Poultry production chain is an integrated sector seen as "off land". However this chain is strongly interacting with territories leading to various impacts. Therefore to deal with sustainability requires transdisciplinarity. The first step is to define the studied dynamic system, here the "poultry production chain * county" aggregate. The second is to share between disciplines a common knowledge on this system through a unique representation. The third is to accept the approaches proposed by other disciplines even though time and space scales are consequently evolving. Due to the approach complexity, fruitful but time?consuming transactions between researchers are observed.