In a simulation examination, we analyzed the effect of the family size and the rate of pairing on the survival of rare genes, to keep the level of variation of the genepool and to avoid the loss of alleles.
The population size was 360 animals. In the simulation, we calculated on the basis of a discrete population. We placed the 360 animals i
There were significant changes in the effect of family size on the genetic variation in the following cases: when the base population had the same gene frequencies in all loci, and when the gene frequencies were between 0.125-0.75. In these cases, we found that the smaller families (10 animals/cluster) were better than the larger families (30 or 90 animals/cluster). The first generation where there accured a loss of alleles was averagely earliest in larger families (90 animal/cluster). This average was 3.37 generations. When we are searched the effects of the different rates of pairing we found those cases most favourable when the ratio of males and females was 1:2 or 1:4 as compared to 1:9. The first generation where there was a loss of alleles was averagely earliest at the ratio of pairing male and females of 1:9 (the mean was 3.05 generations) when the frequency of the rarest allele was 0.0069.
The recently introduced rotating-random mating system is an eligible method for small populations for the preservation of genes.
Genetic variability is very important in small populations. We examined an indigenous bronze turkey population which is bred for gene conservation in order to see if the current mating system maintains genetic variability. The present generation was surveyed using microsatellite markers and a computer model was used to simulate changes in the p...opulation over 100 generations.
The data was analysed using the concept of entrophy from information theory instead of genetic variance so that we could more accurately measure genetic variability.
The results indicate that the breeding method currently in use, rotational line mating, is acceptable with respect to preserving genetic variability, but new selection methods may provide additional protection against the loss of alleles.
Our Faculty has been dealing with the cross-breeding of Hungarian speckled hen to maintain the breed since 1977. We keep two breeds of the Hungarian speckled hen, the bare-neck variant and the feathered-neck type on the pilot farm. Because of the spread of intensive poultry keeping the population of these breeds has become endangered. Beside th...e gene preservation, we endeavour to find the best way for the production-purpose
utilisation of the speckled hen stock. We examined the egg production of these breeds.
The Hungarian Grey Cattle breed is a ‘success-story’ of the national genetic conservation work. Traits of the breed have been subjects of several research projects, although many relationships remained unclear. Our present research results were meant to call attention to a less emphasized trait of the breed: the different horn colour variet...ies. Research work was carried out in the Hungarian Grey stock of the Hortobágy Non-profit Company for Nature Conservation and Gene Preservation. Ratio of the three main horn colour varieties (white, ‘cardy’, green) were determined in the observed female, male and steer stocks. Our results showed no significant differences (P<0,05) in the distribution of the horn colour varieties of the female and bull stocks, and of the female and steer stocks. We found that on the basis of the ratio of white colour, four sub-categories can be distinguished within the ‘cardy’ colour variety. Results of the statistical analysis (P<0,05) confirmed that the colour of the horn and the ratio of the black part on the horn tip are two different traits.
Our College has been dealing with the crossbreeding of two Hungarian speckled hen breeds, the bare-neck and the featheredneck, to maintain the breeds since 1977. Apart from the gene preservation, we endeavour to find the best way for the production-purpose utilisation of the speckled hen stock. On the basis of our experiments the laying hens ca...n be used in small-scale egg production. As for meat production, these pure-breds cannot compete with the various types of the colour-feathered hybrid constructions available in Hungary. On the basis of the results of the cross-breeding with cock-lines of various hybrid types for direct production purposes we can conclude that the Hungarian speckled hen is suitable as a mother line to produce meat-type chickens in alternative breeding systems.