Background

Fertilizer with a high content of phosphorus is a serious environmental problem and there is an urgent need to find solutions that can reduce the content of phosphorus in manure from organic chickens, so that less phosphorus is applied to the fields. New rules mean that the amount of poultry manure that can be spread per ha, will be 22-42% lower than before and thus the amount of livestock manure (if the phosphorus content remains status quo) must be spread per ha is reduced. Alternatively, the agricultural area on the individual farm must be increased, which means that the nitrogen supply to the soil decreases, which will mean a loss in crop yield per ha. Organic egg production has been steadily increasing in recent years and it is important for continued progress and consumer interest that there are solutions that can reduce the phosphorus content in poultry manure, so that producers can continue to have a profitable production without losing eggs - the quality and the welfare of the hens.  

Purpose

ORPHEUS is leading the way in identifying feeding strategies with reduced phosphorus allocation, which are based on new knowledge about optimal feeding of organic hens according to their basic calcium and phosphorus needs, which reduces the hens' pre-excretion. The overall purpose of ORPHEUS is to reduce phosphorus in poultry manure through a significant reduction in the feed content and at the same time develop a new strategy for allocating calcium that lowers the hens' need for phosphorus and reduces excretion. Since phosphorus in plant-based feed is mainly present as phytate-bound phosphorus, which has a low availability in laying hens, supplementation with inorganic phosphorus has been necessary to ensure the hens have a sufficient supply of phosphorus.

Feeding strategies adapted to the age of the hens throughout an entire production period are expected to reduce the addition of or completely phase out the use of expensive inorganic phosphorus, which at some point will not be available because the natural phosphorus resources are exhausted. Implementation of new feed strategies for the benefit of organic egg producers will form the basis for a reduction of the phosphorus content in organic feed in prasis, which reduces phosphorus in the manure that is applied to the fields. The shell quality declines with the age of the hens, and this has major financial consequences for producers and egg packers if the shell quality cannot be maintained at a high level. A new feeding strategy must ensure both good bone health in the hens and a high eggshell quality, so that the proportion of broken eggs is reduced.