No description available.

In the pig and poultry production industries, energy forms the largest and the greatest cost pressure when a diet is formulated. In Australia, cereal grains such as barley, sorghum, and wheat are the main dietary energy sources, comprising more than 60 % of the diet in many cases. Traditionally, during diet formulation, the energy value of a grain has been represented by a single figure for that particular grain type. However, several studies have indicated that the energy availability from different grains fed to pigs and poultry varies significantly even within one grain cultivar. Given these findings, the use of a single value to represent the energy of each grain type during diet formulation, can lead to inefficient utilisation of dietary resources by animals, and thus decreased animal performance and consequently, a decrease in profit for the pig and poultry production industries. Thus, there is an opportunity to develop a rapid and reproducible in vitro assay to accurately assess the available energy values and nutritional quality of each grain type. In order to develop such an assay, further understanding of factors that affect the available energy values of grains need to be explored. Starch, which is hydrolysed into glucose by animals, is the most abundant energy component in cereal grains, and there is evidence suggesting that variations in digestible or metabolisable energy values may be related to the extent of starch digestibility. For example in poultry, variations in the in vitro digestibility of starch between several wheat cultivars have been shown to correlate with their in vivo available metabolisable energy values. However, it is not known to what extent starch digestibility varies between cultivars of other grain types such as barley and sorghum. There is an increasing body of evidence suggesting that differences in the physical and chemical properties of cereal grains may play an important role in influencing starch digestibility and, consequently, animal performance. Thus, the general hypothesis of this study was that starch digestibility varies between barley, sorghum and wheat, and between cultivars within grain types and this is related to specific chemical and physical characteristics of the grains. To examine this, the following issues were investigated using 18 barley, 15 sorghum and 10 wheat cultivars : 1 ) an in vitro glucose release index ( GRI ) assay was developed to assess starch digestibility within and between the cereal grain types and, 2 ) the GRI was correlated to both starch - related ( e.g., starch content, starch granule size, the amylose to amylopectin ratio, starch gelatinisation properties ) and non - starch - related ( e.g., non - starch polysaccharide composition, kernel hardness, the presence of protein matrix and milling quality ) physical / chemical characteristics within and between the cereal grains. Results revealed significant variations in the GRI both between grains and within a given grain type. The GRI values ranged between 27 - 45 %, 25 - 54 % and 32 - 53 % in barley, sorghum and wheat respectively. Correlation analysis revealed that the GRI in barley, sorghum and wheat was influenced by the physical and chemical characteristics of starch - and non - starch - related grain properties, although the type of characteristic influencing GRI was specific to the grain type. In barley, the ratio of amylose to amylopectin, starch gelatinisation and kernel hardness influenced the GRI. In sorghum, the GRI was influenced by the ratio of amylose to amylopectin, the presence of a protein matrix surrounding starch granules and kernel hardness. Finally in wheat, the presence of protein matrix and milling quality influenced the GRI. It was also shown that the extract viscosity of grains within barley and wheat, but not sorghum, varied significantly. In conclusion, the results from this study indicate that ; 1 ) the GRI assay may be used to identify some factors that affect in vivo starch digestibility within and between barley, sorghum and wheat, 2 ) starch digestibility ( as assessed by the GRI ) may be influenced by some physical and chemical characteristics of cereal grains, and that these characteristics are specific to the type of grain The physical and chemical characteristics that may influence starch digestion will be discussed in relation to their potential physiological effects on energy digestion, and utilisation in animals. The information generated will provide a basis for future studies that will ultimately assist in the design of in vitro assays to predict energy availability from barley, sorghum and wheat grains fed to pigs and poultry, and contribute to the more efficient use of grains in monogastric production systems. / Thesis (Ph.D.)--Department of Animal Science, 2002.

Thesis (Ph.D. (Education)) - Rhodes University, 2009.

No description available.

No description available.

Despite continued pursuit of development interventions to improve people’s livelihoods and reduce poverty, intended and actual outcomes of developments interventions may differ. Some scholars attribute this variation to flawed conceptualisation of development interventions while others view this divergence as evidence that implementation processes are complex and actual outcomes result from adaptations of the interventions by actors. To move beyond the discursive approaches to analysis of development interventions, this thesis addresses the question how do actors adapt them, why and with what outcomes in the long run? Empirically, it looks at how project officers and farmers adapted the National Dairy Development Project (NDDP), a dairy intervention implemented in Kenya between 1980 and 1995, and its long run outcomes. The intervention promoted zero grazing, intensive management of dairy cattle whose implementation by farmers was expected to increase land productivity as a means to address land scarcity, increase milk production and reduce poverty through generation of incomes from milk sales. The methodology of this thesis links mechanisms, contexts, and outcomes, three elements of realist explanation, to understand adaptations and outcomes of development interventions. Through thematic synthesis of in-depth interviews and analysis of project documents, this thesis explains adaptations and long run outcomes of the NDDP. Findings reveal that developers and farmers adapted several components of the intervention. With close reference to context, incentives and continuity pressures, this thesis utilises intervention effectiveness and matching mechanisms to explain how project officers adapted the NDDP. Further, through fit and resistance mechanisms, this thesis explains how farmers adapted zero grazing in the context of inadequate fodder, labour shortage and lack of resources to invest in dairy. In the long run, findings show that the intervention diminished as evident in coexistence of indigenous and modern dairy technologies and non-implementation of any dairy technologies by farmers. Despite adaptations of zero grazing by project officers and farmers, intensification of dairy cattle management has diminished in the context of resource constraints, neoliberal policies and labour shortage. Consequently, the objective to increase land productivity through intensive dairy cattle management, the rationale for initiation of the intervention, remains unresolved. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2014.

Thesis--Universität Bielefeld, 1997. / Includes bibliographical references (p. [511]-530).

O objetivo deste trabalho foi determinar e quantificar os fatores inerentes ao leilão que afetam o preço de venda de bezerros de corte. Foram coletados em 148 leilões nas cidades de Dois Vizinhos e Francisco Beltrão dados referentes ao preço de venda (PV), local (L) e mês (M) da realização do leilão,grupo genético (GG) e tamanho do lote (TL), peso médio (PE) e sexo (S) dos animais.Foram observados 4.312 lotes correspondendo a 48.588 animais pesando entre 100 e 250 kg de janeiro de 2004 a dezembro de 2014. Os lotes foram classificados de acordo com suas características, em sete grupos genéticos. Nos lotes B, C e Z, predominaram animais de raças Britânicas, Continentais e Zebuínas, respectivamente. Enquanto que, para os grupos BC, BZ e CZ, admitiram-se os seus cruzamentos. Os lotes denominados XX não eram homogêneos geneticamente. Os valores foram deflacionados através do IGP-DI e atenderam os pressupostos paramétricos. O preço de venda foi padronizado em função da mediana anual, assumindo-se que seu valor corresponde a 100%, e os demais valores variaram em sua função. As análises foram realizadas através de funções desenvolvidas e pacotes do software R. A análise de trilha quantificou os efeitos diretos e indiretos das variáveis tomadas como explicativas sobre o preço de venda, em seguida realizaram-se análises de regressão e teste de Tukey. No geral o efeito direto do peso médio foi o maior (0,7), seguido do sexo (0,38). O menor efeito direto foi do grupo genético (-0,075) e do local (-0,04). Observou-se relação exponencial crescente entre peso médio do lote e preço de venda, e relação decrescente (-0,0003 pontos percentuais por quilograma) entre preço kg-1 e peso médio do lote, onde os machos, no geral, foram 15,74% mais valorizados que as fêmeas. O cruzamento entre raças Britânicas x Zebuínas foi o grupo genético mais valorizado, não diferindo das Britânicas (8,93 e 3,57%, respectivamente). E a comercialização no mês de novembro alcançou a maior bonificação, seguida de fevereiro (9,57 e 8,84%, respectivamente, sempre em relação a mediana do ano). O preço de venda cresce linearmente 0,3284 pontos percentuais para cada animal acrescido no lote. Concluiu-se que o peso médio do lote é a variável mais importante na formação do preço de venda, seguido do sexo dos animais. / The objective of this study was to determine and quantify the inherent factors auction that affect the selling price of beef calves. The data were collected in 148 auctions in the cities of Dois Vizinhos and Francisco Beltrao on the selling price (PV), location (L) and month (M) of the auction, genetic group (GG) and lot size (TL) average weight (PE) and sex (S) of animals. 4,312 lots corresponding to 48,588 animals weighing between 100 and 250 kg of January 2004 to December 2014 were observed were classified according to their characteristics in seven genetic groups. In lots B, C and Z, predominated animal breeds British, Continental and Zebu, respectively. While, for BC and BZ CZ groups were admitted their cross. Lots called XX were not genetically homogeneous. The values were deflated by the IGP-DI and met the parametric assumptions. The selling price was standardized by the yearly median, assuming that its value corresponds to 100%, and the other values varied in their function. Analyses were performed by developed functions and software packages R. Path analysis quantified the direct and indirect effects of the variables taken as explanatory of the selling price, then were carried out regression analyzes and Tukey test. Overall the direct effect of the average weight was the highest (0.7), followed by gender (0.38). The smaller direct effect was the genetic group (-0.075) and location (-0.04). There was growing exponential relationship between average weight of the lot and selling price, and decreasing ratio (-0.0003 percentage point per kilogram) between kg-1 price and average weight of the lot, where the males, in general, were 15.74% more valued than females. The cross between British x Zebu breeds was the most valued genetic group did not differ from the British (8.93 and 3.57%, respectively). And the market in November reached the highest bonus, followed by February (9.57 and 8.84%, respectively, always compared to median year). The selling price increases linearly 0.3284 percentage points for each animal plus in the lot. It was concluded that the average weight of the lot is the most important variable in the formation of the selling price, followed by the sex of the animals.

O objetivo deste trabalho foi determinar e quantificar os fatores inerentes ao leilão que afetam o preço de venda de bezerros de corte. Foram coletados em 148 leilões nas cidades de Dois Vizinhos e Francisco Beltrão dados referentes ao preço de venda (PV), local (L) e mês (M) da realização do leilão,grupo genético (GG) e tamanho do lote (TL), peso médio (PE) e sexo (S) dos animais.Foram observados 4.312 lotes correspondendo a 48.588 animais pesando entre 100 e 250 kg de janeiro de 2004 a dezembro de 2014. Os lotes foram classificados de acordo com suas características, em sete grupos genéticos. Nos lotes B, C e Z, predominaram animais de raças Britânicas, Continentais e Zebuínas, respectivamente. Enquanto que, para os grupos BC, BZ e CZ, admitiram-se os seus cruzamentos. Os lotes denominados XX não eram homogêneos geneticamente. Os valores foram deflacionados através do IGP-DI e atenderam os pressupostos paramétricos. O preço de venda foi padronizado em função da mediana anual, assumindo-se que seu valor corresponde a 100%, e os demais valores variaram em sua função. As análises foram realizadas através de funções desenvolvidas e pacotes do software R. A análise de trilha quantificou os efeitos diretos e indiretos das variáveis tomadas como explicativas sobre o preço de venda, em seguida realizaram-se análises de regressão e teste de Tukey. No geral o efeito direto do peso médio foi o maior (0,7), seguido do sexo (0,38). O menor efeito direto foi do grupo genético (-0,075) e do local (-0,04). Observou-se relação exponencial crescente entre peso médio do lote e preço de venda, e relação decrescente (-0,0003 pontos percentuais por quilograma) entre preço kg-1 e peso médio do lote, onde os machos, no geral, foram 15,74% mais valorizados que as fêmeas. O cruzamento entre raças Britânicas x Zebuínas foi o grupo genético mais valorizado, não diferindo das Britânicas (8,93 e 3,57%, respectivamente). E a comercialização no mês de novembro alcançou a maior bonificação, seguida de fevereiro (9,57 e 8,84%, respectivamente, sempre em relação a mediana do ano). O preço de venda cresce linearmente 0,3284 pontos percentuais para cada animal acrescido no lote. Concluiu-se que o peso médio do lote é a variável mais importante na formação do preço de venda, seguido do sexo dos animais. / The objective of this study was to determine and quantify the inherent factors auction that affect the selling price of beef calves. The data were collected in 148 auctions in the cities of Dois Vizinhos and Francisco Beltrao on the selling price (PV), location (L) and month (M) of the auction, genetic group (GG) and lot size (TL) average weight (PE) and sex (S) of animals. 4,312 lots corresponding to 48,588 animals weighing between 100 and 250 kg of January 2004 to December 2014 were observed were classified according to their characteristics in seven genetic groups. In lots B, C and Z, predominated animal breeds British, Continental and Zebu, respectively. While, for BC and BZ CZ groups were admitted their cross. Lots called XX were not genetically homogeneous. The values were deflated by the IGP-DI and met the parametric assumptions. The selling price was standardized by the yearly median, assuming that its value corresponds to 100%, and the other values varied in their function. Analyses were performed by developed functions and software packages R. Path analysis quantified the direct and indirect effects of the variables taken as explanatory of the selling price, then were carried out regression analyzes and Tukey test. Overall the direct effect of the average weight was the highest (0.7), followed by gender (0.38). The smaller direct effect was the genetic group (-0.075) and location (-0.04). There was growing exponential relationship between average weight of the lot and selling price, and decreasing ratio (-0.0003 percentage point per kilogram) between kg-1 price and average weight of the lot, where the males, in general, were 15.74% more valued than females. The cross between British x Zebu breeds was the most valued genetic group did not differ from the British (8.93 and 3.57%, respectively). And the market in November reached the highest bonus, followed by February (9.57 and 8.84%, respectively, always compared to median year). The selling price increases linearly 0.3284 percentage points for each animal plus in the lot. It was concluded that the average weight of the lot is the most important variable in the formation of the selling price, followed by the sex of the animals.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management