Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Food and Business Economics." Includes bibliographical references (p. 121-127).

Pasture-based dairies have become more prevalent in recent years due to a higher proportion of organic milk demand and production. Organic certification requires that animals must graze at least 120 days in each growing season. However, dry matter intake is often limited when dairy animals receive most of their herbage from pasture, resulting in lower animal performance and milk production. The purpose of this study was to analyze the complimentary effect of high energy grasses with birdsfoot trefoil (BFT) tannins to improve intake of dairy heifers. Jersey heifers were rotationally grazed for 105 days in 2017 and 2018 on eight different pasture treatments, which included monocultures of perennial ryegrass (PR), orchardgrass (OG), meadow bromegrass (MB), and tall fescue (TF), with each respective grass also planted in mixture with BFT. Intake was measured by sampling herbage before and after each seven-day grazing period and was from greatest to least as follows: MB+BFT, OG+BFT, OG, MB, PR+BFT, TF+BFT, PR, TF. Physical characteristics such as pasture bulk density, herbage height, herbage allowance, leaf pubescence, leaf softness, and birdsfoot trefoil content as well as nutritional properties such as fat, non-fibrous carbohydrates, fiber, and energy were all associated with intake. Crude protein and ash were also associated with intake. While PR+BFT did not have the greatest overall intake, it was the only treatment that consistently had greater intake than its respective grass monoculture (PR). Since it had more energy and tannins than all other grasses, a complimentary effect between energy and tannins to increase intake was likely. The fact that both physical and chemical herbage characteristics were associated with intake shows the importance of planting the right species in pasture as well as making proper management decisions to maximize nutritive value and herbage intake.

The thesis presented consists of two essays that analyze input substitution and decision making in crop and livestock production systems. The first essay consists of a whole-farm analysis that sought to optimize feed mixes and enterprise combinations for an organic dairy operation in the Southeastern United States. This was accomplished through mathematical programming where whole-farm net returns were maximized, and total feed costs were minimized simultaneously for four milk production level cases. Additionally, the sensitivity of the system and break-even milk price were explored. Results suggest substitutability in ration components where an increase in supplemental feeds is justified by additional milk output and sales. The second essay utilizes econometric methods and hedonic modeling to explore factors that drive the price of row crop planters on the used machinery market. Factors relating to make, age, condition, planter specifications, sale type, spatial aspects, seasonality, and year of the sale were analyzed. Results suggest non-linear relationships for row number and age relative to price and interactions between variables make and age that imply varying depreciation depending on the manufacturer. An additional break-even analysis relating to pasture yields and planter purchase price was conducted to explore these primary concepts in further detail.

Made available in DSpace on 2014-08-20T14:38:44Z (GMT). No. of bitstreams: 1 Tese_Luciana_Honorato.pdf: 1136712 bytes, checksum: 9bcd7bd40d2f4171d6f284b047c93435 (MD5) Previous issue date: 2011-05-02 / The aim of this study were: I) to characterize the organic dairy farms in Santa Catarina, identify the motivations and evaluation of producers on the particular production system, in comparison to conventional farms and; II) to compare indicators of health and animal welfare (AW) of dairy herds, management systems and milk quality in both systems. We selected 17 organic dairy farms or in the conversion process and 17 conventional farms. All producers were visited twice: once in March, once in September/2010, which were open interviews about the historic and farmer s opinions on organic production and an evaluation on the structuring of production farms, discussed the differences between the systems. The technologies and management practices adopted were analyzed in the light of current legislation in order to estimate the contribution needed to ensure the permanence of these families in the organic system. One question in the interviews was examined the farmers' perceptions about animal welfare. Data on environment, food and health management, clinical examination of animals and bulk tank milk samples were collected. Notes on diseases and treatments done in animals were evaluated within the period. Our results indicate that the reduction in production costs and benefits to health and environment are factors that motivate the organic, while the lack of technical support and logistics market are cited as major barriers. It is also evident that farmers know little about the recent regulations, which limits its suitability standards. Organic farmers make production less intensive than conventional ones, where the composition of the herd and feed management are key differences. Both systems kept similar level of animal health, despite greatest difficulty of organic in controlling ectoparasites in summer. We found a lower incidence of disease in animals in the organic, and were reduced use of antimicrobials than in conventional, which is an important indicator of welfare animal and food safety. The levels of animal welfare in some way correspond with the farmers' perceptions on the subject, so improvements could occur via changes in attitudes of the producers. / Os objetivos desse trabalho foram: I) caracterizar os produtores de leite orgânico da região oeste de Santa Catarina, identificar suas motivações e sua avaliação particular sobre o sistema de produção em comparação aos produtores convencionais e, II) comparar indicadores de saúde e bem-estar animal (BEA) dos rebanhos leiteiros, manejos e qualidade do leite nos dois sistemas. Foram selecionadas 17 unidades leiteiras orgânicas ou em fase de conversão e 17 unidades convencionais similares, de agricultores familiares. Foram feitas duas visitas à cada propriedade, em março e setembro de 2010, onde foram feitas entrevistas abertas sobre o histórico e opiniões sobre a produção orgânica e, na avaliação sobre a estruturação das unidades produtivas, foram discutidas as diferenças entre os sistemas. As tecnologias e manejos adotados foram analisados à luz da legislação vigente a fim de se estimar o aporte necessário para garantir a permanência dessas famílias no sistema orgânico. A percepção dos produtores sobre bem-estar animal foi analisada por intermédio de uma questão pontual dentro das entrevistas. Também foram feitas observações do ambiente, manejo sanitário e alimentar, exame clínico dos animais, avaliação do leite total e anotações sobre doenças e tratamentos feitos nos animais dentro do período. Os resultados indicam que a redução nos custos de produção e benefícios a saúde e ambiente são fatores que motivam os produtores orgânicos, enquanto a falta de suporte técnico e logística de mercado são apontadas como entraves importantes. Percebe-se também que os produtores conhecem pouco sobre as recentes normativas, o que limita sua adequação aos padrões. Os produtores orgânicos desenvolvem uma produção menos intensiva do que os convencionais, onde a composição do rebanho e manejo alimentar são as principais diferenças. Os sistemas mantêm níveis similares de saúde animal, porém, o sistema orgânico enfrenta uma dificuldade maior em controlar os ectoparasitas no verão. Foi encontrada uma incidência menor de doenças nos animais no sistema orgânico e, consequentemente, um menor uso de antibióticos sintéticos do que no convencional, o que é importante para o bem-estar animal e segurança alimentar. Os níveis de bem-estar animal foram relacionados ao sistema e correspondem de certa forma, com a percepção dos produtores sobre o tema, portanto, melhorias poderiam ocorrer via mudança de atitudes dos produtores.

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