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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Consumo, eficiência alimentar e exigências nutricionais de vacas de corte na lactação e terminação / Intake, feed efficiency and nutritional requirements of lactating and fattening beef cows

Tiago Zanetti Albertini 19 January 2007 (has links)
O objetivo deste trabalho foi estimar as exigências e a eficiência energética de vacas de corte lactantes e não gestantes, bem como do par vaca/bezerro. Posteriormente foi correlacionada a eficiência do par vaca/bezerro durante a lactação com a eficiência das mesmas vacas durante a terminação. Na fase de lactação os pares vaca/bezerro foram avaliados desde após o nascimento (17±5, d DP) até a desmama (210 d). Após a desmama foi conduzido o ensaio de terminação (67 d) e abate somente das matrizes. Foram avaliadas 10 vacas adultas ½ Caracu x Nelore (CN) e 10 ½ Angus x Nelore (AN), acasaladas com touros Red Angus (RA) e Canchim (CC), respectivamente. Na lactação o oferecimento da dieta (2,30 Mcal EM/kg e 12,4% PB) variou individualmente ao longo do período com objetivo de manter constante o peso das matrizes ao longo da lactação. A mesma dieta foi oferecida a vontade para a progênie. Durante o ensaio de terminação em confinamento a dieta (2,37 Mcal EM/kg e 10,5% PB) foi fornecida à vontade. A ingestão de matéria seca das matrizes foi de 92,4 g MS/kg PM0,75 (CV=3,2%; P=0,458). Vacas AN apresentaram produção de leite corrigida para gordura 12% superior (P<0,05). A concentração energética do leite (Mcal/kg) das vacas CN foi 9,4% superior (P<0,05). A eficiência (Mcal leite/Mcal EM ingerida) não foi diferente. A exigência de energia metabolizável de lactação (EMl) foi maior (P<0,05) para vacas AN em relação as CN, 90,1 e 74,2 (EMl, kcal EMl/kg PM0,75), respectivamente. Bezerros ½CC¼AN¼NE apresentaram ingestão de energia metabolizável (IEM) proveniente do leite 11,3% (P<0,05) superior. Bezerros ½RA¼CR¼NE foram 10,7% mais eficientes (g GP210d/Mcal IEM leite+dieta sólida). Não houve diferença para eficiência dos pares vaca/bezerro, contudo houve considerável variação individual, onde a eficiência média foi 35,3 g GP210d/Mcal IEM par (CV=11,5%). A eficiência do par foi positivamente relacionada ao ganho do bezerro (r=0,79; P<0,01) e negativamente relacionada à IEM do par (r=-0,58; P<0,05). Vacas CN ao abate apresentaram EGS 29% menor, AOL 13% maior e maior proteína no corpo vazio (P<0,05). Vacas AN apresentaram 14,7% maior proporção de órgãos internos relativo ao peso vazio e maior peso dos intestinos (P<0,01). As correlações fenotípicas demonstraram associação entre as eficiência de secreção do leite das vacas nas fase de lactação e de ganho de peso na fase de terminação (r=0,43; P=0,09). A eficiência de secreção de leite das vacas na lactação apresentou correlação com a eficiência do par (r=0,68; P<0,01). O consumo alimentar residual (CAR) das vacas na terminação foi correlacionado com o CAR das vacas em lactação (r=0,53; P<0,05) e com o CAR dos pares (r=0.62; P<0.01). Isso indica que vacas de corte mais eficientes durante a terminação são também mais eficientes no período de cria. / This study estimated the requirements and feed efficiency of non-pregnant lactating beef cows, as well as cow calf pairs. It also correlated the efficiency of the cows and their progeny during lactation to efficiency determined for the same cows in a finishing trial after weaning. In the lactating phase cow calf pairs were evaluated from just after birth (17±5, d) to weaning at 210 d. The finishing trial for the mature cows started after weaning and lasted 67 d after wich cows were slaughtered. Twenty adult cows were evaluated, 10 ½ Caracu x Nelore (CN) and 10 Angus x Nelore, bred to Red Angus (RA) and Canchim (CC) bulls, respectively. During lactation the diet (2.30 Mcal ME/kg and 12.4% CP) was offered in variable amounts to maintain individual live weight and condition score constant. The same diet was offered ad libitum to the calves. During the finishing phase cows were fed ad libitum (2.37 Mcal ME/kg e 10.5% CP). The dry matter feed intake of cows was 92,4 and SD 2,9 g DM/kg BW0,75. AN cows had fat corrected milk 12% higher compared to CN cows (P<0.05). However, milk energy content (Mcal/kg) was 9.4% higher (P<0.05) for CN cows. Efficiency of milk production (Mcal milk/Mcal ME intake) was not different. Metabolizable energy for lactation (MEl) was higher (P<0.05) for AN cows in comparison to CN, respectively 90.1 and 74.2 (MEl, kcal MEl/kg BW0,75). ME milk intake was 11.3% (P<0.05) higher for ½CC¼AN¼NE calves. Rates of gain were not different between calves, but ½RA¼CR¼NE were 10.7% more efficient (g LWG210d/Mcal MEI milk+solid diet). There was no difference in cow calf pairs efficiency, but there was a great individual variability with a mean of 35,31 g and SD of 4,08 g LWG210d/Mcal EM for the pair. Cow/calf pair efficiency was positively related to calf weight gain (r=0.79; P<0.01) and negatively to the pair metabolizable energy intake (r=-0.58; P<0.05). At slaughter CN cows presented backfat thickness 29% lower, longissimus muscle area 13% higher and higher empty body weight protein (P<0,05). AN cows had 14.7% higher relative internal organ weight and higher total intestine weight (P<0.01). The phenotypical correlations between efficiency indexes indicate moderate association between cow efficiency measured during lactation and in a short finishing period after weaning (r=0.43; P=0.09). Exist correlations between cow efficiency lactation and efficiency of the pair (r=0.68; P<0.01). Residual Feed Intake (RFI) during the finishing phase was moderately correlated to the RFI calculated during the lactation period for the cow calf pairs RFI (r=0.62; P<0.01) and the cows (r=0.53; P<0.05) indicated that beef cows more efficient in feed conversion during the finishing phase are more efficient during the lactation period.
302

Efficiency of protein utilization of forage legumes for milk production on goats

Katsande, Simbarashe 11 February 2016 (has links)
Department of Animal Science / PhD (Agric)
303

Cows Back to Pasture – Unlock Climate Change Mitigation Potentials in Dairy Farming at Increasing Milk Production

Wolf, Patricia 17 December 2021 (has links)
Die Arbeit liefert ein umfassendes Verständnis der (1) Auswirkungen auf Landnutzung und Treibhausgas (THG)-emissionen im Zusammenhang mit der deutschen Milchproduktion im Zeitraum von 2000 bis 2015 und bis 2030, (2) Unsicherheiten hinsichtlich der Bewertung der THG-emissionen der Milchproduktion und (3) Bewertung der Anwendbarkeit des zugrundeliegenden Modells für andere Länder als Deutschland. Landnutzung stellt die Anbaufläche von Futter für bestimmte Milchleistungen dar. Die Arbeit konzentrierte sich auf die Landnutzungsänderung zwischen Grün- und Ackerland durch Änderung der Milchkuhrationen. Ein Ökobilanz-Modell wurde entwickelt, um die Auswirkungen der Entwicklung der deutschen Milchproduktion und -leistung (typische Rationen unter deutschen Bedingungen) bis 2030 für drei Weidesysteme (ohne Weide, Halbtags- und Ganztagsweide) zu simulieren. THG-emissionen wurden für die gesamte Produktionskette berechnet, beginnend mit dem Pflanzenbau. Eingangsdaten für Ökobilanz-Studien von Lebensmitteln werden von Variabilität und Unsicherheiten beeinflusst. Ein systematischer Ansatz (Kombination aus lokaler und globaler Sensitivitätsanalyse) wurde verwendet, um wesentliche Eingangsparameter für die Bewertung der THG-emissionen der Milchproduktion zu identifizieren. Zu diesem Zweck wurden drei Rationen, welche die Weidesysteme im Jahr 2030 repräsentieren, ausgewählt. Die lokale Sensitivitätsanalyse diente der Identifikation der einflussreichsten Parameter, die globale der Identifikation der wichtigsten Parameter. Die USA dienen der Prüfung der Anwendbarkeit des Modells für andere Länder. Produktionssystem, verfügbare Daten und IPCC Tier-Methoden werden mit dem deutschen System und zugehörigen Daten verglichen. Diese Arbeit liefert wichtige Erkenntnisse zur künftigen Intensivierung der Milchproduktion sowie zu Klimaschutzpotenzialen in Abhängigkeit der Fütterungsstrategie. Darüber hinaus trägt sie zur Verringerung der Unsicherheiten künftiger Studien zur Milchproduktion bei. / This thesis provides an comprehensive understanding of: (1) impacts on land use and greenhouse gas (GHG) emissions related to the German milk production in the period from 2000 to 2015 and further until 2030, (2) uncertainties with regard to the assessment of GHG emissions of milk production and (3) evaluation of applicability of the underlying life cycle assessment (LCA) model for countries other than Germany. Land use represents the acreage needed to provide sufficient feed for certain milk yields. This research focusses on land use change between grassland and cropland as an effect of changing dairy cow diets. A LCA model, which reflects typical dairy cow diets under German conditions, was developed to simulate the impact of the German development of milk production and yield until 2030 for three grazing systems (zero-, restricted and unrestricted grazing). GHG emissions have been calculated for the whole production chain, beginning with crops cultivation. Input parameter of LCA studies of food products are affected by variability and uncertainty. A systematic approach (combining local and global sensitivity analysis) was used to identify essential input parameters for the assessment of GHG emissions of milk production. Three diets representing the grazing systems in the year 2030 were selected for this purpose. Local sensitivity analysis was used to identify the most influential parameters, global sensitivity analysis was used to identify the parameters which are most important. The United States of America are taken as example to verify the applicability of the LCA model for other countries. Production system, available data, and IPCC tier methods were compared with the German system and data. This thesis provides important insights on future intensification of milk production along with climate change mitigation potentials depending on the feeding strategy. Moreover, it contributes to the reduction of uncertainties of future LCA studies of milk production.
304

The management and control of milk hygiene in the informal sector by environmental health services in South Africa

Agenbag, Michael Hermanus Albertus January 2008 (has links)
Thesis (M. Tech.) -- Central University of Technology, Free State, 2008 / Local government (LG) is under increasing pressure from the milk industry and consumers regarding their ability and willingness to carry out their mandate with regard to the quality control of milk, especially in the informal sector. The government and the milk industry currently have programmes underway to stimulate economic activities in the informal sector, targeting emerging cattle farmers for the production of milk as part of government’s Accelerated Shared Growth Initiative of South Africa (ASGISA). These initiatives further increase the number of informal milk producers and distributors, which holds a further challenge to regulatory authorities. At the same time, the quality of milk from the informal milk-producing sector poses a serious public health concern. Most of the milk produced and sold by the informal sector is raw (unpasteurised), which does not meet the minimum statutory requirements, and the milking practices applied by the informal sector also do not comply with best practice compliance standards. Local authorities (LAs) are statutorily responsible for registering milking parlours and controlling milk hygiene quality from production stage to purchase stage in order to ensure safe and wholesome dairy products to the consumer. Therefore, LG should play an increasingly important role in ensuring that safe and wholesome milk is produced and distributed to the consumers. All metropolitan municipalities (metros) and district municipalities (DMs) should be authorised by the Ministry of Health to enforce the Foodstuffs, Cosmetics and Disinfectants Act, 1972 (Act 54 of 1972) through their authorised officials – mainly environmental health practitioners (EHPs). Secondly, LG should have specific programmes, systems and resources to register, monitor, evaluate and control milk production and distribution outlets for continued compliance
305

Performance and health of dairy cows incompletely milked during the first five days in milk

Krug, Catarina 06 1900 (has links)
No description available.
306

Análise da sustentabilidade da atividade bovina leiteira no Município de Pombal, Paraíba. / Analysis of the sustainability of dairy cattle activity in the Municipality of Pombal, Paraíba.

CARVALHO, Jacqueline Liedja Araujo Silva. 15 May 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-15T16:52:35Z No. of bitstreams: 1 JACQUELINE LIEDJA ARAUJO SILVA CARVALHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1821177 bytes, checksum: 5edf83fb0f87d1e2e3a52d083f218e97 (MD5) / Made available in DSpace on 2018-05-15T16:52:35Z (GMT). No. of bitstreams: 1 JACQUELINE LIEDJA ARAUJO SILVA CARVALHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1821177 bytes, checksum: 5edf83fb0f87d1e2e3a52d083f218e97 (MD5) Previous issue date: 2013-09-26 / O Brasil tem um dos maiores rebanhos bovino leiteiros do mundo. No entanto, apesar de estar entre os grandes produtores mundiais de leite, a pecuária leiteira nacional é bastante heterogênea. Parte de algumas regiões como o Nordeste brasileiro, ainda encontra-se em desenvolvimento para alcançar os padrões de qualidade e quantidade e chegar ao mercado competitivo, como por exemplo, o município de Pombal, que estar localizado no Sertão da Paraíba, área do presente estudo, que é reconhecida em âmbito estadual, por seu potencial leiteiro. Neste contexto, esta pesquisa tem o objetivo de fazer uma análise da sustentabilidade da bovinocultura leiteira de Pombal, nos seus aspectos institucional (tecnológica), social, econômica e ambiental. Para a execução desse estudo, foram necessárias visitas in loco e aplicação de questionários semi-estruturados, a 50 produtores de leite, pertencentes a trinta e duas áreas rurais desse município. A partir das respostas, foram calculados em indicadores, utilizando o método do PNUD/ONU (1998), cujos resultados variaram de 0 (zero) a 100 (cem) e foram divididos em quatro graus de sustentabilidades: crítico, ruim, bom e excelente. Em seguida, aplicado na fórmula matemática denominada de IGS (Índice Global de Sustentabilidade) desenvolvido por González e Carvajal (2002). Quando o resultado do IGS for menor ou igual a 50%, a atividade apresenta-se no campo da insustentabilidade e será mais sustentável próximo a 100%. Os resultados na dimensão institucional apresentaram índices de 37%, na dimensão social em 58%, ambos considerados graus ruins de sustentabilidade. Na dimensão ambiental índices de 60%, ambos considerados graus bons para a sustentabilidade e, finalmente, a dimensão econômica com grau 36%, em nível ruim para a sustentabilidade. O IGS calculado foi de 47,74% o que não pode ser considerado sustentável. Desta forma, os resultados obtidos identificam que a produção bovina leiteira, de Pombal, necessita de atenção, com mais políticas públicas para o setor, não apenas no aspecto econômico, mas também nas dimensões sociais e ambientais, possibilitando melhorias na qualidade de vida dos envolvidos, como também, na conservação dos recursos naturais. / Brazil has one of the largest dairy cattle herds in the world. However, despite being among the major world producers of milk, the national dairy industry is quite heterogeneous. Part of some regions such as the Brazilian Northeast, is still under development to meet the standards of quality and quantity and get the competitive market, such as the municipality of Pombal, to be located in the backlands of Paraiba, the present study area, which is recognized statewide for its dairy potential. In this context, this study aims to make an analysis of the sustainability of dairy cattle of Pombal, in their institutional (technological), social, economic and environmental aspects. For the execution of this study, site visits and application of semi-structured questionnaires, 50 dairy farmers, belonging to thirty- two rural areas of this municipality were necessary. From the responses, indicators were calculated using the method of UNDP / UN (1998), whose results ranged from 0 (zero) to 100 (one hundred) and were divided into four grades of sustainabilities: critical, poor , good or excellent. Then applied to the mathematical formula called GSI (Global Sustainability Index) developed by González and Carvajal (2002 ). When the result of the IGS is less than or equal to 50%, the activity is presented in the field of unsustainability will be more sustainable and close to 100% . The results presented in the institutional dimension ratios of 37%, the social dimension in 58%, both considered bad grades sustainability. In the environmental dimension ratios of 60%, both considered good grades for sustainability and ultimately the economic dimension with grade 36% in bad for the sustainability level . The calculated IGS was 47.74% which can not be considered sustainable. Thus, the results identify that the dairy cattle production, Pombal, needs attention, most public policies for the sector , not only in economics but also in social and environmental dimensions, enabling improvements in the quality of life of those involved, but also to conserve natural resources.
307

Um estudo da aliança estratégica da CONFEPAR, sob a ótica das preferências dos produtores de leite vinculados / A study of the strategic alliance CONFEPAR, from the viewpoint of bound to the alliance milk producers' preferences

Schwans, Scheila Aparecida Kulka 05 July 2011 (has links)
Made available in DSpace on 2017-07-10T18:33:52Z (GMT). No. of bitstreams: 1 Scheila A Kulka Schwans.pdf: 2754077 bytes, checksum: ac47ea5ec8b5d0f2c56132694b4373be (MD5) Previous issue date: 2011-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The economic transformations that happened in the 1990 s have conditioned the formation of strategic alliances among singular milk cooperatives in the state of Paraná. For this study, the research environment was the conglomerate of singular cooperatives bound to the Cooperativa Central Agroindustrial Ltda CONFEPAR, cooperatives which form one of four dairy products alliances. After a decade of existence of this alliance, this study tried to know the aspirations of milk producers bound to it, that is, subsidies were sought for a reevaluation of the strategies adopted by this alliance. The study deals with the following theme: A study of the strategic alliance CONFEPAR, from the viewpoint of bound to the alliance milk producers preferences , with its main goal as to verify the preferences of milk producers bound to the singular cooperatives that form this strategic alliance. In order to guarantee growth and to obtain competitive advantages for the group and the maintenance of these producers, it is necessary to continuously reevaluate business strategies. From this viewpoint, the value of such a study is stressed, because knowing these preferences may represent an important differential to structure new strategies, and to satisfy the involved producer s individual needs. To obtain the goals proposed by this study, a research using Declared Preference technique was conducted, a technique which made possible, after statistical treatment through the software LMPC, to evidence which are the most statistically relevant preferences from the bound to the alliance milk producers viewpoint. / As transformações econômicas ocorridas na década de 1990 condicionaram a formação de alianças estratégicas entre as cooperativas singulares de produtores de leite no Paraná. Para esse estudo, o ambiente de pesquisa foi o conglomerado de cooperativas singulares vinculadas à Cooperativa Central Agroindustrial Ltda CONFEPAR, cooperativas as quais formaram uma das quatro alianças de produtos lácteos. Após uma década de existência dessa aliança buscou-se, com esse estudo, conhecer as aspirações dos produtores de leite vinculados a ela, ou seja, buscaram-se subsídios para uma reavaliação das estratégias adotadas por essa aliança. Nesse sentido, o estudo aborda o tema: Um estudo da aliança estratégica da CONFEPAR, sob a ótica das preferências dos produtores de leite vinculados , tendo como objetivo geral verificar as preferências dos produtores de leite vinculados às cooperativas singulares que compõem essa aliança estratégica. Com o intuito de garantir o crescimento e a obtenção de vantagens competitivas para o grupo e a manutenção desses produtores, é necessário continuamente reavaliar estratégias de negócios. Nesse sentido, salienta-se o valor de tal estudo, pois conhecer essas preferências pode representar um diferencial importante na estruturação de novas estratégias, e ainda satisfazer os anseios individuais dos produtores envolvidos. Para atingir os objetivos propostos por esse estudo fez-se uma pesquisa utilizando a técnica de Preferência Declarada, técnica com a qual foi possível, após tratamento estatístico com o software LMPC, evidenciar quais são as preferências estatisticamente mais relevantes na visão dos produtores de leite vinculados à aliança estratégica estudada.

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