Strategies of reduced feeding on N and P to farm animals, procedures to minimize N and P-load of soils in areas with highly intensive pig production.

Publication Type

Contribution to conference

Authors

Drochner, W.

Year of publication

2003

Published in

International Scientific Conference: Lithuanian University of Agriculture - dedicated to commemorate 100 years anniversary of Prof. Bronius Baginskas

Editor

Lithuanian Soil Sci. Society at the Section of Agriculture and Forestry Sci. of the Lithuanian Adademy of Sciences

Page (from - to)

26

Conference name

Achievements and tasks of soil science and plant nutrition in the course of integration into the EU

Conference location

Kaunas /Litauen

Conference date

09.-10.10.2003

Keywords

environment, farm, N-balance, P-balance

Environmental problems with high levels of N and P in manure of pigs and cattle are depending on the level of animals kept per ha of land. The main aim is an equilibrium o the N- and P-balance on farm level. That means, that N and P input and export from the farm should be in an equilibrium. The calculation of a farm balance should include fertilizers, manure, nutrients "imported" by use of commercial mixed feeds and export concerning crops sold, products of animal origin (milk, meat, eggs etc.) sold and by that exported from the farm. In Western Europe so called "Düngeeinheiten" (fertilizer units) are calculated, thus prescribing a certain level of animals kept per area of cultivated land. The strategies to improve the efficacy of animal production concerning N and P utilisation and thus preventing a too high level of N and P loaded per unit of arable land are: 1) improving bioavailability of N and P-sources, 2) strict optimizing the relation between requirement and supply. Concerning point 1, the quality of proteins (biological value) in monogastric animals is the main point which can be optimized by combination of proteins, use of synthetic essential amino acids (mainly lysine). In ruminants the N efficacy is depending on the ruminal N-balance and the level of ruminal by-pass protein. Both can be optimized. Bioavailability of P is partly depending on differences between different sources of mineral P. In monogastric animals the use of phytate-P can be optimized by addition of enzymes of microbial and with restrictions - even of plant origin. In ruminants differences between different sources of P are small. Concerning point 2, the strategies are more complex. Main aspect is an Optimum of harmonization between nutrient supply and production. In growing pigs and cows for instance, the deposition of protein per day is quite constant and energy deposition rises continuously. So the protein/energy ratio should be adapted to the requirements. This can be managed by spe