• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1625-1630
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• 2007

A simulation study was conducted to evaluate the effect of reciprocal cross on the detection and characterization of Mendelian QTL in $F_2$ QTL swine populations. Data were simulated under two different mating designs. In the one-way cross design, six $F_0$ grand sires of one breed and 30 $F_0$ grand dams of another breed generated 10 $F_1$ offspring per dam. Sixteen $F_1$ sires and 64 $F_1$ dams were randomly chosen to produce a total of 640 $F_2$ offspring. In the reciprocal design, three $F_0$ grand sires of A breed and 15 $F_0$ grand dams of B breed were mated to generate 10 $F_1$ offspring per dam. Eight $F_1$ sires and 32 $F_1$ dams were randomly chosen to produce 10 $F_2$ offspring per $F_1$ dam, for a total of 320 $F_2$ offspring. Another mating set comprised three $F_0$ grand sires of B breed and 15 $F_0$ grand dams of A breed to produce the same number of $F_1$ and $F_2$ offspring. A chromosome of 100 cM was simulated with large, medium or small QTL with fixed, similar, or different allele frequencies in parental breeds. Tests between Mendelian models allowed QTL to be characterized as fixed (LC QTL), or segregating at similar (HS QTL) or different (CB QTL) frequencies in parental breeds. When alternate breed alleles segregated in parental breeds, a greater proportion of QTL were classified as CB QTL and estimates of QTL effects for the CB QTL were more unbiased and precise in the reciprocal cross than in the one-way cross. This result suggests that reciprocal cross design allows better characterization of Mendelian QTL in terms of allele frequencies in parental breeds.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1357-1363
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• 2012

Pigs may need to be exploited as xenotransplantation donors due to the shortage of human organs, tissues and cells. Porcine endogenous retroviruses (PERVs) are a significant obstacle to xenotransplantation because they can infect human cells in vitro and have the potential for transmission of unexpected pathogens to humans. In this research, 101 pigs, including four commercial breeds (23 Berkshire, 13 Duroc, 22 Landrace and 14 Yorkshire pigs), one native breed (19 Korean native pigs) and one miniature breed (10 NIH miniature pigs) were used to investigate insertional variations for 11 PERV loci (three PERV-A, six PERV-B and two PERV-C). Over 60% of the pigs harbored one PERV-A (907F8) integration and five PERV-B (B3-3G, B3-7G, 742H1, 1155D9 and 465D1) integrations. However, two PERV-A loci (A1-6C and 1347C1) and one PERV-B locus (B3-7F) were absent in Duroc pigs. Moreover, two PERV-C loci (C2-6C and C4-2G) only existed in Korean native pigs and NIH miniature pigs. The results suggest that PERV insertional variations differ among pig breeds as well as among individuals within a breed. Also, the results presented here can be used for the selection of animals that do not have specific PERV integration for xenotransplantation research.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.6
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• pp.842-850
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• 2018

Objective: Several studies have reported the development of new molecular methods for the prognosis and diagnosis of male fertility based on biomarkers aimed at overcoming the limitations of conventional male fertility analysis tools. However, further studies are needed for the field application of these methods. Therefore, alternative methods based on existing semen analysis methods are required to improve production efficiency in the animal industry. Methods: we examined the possibility of improving litter size in various pig breeds using combined Hoechst 33258/chlortetracycline fluorescence (H33258/CTC) staining. The correlation between field fertility and capacitation status by combined H33258/CTC staining in different ejaculates spermatozoa (n = 3) from an individual boar (20 Landrace, 20 Yorkshire, and 20 Duroc) was evaluated as well as overall accuracy. Results: The acrosome reacted (AR) pattern after capacitation (%) was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 75%, 75%, and 70% in Landrace, Yorkshire, and Duroc pigs, respectively. The difference (${\Delta}$) in AR pattern before and after capacitation was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 80%, 65%, and 55% in Landrace, Yorkshire, and Duroc pigs, respectively. However, the difference (${\Delta}$) in capacitated (B) pattern before and after capacitation was negatively correlated with the litter size of Landrace pigs and the overall accuracy was 75%. Moreover, average litter size was significantly altered according to different combined H33258/CTC staining parameters. Conclusion: These results show that combined H33258/CTC staining may be used to predict male fertility in various breeds. However, the selection of specific efficiency combined H33258/CTC staining parameters requires further consideration. Taken together, these findings suggest that combined H33258/CTC staining may constitute an alternative method for predicting male fertility until such time as fertility-related biomarkers are further validated.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1529-1535
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• 2013

The TBC1D1 plays a key role in body energy homeostasis by regulating the insulin-stimulated glucose uptake in skeletal muscle. The present study aimed to identify the association between genetic polymorphisms of TBC1D1 and body weight (BW) in rabbits. Among the total of 12 SNPs detected in all 20 exons, only one SNP was non-synonymous (c.214G>A. p.G72R) located in exon 1. c.214G>A was subsequently genotyped among 491 individuals from two rabbit breeds by the high-resolution melting method. Allele A was the predominant allele with frequencies of 0.7780 and 0.6678 in European white rabbit (EWR, n = 205) and New Zealand White rabbit (NZW, n = 286), respectively. The moderate polymorphism information content (0.250.05). Our results implied that the c.214G>A of TBC1D1 gene might be one of the candidate loci affecting the trait of 35 d BW in the rabbit.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.377-382
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• 2002

This study was carried out for the simultaneous genetic evaluation of swine breeds from the seedstock farms in Korea. The performance tested production records of 96,842 heads and the litter records of 90,396 litters from 1995 to 2001 were analyzed to estimate the breeding values and the breed effects of days to 90kg, daily gain, back fat thickness, loin muscle area, lean meat percent, total litter size and number born alive from Landrace, Yorkshire and Duroc. Estimated breed effects of traits had shown the characteristics of the breeds. Landrace was superior in back fat thickness and lean meat percent to other breeds. Yorkshire had shown good performance in lean meat percent, loin muscle area, total litter size and number born alive. Duroc was superior to the other breeds in days to 90kg and daily gain. Conclusively, the multi-breed genetic evaluation would result in higher connectedness and provide convenience for the routine genetic evaluation process of swine performance and reproduction test.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.11-14
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• 2003

To evaluate the ewe reproductive performances of three Iranian local sheep breeds, namely Moghani, Chal and Zel, 27 rams and 473 ewes were used as the foundation flock in a crossbreeding program. The three breeds were crossed amongst themselves reciprocally. Ram breed and ewe breed showed a two-way interaction on apparent fertility. The Zel ewes showed higher fertility than the Chal and Moghani ewes (94.4 vs 77.3 and 84.6%). Prolificacy among main and individual mating groups were not significantly different (p>0.05). Zel ewes were 22.3 and 14.8% more reproductive (p<0.05) than Chal and Moghani ewes, respectively. Zel and Moghani ewes showed higher (p<0.05) ewe productivity than Chal ewes. Ram breed had a significant (p<0.05) effect on ewe efficiency. The Zel rams were not completely successful to mate with Chal ewes, this caused a to way-interaction between ram and ewe breeds. The Zel ewes mated with Chal and Moghani rams showed 26.1 and 28.5% more efficiency than those mated with Zel rams. This observation strongly supports the use of crossbreeding to improve the efficiency of the Zel ewes. With decreasing lamb mortality, through supplemented feeding of lambs in pre-weaning period, and increasing litter weight, through crossbreeding, it should be possible to improve the efficiency of Zel ewes even better than Chal and Moghani ewes. Small body size of Zel ewes that needs the lower maintenance requirements would be a well advantageous to using Zel ewes as the dam herd to produce commercial lambs in north area of Iran.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.155-160
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• 2008

Several studies have reported quantitative trait loci (QTL) for meat quality on porcine chromosome 2 (http://www.animalgenome.org/QTLdb/pig.html). For application of the molecular genetic information to the pig industry through marker-assisted selection, single nucleotide polymorphism (SNP) markers were analyzed by comparative re-sequencing of polymerase chain reaction (PCR) products of 13 candidate genes with DNA from commercial pig breeds such as Berkshire, Yorkshire, Landrace, Duroc and Korean Native pig. A total of 34 SNPs were identified in 15 PCR products producing an average of one SNP in every 253 bp. PCR restriction fragment length polymorphism (RFLP) assays were developed for 11 SNPs and used to investigate allele frequencies in five commercial pig breeds in Korea. Eight of the SNPs appear to be fixed in at least one of the five pig breeds, which indicates that different selection among pig breeds might be applied to these SNPs. Polymorphisms detected in the PTH, CSF2 and FOLR genes were chosen to genotype a Berkshire-Yorkshire pig breed reference family for linkage and association analyses. Using linkage analysis, PTH and CSF2 loci were mapped to pig chromosome 2, while FOLR was mapped to pig chromosome 9. Association analyses between SNPs in the PTH, CSF2 and FOLR suggested that the CSF2 MboII polymorphism was significantly associated with several pork quality traits in the Berkshire and Yorkshire crossed F2 pigs. Our current findings provide useful SNP marker information to fine map QTL regions on pig chromosome 2 and to clarify the relevance of SNP and quantitative traits in commercial pig populations.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.180-188
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• 2018

Objective: The aim of this study was to investigate the effect of single nucleotide polymorphisms (SNPs) of the melanogenesis associated transcription factor (MITF) and dopachrome tautomerase (DCT) genes on plumage coloration in Asian native duck breeds. MITF encodes a protein for microphthalmia-associated transcription factor, which regulates the development and function of melanocytes for pigmentation of skin, hair, and eyes. Among the tyrosinase-related family genes, DCT is a pigment cell-specific gene that plays important roles in the melanin synthesis pathway and the expression of skin, feather, and retina color. Methods: Five Asian duck varieties (black Korean native, white Korean native, commercial Peking, Nageswari, and Bangladeshi Deshi white ducks) were investigated to examine the polymorphisms associated with plumage colors. Among previously identified SNPs, three synonymous SNPs and one indel of MITF and nine SNPs in exon regions of DCT were genotyped. The allele frequencies for SNPs of the black and white plumage color populations were estimated and Fisher's exact test was conducted to assess the association between the allele frequencies of these two populations. Results: Two synonymous SNPs (c.114T>G and c.147T>C) and a 14-bp indel (GCTGCAAAC AGATG) in intron 7 of MITF were significantly associated with the black- and white-colored breeds (p<0.001). One non-synonymous SNP [c.938A>G (p.His313Arg)] in DCT, was highly significantly associated (p<0.001) and a synonymous SNP (c.753A>G) was significantly associated (p<0.05) with black and white color plumage in the studied duck populations. Conclusion: The results of this study provide a basis for further investigations of the associations between polymorphisms and plumage color phenotypes in Asian duck breeds.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.183-191
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• 2019

Claw lesion is one of the major causes of lameness in sows and the lameness is one of the reasons for culling of sows from the swine herd. This survey was conducted on sows in total of 8 farms with a total of 684 pigs. The lesions observed in the study were horizontal and vertical claw cracks (CWH & CWV), differences in the length of toes (T) and/or in the length of dew claws (DC) according to crates, breeds and parity of sows. Scores of claw lesions were assigned on 0, 1, 2, and 3 at each foot depending on the severity of the claw lesions. The sows' parity was classified into 1 to 2, 3 to 4, 5 to 8. Prevalence rate of claw lesions in sows raised on punched plastic crate was higher than that in sows raised on tribar crate. In prevlence rate by breeds, inbreed Landrace sows showed higher than that of Yorkshire sows. According to 4 claw lesions, the length of DC was the highest at parity 3~4 and CWV was the lowest at parity 3~4 in F1 crossbred sows raised on punched plastic crates, respectively. In Yorkshire breeds raised on punched plastic crates, the length of DC at parity 5~8 was the lowest and CWH was the highest at parity 3~4, respectively. In Landrace breeds raised on tribar crates, CWH was the highest at parity 1~2 and CWV was the lowest at parity 3~4, respectively. The high parity in F1 crossbred sows showed high prevalence rate of claw lesions than that of low parity and other inbreed sows, respectively. These results may be useful as elementary data in establishment of welfare quality protocol and preventive measures to reduce economic losses from craw lesions in sows.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1566-1572
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• 2020

Objective: The extensive breeding of commercial chickens has led to a sharp decrease in the resources of many indigenous chickens, especially the indigenous chickens in the southeastern coastal region, which are on the verge of extinction, and the indigenous chickens in the northwestern region of China, which are also at risk. However, there are few reports on the evaluation of genetic diversity and conservation of genetic resources of indigenous chickens in remote areas in the Northwest of China. Methods: In the present study, the genetic diversity and phylogenetic relationship of six indigenous chickens from different regions were studied based on variation in mitochondrial DNA control region (D-loop), and the degree of introgression from commercial breeds into these chickens was determined by the amount of haplotype sharing between indigenous and commercial breeds. Results: Twenty-five polymorphic sites and 25 haplotypes were detected in 206 individuals. Principal component analysis showed that the Jingning chicken had the highest genetic diversity among the six indigenous chickens. According to the degree of introgression, the six indigenous breeds may be involved in haplotype sharing with commercial breeds, and the introgression from commercial chickens into the Haidong chicken is the most serious. Conclusion: The genetic uniqueness of indigenous chickens has been eroded, so it is necessary to consider the protection of their genetic resources. Phylogenetic analysis suggests that the six indigenous chickens have two major matrilineal origins: one from Yunnan or its surrounding areas in China and the other from the Indian subcontinent.