Feeding strategies for laying hens in housing systems with open-air runs according to organic farming principles

The objective of the research project was the investigation of ecological feeding strategies for laying hens in free range farming in order to obtain data on production performance and optimal diet formulation. In the first part the feeding of an all-mash feed was compared with a combined feeding system. The combined feed consisted of a supplementary feed offered ad libitum plus wheat grains limited to 60 g/hen/day. In a second part all hens were fed with combined feed but only one group had entry to the open-air run. The experiment was performed in a mobile housing system and replicated in a similar furnished solid housing system. In each experiment 900 Tetra-SL-hens were randomly assigned to two groups and housed in two similar compartments of an aviary hen house. The experimental parameters were laying performance, feed intake, egg quality, and the influence of the environmental temperature. In the first part the combined feeding system significantly improved the laying performance with a significant increase in feed intake compared with the all-mash feeding. There were no differences in egg quality. The environmental temperatures showed no influence on egg production. In the second part the effect of combined feeding with or without access to open-air runs with grass was studied. The free range system significantly improved the laying performance with a significant increase in feed intake and egg weight. The egg quality was not influenced by outdoor access. The environmental temperatures did not influence the egg production. Furthermore, free range farming, as a natural housing system for laying hens, significantly improved the egg production and feed conversion accompanied by a higher feed intake. In conclusion, combined feeding along with free range has a beneficial impact on egg performance of laying hens in organic husbandry.