Reducing Protein Content in Pig Feed

Excessive nitrogen inputs from the air lead to over-fertilisation of sensitive ecosystems. Continuous feeding optimisation can make an important contribution to reducing ammonia losses and thus nitrogen inputs.

To protect sensitive ecosystems, the federal government has decided that nitrogen losses from agriculture should be reduced by 20% by 2030. If N excretion via urine is reduced through optimised feeding, nitrogen emissions can be reduced along the entire loss chain, from the barn to the paddock and the slurry store to spreading. The aim of this study is to record the status of protein supply in pig farming in cooperation with the industry and to show both the development over the last ten years and the potential for optimisation.

Considerable reduction in crude protein content since 2008

A survey conducted in 2021 in collaboration with the pig-farming industry covered 88.5% of the market share of complete feed for pigs. Standard content parameters of different feeds were recorded from the feed product ranges. The data (figure 1) show that the average crude protein content (g RP/kg) has decreased in all feed categories since the last survey (2008). In pig fattening, the crude protein content of finishing feeds (136.35 g RP/kg) has decreased the most compared to the other feed types (-19.41 g RP/kg). However, only just under 50% of the fattening farms with complete feed use finishing feed. In the case of breeding sows, the crude protein content of gestation feed (127.67 g RP/kg) in particular has fallen since 2008 (-11.45 g RP/kg).

Figure 1: Crude protein content of pig feed: Comparing the 2008 and 2021 survey results.

The crude protein content of pig feed has fallen since 2008. An important contribution to the reduction of N losses is made by the use of protein-reduced finishing feeds, as these are the most important feeds in terms of quantity. However, only 50% of the farms use finishing feeds. The universal use of finishing feed could lead to a considerable reduction in N surpluses. A second area with interesting potential for optimisation is the gestation phase, as the crude protein requirement of gestating sows changes in the course of pregnancy. Here, adapted phase feeding systems should be developed and tested.


  • The average crude protein content has decreased in all feed categories (piglet, fattening and sow feed) since 2008 and the energy content has increased slightly.  
  • In pig fattening, crude protein in finishing feeds has been reduced the most compared to the other feed types (-19.4 g RP/kg since 2008). This reduction has a great influence on the total protein input because most feed is consumed in the finishing phase.
  • Today, only just under 50 % of fattening farms using complete feed work with phase feeding with protein-reduced finishing feed. The resulting protein surplus should be eliminated through the consistent implementation of phase feeding.
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