Reduced crude protein–level in chicken feeds for reduced ammonia volatilization

Ammonia volatilization from poultry facilities are the biggest environmental challenge in the production. Reducing the crude protein level in feed is considered the best available tool to decrease nitrogen excretion and ammonia volatilization from poultry production. A lower crude protein level in feed is also considered as a strategy to reduce the use of protein ingredients such as imported soybean meal in favour of increased use of domestic feed ingredients, and might promote Swedish protein production.

Today, Swedish broiler feed is optimized based on both optimal levels of total crude protein and essential amino acids. Crude protein provides a sufficient amount of nitrogen to enable protein synthesis, but unlike the requirements for essential amino acids, the minimum requirement for crude protein is not clearly defined. A risk associated with low crude protein levels in feed is that amino acids that are normally present in sufficient amounts become limiting, which can negatively affect animal production. However, in recent years, the availability of crystalline and synthetic amino acids has increased.

The possibility to add more crystalline and synthetic amino acids to feed and thus balance the feed with a broader range of amino acids could potentially reduce the risks associated with low crude protein levels. However, there are still uncertainties regarding the absorption and utilization of crystalline and synthetic amino acids compared to natural protein sources. Among the concerns, there is a fear that a high inclusion of crystalline and synthetic amino acids may reduce feed intake and consequently also growth. Currently, low crude protein levels work better in corn-based feeds than in wheat-based feeds, but the reason for this is not yet fully understood.

In this project, we will investigate whether increasing the inclusion of i.e. fat, fibre, and crystalline and synthetic amino acids can enable a reduction of the current crude protein level in wheat-based broiler feed with maintained production performance and reduced ammonia volatilization.

Project manager:

Emma Ivarsson, THV, Emma.Ivarsson@slu.se, CV-page

Doctoral student:

Theodoros Vasileiou, THV, theodoros.vasileiou@slu.se

Project group:

Helena Wall, THV, Åsa Myrbeck, RISE, Maja Hoffer, Lantmännen Lantbruk