949 resultados para livestock grazing


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Microzooplankton (the 20 to 200 µm size class of zooplankton) is recognised as an important part of marine pelagic ecosystems. In terms of biomass and abundance pelagic ciliates are one of the important groups of organism in microzooplankton. However, their rates - grazing and growth - , feeding behaviour and prey preferences are poorly known and understood. A set of data was assembled in order to derive a better understanding of pelagic ciliates rates, in response to parameters such as prey concentration, prey type (size and species), temperature and their own size. With these objectives, literature was searched for laboratory experiments with information on one or more of these parameters effect studied. The criteria for selection and inclusion in the database included: (i) controlled laboratory experiment with a known ciliates feeding on a known prey; (ii) presence of ancillary information about experimental conditions, used organisms - cell volume, cell dimensions, and carbon content. Rates and ancillary information were measured in units that meet the experimenter need, creating a need to harmonize the data units after collection. In addition different units can link to different mechanisms (carbon to nutritive quality of the prey, volume to size limits). As a result, grazing rates are thus available as pg C/(ciliate*h), µm**3/(ciliate*h) and prey cell/(ciliate*h); clearance rate was calculated if not given and growth rate is expressed as the growth rate per day.

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Microinsurance is widely considered an important tool for sustainable poverty reduction, especially in the face of increasing climate risk. Although index-based microinsurance, which should be free from the classical incentive problems, has attracted considerable attention, uptake rates have generally been weak in low-income rural communities. We explore the purchase patterns of index-based livestock insurance in southern Ethiopia, focusing in particular on the role of accurate product comprehension and price, including the prospective impact of temporary discount coupons on subsequent period demand due to price anchoring effects. We find that randomly distributed learning kits contribute to improving subjects' knowledge of the products; however, we do not find strong evidence that the improved knowledge per se induces greater uptake. We also find that reduced price due to randomly distributed discount coupons has an immediate, positive impact on uptake, without dampening subsequent period demand due to reference-dependence associated with price anchoring effects.

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Drought spells can impose severe impacts in most vulnerable farms. It is well known that uninsured exposure exacerbates income inequality in farming systems. However, high administrative costs of traditional insurance hinder small farmers? access to risk management tools. The existence of moral hazard and systemic risk prevents the implementation of traditional insurance programs to address drought risk in rural areas. Innovative technologies like satellite images are being used to derive vegetation index which are highly correlated with drought impacts. The implementation of this technology in agricultural insurance may help to overcome some of the limitations of traditional insurance. However, basis risk has been identified as one of the main problems that hinder the acceptance of index insurance. In this paper we focus on the analyses of basis risk under different contract options in the grazing lands of the Araucanía region. A vegetation index database is used to develop an actuarial insurance model and estimate risk premiums for moderate and severe drought coverage. Risk premium sharply increases with risk coverage. In contrast with previous findings in the literature, our results are not conclusive and show that lowering the coverage level does not necessarily imply a reduction in basis risk. Further analyses of the relation between contract design and basis risk is a promising area of research that may render an important social utility for most vulnerable farming systems.