Call number: LD2668 .T4 1985 B74 / Master of Science

Thesis (Ph.D. ( Animal breeding)) --University of Limpopo, 2012 / Refer to document / the Agriculture Research Council

Copies of 16 publications from the thesis, authored and co-authored by the author, included as appendix. / Includes bibliographical references (leaves 195-220). / 1 v. (various pagings) : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines 3 hypotheses: that the lipid levels and fatty acid composition of meat produced in Australia may vary between cattle genotypes, ages, sexes, seasons, and anatomical sites of sampling; that genetic variation may be sufficiently large to warrant selective crossbreeding of dams to different sire genotypes as an improvement strategy in the proportion of monounsaturated fatty acids in beef; and, that genotype differences in bovine tissue may exist when phospholipid and triacylglycerol fractions of total lipids are analysed separately, regardless of fatness of the cattle. Genetic variation in fatty acid composition of 7 different cattle breads were examined in experiments using non-lactating cows, yearling steers, yearling heifers and weaner calves. Breed differences were found in the muscle and adipose tissues when phospholipid and triacylglycerol fractions were analysed separately regardless of the fatness of the cattle. Differences in age, sex, season and anatomical site were also significant. The study concludes that breed differences in fatty acid composition are related to fatness and stage of maturity such that early-maturing cattle are fatter, contain higher proportions of unsaturates, and have softer fats with low melting points than lean, late-maturing cattle. It is recommended that total lipids be separated into triacylglycerol and phospholipid fractions and analysed separately. Desturation indexes could be used as a biochemical marker for beef breeding decisions, and genetic parameters presented used for future selection indices for fatty acids in carcass quality assessment. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1999

No description available.

In order to investigate the use of fuzzy logic in decision-support systems (DSS) for dairy cattle breeding, a first-generation prototype software system was developed. The objectives were to determine the advantages and limitations of fuzzy logic for this type of application, and to establish a basis for the development of more complete DSS in the future. The goal of the prototype DSS was to make culling decisions on the basis of monthly production data. An analysis of the development process of this prototype demonstrated the importance of creating a thorough methodology for the elicitation and implementation of knowledge. A framework for the development of fuzzy decision-support systems was established, consisting of four phases: the project groundwork phase, elicitation of knowledge from the expert, implementation of that knowledge, and system validation. In this framework, it is proposed that, in the case of multiple experts, knowledge can be amalgamated or aggregated. Once this framework was established, a second-generation prototype DSS was developed. Contrary to the first-generation prototype, where the encoded expertise was limited to three experts from the same domain, the second-generation prototype considered the knowledge of two individuals from each of three domains (Dairy researchers, Producers, and Dairy herd improvement specialists). An aggregation approach was used which involved the development and maintenance of separate modules, each containing the compiled expertise of one of the six experts.

The purpose of this survey is to identify and investigate the impact of management on communal cattle farmers of Madikwe in the Province of North West. Quantitative research was conduct to find information from some of the stakeholders such as farmers, herdsmen and youth. The survey method was used to conduct the study. The population approached were farmers, herdsmen and chiefs. 4000 respondents were expected to complete the questionnaires, but only 350 respondents returned usable questionnaires which were analysed. The quantitative research conducted revealed that communal farmers of Madikwe are not practicing sound farm management. These farmers are not maximizing profits and keeping accurate records for cattle farming. / (MBA) North West University, Mafikeng Campus, 2004

Crossbreeding parameters (additive (a), dominance (d) and additive x additive (aa) epistatic effects for individual $ sp{ rm (I)}$ and for maternal $ sp{ rm (M)}$ performance) on body weight growth and first lactation performance traits of females from a crossbreeding experiment between Holstein (H) and Ayrshire (A) based lines were estimated by individual animal models, incorporating all known additive genetic relationships amongst animals, through restricted maximum likelihood and mixed-model methodologies. / The growth traits (asymptotic weight (A), rate parameter (k), inflection parameter (m), average lifetime absolute growth rate (AGR), average lifetime absolute maturing rate (AMR) and average lifetime relative growth rate (RGR)) were estimated by fitting the nonlinear equation, W$ sb1$ = A(1 $ pm$ be$ sp{ rm -kt}) sp{ rm M}$, to the observed weight-age data of 3076 individual females. / Results from the analyses of growth traits indicated that the H line exceeded the A line in addition genetic effects for individual performance (a$ sp{ rm I}$) for both A and AGR. The H line also exceeded the A line in additive effects for maternal performance (a$ sp{ rm M}$) in trait A. Both dominance (d) and additive x additive (aa) epistatic effects were statistically important in most cases. Individual heterosis (h$ sp{ rm I}$ = d$ sp{ rm I}$ $-$ 0.5aa$ sp{ rm I}$) was positive for traits A and AGR, whereas maternal heterosis (h$ sp{ rm M}$ = d$ sp{ rm M}$ $-$ 0.5aa$ sp{ rm M}$) was negative for A and positive for AMR. Total heterosis (TH = h$ sp{ rm I}$ + h$ sp{ rm M}$) had positive effects on AGR and AMR. For all growth traits, heterosis retained in advanced crossbred generations was statistically irrelevant. The overall conclusion was that crossbreeding systems designed to capitalize on TH would produce faster growing and earlier maturing animals. / The analyses of production traits found the additive effect of the H line for individual performance to be a major factor to increase yields of milk, protein and fat. On the other hand, line maternal and cytoplasmic source tended to favour the A line, but none reached statistical significance in any of the traits. Results indicate that two-line specific crosses or synthetic development would be sound breeding strategies for taking advantage of first cross heterosis or of line additive differences, respectively. / Estimates of crossbreeding parameters from mixed-model analyses, were found to be more reliable than those from ordinary least squares analyses. (Abstract shortened by UMI.)

Zur Verbesserung der Fleischqualität wurde die japanische Fleischrinderrasse Wagyu (wa = Japan, gyu = Rind) in die in Sachsen etablierten Rassen eingekreuzt. Aus den Kreuzungen mit Fleisch-Fleckvieh, Angus und Hybridtieren entstanden 90 Kälber mit unterschiedlich hohem Wagyugenanteil. Über sechs Jahre wurden in drei Betrieben das Wachstum, die Mast- und Schlachtleistung und die Fleischqualität der Aufzucht untersucht. Der für Wagyu typisch hohe Gehalt an Rohfett führt bei Einkreuzungen zu einer Verbesserung der Fleischqualität. Insbesondere bei Färsen ist das Fleisch zarter und von besserem Aroma.

This thesis take the form of an ethnographic exploration of a bull-breeding estate called Partido de Resina (formerly Pablo Romero) in the countryside near Seville in Andalusia. The estate, founded in 1885, produces fighting bulls for taurine events in Southern France, Spain and Portugal. At the heart of the thesis is the life cycle of the fighting animals, every chapter being anchored to a particular point in the bull-breeding calendar and the lives of the stock. Each chapter draws out specific qualities of the world of the bulls from the perspective of Partido de Resina, rooting the bulls and their people in a wider Spanish and Andalusian landscape and history, with a focus on technical know-how and everyday ethics after the 2008 financial crisis. The professionals who care for the Partido de Resina bulls, cows, and calves are the human protagonists of this project; their working routines, hopes, concerns, and stories described through their interactions with the animals which they look after. The core anthropological argument in the thesis is to show how different ethnographically salient forms of life emerge on and around the estate, sometimes weighted towards individual animals, sometimes towards bits of taurine bodies, or breeds, types, lineages, cohorts, and other groupings of stock. The varied, dynamic presence of animal life is contextualised in the literature of the 'animal turn' in anthropology, which has drawn non- human life into the ethnographic foreground. A case is made for a nuanced and contextual ethnographic attention to animal life and interiority as it emerges in the field, without an a priori emphasis on animal personhood or subjectivity. In foregrounding the qualities and concerns encountered and worked through during both routine livestock maintenance and extraordinary, definitive events like bullfights, the emergent, multiple character of taurine forms of existence become apparent.

Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Animal Production Management))--University of Pretoria, 2006. / Animal and Wildlife Sciences / unrestricted