effective population size, animal, breeds, genetic resources
Abstract
The objective of this study was to analyse data of farm animal monitoring and to estimate the status and effective population size of Lithuanian farm animal breeds. The principles of conservation of Lithuanian farm animal genetic resources and evaluation of Lithuanian breed status are based on the experience of animal breeding in small conserved herds and on the criteria of global strategy of FAO for the management of farm animal genetic resources. The minimal size of the conserved population was determined according to the breeding possibility of isolated animals without considerable inbreeding increase and regarding to the evaluation standards for breeding animals. The numbers of animals from native breeds were stabilized and even had increased for some breeds. After restoration and conservation of Lithuanian old native breeds’ it seems that Lithuanian animal breeds could experience bottleneck effect. Effective population size for many Lithuanian breeds is below 50 till now, there is driftless reproduction and, therefore, the survival of the population is uncertain. The inbreeding can be minimized by having a larger effective population size (more than 50) and by using special mating schemes to maintain genealogical structure. The first decision in setting up conservation schemes was to carry forward the existing variability in the breeds. This is mainly concerned with the size of available resources, which could be adjusted by choosing individuals for conservation action from different lines and by carrying out planned mating between the chosen animals. Although the establishment of isolated herds with four non-related groups based on founders generation and implementation of special mating schemes had prevented the total disappearing of Lithuanian old animal breeds, the amounts of the compensatory payments are not sufficient for successful conservation of Lithuanian farm animal breeds. Despite the numbers of animals from rare Lithuanian breeds were stabilized and even have increased for some breeds, the numbers of sires should be increased and higher requirements for pure breeding and participation in the programme must also be considered.
