Population size in conservation of local chicken breeds in chosen European countries

Local chicken breeds are a vital reservoir of gene resources. Because of small population sizes they can survive only if there is someone who takes responsibility for their preservation. This study analyzed conservation populations of 41 locally adapted chicken breeds and strains in Poland (8 breeds and strains), Denmark (1 breed), Hungary (8 breeds and varieties), Italy (20 breeds and strains) and Slovakia (4 breeds and strains). Sources of information were mainly materials shared by institutions dealing with this topic in their home countries. The stress was put to comparison of diverse morphological and reproductive traits in hens. Effective population sizes and hypothetical inbreeding increments were investigated within genetic groups. Various countries implement different methods of conservation of their genetic resources. A huge activity of hobbyists in cooperation with research institutions was found in Italy, in contrary to a lack of conservation projects in Denmark. In Poland, Hungary and Slovakia genetic reserve stocks were analyzed in-situ. Genetic variety of studied breeds was found in diversified and unique morphological traits. Adaptation to local environment which is reflected in performance of birds was expressed in low to moderate production, high fertility and hatchability rates, as well as resistance to many diseases and poor management. In conserved stocks with small sex ratios increasing number of males will allow to reducing population sizes of some breeds without any effects or changes in effective population size or in inbreeding rate. The latter was assessed as not high (about 0.02-0.71 percent per generation). Results are an incentive to significant improvement in the accessibility of genetic resources through research and development. They are also shown as confirmation of validity of international efforts to conserve locally adapted breeds.