ifoam'96 Book of Abstracts 11th IFOAM Scientific Conference 11-15 August 1996, Copenhagen, Denmark

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Workshop

Livestock: A methodology to assess the impactW2/P3

Institute of Animal Breeding and Genetics, Department of Livestock Ecology, Justus Liebig University Giessen, Ludwigstr. 21, 35390 Giessen, Germany

A methodology to quantify and evaluate environmental effects that is applicable for different types of farms has not yet been agreed on. The present paper suggests to use a list of indicators that characterize the impact of a particular farm on the environment. Emphasis is put on the effects related to livestock.
The conceptual indicator model of the OECD distinguishes three categories of environmental indicators: state indicators, response indicators and pressure indicators. Indicators that describe the pressure of a livestock husbandry system on the state of the environment were defined at farm level. With the aim of minimizing the expenses for data collection the book keepingsystem is used as an important data base. Data from conventionaland organic central German farms were collected and analysed to optimize the methodology. The following aspects are considered: 1) The individual animal N and P balance is set up if sufficient data areavailable. Herd averages are used alternatively to estimate barn nutrient flows. 2) Farmgate balances for the main nutrients offer additional information about the efficiency of nutrient input. 3) The manure management is analysed with respect to storage and distribution techniques in order to identify reasons for high nutrientlosses. 4) Methane emissions are estimated taking the prevalent feeding and manure storage system as the influencing variables. 5) The ammonia emissions result from the comparison between manure storage and feed composition. 6) Toxic substances in feed or other production factors are likewise considered. 7) The energy utilisation of animal husbandry is calculated by taking theimported feed sources as the main influencing factor. 8) The animal welfare is assessed with the Animal Welfare Index (TGI 200).
Different ways of achieving the data on the farms are presented and discussed. The database that has been developed is to be used by the farmers to monitor possible environmental effects of different management measures. The goal is to minimize the environmental impact of livestock assuming that a set of production factors isgiven and can be used alternatively.