Dissertations / Theses on the topic 'CATWOE Analysis'

Záměrem předložené disertační práce je porozumět tomu, jak investoři v konkrétním společenském kontextu vnímají význam kvality informačních systémů. Ze studia literatury zabývající se přístupy a rámci hodnocení kvality informačních systémů vyplývá, že tato kvalita je obecně hodnocena z hlediska striktního přístupu. V této práci je ukázáno, že kvalitu informačního systému lze smysluplně pochopit použitím interpretačního paradigmatu a že kvalita informačního systému je definována společensky a ovlivňována kontextem tohoto systému. Studie byla zahájena průzkumem dvaceti libyjských organizací. Podrobnější data byla získána z případové studie dvou vybraných libyjských organizací působících ve veřejném sektoru. Při empirické analýze nashromážděných dat bylo využito rámce mnohočetné perspektivy, který zahrnuje hlediska teorie strukturalizace, pojem mnohočetných perspektiv a metodologii měkkých systémů. V práci se dospělo ke zjištění, že: a) kvalita informačních systémů je pojata šíře, než je tomu u tradiční definice kvality, b) mnohočetné perspektivy kvality informačních systémů jsou ovlivněny opakovanou interakcí mezi investorem a institucionálními vlastnostmi kontextu informačního systému a že c) rozdílné hodnoty v kulturním prostředí a vnějším kontextu ovlivňují rozsah působnosti investora a interakce v kontextu informačního systému. Ze závěru práce vyplývá, že společenská skladba mnohočetných perspektiv kvality informačního systému je ovlivněna strukturalizačními procesy mezi investory a vlastnostmi v kontextu informačního systému.

Jembrana disease is an acute and severe disease of Bali cattle (Bos javanicus) endemic in Indonesia that is caused by a bovine lentivirus designated Jembrana disease virus (JDV). Previous studies have demonstrated that it is possible to induce a protective immunity against the disease by immunisation with a crude whole virus vaccine prepared from the tissues of infected cattle. This vaccine has been demonstrated to ameliorate the clinical signs of disease resulting from exposure to virus infection but a safer vaccine amenable to commercial production techniques is required. JDV, like all lentiviruses, encodes a transcriptional trans-activator Tat protein that is encoded from one or both of two exons of the tat gene. Tat is particularly essential for virus replication and it was hypothesised that the induction of an immune response in cattle against JDV Tat may effect protection against virus infection. Investigations were therefore conducted on JDV Tat to provide basic information on the protein that would enable it to be further investigated as a potential immunogen for incorporation into vaccines for the control of Jembrana disease. Analysis of tat transcripts obtained from tissues of cattle infected with three strains of JDV suggested that, during the acute clinical disease, Tat produced at this stage of the disease process was translated from the first coding exon only. Nucleotide variation in this exon, which would have translated into amino acid variations in the Tat protein, was evident especially between strains from geographically different regions of Indonesia. There was; however, conservation of the essential functional domains of cysteine-rich, core and basic regions, which suggested immunity to a single Tat protein might protect against infection by heterologous strains. Subsequent studies on Tat reported in the thesis therefore concentrated on the protein encoded by tat exon 1 of a single strain of JDV. The exon 1 of tat was cloned into the pGEX vector and recombinant Tat expressed in Escherichia coli. Methods for the purification of the expressed protein were developed. Immunogenicity of the recombinant protein was initially demonstrated by inoculation of the protein into a sheep which developed a high titred specific antibody response. Antibodies induced by this recombinant protein recognised native Tat proteins produced by three JDV strains in Bali cattle and provided a valuable reagent for the subsequent detection of Tat in vitro and in vivo. Aspects of the antibody response to Tat were determined in cattle that had been infected naturally or experimentally with JDV, and compared with the levels of antibody to the immunodominant capsid protein. Tat antibodies were detected in 23 % of 128 Bali cattle from Jembrana disease-endemic areas of Indonesia; in all these cattle, evidence of previous virus infection had been demonstrated by detection of antibody to the JDV capsid protein by Western blot analysis. In cattle experimentally infected with JDV, low levels of serum antibody to Tat were detected by Western blot in the first month post-infection but the levels of antibody then decreased; levels of antibody to the JDV capsid protein increased over the 6-month observation period following infection. The detection of Tatantibody soon after the acute clinical disease suggested that this protein is secreted extracellularly during JDV infection in cattle. In contrast to the antibody response to Tat in JDV-infected cattle, an apparently greater antibody response to Tat was induced by injection of recombinant Tat in Bali cattle. The strong antibody response resulting from inoculation of the recombinant Tat and low levels of Tat antibody in animals that had been naturally or experimentally infected with virus suggested there might be a conformational difference in the recombinant and native Tat protein and that the native protein was a poor immunogen, or that the levels of Tat in infected cattle were too low to induce a strong antibody response. As an alternative means of inducing an immune response to JDV Tat, perhaps one associated with a greater cell-mediated rather than an antibody response, a candidate tat DNA vaccine was produced by insertion of tat exon 1 into a DNA vaccine vector. Transfection of this naked DNA plasmid into mammalian cells induced the expression of a functional Tat protein which maintained antigenicity. The results suggested this construct merits further animal studies attempting to induce a protective immune response against Jembrana disease in cattle. A method of assaying the trans-acting function of Tat was also developed which will have application for quality control procedures for large-scale production of tat DNA vaccine.

The aim of this project was to isolate a functional BoLA class I gene, to transfect this into L cells and to investigate the possibility of a second BoLa class I locus. Attempts to isolate a functional BoLA class I gene from a cosmid library were unsuccessful, but clones encoding complete BoLA genes were successfully identified from a bacteriophage library. This library was made from animal 10769 which has BoLA type w10/w11 and the genes were identified with a class I cDNA probe, pBoLA-1. These clones were transfected into mouse L cells to look for expression. One of the clones, 19.1, expressed class I molecules when analysed by indirect immunofluorescence on the FACScan and by fluorescence microscopy. The Northern blot analysis confirmed class I transcription products when probed with pBoLA-1. Clone 19.1 was identified as encoding a w11 gene by a microlymphocytotoxicity test. Also in a T cell cytotoxicity assay, Ltk 19.1 cells were killed by alloreactive anti w11 cytotoxic T cell clones but not by anti w10 clones. Nucleotide sequencing of gene encoded in 19.1 demonstrated homology between this and BoLA cDNA clones and HLA. Therefore a functional BoLA class I gene with a BoLA type w11 was isolated and is a stepping stone to many other investigations.

The aims of this project were i) to take measures of behaviour in cattle that could be demonstrated to be reliable indicators of temperament traits, and ii) to look for areas of the genome harbouring genes involved in these traits. Behavioural tests were carried out on a large number of animals from a Charolais x Holstein cross-bred herd. Four different tests were examined for their potential to measure different temperament traits: a Flight-from-Feeder Test (FF), a Social Separation Test (SS), a Novel Object Test (NO) and a Handling Test (HA). The results of the tests were assessed using two criteria: inter-animal variability and intra-animal repeatability. The FF, SS and HA Tests showed high values in these two criteria. Experiments were then carried out to validate these three tests, by examining whether relationships were seen between responses from different test situations that were though to measure the same traits. Full validation of the three tests was not achieved. Experiments were also carried out to investigate how stable the behaviour measurements remained with increasing age. Results of SS and HA Tests carried out at four months of age were compared with those from the same tests repeated on the animals at 12 months of age. A relationship was found between SS measures from the two ages. Results from behavioural tests carried out on heifers at 10 months of age were compared with behaviour scored in the dairy parlour at 30 months. The measurements at the younger age were not predictive of adult behaviour in the diary. In order to localise areas of the genome involved in the behavioural traits, preliminary Quantitative Trait Loci (QTL) analysis was carried out on four chromosomes. Associations between behavioural phenotypes from the FF and SS Tests and the inheritance of DNA markers were examined for a large number of animals. The possible effects of environmental factors on the test results were examined prior to the analysis. Four putative QTL locations were identified.

Orientador: Roberto Carvalheiro
Coorientador: Danísio Prado Munari
Coorientador: Haroldo Henrique de Rezende Neves
Banca: Fernando Sebastián Baldi Rey
Banca: Idalmo Garcia Pereira
Resumo: O objetivo deste estudo foi estimar os componentes de variância para a característica aprumo em bovinos da raça Nelore, e realizar estudos de associação genômica ampla para identificar possíveis regiões genômicas relacionadas com sua expressão. Os registros de aprumo foram obtidos pela atribuição de escores visuais em dois momentos diferentes: FL1) característica binária medida ao sobreano, com o objetivo de identificar se o animal apresenta (FL1=1) ou não (FL1=0) defeito de aprumo; FL2) escores de aprumo variando de 1 (menos desejável) a 5 (mais desejável), foram designados aos animais top 20% para o índice de seleção adotado pelo programa de melhoramento genético de bovinos de corte PAINT (CRV Lagoa), e foram medidos em torno de 2 a 5 meses após a avaliação de sobreano. As características FL1 e FL2 foram avaliadas em conjunto com peso ao sobreano (YW). Os componentes de variância e covariância e os valores genéticos foram estimados por inferência Bayesiana, por meio de modelo animal bi-característica (três análises: FL1-FL2, YW-FL1 e YW-FL2). O estudo de associação genômica ampla (GWAS) para FL1 e FL2 foi realizado utilizando o método weighted single-step GBLUP, a partir do qual foram estimados os efeitos dos SNPs. As janelas top 10 de 1 Mb que explicam a maior proporção da variância genética foram observadas para cada característica. As médias (erros padrão) a posteriori das estimativas de herdabilidade foram iguais a 0,18 (0,04) e 0,39 (0,07), para FL1 e FL2, respectivamente. A estimativa de correlação genética entre FL1 e FL2 (-0,47) foi de moderada magnitude e negativa, conforme esperado, considerando que o escore de classificação que favorece cada característica corresponde a valores numéricos atribuídos em sentidos opostos. A correlação genética estimada entre FL2 e YW (0,39) sugere que a média do peso ao sobreano da população em estudo não é alta a ponto de causar...
Abstract: The aim of this study was to estimate variance components of two traits associated to feet and legs in Nelore cattle and identify putative genomic regions underlying the expression of these traits through genome-wide association (GWA) analyses. Feet and legs was evaluated by the assignment of visual scores at two different moments: FL1) binary trait measured at yearling (about 550 days of age), aimed to identify whether an animal had defects related to feet and legs (FL1=1) or not (FL1=0); FL2) feet and legs score ranging from 1 (less desirable) to 5 (more desirable) was assigned to the top 20% animals for the selection index adopted by the beef cattle breeding program PAINT (CRV Lagoa), which were measured around 2-5 months after the evaluation of yearling. The FL1 and FL2 traits were evaluated together with yearling weight (YW). The components of variance and covariance and breeding values were estimated by Bayesian inference, using two-trait animal models (three analyses: FL1-FL2, YW-FL1 and YW-FL2). The genome-wide association (GWA) analyses for FL1 and FL2 was performed using the weighted single-step GBLUP method, from which were estimated the SNP effects. Functional annotation was focused on the ten 1Mb windows explaining the largest fraction of the genetic variance for each trait. Posterior means (standard errors) of heritability estimates were equal to 0.18 (0.04) and 0.39 (0.07), for FL1 and FL2, respectively. The estimate of genetic correlation between FL1 and FL2 (-0.47) was of moderate magnitude and negative, as expected considering that the classification score that favors each trait represents numerical values assigned in opposite directions. The genetic correlation estimated between FL2 and YW (0.39) suggests that the average yearling weight of the studied population is currently not high enough to cause a negative association with feet and legs problems. The genetic trends estimated for FL1 and FL2 (-0.043 and ...
Mestre

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O objetivo deste estudo foi estimar os componentes de variância para a característica aprumo em bovinos da raça Nelore, e realizar estudos de associação genômica ampla para identificar possíveis regiões genômicas relacionadas com sua expressão. Os registros de aprumo foram obtidos pela atribuição de escores visuais em dois momentos diferentes: FL1) característica binária medida ao sobreano, com o objetivo de identificar se o animal apresenta (FL1=1) ou não (FL1=0) defeito de aprumo; FL2) escores de aprumo variando de 1 (menos desejável) a 5 (mais desejável), foram designados aos animais top 20% para o índice de seleção adotado pelo programa de melhoramento genético de bovinos de corte PAINT (CRV Lagoa), e foram medidos em torno de 2 a 5 meses após a avaliação de sobreano. As características FL1 e FL2 foram avaliadas em conjunto com peso ao sobreano (YW). Os componentes de variância e covariância e os valores genéticos foram estimados por inferência Bayesiana, por meio de modelo animal bi-característica (três análises: FL1-FL2, YW-FL1 e YW-FL2). O estudo de associação genômica ampla (GWAS) para FL1 e FL2 foi realizado utilizando o método weighted single-step GBLUP, a partir do qual foram estimados os efeitos dos SNPs. As janelas top 10 de 1 Mb que explicam a maior proporção da variância genética foram observadas para cada característica. As médias (erros padrão) a posteriori das estimativas de herdabilidade foram iguais a 0,18 (0,04) e 0,39 (0,07), para FL1 e FL2, respectivamente. A estimativa de correlação genética entre FL1 e FL2 (-0,47) foi de moderada magnitude e negativa, conforme esperado, considerando que o escore de classificação que favorece cada característica corresponde a valores numéricos atribuídos em sentidos opostos. A correlação genética estimada entre FL2 e YW (0,39) sugere que a média do peso ao sobreano da população em estudo não é alta a ponto de causar ...
The aim of this study was to estimate variance components of two traits associated to feet and legs in Nelore cattle and identify putative genomic regions underlying the expression of these traits through genome-wide association (GWA) analyses. Feet and legs was evaluated by the assignment of visual scores at two different moments: FL1) binary trait measured at yearling (about 550 days of age), aimed to identify whether an animal had defects related to feet and legs (FL1=1) or not (FL1=0); FL2) feet and legs score ranging from 1 (less desirable) to 5 (more desirable) was assigned to the top 20% animals for the selection index adopted by the beef cattle breeding program PAINT (CRV Lagoa), which were measured around 2-5 months after the evaluation of yearling. The FL1 and FL2 traits were evaluated together with yearling weight (YW). The components of variance and covariance and breeding values were estimated by Bayesian inference, using two-trait animal models (three analyses: FL1-FL2, YW-FL1 and YW-FL2). The genome-wide association (GWA) analyses for FL1 and FL2 was performed using the weighted single-step GBLUP method, from which were estimated the SNP effects. Functional annotation was focused on the ten 1Mb windows explaining the largest fraction of the genetic variance for each trait. Posterior means (standard errors) of heritability estimates were equal to 0.18 (0.04) and 0.39 (0.07), for FL1 and FL2, respectively. The estimate of genetic correlation between FL1 and FL2 (-0.47) was of moderate magnitude and negative, as expected considering that the classification score that favors each trait represents numerical values assigned in opposite directions. The genetic correlation estimated between FL2 and YW (0.39) suggests that the average yearling weight of the studied population is currently not high enough to cause a negative association with feet and legs problems. The genetic trends estimated for FL1 and FL2 (-0.043 and ...

Orientador: Ana Fabrícia Braga Magalhães
Resumo: ABSTRACT – Preweaning calf mortality is one of main causes of economic losses in beef cattle, since most of economic incomes are represented by the number of weaned calves available for sale. It is also detrimental for genetic progress due to the reduction of young candidates for selection. The inclusion of molecular markers in genetic analysis allows a better understanding of genetic mechanisms underlying calf mortality. The objectives of this study were: i) to estimate direct and maternal heritability of preweaning calf mortality in Nellore cattle and ii) to seek for genomic regions and candidate genes affecting direct and maternal effects of preweaning calf mortality in Nellore cattle. Variance components were estimated via Bayesian Inference using a threshold animal model, that included the systematic effects of contemporary group, birth weight as linear covariate, and age of dam at calving as linear and quadratic covariates. The direct and maternal genetics, and the residual were fitted as random effects. The final dataset used contained phenotypic records on 67,196 animals, offspring of 1,469 sires and 30,970 dams. The SNPs effects were estimated based on the weighted single-step GBLUP approach, using information of 8,443 genotyped animals with 410,936 SNPs. Direct and maternal heritability estimates were of 0.2143±0.0348 and 0.0137±0.0066, respectively. The top 10 genomic regions accounted for 13.61 and 14.23% of direct and maternal additive genetic variance and harbor... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre

Thesis (M.S.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 7, 2009) Includes bibliographical references.

In this study the effects of blood sampling, transportation and slaughter on certain blood variables (sodium, potasium, chloride, glucose, lactates, lipids, proteins, colloidal osmotic pressure, cortisol, ACTH, T3, TSH, osmolality etc.) of cattle were investigated. The experimental animals, crossbreed (Brahman, Afrikander and Hereford) heifers and oxen obtained from Kanhym Estates, Middelburg, were unaccustomed to handling. One group of animals was subjected to the stress of sampling with restraint, a second group was sampled with restraint after transportation and a third group had blood taken after slaughter at the Kanhym abattoir at Balfour. Control blood samples were obtained from Friesland dairy cows accustomed to handling and blood sampling and from crossbreed oxen unaware of the sampling procedure. Both control and experiment groups were studied in the same season. (April and May, 1984). Results were analysed and compared statistically. The blood cortisol, ACTH, lactates and glucose were significantly higher in the experimental groups than in the control group. Cortisol and ACTH values were significantly higher, and the lactate and glucose values significantly lower in the group subjected to the stress of sampling with restraint than in the other two experimental groups. Therefore, if the variables measured are an assessment of stress and change because of stress, then the animals investigated experienced stress. In addition, cattle unaccustomed to handling perceive the slaughtering process as less stressful than blood sampling in a crush (based on cortisol and ACTH results).

An engineering analysis of the fugitive particulate matter emissions from a feedyard is not simple. The presence of an evening dust peak in concentration measurements downwind of a feedyard complicates the calculation of an average 24-h emission flux for the feedyard. The evening dust peak is a recurring event that occurs during evening hours when particulate matter concentration measurements increase and decrease dramatically during a short period of time. The concentrations measured during the evening can be up to 8 times the concentrations measured throughout the rest of the day. There is a perception that these concentration increases are due to increases in cattle activity as the temperature decreases during the evening. The purpose of Objective 1 of this research was to quantify the changes in concentrations based on changes in meteorological conditions and/or cattle activity. Using ISCST3, a Gaussian-based EPAapproved dispersion model used to predict concentrations downwind of the feedyard , the results of this work indicate that up to 80% of the increase in concentrations can be attributed to changes in meteorological conditions (wind speed, stability class, and mixing height.)The total fugitive particulate matter emissions on a cattle feedyard are due to two sources: unpaved roads (vehicle traffic) and pen surfaces (cattle activity). Objective 2 of this research was to quantify the mass fraction of the concentration measurements that was due to unpaved road emissions (vehicle traffic). A recent finding by Wanjura et al. (2004) reported that as much as 80% of the concentrations measured after a rain event were due to unpaved road emissions. An engineering analysis of the potential of the unpaved road emissions versus the total feedyard emissions using ISCST3 suggests that it is possible for 70 to 80% of the concentration measurements to be attributed to unpaved road emissions. The purpose of Objective 3 was to demonstrate the science used by ISCST3 to predict concentrations downwind of an area source. Results from this study indicate that the ISCST3 model utilizes a form of the Gaussian line source algorithm to predict concentrations downwind of an area source.

At the heart of long term sustainable soil management is chemical fertility through the retention of exchangeable cations. Many current concepts of cation exchange and its relationship with base cation availability remain unchanged over the past century. Despite considerable advancements in analytical techniques many methods used today would be familiar to our forefathers. Comparative studies were undertaken in this thesis to understand how techniques to measure exchangeable soil ions could be enhanced and matched to defined scenarios. The total amount of cations that can be retained electrostatically on soil surfaces is termed the cation exchange capacity (CEC). An ability to systematically and consistently measure CEC is an essential step in soil characterisation. Compulsive exchange methods (using either 1.0 M NH4OAc or 0.05 M BaCl2) at a fixed pH value for determining CEC were scrutinised but acknowledged to be prone to systematic artefacts. The relationship between soil pH, soil texture and CEC was soil specific. When the batch method was compared with the column leach method, the former was more consistent for all soils. For calcareous soils BaCl2 was more suitable but NH4OAc was more generally applicable. The CEC was consistently significantly greater by the compulsive technique when compared with the effective method. The NH4OAc extraction method was applied to soils contaminated with potentially toxic elements (PTEs). The exchangeable concentration of PTEs correlated with total PTE loading. However, the exchangeable Ca decreased with amendment rate confirming an exchange of sites by PTEs. The compulsive technique extracted PTEs that were significantly 2 negatively correlated with soil basal respiration, phosphatase activity, potential nitrification rate (PNR) and the soil microbial biomass carbon. This confirms that of this method is evaluating the bioavailable/bioreactive fraction. Soil cation exchange capacity and exchangeable base cations increased commensurate with the amendment loading of bentonite and charcoal. The exchange capacity was also soil specific. Following amendments, the exchange capacity was higher after six weeks than after thirty weeks. This means that the amendment performance became impaired with time perhaps as the fine soil particles coated the ameliorant causing a decline in CEC. The difference between the effective and compulsive CEC was described as the calculated CEC. This was very sensitive to soil pH and was confirmed in a detailed study at a site where pH plots were amended over a five decade period. As pH rose, so did the exchangeable fraction of Ca, Mg and K. As the pH declined, Al, Fe and Mn exchangeability increased. Extraction techniques must be sympathetic of the soil pH value. The quantification and characterisation of exchangeable cations remains as fundamental a component of soil science today as it was a century ago.

The use of feed additives (e.g. yeasts products) for reduction of ruminants’ methane (CH4) production has drawn the attention of cattle nutritionists and environmentalists. Although there are many relevant studies on this topic, but the obtained results for dairy and beef cattle are contradictory. Therefore, the objective of the present study is to examine the effect of yeast (Saccharomyces cerevisiae) on reduction of CH4 production in dairy and beef cattle using meta-analytic methods. After compilation of relevant articles published between 1990 and 2016 and applying exclusion and inclusion criteria, meta-analyses of data from dairy and beef cattle were applied for the pooled dataset or for each animal category (dairy or beef). The effect size of yeast on CH4 production (g/day) and CH4 production per dry matter intake (CH4/DMI (g/kg)) was estimated as standardized mean difference at 95% confidence interval. In addition, heterogeneity across studies was tested by using Q test and I2 index. Study bias was verified through Funnel plot and trim-and-fill method. The results of meta-analysis of all 3 groups of animals (all cattle, dairy cattle, and beef cattle) suggested that effect size of yeast on CH4 production (g/day) and CH4/DMI (g/kg) was not significant. In other words, the use of yeast for dairy and beef cattle did not reduce CH4 production and CH4/DMI (g/kg) significantly. The results of Q test and I2 index suggest that there is no heterogeneity between different studies on CH4 production and CH4/DMI (g/kg) so that value of I2 index of CH4/DMI (g/kg) in dairy and beef cattle was about 14% while for dairy cattle, the index is about 40%. There was no study bias of CH4 production as well as CH4/DMI (g/kg). As shown in funnel plot, the studies are more concentrated in the lowest part of the plot. The results of meta-analysis suggest that use of yeast (Saccharomyces cerevisiae) as feed additive does not offer significant results in terms of reduction of CH4 production in dairy and beef cattle. It is recommended to conduct further studies on effect of different doses of yeast, use of yeast products, different strains and experimental designs.

This research sought to elucidate the molecular mechanism by which a recently described family of ion transport proteins, the cation diffusion facilitators (CDFs), transfer ions across biomembranes. Using the Escherichia coli homologs ZitB, and FieF, as well as CzcD from Cupriavidus metallidurans CH34 as models, the amino acids essential to CDF function were identified, and the transport behavior of ZitB and its homolog FieF, were described.Site-directed ZitB mutants were used to determine the necessity of individual amino acids. The mutation of several well-conserved acidic residues resulted in the loss of a ZitB-mediated zinc-resistant phenotype in the zinc-sensitive E. coli strain GG48. ZitB also complemented the potassium uptake deficient strain TK2420, suggesting that ZitB works as an antiporter, possibly allowing potassium into the cell while effluxing zinc.This result was further investigated in experiments using everted membrane vesicles(EMVs). Vesicles bearing ZitB accumulated 65Zn(II) in a NADH-dependent manner, with an apparent KM of 1 micromolar. This accumulation was inhibitable by the protonophore FCCP, suggesting CDF dependence upon the proton motive force. Similar results were obtained using both EMVs and proteoliposomes containing the CDF homologs CzcD, from C. metallidurans CH34, and FieF from E. coli. Despite facilitating 65Zn(II) uptakeinto EMVs, fieF transcription was zinc and iron-dependent, but independent of the ironuptake regulator Fur. FieF expression in trans complemented the iron-sensitive phenotypeof a strain lacking fur, causing it to accumulate less 55Fe than wild type. Reconstituted proteoliposomes containing FieF also accumulated less 55Fe than those without.This research confirms that CDF proteins likely depend on the cell's proton gradient, effluxing substrate in a metal:proton antiport arrangement. Substrate acquisition and throughput is facilitated by a set of acidic amino acids and histidines. The relatively lowapparent KM of ZitB suggests a homeostatic role for the protein; however, the iron-inducibilityof fieF hints at a role in iron detoxification, so the cellular functions of the CDF family may be quite diverse, even within the bacteria.

京都大学
新制・課程博士
博士(人間・環境学)
甲第23286号
人博第1001号
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 内本 喜晴, 教授 田部 勢津久, 教授 高木 紀明
学位規則第4条第1項該当
Doctor of Human and Environmental Studies
Kyoto University
DFAM

Kyoto University (京都大学)
0048
新制・課程博士
博士(人間・環境学)
甲第22549号
人博第952号
新制||人||226(附属図書館)
2019||人博||952(吉田南総合図書館)
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 内本 喜晴, 教授 吉田 寿雄, 准教授 戸﨑 充男
学位規則第4条第1項該当

Master of Science
Department of Biological and Agricultural Engineering
Zifei Liu
This study reviewed state-of-the-art cattle enteric methane (CH4) emissions with three reported measuring units: g/head/d, g/kg DMI (dry matter intake), and %GEI (gross energy intake). Cattle emissions studies included in this meta-analysis were reported from 1995 to 2013. Fifty-five published studies were analyzed with specific objectives: (1) to gain basic information regarding magnitudes and distributions of enteric CH4 emission rates with various units, regions, cattle types and feed situations; (2) to identify and evaluate effects of influence factors or diet mitigation techniques on enteric CH4 emissions; and (3) to evaluate Intergovernmental Panel on Climate Change (IPCC) approaches to estimate enteric CH4 emissions. Emissions data (n=165) with the unit of g/head/d had large variances and non-normal distribution, and were not homogeneous across the studies. Emissions data (n=134) with the unit of g/kg DMI were not homogeneous across the studies, while emissions data (n=76) with the unit of %GEI had small variances and normal distribution, and were homogeneous across the studies. Therefore, data with the unit of %GEI may be better for meta-analysis compared to data with the units of g/head/d and g/kg DMI; however, the number of data with the unit of %GEI was small relative to the number of data with the units of g/head/d and g/kg DMI. Enteric CH4 emissions with the unit of g/head/d are significantly influenced by geographic region, cattle classification, sub-classification, humidity, temperature, body weight, and feed intake. Emissions and feed intake had a strong positive linear relationship with R2 of 0.75 (n=148). Emissions with the unit of g/kg DMI are significantly affected by humidity, body weight, and feed intake. The relationship between emissions and feed intake is positive. Emissions with the unit of %GEI are significantly associated with humidity, production stage, and body weight. IPCC Tier 1 and Tier 2 estimated emissions were approximate to most of the measured enteric CH4 emissions; however, the residuals were not normally distributed. Based on results from PRD method and paired t-tests, IPCC Tier 1 overestimated emissions in Asian studies, underestimated emissions in European studies for beef cattle, and underestimated emissions in Oceanian studies for dairy cattle. IPCC Tier 2 underestimated emissions in Asian studies for beef cattle. The underestimated emissions of IPCC Tier 2 in Asian studies might result from no consideration of effects from production stage and body weight.

The British cattle population hosts a diverse community of endemic pathogens that impact the sustainability of beef and dairy production. As such, there has been a tremendous amount of ongoing research to develop more cost-effective strategies for controlling disease at the industry level. Cattle movements have come under particular scrutiny over the past decade both because of their role in spreading many economically important diseases and because the movements of individual cattle in Great Britain have been explicitly recorded in a centralized electronic database since 1998. Numerous studies have shown that these cattle movements organize into complex networks with key structural and temporal features that influence transmission dynamics. Building on previous work, this thesis used a variety of epidemiological and statistical models to highlight limitations in the current approaches to controlling disease as well as opportunities for reducing endemic disease prevalence through targeted interventions. Empirical disease data from the national bovine tuberculosis (bTB) control programme and from two seroprevalence studies of bovine viral diarrhoea virus (BVDV) in Scottish cattle herds were used in conjunction with movement data from the Cattle Tracing System (CTS) database. Endemic diseases are often challenging to control due to lack of affordable and accurate diagnostic tests as well as the presence of subclinically infected carriers that can easily escape detection. There was evidence that combined issues with the sensitivity and specificity of routine surveillance methods for bTB were contributing to a low level of disease transmission within and between Scottish cattle herds from 2002 to 2009. For BVDV, herds that purchased pregnant beef dams, beef dams with a calf at foot, and open dairy heifers were significantly more likely to be seropositive even though these movements were responsible for only a small number of network contacts. In both cases, targeting the subset of high risk movements with disease specific biosecurity measures may be a more cost-effective use of limited national disease control resources. Other researchers have suggested that control strategies should target multiple diseases simultaneously to reduce trade-offs in resource allocation. Using key indicators of herd reproductive performance derived from the CTS database, it was shown that improving the reproductive management of herds operating below industry standards could reduce endemic disease prevalence by reducing the movements of replacement breeding cattle. A series of network generation algorithms were also developed to study the effects of restricting contact formation based on key demographic and network characteristics of actively trading cattle farms. Strategies that increased network fragmentation either by forcing highly connected farms to form contacts with other highly connected farms or preventing the formation of movements with a high predicted betweenness centrality were found to be particularly effective in limiting disease transmission. For these models to be useful in guiding future policy decisions, it is important to incorporate financial and behavioural drivers of dynamic network change. Following the introduction of pre- and post-movement testing requirements for cattle imported into Scotland from endemic bTB regions, there was a significant decline in cross-border movements, which has likely contributed to the decreasing risk of bTB outbreaks as much as testing itself. Many endemic cattle diseases such as BVDV also spread through local transmission mechanisms, which may undermine the success of disease control programmes that exclusively target cattle movements. There was also evidence that in the absence of national animal legislation, few farmers were likely to adopt biosecurity measures against BVDV. This may be related to the perceived inefficacy of recommendations as well as general unawareness of farm disease status due to the non-specific clinical signs of BVDV outbreaks. Although the CTS database was originally intended for use in slaughter traceback investigations, results from this thesis show how the basic records of births, deaths, and movements can be used to generate valuable insights into the epidemiology of endemic cattle diseases. The findings also emphasize that the management decisions of individual herds can have a substantial impact on industry level transmission dynamics, which offers unique opportunities to develop novel and more cost-effective disease control programmes.

Master of Science
Department of Agricultural Economics
Kevin C. Dhuyvetter
The 2008 National Stocker Survey defines the backgrounding/stocking of cattle as ―operations where calves are grown after weaning and/or preconditioning but before the feedlot. This includes calves purchased for this purpose as well as those retained by cow-calf producers post-weaning, but before marketing or retention through the feedlot. Backgrounding offers many benefits to farmers including, but not limited to, adding value to their feedstuffs—hay, grain, etc.—by feeding it to their cattle and potentially spreading risk by increasing marketing time or engaging in contracts with feedlots. However, producers also take on increased costs as it takes more time to wean, bunk-train, vaccinate, etc. compared to other operations in the cattle industry. This thesis attempts to analyze two studies using the 2008 National Stocker Survey. The first is how producer and operation characteristics—producer age, type of operation, income derived from backgrounding—relate to why producers find variables such as cattle prices, animal health management, marketing practices, and nutrition important. The second is how producer and operation characteristics relate to producers that use futures market contracts and options on futures. Binary and ordered logit models were used to find the statistical significance of the aforementioned studies.Since this survey was specifically designed to profile the stocking/backgrounding industry, some of the estimated models did not add a lot of value beyond the summary statistics for the various dependent variables. That is, the ordered logit models did not identify any strong relationships given that almost all of the producers that responded to these questions found feeder cattle prices, animal health management, marketing practices, and nutrition very important, which can be seen by analyzing the summary statistics. In addition, the binary logit models that were used for the futures market contract and options on futures models, found that the best way to pinpoint producers using either futures contracts or options was if producers were already using risk management strategies. Therefore, the survey’s purpose of profiling the stocker industry may be its best use.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016.
The main purpose of this study is to understand the application of ion exchange chromatography on separation of charged ions of elements. Ion exchange chromatography is an analytical method, which is used for the separation of elements, quantitation and qualitation. The use of Amberlyst 15 resin as a source of separation for metal ions has been investigated and studies in various academic disciplines such as chemistry and material science. In this research study, Amberlyst 15 resin was investigated in order to understand the separation of positively charged divalent elements ions (Zn2+, Cu2+, Co2+ and Ni2+). The use of nitric acid and methanol mixture enhanced separation of these metal ions by ensuring that nitric acid is constant and varying methanol concentration. In this study, it was found that the resin has a high affinity for the metal ions at high methanol concentration, hence the distribution coefficient values increase but decreases at low methanol concentrations. The complexities of molecular structure of the salts of the elements provide the more understanding of the metal ion interaction with the resin particle. Furthermore, the role and strength of nitric acid to break the structural bonds and release the metal ions to get sorbed on the resin remains the most essential factor of understanding distribution coefficient values. Method validation parameters such as linearity, precision and accuracy of the method were determined. The method precision and accuracy were determined from the QC samples which is expressed as relative error (%RE) with the total coefficient of variation (%CV’s) were < 20%.

Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains vi, 163 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 132-136).

This study analyzes the economic impact of a recent gene marker innovation for seedstock selection in beef cattle. Gene markers are being developed for many beef cattle attributes; this study focused on the tenderness quality of beef using two categories: tender and tough. The study begins by describing conventional procedures for seedstock selection, the science which underlies selection by gene markers and other non-genetic procedures currently being used to improve beef tenderness. After describing the commercialization of the gene marker innovation, a stylized model of a beef supply chain is constructed. The supply chain consists of a representative consumer, a producer/processor group and a monopolist supplier of the patented technology. Welfare changes resulting from the adoption of the innovation were simulated using four sets of demand elasticity data from literatures. An important focus of this research is determining how the economic surplus from the innovation will be shared by consumers, producers and the gene marker monopolist. The consumer and gene marker monopolist benefit from the technology unless the marginal and fixed cost variables (not estimated in this study) of the monopolist, are excessively high. Producer surplus was simulated as positive with three of the four elasticity data sets. The share of surplus capture by producers is generally low relative to the gains captured by consumers and the gene marker monopolist. Comparative static analysis reveal that the benefit from the innovation varies across breeds, being higher for breeds in which the favorable form of the marker gene is more likely to be present. Despite the apparent benefits of the innovation for beef supply chain participants, reported interviews with industry scientists reveal that markers should not be viewed as a replacement for conventional selection techniques. Indeed, selecting seedstock on the basis of a small number of available markers is not likely to produce the benefits that are currently being promised by life science companies. Consequently, this study recommends that the innovation be incorporated into existing seedstock selection practices. Much more analysis is needed to understand the full economic impact of gene markers for beef tenderness and for other beef quality attributes.

Thesis (M.S.)--University of Kentucky, 2005.
Title from document title page (viewed on November 8, 2005). Document formatted into pages; contains viii, 90 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 86-88).

Thesis (M.S.)--Michigan State University. Dept. of Agricultural, Food, and Resource Economics, 2008.
Title from PDF t.p. (viewed on July 28, 2009) Includes bibliographical references (p. 105-108). Also issued in print.

Accurate economic quantification of the effects of Fasciola gigantica infections in cattle and sheep is essential to justify allocation of resources for control programmes. The present studies considered the comparative pathogenesis and economic loss caused by F. gigantica infection in young cattle and sheep of different breeds. Young cattle (Friesian and Boran) and sheep (Dorper and Red Maasai) were infected with single doses of F. gigantica metacercariae to produce chronic infections in cattle and acute, subacute and chronic infections in sheep. The animals were monitored parasitologically, biochemically and serologically. Immunochemical analysis of F. gigantica excretions/secretions using Western blotting and ³⁵S-methionine biosynthetic radio-labelling were carried out with a view to identifying polypeptides of potential use in early prepatent diagnosis and protection and also to determine if there were any apparent species or breed differences in humoral antibody response to the parasite which may correlate with the differences in susceptibility/resistance to infection noted in the two species. When examined by routine meat inspection procedures, all the livers of infected cattle and sheep were condemned as unfit for human consumption. Based on the prepatent periods, weight loss and degrees of liver damage, production losses were found to be less severe in the Friesians than the Borans. Friesians, infected with 0.95 flukes/kg live weight lost an equivalent of 63g/fluke/year while the Borans, which had 1 fluke/kg live weight lost 157g/fluke/year. The Borans had higher haematological values (RBC counts, PCVs and haemoglobin concentrations) suggesting that they were less liable to develop anaemia as a result of infection than the Friesians. Interbreed differences were also seen in live weights and carcass weights of sheep. Mortalities were encountered at all levels of infection in sheep but were heaviest in acute infections where animals died at 12 weeks p.i. Subacute infections caused heavier live weight losses than chronic infection (4.2 and 4.5 g/fluke/week) in the infected Dorpers and Red Maasai respectively and there was a lower recovery from the latter, while chronic infections resulted in a loss of 2.4 and 3.1g/fluke/week respectively.

Orientador: Lucia Galvão de Albuquerque
Resumo: A seleção de animais geneticamente superiores com base na informação genômica tem sido uma tendência crescente e promissora em programas de melhoramento. No entanto, os principais métodos de predição genômica envolvem modelos paramétricos, que em sua maioria, assumem somente variância aditiva para o efeito dos marcadores, ignorando-se possíveis relações não-lineares. A consideração de tais efeitos pode ser importante para melhorar a habilidade de predição em características com arquitetura genética complexa. Recentemente, tem crescido o interesse em métodos de predição semi e não paramétricos. Dentro desse contexto, os métodos de aprendizagem de máquina tais como Redes Neurais Artificiais (ANN), “Random Forest” (RF) e “Support Vector Machines” (SVM) são alternativas interessantes. Os objetivos do presente estudo foram: i) Comparar o desempenho preditivo do modelo “Genomic Best Linear Unbiased Predictor” (GBLUP) e de métodos de aprendizagem de máquina em populações simuladas de bovinos de corte, apresentando diferentes níveis para efeitos de dominância; ii) Investigar a habilidade de predição de diferentes métodos de aprendizagem de máquina para predição genômica de características reprodutivas em bovinos da raça Nelore; iii) Desenvolver um estudo de associação genômica ampla (GWAS) utilizando a metodologia “Random Forest”, a fim de buscar genes candidatos para idade ao primeiro parto em novilhas da raça Nelore. No primeiro estudo, o genoma simulado compreendeu um painel de SN... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The selection of genetically superior animals based on genomic information has been an increasing and promising trend in breeding programs. However, the main methods used for genome-enabled prediction involve parametric models that mostly assume only additive variance for markers effects, ignoring possible nonlinear relationships. Accounting for such effects may be important to improve the predictive ability for traits with complex genetic architecture. The interest in semi and non-parametric prediction methods has recently increased. Within this context, machine learning methods such as Artificial Neural Networks (ANN), Random Forest (RF) and Support Vector Machines (SVM) are an interesting alternative. The aims of the present study were: i) To compare the predictive performance of Genomic Best Linear Unbiased Predictor (GBLUP) and machine learning methods in simulated beef cattle populations presenting different degrees of dominance; ii) To investigate the predictive ability of different machine learning for genome-enabled prediction of reproductive traits in Nellore cattle and compare their performance with parametric approaches (GBLUP and BLASSO); iii) To perform a genome-wide association study (GWAS) using the Random Forest approach for scanning candidate genes for age at first calving in Nellore heifers. In the first study, the simulated genome comprised 50k single nucleotide polymorphisms (SNPs) and 300 QTL (Quantitative Trait Loci), both biallelic and randomly distrib... (Complete abstract click electronic access below)
Doutor

Cattle producers are faced with difficult decisions on how they market theircalves. This study examines the different characteristics that play a role in determiningthe price of a group of animals. Identifying characteristics that determine pricedifferentials relative to the price premium given to producers participating in CPH salesis important information when producers are making a marketing decision. The modeldeveloped in this study provides producers with evidence of what characteristics generatethe highest price, as well as relative differences between sales locations and types ofsales. The more information available to producers, the better equipped they are to makedecisions.

Master of Science
Department of Agricultural Economics
Glynn Tonsor
The purpose of our analysis was to examine production strategies in the backgrounder and stocker segments of the beef industry within the Flint Hills region of Kansas. The time period analyzed encompassed 1996-2015. September and November placements of steers in the backgrounding sector of the industry were analyzed with an intended March sale date. Placements considered included 425, 500, and 575 pound steers. April and May placements of steers were analyzed for the industry’s stocking sector with an intended July sale date. Placements considered included 450, 600, and 750 pound steers. Within our analysis historical ex-post net incomes were analyzed, prediction errors were calculated (net income, revenue, and cost of gain), and market incentives/signals were analyzed. While for our historical ex-post net income analysis we did not identify one of the four placement strategies as superior in all 20 years of our analysis, we did find scenarios that were typically superior to others. In terms of backgrounding, November placements were typically superior to September placements, in terms of stocking April placements were typically superior to May placements, and when comparing backgrounding and stocking scenarios stocking scenarios were typically superior. In terms of prediction errors, we found that revenue errors are the main drivers of net income error. In general, within the backgrounding scenarios typical producers who are representative of our model assumptions generally overestimate net incomes which is detrimental to them (make lower profits than they anticipate making), while in stocking scenarios producers underestimate net incomes which is generally beneficial to them (make larger profits than they anticipate making). Market signal/incentive and ex-post net income analysis both indicated that steer weight at time of sale was a large factor influencing backgrounder profitability and decision making, and that pasture rents were a large factor influencing stocker profitability and decision making. In all four scenarios it proved economically beneficial to place lighter steer rather than heavy steers. Further research may include, but is not limited to; adding bulls and heifers to our model, analyzing different placement weights within our model, and allowing for animal performance variability within our model.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The aim of this study was to evaluate the Simbra breed of cattle for certain non-genetic as well as genetic parameters influencing live weight traits in the breed. Live weight traits included birth weight (BW), weaning weight at 200 days of age (WW), yearling weight at 400 days of age (YW) and 600 day weight. The Simmental and Simbra Breeders’ Society of Southern Africa availed 148751 records for analysis from the year 1987 till 2009. Due to deficiencies of various kinds in the data and the restrictions imposed for the purposes of the analysis, 56.44% of the records were discarded for BW, 76.55% for WW, 91.54% for YW and 96.32% for 600-day weight. Non-genetic parameters affecting BW, WW, YW and 600-day weight were analysed using the General Linear Models procedure of the Statistical Analysis System (SAS, 2004) software. During this procedure sex of calf, breed composition of calf, breeder of calf, month of birth, year of birth and dam age were fitted in the models. BW, WW, YW and Mature Cow Weight (MCW) were fitted as covariates where possible. It was determined that the fixed effects of sex, dam age, breeder, year and month had a significant (P < 0.05) effect of BW and WW while dam age was not significant (P > 0.05) for YW or 600-day weight. Breed was found non significant for YW. Breeder of the calf accounted for the most variation in BW, WW, YW as well as 600-day weight with a contribution of 17.55%, 25.77%, 18.35% and 10.71% respectively. Tukey’s multiple range tests were performed for testing differences between least square means. Results indicated male calves to be significantly heavier than females for all four traits measured. Breed composition differences were found significant until WW. Calves with higher Brahman percentage weighted more at birth while calves with higher Simmental percentage weighed more at weaning. Middle-aged dams were found to account for heavier calves at both BW and WW while very young dams and very old dams produced lighter calves for the two live weight traits. A number of years showed a significant difference from each other for all the traits measured as well as month of birth. (Co) variance components and the resulting genetic parameters were estimated using single-traits and three-traits analysis by means of Restricted Maximum Likelihood procedures (Gilmour et al., 2002). Appropriate models were selected by means of Log likelihood ratios tests and implemented to estimate genetic parameters for each of the traits studied. Direct additive heritabilities for BW, WW, YW and 600-day weight in the Simbra were respectively 0.56 ± 0.08, 0.67 ± 0.09, 0.70 ± 0.11 and 0.10 ± 0.03 when the most suitable animal model was fitted in single-trait analyses for each trait. Single traits analysis also included maternal additive as well as the correlation between direct additive and maternal additive for BW, WW and YW. Maternal additive heritability estimates of 0.24 ± 0.07, 0.33 ± 0.06 and 0.38 ± 0.07 was obtained for BW, WW and YW. Correlation estimates between direct additive and maternal additive were -0.75 ± 0.07, -0.93 ± 0.07 and -0.85 ± 0.08 for BW, WW and YW respectively. Furthermore, dam permanent environment was included as an additional random effect that increased the log likelihood value significantly. A value of 0.04 ± 0.05 was obtained for dam permanent environment estimate for WW. When a three traits analysis was done for the same traits, but using a significantly smaller data set, direct additive heritabilities of 0.24 ± 0.07 for BW, 0.33 ± 0.06 for WW and 0.38 ± 0.07 for YW were obtained. Genetic and environmental correlation estimates of 0.18 ± 0.16 and 0.09 ± 0.06 between BW and WW; 0.27 ± 0.16 and 0.07 ± 0.06 between BW and YW; as well as 0.52 ± 0.10 and 0.45 ± 0.05 between WW and YW were obtained during the three-trait analysis. The magnitude of the heritabilities obtained in this study indicates that the opportunity exists to make genetic progress through proper selection objectives.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die Simbra bees ras te evalueer op grond van sekere niegenetiese so wel as genetiese parameters wat lewende gewig beïnvloed. Gereelde en akkurate opnames van lewende gewig, is ‘n goeie indikasie van groei potensiaal en is ‘n minimim vereiste vir meeste beesras telings genootskappe. Lewende gewigs eienskappe sluit in geboorte gewig (BW), speen gewig gemeet op 200 dae (WW), jaaroue gewig gemeet op 400 dae (YW) en finale gewig gemeet op 600-dag gewig. Die Simmentaler en Simbra genootskap van Suid Afrika het 148751 rekords beskikbaar gestel vir evaluasie vanaf die jaar 1987 tot 2009. Daar was egter groot tekort komings aan die gewewe data en dus is daar 56.44% van die rekords vir BW nie gebruik nie, 76.55% vir WW, 91.54% vir YW en 96.32% vir 600-dag gewig. Nie-genetiese parameters wat die onderskeie lewende gewigte beïnvloed het, is geanaliseer deur Algemene Lineêre Modelle met behulp van die Statistiese Analitiese Sisteem (SAS, 2004) sagteware. Gedurende die analise is geslag van die kalf, ras samestelling, teler van die kalf, maand van geboorte, jaar van geboorte asook moeder ouderdom gepas in die modelle vir die onderskeie gewigte. Geboorte gewig, speen gewig, jaaroue gewig asook volwasse koei gewig is gepas in elk van die modelle as ko-variate. Volgens die resutate is daar vasgestel dat geslag van die kalf, moeder ouderdom, teler, jaar, maand en volwasse koei gewig almal ‘n betekenisvolle (P < 0.05) invloed gehad het op BW en WW. Die moederouderdom was nie betekenisvol (P > 0.05) vir YW of 600-dag gewig nie. Die ras samestelling was ook nie betekenisvol gevind vir YW. Teler van die kalf was verantwoordelik vir die meeste variasie in BW, WW, YW asook 600-dag gewig met ‘n bydrae van 17.55%, 25.77%, 18.35% en 10.71% onderskeidelik. Tukey se veelvuldige vergelykings toets is gebruik om onderskeid te tref tussen “least square means”. Resultate het aangedui dat manlike diere swaarder weeg as vroulike diere tot en met finale gewig. Ras samestelling vir BW en WW was betekenisvol verskillend vir die diere. Kalwers met ‘n hoër Brahmaan persentasie het swaarder BW opgelewer as dié met ‘n hoër Simmentaler persentasie, terwyl kalwers met ‘n hoër Simmentaler persentasie swaarder geweeg het met speen en dus ideal is vir speen kalwer produksie stelsels. Middel-jarige moeders het swaarder kalwers geproduseer met geboorte en speen as baie jong en - ou moeders. Sommige jare waarin van die kalwers gebore is, het ook betekenisvol van mekaar verskil asook die maand waarin die kalf gebore is. Ko) variansie faktore en opeenvolgende genetiese parameters is bepaal met behulp van enkeleienskap analises asook meervuldige-eienskap analises deur middel van die “Restricted Maximum Likelihood” prosedure (Gilmour et al., 2002). Modelle is opgestel vir elk van die gewigte deur die geskikte genetiese terme toe te voeg en te toets met behulp van “Log likelihood tests” om sodoende die onderskeie genetiese parameters te bepaal. Direkte genetiese oorerflikhede bepaal deur enkeleienskap analises vir die Simbra ras was as volg, 0.56 ± 0.08 vir BW, 0.67 ± 0.09 vir WW, 0.70 ± 0.11 vir YW en 0.10 ± 0.03 vir 600-dag gewig. Die direkte maternale genetiese oorerflikhede tydens dieselfde enkel-eienskap analise vir die onderkeie gewigte was 0.24 ± 0.07 vir BW, 0.33 ± 0.06 vir WW en 0.38 ± 0.07 vir YW. Korrelasies tussen direkt genetiese en direk maternale eienskappe was sterk negatief. ‘n Waarde van -0.75 ± 0.07 is bepaal vir BW, -0.93 ± 0.07 vir WW en -0.85 ± 0.08 vir YW. ‘n Adisionele faktor was ook ingelsuit vir WW, naamlik die permanente omgewing van die moeder, wat ‘n waarde opgelewer het van 0.04 ± 0.05. Tydens die veelvuldige-eienskap analise het die oorerflikhede merkwaardig verminder vir die betrokke gewigte en kan ook waargeneem word as die meer korrekte genetiese weergawe. Direkte genetiese oorerflikhede van 0.24 ± 0.07 vir BW, 0.33 ± 0.06 vir WW en 0.38 ± 0.07 vir YW was bepaal. Hierdie matig tot hoë parameters dui op genetiese vordering deur middel van korrekte seleksie prosedures. Genetiese- en omgewing korrelasies is ook bepaal tydens die analise en het positiewe waardes opgelewer. ‘n Genetiese korrelasie waarde van 0.18 ± 0.16 tussen BW en WW is bepaal asook ‘n waarde van 0.27 ± 0.16 tussen BW en YW en ‘n waarde van 0.52 ± 0.10 tussen WW en YW. Hierdie korrelasies dui daarop dat na-speengewigte vermeerder kan word deur te selekteer vir verhoogde WW sonder om BW dramties te vermeerder. Omgewings korrelasie waardes van 0.09 ± 0.06 tussen BW en WW, 0.07 ± 0.06 tussen BW en YW asook ‘n waarde van 0.45 ± 0.05 tussen WW en YW is gevind. Genetiese neigings is bepaal vir die onderskeie gewigte deur die gemiddelde voorspelde teelwaardes aan te teken teenoor elke jaar wat bereken was tydens die enkel-eienskap analises vir die onderskeie gewigte. Groot variasie asook negatiewe tendense vir WW en YW is ondervind van jaar tot jaar en dui daarop dat die seleksie doelwitte vir lewendige gewig nie in plek gestel is nie en is dit nodig om te her evalueer.

Thesis (PhD (Agric))--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: It is generally accepted that feed intake and growth (gain) are the most important economic components when calculating profitability in a growth test or feedlot. Feeding cost of animals is a major determinant of profitability in livestock production enterprises. Genetic selection to improve feed efficiency aims to reduce the cost of feeding in beef cattle production and thereby improve profitability. The objective of this study was to define a clear selection objective to enable South African beef breeders and especially the feedlot industry to select for post-weaning growth or feedlot performance and to identify factors influencing profitability in a feedlot environment. Because of the recording of individual feed intake and weight gain values in the South African Agricultural Research Councils' centralized growth tests, it was also possible to calculate a phenotypic value for feedlot profitability (R-value) for each bull tested in a centralized growth test. (Co)variances, using multitrait as well as random regression models, for and between feedlot profitability, weaning weight and other production, reproduction and efficiency traits were estimated. Residual feed intake (RFI) and feed conversion ratio (FCR) as efficiency traits were also compared to growth (average daily gain (ADG), weaning weight (WW) and shoulder height (SHD)), reproductive (scrotum circumference (SCR)) and profitability (feedlot profitability) traits measured in growth tests of young Bonsmara bulls. Consequently, a single post-weaning growth selection index value based on the economic and breeding values of different selection criteria related to feedlot profitability was composed. (Co)variance components, heritabilities and genetic correlations for and between initial weight (lW), final weight (FW), total feed intake (FI) and shoulder height (SHD) were estimated through the use of multitrait restricted maximum likelihood (REML) procedures. These breeding values (EBV s) were then used in a selection index to calculate a single economical value for each animal. This economical value is an indication of the gross profitability value or gross test value (GTV) of the animal in a post-weaning growth test. The heritability estimate of 0.36 for R-value, obtained from the multitrait analysis, shows that this trait is genetically inherited and that it can be selected for. The heritability for R-value obtained from the single trait random regression model varied between 0.57 and 0.62. The genetic correlations between the R-value and the other traits, obtained from the multitrait analysis, varied from negligible to high. The heritability estimated for FCR was 0.34 and for RFl 0.31 with a genetic correlation estimate of 0.75 between the traits. The estimated genetic correlation between profitability (R-value) and FCR and RFl were -0.92 and -0.59, respectively. The genetic correlation estimate of -0.92 between FCR and R-value is largely due to the part-whole relationship between these two traits. This is also shown in their genetic trends. The genetic correlations and expected correlated responses between RFl and FCR with R-value suggest that indirect selection for R-value through the direct selection for FCR and/or RFl will result in slower genetic progress in Rvalue than direct selection for R-value. However, where the R-value cannot be calculated and/or where direct selection for R-value is not possible, it would be better to select indirectly for R-value through the use of FCR rather than RF!. Consequently, a regression equation was developed (with an R2 of 0.82) to estimate a feed intake value for all performance-tested Bonsmara bulls which were group fed and whose feed intakes were unknown. These predicted feed intake values made it possible to calculate a feedlot or post-weaning growth profitability value (R-value) for all tested bulls even where individual feed intakes were unknown. Subsequently, an R-value for each bull was calculated in a favourable economic environment (FEE), an average economic environment (AEE) and in an unfavourable economic environment (VEE). The high Pearson and Spearman correlations between the EBV s based on AEE and the other two environments suggested that the average economic environment could be used to calculate EBVs for R-value or feedlot growth profitability. It is therefore not necessary to change the carcass, weaner or feed price on a regular basis to account for possible re-rankings based on R-value EBVs. Heritabilities for lW, FW, Fl and SHD were 0.41, 0.40, 0.33 and 0.51, respectively. The highest genetic correlations between these traits were the 0.78 (between lW and FW) and 0.70 (between Fl and FW). GTV values varied between -R192.l7 and R231.38, with an average of R9.31. The Pearson correlations between EBVs (for production and efficiency traits) and GTV range from -0.51 to 0.68. The lowest correlation (closest to zero) was 0.26 between the Kleiber ratio (KLB) and GTV. Correlations of 0.68 and -0.51 were estimated between average daily gain (ADG) and GTV and feed conversion ratio (FCR) and GTV, respectively. The heritabilities of the different traits included in the selection index suggest that it is possible to select for a GTV. The selection index can benefit feedlotting In selecting offspring of bulls with high GTV values to maximize profitability. The Pearson and Spearman correlations between the R-value EBVs and the index values (GTV) were very high (0.97). This high correlation of 97% indicates that it is not important which method is used to calculate a genetic post-weaning growth of feedlot profitability value. The selection index value is, however, more simplified than the feedlot profitability with less assumption. Therefore, it is recommended that the post-weaning selection index value be used as a selection objective in breeding programmes to improve post-weaning growth profitability rather than the more complex feedlot profitability value.
AFRIKAANSE OPSOMMING: 'N GENETIESE ANALIESE VAN DIE BIOLOGIESE EN EKONOMIESE DOELTREFFENTHEID VAN NASPEENSE GROEI IN VLEISBEESTE IN DIE VOERKRAAL: Dit word algemeen aanvaar dat voerinname en groei die twee ekonomies mees belangrike komponente in die berekening van 'n naspeense groei- of voerkraalwinsgewindheidswaarde is. Voerkostes is 'n bepalende faktor van winsgewindheid in enige lewendehawe boerderypraktyk. Seleksie om voerdoeltreffendheid te verbeter, verminder dus die voerkostes in vleisbeesproduksie en gevolglik 'n verhoging in die winsgewindheid. Die doelwit van die studie was om faktore te identifiseer wat 'n invloed op winsgewindheid in die voerkraaiomgewing het asook om 'n duidelike seleksiedoelwit te formuleer wat die Suid- Afrikaanse vleisbeesteiers en veral die voerkraalbedryf instaat sal kan stelom vir naspeense groeidoeltreffendheid ofvoerkraalwinsgewindheid te selekteer. As gevolg van die aantekening en rekordhouding van weeklikse individuele voennnames en gewigstoenames van alle prestasiegetoetsde bulle, in 'n gesentraliseerde groeitoets deur die Suid- Afrikaanse Landbou Navorsingsraad getoets, was dit moontlik om vir elk van hierdie bulle 'n fenotipiese voerkraalwinsgewindheidswaarde (R-waarde) te kon bereken. (Ko)variansies is vir en tussen voerkraalwinsgewindheid, speengewig en ander produksie-, reproduksie- en doeltreffendheidseienskappe bereken deur van meereienskap en ewekansige regressie modelle gebruik te maak. Twee doeltreffendheidseienskappe naamlik residuele voerinname (RFI) en voeromsetverhouding (FCR) is ook met groei (gemiddelde daaglikse toename (ADG), speengewig (WW) en skouerhoogte (SHD)), reproduksie (skrotumomvang (SCR)) en winsgewindheidseienskappe (voerkraalwinsgewindheid (R-waarde)) vergelyk, om sodoende te bepaal watter een die mees geskikte eienskap is om indirek vir voerkraalwinsgewindheid of groei, gebaseer op teeltwaardes en ekonomiese waardes vir die verskillende eienskappe, wat 'n invloed op naspeense groei winsgewindheid het, gestruktueer. (Ko)variansiekomponente, oorerflikhede en genetiese korrelasies vir en tussen begingewig (lW), eindgewig (FW), voerinname (FI) en skouerhoogte (SHD) is bereken deur van 'n meereienskap (REML) ontleding gebruik te maak. Hierdie teelwaardes (EBVs) is vervolgens in 'n seleksie-indeks gebruik om 'n enkele ekonomies of voerkraal-winsgewindheids seleksie-indekswaarde (GTV) vir elke dier te bereken. Hierdie ekonomiese waarde is 'n aanduiding van die bruto winsgewindheidswaarde ofbruto toetswaarde (GTV) van die dier in 'n naspeentoets. Die oorerflikheid, vanuit die meereienskapontleding vir R-waarde beraam, was 0.36. Hierdie oorerflikheid dui daarop dat die eienskap oorerflik is en dat dit wel moontlik is om daarvoor te selekteer. Die ooreflikhede van R-waarde, voorspel vanuit die enkeleienskap ewekansige regressieontleding varieer tussen 0.57 en 0.62. Die genetiese korrelasie tussen R-waarde en ander eienskappe, vanuit die meereienskap ontleding beraam, varieer tussen weglaatbaar klein tot hoog. Die oorerflikheid van FeR was 0.34 en van RFI 0.31 met 'n genetiese korrelasie van 0.75 tussen die twee eienskappe. Die genetiese korrelasie tussen R-waarde en FeR, en R-waarde en RFI was onderskeidelik -0.92 en -0.59. Die rede vir die hoë negatiewe genetiese korrelasie tussen R-waarde en FeR van -0.92 is omdat dieselfde komponente in die berekening van die twee eienskappe gebruik is. Dit word ook in die genetiese tendense weerspeël. Die genetiese korrelasies en verwagte gekorreleerde responsies tussen R-waarde en FeR, en tussen R-waarde en RFI dui daarop dat stadiger genetiese vordering verkry sal word in R-waarde deur direkte seleksie vir beide FeR en RFI as wat verkry sal word deur die direkte seleksie vir R-waarde. Wanneer 'n R-waarde egter nie bereken kan word nie of waar dit nie moontlik is om direk vir R-waarde te selekteer nie, sal vinniger genetiese vordering in R-waarde gemaak word deur die direkte seleksie vir FeR as vir RF!. 'n Regressievergelyking is geformuleer (met 'n R2 van 0.82) om vir alle prestasiegetoetsde bulle, waar bulle in 'n groep gevoer is en individuele voerinnames onbekend is, 'n voerinnamewaarde te voorspel. Hierdie voorspelde voerinnames maak dit moontlik om vir elke prestasiegetoetsde bul ,'n naspeengroei- of voerkraalwinswaarde (R-waarde) te bereken, al is hulle individuele voerinnames onbekend. Vervolgens is drie verskillende R-waarde vir vleisproduksie vir elke bul bereken naamlik, in 'n gunstige ekonomiese omgewing (FEE), 'n gemiddelde ekonomiese omgewing (AEE) en 'n ongunstige ekonomiese omgewing (VEE). Die hoë Pearson en Spearman korrelasies tussen die EBVs vir R-waarde, bereken in die AEE en die EBVs in die ander twee ekonomiese omgewings, dui daarop dat die AEE gebruik kan word om EBVs vir naspeense groeiof voerkraalwins te bereken. Dit is dus nie nodig om op 'n gereelde grondslag die karkasprys, lewendige speenkalfprys of die voerprys te verander nie. Oorerflikhede, vanuit die meereienskap ontledings VIr lW, FW, FI en SHD verkry, was onderskeidelik 0.41, 0.40, 0.33 en 0.51. Die hoogste genetiese korrelasies tussen die eienskappe was 0.78 tussen lW en FW en 0.70 tussen FI en FW. GTV indekswaardes varieer tussen -Rl92.17 en R231.38 met 'n gemiddelde waarde van R9.31. Die Pearson korrelasies tussen die EBVs van produksie- en doeltreffenheidseienskappe en GTV het tussen -0.51 en 0.68 gevarieer. Die korrelasie naaste aan zero, van 0.26, was die korrelasie tussen GTV en die Kleiber-verhouding. Die korrelasies tussen GTV en ADG, en GTV en FeR was onderskeidelik 0.68 en -0.51. Die oorerflikhede van die verskillende eienskappe wat in die seleksie-indeks ingesluit is, dui daarop dat die indekswaarde weloorerflik is en dat seleksie hiervoor wel moontlik is. Hierdie indekswaarde kan deur die voerkraaiindustrie gebruik word om nageslag van diere met hoë GTV waardes te selekteer om sodoende maksimum wins uit die voerkraai te genereer. Die Pearson en Spearman korrelasies tussen R-waarde EBVs en die indekswaardes (GTV) was besonder hoog (0.97). Hierdie hoë korrelasie dui daarop dat dit geen verskil sal maak watter een van die twee metodes gebruik word in die berekeninge van 'n naspeense groei- of voerkraalwinswaarde nie. Die seleksie-indeks metode is egter minder gekompliseerd met minder aannames as in die geval van die rekeningkundige fenotipiese benadering (R-waarde). As gevolg hiervan, word die naspeense seleksie-indeks waardes (GTV) aanbeveel om te gebruik as 'n teeldoelwit in telingsprogramme om naspeense groei- of voerkraaiwins geneties te verbeter, eerder as die meer gekompliseerde fenotipiese voerkraaiwins (R-waardes) metode.