflatoxin in shelled peanuts under varying treatment and packaging conditions. In addition, the appropriate pre-storage treatments and packaging needed to reduce aflatoxin production and to maintain quality of shelled and in-shell peanuts in storage under tropical environments were studied. Another aim was to determine the impact of the switch to hermetic storage on peanut farming and marketing profitability in Ghana. Different peanut treatments, with and without Aspergillus flavus fungi, were packaged in different systems; specifically, polypropylene woven sacks and hermetic packaging. Peanuts were analyzed for fungi growth, aflatoxin production and lipid oxidation (peroxide value and p-Anisidine value). Partial roasting and blanching of peanuts eliminated aflatoxigenic fungi and halted aflatoxin production in stored peanuts, increased the effectiveness of peanut sorting and, hence, helped reduce or eliminate aflatoxin levels along the peanut value chain. Additionally, the results of this study demonstrated that hermetic storage, by suppressing aflatoxin production, has the potential for maintaining peanut quality vis a vis polypropylene woven packaging. Profitability analysis conducted as part of this study revealed that the use of the hermetic storage system would not only improve farmer and trader profits, but also reduce the incidence of various ailments attributed to aflatoxins. / Ph. D.

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