15 research outputs found

    Agriculture and Dairy Production Systems in China: An Overview and Case Studies

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    The Chinese dairy industry is growing rapidly. Since 1980, the rate of increase in dairy cattle in China's dairy industry (+210,000 cows per year) is 1.7 times higher than the rate of decline of dairy cattle in the US dairy industry (-124,000 cows per year). If the current trends do not change, there will be as many dairy cows in China as in the US-approximately 7.45 million cows in 2012. This two-part Discussion Paper presents the context in which the Chinese dairy industry is developing (Part I) and a study of the Dairy Farm systems and case studies of five farms in the Province of Yunnan, the city of Beijing and the province of Heilongjiang (Part II).Chinese Dairy Industry, Dairy Cows in China, Development of the Chinese Dairy Industry, Chinese Dairy Farm Case Studies, Consumer/Household Economics, Farm Management, International Development, International Relations/Trade, Productivity Analysis,

    Forage nutritive value and predicted fiber digestibility of Kernza intermediate wheatgrass in monoculture and in mixture with red clover during the first production year

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    Kernza intermediate wheatgrass is thefirst perennial grain crop in the world and has been de-veloped with conventional breeding to increase seed yield of forage intermediate wheatgrass(Thinopyrum intermedium(Host) Barkworth & D.R. Dewey). When managed for dual-use (grainand forage), Kernza intermediate wheatgrass can produce grain, crop residue (straw) in thesummer, and green forage in the spring and fall. Mixtures of this grass with legumes could in-crease forage yield and nutritive value and provide other environmental and economic benefits.Despite the growing interest in these dual-use production systems, forage nutritive value ofKernza intermediate wheatgrass forage in a dual-use system in the Upper Midwest is unknown. Areplicatedfield experiment was established in two locations in southern Wisconsin (Arlingtonand Lancaster) with two treatments: Kernza intermediate wheatgrass grown in monoculture andmixture with red clover (Trifolium pratenseL.). Forage samples were collected at late vegetativestage in the spring, at grain harvest in the summer, and at the end of the regrowth period in thefall. Forage nutritive value of the monoculture was greatest in the spring with 456, 249 and 225 gkg−1for neutral detergentfiber (NDF), acid detergentfiber (ADF) and crude protein (CP), re-spectively; lowest in the summer with 702, 427 and 51 g kg−1NDF, ADF and CP, respectively,and intermediate in the fall with 590, 337 and 119 g kg−1NDF, ADF and CP, respectively.Predicted total-tract neutral detergentfiber digestibility (ttNDFD) was 0.53 for the spring forageand averaged 0.37 for the summer and fall forage, with no differences between the mixture andmonoculture. The relative forage quality (RFQ) for the monoculture was 175 for the springforage, 65 for the summer residue, and 116 for the fall. Intercropping red clover with Kernzaintermediate wheatgrass increased CP of the summer crop residue by 69%, and increased CP andRFQ of the fall forage by 49% and 11%, respectively, while reducing NDF and ADF of the fallforage by 25% and 18%, respectively. Therefore, Kernza intermediate wheatgrass forage is sui-table for lactating beef cows, dairy cows, and growing heifers when harvested in the spring andfall, and it offers high potential for dual-use grain and forage systems

    Development of an equation to estimate the enteric methane emissions from Holstein dairy cows in Canada

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    The aim of this study was to use dietary factor, including the type of fats, and animal characteristics, to predict enteric CH4 emissions from dairy cows under Canadian conditions. For this purpose, 193 individual observations, from six different trials assessing the impact of dietary modification on enteric CH4 production, were analyzed. Animal (milk yield [MY], milk fat content, milk protein content, days in milk [DIM], body weight [BW], dry matter intake [DMI]) and dietary variables (organic matter [OM], crude protein [CP], neutral detergent fiber [NDF], acid detergent fiber [ADF], starch, EE, rumen-inert fat and unprotected fat [EE–rumen-inert fat]: as % of dry matter [DM]) were tested. A fivefold cross validation was used to obtain the following equation: CH4 (g d-1) = –1260.4 + 1.9 × MY (kg d-1) + 62.8 × milk fat (%) – 18.4 × milk protein (%) + 11.0 × DMI (kg d-1) + 0.3 × BW (kg) + 58.3 × NDF (% of DM) – 0.8 × NDF2 (% of DM) + 1.9 × starch (% of DM) – 2.4 × EE–rumen-inert fat (% of DM). The mean estimate from the proposed equation (474 g CH4 cow-1 d-1; r = 0.83, RMSE = 40.0) was close to the observed mean emission (476 g CH4 cow-1 d-1). The proposed model has a higher precision to predict CH4 emission from cows fed typical Canadian diets than other models and can be used to evaluate CH4 mitigation strategies.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Prácticas de alimentación animal y de fertilización, y emisión de gases de efecto invernadero en granjas lecheras de Dos Pinos, Costa Rica

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    Se estimaron las emisiones de metano (CH4) y óxido nitroso (N2O) en 104 granjas lecheras en Costa Rica, utilizando los procedimientos del IPCC. El estudio indica que las decisiones de los productores respecto a las estrategias de alimentación de sus vacas en ordeño tienen un impacto sustancial en las emisiones de CH4 por kg de leche. Se estimaron emisiones de CH4 bajas por kg de leche en aquellas granjas donde las vacas de alta producción consumían raciones con concentraciones menores de fibra detergente neutro y cantidades mayores de concentrados. Las horas dedicadas al pastoreo no influyeron en las estimaciones del consumo de pasto ni en las emisiones de CH4. Sin embargo, una mayor eficiencia alimenticia parecía ser un factor clave en la reducción de las emisiones de CH4 por kg de leche. El estudio también mostró que emisiones de N2O más altas estaban asociadas con la aplicación de mayores cantidades de fertilizantes comerciales de nitrógeno. Sin embargo, la principal fuente de emisiones de N2O fueron las excretas de las vacas durante el pastoreo. Futuras estrategias para reducir, a nivel de granja, las emisiones de CH4 por kg de leche en las explotaciones lecheras especializadas, podrían incluir la incorporación de grasas alimenticias en las raciones, alimentación con cantidades adecuadas de concentrados y alimentación con forrajes más digeribles. Aunque estos resultados estén fuertemente influenciados por los supuestos que se emplean en los cálculos de las emisiones de CH4 y N2O, sí realzan las áreas críticas que determinan las emisiones de gases de efecto invernadero a nivel de granja lechera.Emissions of methane (CH4) and nitrous oxide (N2O) based on the feeding systems of 104 dairy farms in Costa Rica were estimated using IPCC procedures. This study indicated that farmers’ decisions, which determine the feeding strategies for lactating cows, have a substantial impact on CH4 emissions per kg of milk. Lower CH4 emissions per kg milk were estimated on farms with high-producing cows consuming rations with lower neutral detergent fiber concentrations and higher amounts of concentrates. Hours spent in pasture did not influence estimated grass intake or CH4 emissions. However, higher feed efficiency appeared to be a key factor in reducing CH4 emissions per kg of milk. The study also showed that higher N2O emissions were associated with higher amounts of commercial nitrogen fertilizer application; however, the main source of N2O emissions was from the manure deposited during the grazing period. Future approaches to reduce farm gate emissions of CH4 per kg of milk in specialized dairy farms could include incorporating dietary fats in rations, feeding adequate amounts of concentrates and feeding forage at a more digestible stage. These findings are strongly influenced by the assumptions made in calculating CH4 and N2O emissions but do highlight the critical areas which affect greenhouse gas emissions

    Agriculture and Dairy Production Systems in China: An Overview and Case Studies

    No full text
    The Chinese dairy industry is growing rapidly. Since 1980, the rate of increase in dairy cattle in China's dairy industry (+210,000 cows per year) is 1.7 times higher than the rate of decline of dairy cattle in the US dairy industry (-124,000 cows per year). If the current trends do not change, there will be as many dairy cows in China as in the US-approximately 7.45 million cows in 2012. This two-part Discussion Paper presents the context in which the Chinese dairy industry is developing (Part I) and a study of the Dairy Farm systems and case studies of five farms in the Province of Yunnan, the city of Beijing and the province of Heilongjiang (Part II)

    Environmental and economic impacts of feeding strategies in Costa Rican dairy farms

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    El objetivo de este trabajo fue analizar las prácticas de alimentación en fincas lecheras de Costa Rica y su influencia en las emisiones de gases con efecto invernadero (GEI). Se evaluó metano (CH4), óxido nitroso (N2O) y el índice ingresos sobre gastos de alimentación (IOFC). El estudio se llevó a cabo en 104 fincas lecheras, las cuales se distribuyeron en un rango de altitud entre los 1000 y 2400 msnm. Mediante un análisis de conglomerados en función de alimentos consumidos, tiempo de animales en pastoreo, áreas destinadas a potreros y pastos de corte. Se identificaron cuatro estrategias de alimentación, las cuales presentaron diferencias en las proporciones de categorías de alimentos que componen la ración diaria. Las emisiones, expresadas como dióxido de carbono equivalente por leche corregida (CO2eq/LCGP), fueron mayores para las estrategias de alimentación altas en forraje y bajas para estrategias en altitudes elevadas. El concentrado representó los mayores costos de alimentación en todas las estrategias, y significó más del 50% en el sistema de producción basado en el uso intensivo de concentrado; mientras que el costo de los fertilizantes fue más elevado en las producciones a base de pastos. Los ingresos por venta de leche fueron mayores en la estrategia del sistema intensivo. Sin embargo, el IOFC no presentó diferencias entre las estrategias a pesar de las diferencias en producción de leche. Las estrategias de alimentación influyeron en las emisiones de GEI y en los costos de alimentación. Las estrategias asociadas con menores emisiones dentro de la finca fueron las más dependientes de insumos externos.The aim of this study was to analyze feeding practices in Costa Rica’s dairy farms and their influence on greenhouse gas emissions (GHG). Methane (CH4), nitrous oxide (N2O), and income over feed cost (IOFC) were evaluated. This study was carried out at 104 dairy farms, which were distributed within a range of altitude from 1000 to 2400 meters above sea level. Using cluster analysis based on type of feed, grazing period, areas of forage and pastures; four feeding strategies were identified, which included different proportions of feed categories in daily rations. Emissions expressed as carbon dioxide equivalent per kilo of fat and protein corrected milk (CO2eq/FPCM) were higher for forage feeding strategies and lower for farms found in higher altitudes. Concentrate feed accounted for the higher cost in all feeding strategies, and represented more than 50% in the intensive concentrate based production system, whereas the costs of fertilizers were higher in pasture based feeding strategies. Income from milk sales was higher for the concentrate based feeding strategy. However, IOFC was the same for all feeding strategies in spite of the large differences in daily milk production. Feeding strategies influenced GHG emissions and feeding costs. Feeding strategies associated with lower GHG emissions within the farm were more dependent from external inputs

    Environmental and economic impacts of feeding strategies in Costa Rican dairy farms.

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    The aim of this study was to analyze feeding practices in Costa Rica’s dairy farms and their influence on greenhouse gas emissions (GHG). Methane (CH4), nitrous oxide (N2O), and income over feed cost (IOFC) were evaluated. This study was carried out at 104 dairy farms, which were distributed within a range of altitude from 1000 to 2400 meters above sea level. Using cluster analysis based on type of feed, grazing period, areas of forage and pastures; four feeding strategies were identified, which included different proportions of feed categories in daily rations. Emissions expressed as carbon dioxide equivalent per kilo of fat and protein corrected milk (CO2eq/FPCM) were higher for forage feeding strategies and lower for farms found in higher altitudes. Concentrate feed accounted for the higher cost in all feeding strategies, and represented more than 50% in the intensive concentrate based production system, whereas the costs of fertilizers were higher in pasture based feeding strategies. Income from milk sales was higher for the concentrate based feeding strategy. However, IOFC was the same for all feeding strategies in spite of the large differences in daily milk production. Feeding strategies influenced GHG emissions and feeding costs. Feeding strategies associated with lower GHG emissions within the farm were more dependent from external inputs

    Control of the LiFePO4 electrochemical properties using low-cost iron precursor in a melt process

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    LiFePO4 was prepared from low-cost iron ore concentrate (containing 4.48 wt.% SiO2 and MgO, CaO and Al2O3 below 0.5 wt.% as contaminant) using a melt synthesis. X-ray diffraction (XRD) refinement associated with Mössbauer spectroscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) analyses are used to track the location of Si in the material. It is shown that the iron content in the melt can be used as a means to control the doping rate of elements from iron ore concentrate (IOC) precursor according to the formula (Li1 − zAz)(Fe1 − yMy)(P1 − xSix)O4. Electrochemical behavior of the material is affected by the doping of LiFePO4. While capacity is decreased in doped material, the cycling stability is much improved. When dopants are out of LiFePO4 structure, capacity retention dramatically drops as well as capacity due to the gravimetric impact of impurity phases. A trade-off between high capacity and best cycling performance is necessary. For instance, slight lack of iron in the melt (6 % deficiency) leads to a capacity only 2 % lower than that of pure Fe2O3-based material for the same stoichiometry and fairly good capacity retention

    Electrochemical oxidation and reduction of La4Ni3O10 in alkaline media

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    In this work we used electrochemical polarization for oxidizing and reducing, in a controlled way, the Ruddlesden-Popper phase La4Ni3O10. With a careful choice of electrochemical parameters, we were able to obtain samples of La4Ni3O10±delta never obtained before..
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