Bøger af Ngo Thi Kim Cuc

The overall goal of this study was to characterize the genetic diversity of the Vietnameselocal chicken breeds and to identify population priorities for conservation. The specificaims were 1) to assess and explain the population genetic structure of the Vietnamesebreeds, 2) to characterize the Vietnamese breeds in relation to the Chinese breeds andwild chickens, 3) to estimate conservation potentials for conservation priorities of theVietnamese breeds, and 4) to define an optimal allocation of limited conservation fundsto them.First genetic diversity within and between the Vietnamese breeds was analysed at theautosomal level using 29 microsatellites. A total of 353 individuals of nine Vietnameselocal breeds and two breeds of Chinese origin were studied. The Vietnamese breeds weresampled from the northern and southern parts of Vietnam while the two Chinese breeds(NIAS Chinese breeds) have been kept at the National Institute of Animal Sciences,Hanoi. The results revealed a high level of diversity within Vietnamese breeds. Analysingthe genetic structure using the software package STRUCTURE suggested an optimalclustering at K = 6. These groups encompassed four homogeneous clusters, one formedby the two Chinese breeds and the other three representing a single breed each: theMekong Delta breed Ac, the South Central Coast breed Choi, and the Red River Deltabreed Dong Tao. The six remaining breeds formed two additional admixed clusters. Thisfinding indicates that sub-structuring of the Vietnamese chicken breeds is related to theirgeographical distribution. The two NIAS Chinese breeds are genetically distinct from theVietnamese breeds.

Genetic diversity within and between nine Vietnamese breeds was analysed at the autosomal level and Mitochondrial DNA. The Weitzman approach for assessing conservation strategies for genetic diversity between breeds was used. To investigate an optimal allocation of conservation funds, three different models were applied. The result showed that at the autosomal level, the Vietnamese local chicken breeds from different agro-ecological zones represent genetically distinct populations. The northern breeds are clearly separated from breed of the South Central Coast and from breed of the Mekong Delta. The Vietnamese local chicken breeds are highly polymorphic and originated from eight maternal lineages. These lineages are present across the country. The expected future diversity of the Vietnamese chicken breeds after 30 to 50 years is only a half of the current diversity and average extinction probability of the breeds was about 49%. Conservation potential of the Vietnamese chicken breeds varies considerably. The three breeds Te, Dong Tao and Ac with the highest conservation potential should be the prime candidates to which conservation funds should be allocated if budgets are limited

This study aimed at (1) to evaluate the present status of H¿mong chicken and describe their phenotypic characteristics and production system, (2) to assess genetic diversity of Hmong chicken population. A total of 55 households in three villages (Phieng Cam, Chieng Chan and Chieng Noi) of Maison District, Sonla province were surveyed. Blood samples of 36 individuals were analyzed using 29 microsatellite markers. The result showed that body weights of chickens in Chieng Chan were lower than in Phieng Cam and Chieng Noi. There was no difference in body weight among the three feather colour variants. No difference was found in most reproduction traits among three villages and three feather colour variants. The results of genetic diversity assessment indicated that the expected heterozygosity varied between 62.7% to 66.8% for three populations tested. The genetic differentiation of three populations was at around 2%. The result of pairwise differentiation test indicated that significant differences were observed between population Chieng Chan with population Phieng Cam and population Chieng Noi but between feather colour variants showed no significant difference.