Keywords: Phosphorus, Dietary phosphate, Feed-stuffs, Animal nutrition, Nitrogen, Protein, Pig nutrition, Low protein diets.
A major factor in the total load of nutrients to agricultural land is animal manure. The characteristics of the manure are related to many factors, of which the animal’s ability to utilise the feed is the most critical one. This may vary significantly due to management of the animals, feed composition and quality, and also animal productivity. Further, in recent years, plant breeding science has changed towards objectives other than simply increased productivity, for example research has been carried out on plant to enhance the utilisation of the availability of phosphorus (P) to animals.
During the last decade there has been a huge effort to minimise the release of excess nitrogen (N) and P into the environment. Every European country with intensive animal production is implementing its own national plan on the protection of the environment, whilst maintaining an economically viable agricultural production.
The efficiency of animal production has improved greatly in recent decades. Breeding, farm building construction, feed and production technology are all important components in this development. Also, in recent years, environmental aspects of animal production have been brought into focus. Consequently, there are strict regulations for the storage and spreading of the manure with the aim of minimising adverse effects on the environment. At the same time the manure is an important source of nutrients for crop production.
In 1890, Fleischer published data demonstrating the capacity of different litter materials to bind nitrogen (N) excreted via the urine. At that time the main objective was to increase the fertiliser value of the manure. Today the same background data are valid in the choice of litter material in order to avoid N losses to the atmosphere.
This second part of the paper discusses the role of N in pig nutrition with special emphasis on environmental aspects.
S-O Malmqvist, Kemira-Kemi AB, Sweden.
L Göransson, LantmÃƒÂ¤nnen Foderutveckling AB, Sweden.
16 pages, 8 tables, 18 refs.