• Animal Bioscience
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• 제34권7호
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• pp.1123-1133
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• 2021

Objective: Shandong indigenous pig breeds are important Chinese pig resources. Their progressive population decline in recent decades has attracted attention towards their conservation. Conservation genetics of these indigenous breeds are essential for developing a conservation and utilization scheme. Methods: A high-density single nucleotide polymorphism (HD-SNP) chip-based comparative analysis of genetic characteristics was performed for seven Shandong indigenous pig breeds in the context of five Western commercial breeds. Results: The results showed that Shandong indigenous pig breeds varied greatly in genetic diversity, effective population size, inbreeding level, and genetic distance with the Western commercial breeds. Specifically, Laiwu and Dapulian displayed low genetic diversity, and had a genetically distant relationship with the Western commercial breeds (average F statistics [F_ST] value of 0.3226 and 0.2666, respectively). Contrastingly, the other five breeds (Yantai, Licha, Yimeng, Wulain, and Heigai) displayed high genetic diversity within breed and had some extent of mixture pattern with the Western commercial breeds, especially Duroc and Landrace (F_ST values from 0.1043 to 0.2536). Furthermore, intensive gene flow was discovered among the seven Shandong indigenous breeds, particularly Wulian, Licha, and Heigai, as indicated by the large cluster formed in the principal component analysis scatterplot and small population differentiation (average of 0.1253) among them. Conclusion: Our study advances the understanding of genetic characteristics of Shandong indigenous breeds and provides essential information for developing an appropriate conservation and utilization scheme for these breeds.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1085-1090
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• 2009

There are currently five primary breeds of Chinese gamecock, the Henan, Luxi, Tulufan, Xishuangbanna andZhangzhou. Though there is historical evidence of cockfighting in China dating as far back as 2,800 years, the origin and genetic relationships of these breeds are not well understood. We used sequence variation from the mtDNA cytb gene and control region (1,697 bp) to examine the domestication history and genetic relationship of the Chinese gamecock. From 75 samples (14-16 per breed) we found 34 haplotypes, and 45 variable nucleotides. Phylogenetic reconstruction indicated multiple origins of the gamecock breeds. The breeds in the north and center of China, Tulufan, Luxi and Henan, clustered together in a haplogroup and may have the same ancestor. However the southern breeds, Zhangzhou and Xishuangbanna clustered into two isolated haplogroups, suggesting another two origins of Chinese gamecock. Meanwhile, extensive admixture was also found because samples from different breeds, more or less, were always grouped together in the same clades. Based on these results, we discuss the possibilities of multiple origins of gamecock breeds, from both ancestral gamecocks as well as other domestic chickens and red jungle fowl.

• Asian-Australasian Journal of Animal Sciences
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• 제25권1호
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• pp.28-32
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• 2012

In the present study, we evaluated the informativeness of SNPs genotyped by the Illumina Bovine SNP50K assay in different cattle breeds. To investigate these on a genome-wide scale, we considered 52,678 SNPs spanning the whole autosomal and X chromosomes in cattle. Our study samples consists of six different cattle breeds. Across the breeds approximately 72 and 6% SNPs were found polymorphic and fixed or close to fix in all the breeds, respectively. The variations in the average minor allele frequency (MAF) were significantly different between the breeds studied. The level of average MAF observed in Hanwoo was significantly lower than the other breeds. Hanwoo breed also displayed the lowest number of polymorphic SNPs across all the chromosomes. More importantly, this study indicated that the Bovine SNP50K assay will have reduced power for genome-wide association studies in Hanwoo as compared to other cattle breeds. Overall, the Bovine SNP50K assay described in this study offer a useful genotyping platform for mapping quantitative trait loci (QTLs) in the cattle breeds. The assay data represent a vast and generally untapped resource to assist the investigation of the complex production traits and the development of marker-assisted selection programs.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.155-161
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• 2011

In this study, mitochondrial DNA (mtDNA) sequence polymorphism was used to assess genetic diversity of nine Vietnamese local chicken breeds. In addition, two Chinese breeds kept in Vietnam were included in the analysis for comparison. A 455-bp fragment of the mtDNA D-loop region was sequenced in 222 chickens of these 11 breeds. As reference, a skeleton was constructed based on chicken mtDNA sequences taken from the Genbank. Haplotypes of the nine Vietnamese local and two Chinese breeds were aligned together with these sequences. The Vietnamese and Chinese breeds showed a high degree of variability. In total, 37 haplotypes were identified in the chicken breeds studied forming eight clades. Thereby, the majority of individuals of the two Chinese breeds grouped together in one clade which is assumed to have its roots in the Indian subcontinent. Although the Vietnamese chicken breeds were distributed across all eight clades, most of them clustered in three main clades. These results suggest that the Vietnamese domestic chickens have originated from multiple maternal lineages, presumably from Yunnan and adjacent areas in China, South and Southwest China and/or surrounding regions (i.e. Vietnam, Burma, Thailand, and India).

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.175-178
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• 1994

A study was conducted at Ijok, Malaysia, to determine the relationship of testicular measurements with libido and semen quality in tropical and imported temperate breeds of sheep. Ten rams each of Malin (M), Siamese Longtail (L), Cross of Merino with Border Leicester (C), Dorset (D) and Suffolk (S) were used for the study. Libido, semen volume and semen quality were recorded monthly for a year together with testicular length, width and circumference. The results showed that there were breed differences in volume and quality of semen where the tropical breeds had better semen compared to the temperate breeds. There was positive and significant correlation between testicle length and semen volume in all the breeds. Testicular length was found to be positively and significantly correlated with motility and sperm concentration in the tropical breeds (L and M). The relationship between libido and testicle measurements in the tropical breeds was not significant (p<0.05). There was variable relationship between the testicular measurements and libido in the temperate breeds where the relationship was significant and negative in breeds C and D and highly significant and positive in S. It was evident that the long testicles influenced the quality of the semen whereas testicles with greater circumference influenced the libido of the rams.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.47.1-47.10
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• 2015

Background: Knowledge of linkage disequilibrium (LD) levels among different populations can be used to detect genetic diversity and to investigate the historical changes in population sizes. Availability of large numbers of SNP through new sequencing technologies has provided opportunities for extensive researches in quantifying LD patterns in cattle breeds. The aim of this study was to compare the extent of linkage disequilibrium among Iranian cattle breeds using high density SNP genotyping data. Results: A total of 70 samples, representing seven Iranian indigenous cattle breeds, were genotyped for 777962 SNPs. The average values of LD based on the $r^2$ criterion were computed by grouping all syntenic SNP pairwises for intermarker distances from 0 Kb up to 1 Mb using three distance sets. Average $r^2$ above 0.3 was observed at distances less than 30 Kb for Sistani and Kermani, 20 Kb for Najdi, Taleshi, Kurdi and Sarabi, and 10 Kb for Mazandarani. The LD levels were considerably different among the Iranian cattle breeds and the difference in LD extent was more detectable between the studied breeds at longer distances. Lower level of LD was observed for Mazandarani breed as compared to other breeds indicating larger ancestral population size in this breed. Kermani breed continued to have more slowly LD decay than all of the other breeds after 3 Kb distances. More slowly LD decay was observed in Kurdi and Sarabi breeds at larger distances (>100 Kb) showing that population decline has been more intense in more recent generations for these populations. Conclusions: A wide genetic diversity and different historical background were well reflected in the LD levels among Iranian cattle breeds. More LD fluctuation was observed in the shorter distances (less than 10 Kb) in different cattle populations. Despite of the sample size effects, High LD levels found in this study were in accordance with the presence of inbreeding and population decline in Iranian cattle breeds.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.314-319
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• 2008

Duck (Anas platyrhynchos) is one of the most important domestic avian species in the world. In the present research, fifteen polymorphic microsatellite markers were used to evaluate the diversity and population structure of 26 Chinese indigenous duck breeds across the country. The Chinese breeds showed high variation with the observed heterozygosity (Ho) ranging from 0.401 (Jinding) to 0.615 (Enshi), and the expected heterozygosity (He) ranging from 0.498 (Jinding) to 0.707 (Jingjiang). In all of the breeds, the values of Ho were significantly lower than those of He, suggesting high selection pressure on these local breeds. AMOVA and Bayesian clustering analysis showed that some breeds had mixed together. The FST value for all breeds was 0.155, indicating medium differentiation of the Chinese indigenous breeds. The FST value also indicated the short domestication history of most of Chinese indigenous ducks and the admixture of these breeds after domestication. Understanding the genetic relationship and structure of these breeds will provide valuable information for further conservation and utilization of the genetic resources in ducks.

• Animal Bioscience
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• 제34권5호
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• pp.789-800
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• 2021

Objective: Conservation and genetic improvement of cattle breeds require information about genetic diversity and population structure of the cattle. In this study, we investigated the genetic diversity and population structure of the three cattle breeds in the Korean peninsula. Methods: Jeju Black, Hanwoo, Holstein cattle in Korea, together with six foreign breeds were examined. Genetic diversity within the cattle breeds was analyzed with minor allele frequency (MAF), observed and expected heterozygosity (HO and HE), inbreeding coefficient (FIS) and past effective population size. Molecular variance and population structure between the nine breeds were analyzed using a model-based clustering method. Genetic distances between breeds were evaluated with Nei's genetic distance and Weir and Cockerham's FST. Results: Our results revealed that Jeju Black cattle had lowest level of heterozygosity (HE = 0.21) among the studied taurine breeds, and an average MAF of 0.16. The level of inbreeding was -0.076 for Jeju Black, while -0.018 to -0.118 for the other breeds. Principle component analysis and neighbor-joining tree showed a clear separation of Jeju Black cattle from other local (Hanwoo and Japanese cattle) and taurine/indicine cattle breeds in evolutionary process, and a distinct pattern of admixture of Jeju Black cattle having no clustering with other studied populations. The FST value between Jeju Black cattle and Hanwoo was 0.106, which was lowest across the pair of breeds ranging from 0.161 to 0.274, indicating some degree of genetic closeness of Jeju Black cattle with Hanwoo. The past effective population size of Jeju Black cattle was very small, i.e. 38 in 13 generation ago, whereas 209 for Hanwoo. Conclusion: This study indicates genetic uniqueness of Jeju Black cattle. However, a small effective population size of Jeju Black cattle indicates the requirement for an implementation of a sustainable breeding policy to increase the population for genetic improvement and future conservation.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1871-1880
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• 2018

Objective: Recently, there has been an increasing interest in conservation of native genetic resources of chicken on a worldwide basis. Most of the native chicken breeds are threatened by extinction or crossing with ecotypes. Methods: Six Saudi native chicken breeds including black naked neck, brown frizzled, black, black barred, brown and gray were used in the current study. The aim of the current study was to evaluate genetic diversity, relationship and population structure of Saudi native chicken breeds based on 20 microsatellite markers. Results: A total of 172 alleles were detected in Saudi native chicken breeds across all 20 microsatellite loci. The mean number of alleles per breed ranged from 4.35 in gray breed to 5.45 in normally feathered black with an average of 8.6 alleles. All breeds were characterized by a high degree of genetic diversity, with the lowest heterozygosity found in the brown breed (72%) and the greatest in the frizzled and black barred populations (78%). Higher estimate of expected heterozygosity (0.68) was found in both black breeds (normal and naked neck) compared to the other chicken populations. All studied breeds showed no inbreeding within breed (negative inbreeding coefficient [$F_{IS}$]). The phylogenetic relationships of chickens were examined using neighbor-joining trees constructed at the level of breeds and individual samples. The neighbor-joining tree constructed at breed level revealed three main clusters, with naked neck and gray breeds in one cluster, and brown and frizzled in the second cluster leaving black barred in a separate one. Conclusion: It could be concluded that the genetic information derived from the current study can be used as a guide for genetic improvement and conservation in further breeding programs. Our findings indicate that the Saudi native chicken populations have a rich genetic diversity and show a high polymorphism.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.309-314
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• 2002

Random Amplified Polymorphic DNA (RAPD) assay was conducted to identify polymorphic markers in Amrithmahal, Krishna Valley, Hallikar, Deoni, Khillari, Ongole and Malnad Gidda breeds of South Indian cattle using twenty six primers. Of the 93 RAPD markers obtained, 53 were present in all breeds, 22 were individual specific and 18 were polymorphic for different breeds. Dual purpose breeds viz., Krishna Valley and Ongole showed less genetic divergence between them as compared to their genetic divergence from draft breeds viz., Amrithmahal, Hallikar and Khillari. Malnad Gidda was found to be a distinctly different from others studied.