A novel design approach for livestock housing based on recursive control - with examples to reduce environmental pollution

Emissions to the air and nutrient losses to the environment (ground water and soil) are inherent to the keeping of animals in high densities in animal houses and cause various problems to men and animal (environmental, health and nuisance). Traditional approaches in animal husbandry, and also the approaches to solve these problems, are often and primarily based on unidirectional technical solutions, in which control is exclusively exerted over both dead matter and living entities. As a consequence, each technical solution to a problem implies increased constraints for the animals involved or end-of-pipe solutions. A novel approach is presented to combine the nature of animals with the prevention and reduction of environmental pollution based on recursive control. This approach is based on the presence, knowledge and use of the natural behaviour of animals and their interrelation in the population. It is claimed that order in complex systems like these can be the result of animal interactions with their environment as well, without detailed human and technical intervention and surveillance. A fundamental precondition for this is a considerable degree of slack, or play, in order to give animals the latitude to adapt to changing local circumstances in the animal house. In this paper, we will outline and discuss this approach both theoretically and practically, using examples with elements that support the theory, like a straw-based group housing system for sows, an aviary housing system for laying hens, and the approach taken by a new concept for the keeping of fattening pigs (Hercules project). We end by drawing some general conclusions on the consequences of this approach for systems design and suggest a number of recommendations for design heuristics