• 한국축산식품학회지
• /
• 제21권2호
• /
• pp.142-148
• /
• 2001

Comparisons in physicochemical characteristics of longissimus muscle between the Korean native pig(KNP: 75kg of slaughter weight and 240 days of age) versus Landrace(110kg of slaughter weight and 180 days of age) are as below. Compared with Landrace, KNP had a greater drip loss resulting from a lower muscle pH and water holding capacity, greater L*(lightness), a*(redness) and b*(yellowness) values in muscle color, and a greater L* value and smaller a* and b* values in attached backfat color. Tenderness were greater in the Korean native pig. Moreover, KNP had a greater number of muscle fibers and a smaller diameter of the fiber when examined by scanning electron microscopy. In sum, the Korean native pig, compared with Landrace, had a greater redness in meat color, a greater whiteness in fat color; the lower WHC and greater tenderness of the former apparently resulted from the lower slaughter weight rather than from a species difference.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권8호
• /
• pp.1078-1087
• /
• 2018

Objective: The genetic diversity of the Landrace population, a representative maternal pig breed in Korea, is important for genetic improvement. Previously, the effective population size (Ne) has been used to infer the genetic diversity of a population of interest. In this study, we aimed to use single nucleotide polymorphism (SNP) data to characterize linkage disequilibrium (LD) and the Ne of the Korean Landrace population. Methods: We genotyped 1,128 Landrace individuals from three representative Korean major grand-grand-parent (GGP) farms using the Illumina PorcineSNP60 version2 BeadChip, which covers >61,565 SNPs located across all autosomes and mitochondrial and sex chromosomes. We estimated the expected LD and current Ne, as well as ancestral Ne. Results: In the Korean Landrace population, the mean LD ($r^2$) of 3.698 million SNP pairs was $0.135{\pm}0.204$. The mean $r^2$ decreased slowly with as the distance between SNPs increased, and remained constant beyond 3 Mb. According to the $r^2$ calculations, 8,085 of 3.698 million SNP pairs were in complete LD. The current Ne (${\pm}$standard deviation) of the Korean Landrace population is approximately 92.27 [79.46; 105.07] individuals. The ancestral Ne exhibited a slow and steady decline from 186.61 to 92.27 over the past 100 generations. Additionally, we observed more a rapid Ne decrease from the past 20 to 10 generations ago, compared with other intervals. Conclusion: We have presented an overview of LD and the current and ancestral Ne values in the Korean Landrace population. The mean LD and current Ne for the Korean Landrace population confirm the genetic diversity and reflect the history of this pig population in Korea.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권9호
• /
• pp.1263-1269
• /
• 2014

Comprehensive information on genetic diversity and introgression is desirable for the design of rational breed improvement and conservation programs. Despite the concerns regarding the genetic introgression of Western pig breeds into the gene pool of the Korean native pig (KNP), the level of this admixture has not yet been quantified. In the present study, we genotyped 93 animals, representing four Western pig breeds and KNP, using the porcine SNP 60K BeadChip to assess their genetic diversity and to estimate the level of admixture among the breeds. Expected heterozygosity was the lowest in Berkshire (0.31) and highest in Landrace (0.42). Population differentiation ($F_{ST}$) estimates were significantly different (p<0.000), accounting for 27% of the variability among the breeds. The evidence of inbreeding observed in KNP (0.029) and Yorkshire (0.031) may result in deficient heterozygosity. Principal components one (PC1) and two (PC2) explained approximately 35.06% and 25.20% of the variation, respectively, and placed KNP somewhat proximal to the Western pig breeds (Berkshire and Landrace). When K = 2, KNP shared a substantial proportion of ancestry with Western breeds. Similarly, when K = 3, over 86% of the KNP individuals were in the same cluster with Berkshire and Landrace. The linkage disquilbrium (LD) values at $r^2_{0.3}$, the physical distance at which LD decays below a threshold of 0.3, ranged from 72.40 kb in Landrace to 85.86 kb in Yorkshire. Based on our structure analysis, a substantial level of admixture between Western and Korean native pig breeds was observed.

• 한국가축번식학회지
• /
• 제11권1호
• /
• pp.22-25
• /
• 1987

This study was carried out to investigate the effects of imported pellet frozen semen on sperm motility and NAR acrosomes after thawing, and the farrowing rates, litter sizes and preweaning body weights after artificial insemination. A total of 28 sows of Landrace, Large White and Duroc were inseminated at the Chungnam Provincial Animal Breeding Station. The results obtained are summarized as follows: 1. Landrace andLarge White had higher sperm motility than Duroc by about 20% and had higher NAR acrosomes by about 10%. 2. The farrowing rates of Landrace, Large White and Duroc were 63.6, 55.6 adn 50.0%, respectively. The number of pigs born alive per litter were larger in Landrace and Large White as compared with Duroc (p<.01). 3. Duroc had the highest mean pig weight at birth, followed by Landrace and Large White (p<.01). The mean pig weights at 21 days and 56 days had no significant differences between the breeds.

• 한국수정란이식학회지
• /
• 제30권2호
• /
• pp.91-97
• /
• 2015

Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권5호
• /
• pp.669-676
• /
• 2007

This study was conducted to detect quantitative trait loci (QTL) affecting growth and body composition in an $F_2$ reference population of Korean native pig and Landrace crossbreds. The three-generation mapping population was generated with 411 progeny from 38 $F_2$ full-sib families, and 133 genetic markers were used to produce a sex-average map of the 18 autosomes. The data set was analyzed using least squares Mendelian and parent-of-origin interval-mapping models. Lack-of-fit tests between the models were used to characterize QTL for mode of expressions. A total of 8 (39) QTL were detected at the 5% genome (chromosome)-wise level for the 17 analyzed traits. Of the 47 QTL detected, 21 QTL were classified as Mendelian expressed, 13 QTL as paternally expressed, 6 QTL as maternally expressed, and 7 QTL as partially expressed. Of the detected QTL at 5% genome-wise level, two QTL had Mendelian mode of inheritance on SSC6 and SSC9 for backfat thickness and bone weight, respectively, two QTL were maternally expressed for leather weight and front leg weight on SSC6 and SSC12, respectively, one QTL was paternally expressed for birth weight on SSC4, and three QTL were partially expressed for hot carcass weight and rear leg weight on SSC6, and bone weight on SSC13. Many of the Mendelian QTL had a dominant (complete or overdominant) mode of gene action, and only a few of the QTL were primarily additive, which reflects that heterosis for growth is appreciable in a cross between Korean native pig and Landrace. Our results indicate that alternate breed alleles of growth and body composition QTL are segregating between the two breeds, which could be utilized for genetic improvement of growth via marker-assisted selection.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권6호
• /
• pp.898-906
• /
• 2014

The objective of this study was to investigate differences in the faecal microbial composition among Lantang, Bama, Erhualian, Meishan, Xiaomeishan, Duroc, Landrace, and Yorkshire sows and to explore the possible link of the pig breed with the gut microbial community. Among the sows, the Meishan, Landrace, Duroc, and Yorkshire sows were from the same breeding farm with the same feed. Fresh faeces were collected from three sows of each purebred breed for microbiota analysis and volatile fatty acid (VFA) determination. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that samples from Bama, Erhualian, and Xiaomeishan sows, which from different farms, were generally grouped in one cluster, with similarity higher than 67.2%, and those from Duroc, Landrace, and Yorkshire sows were grouped in another cluster. Principal component analysis of the DGGE profile showed that samples from the foreign breeds and the samples from the Chinese indigenous breeds were scattered in two different groups, irrespective of the farm origin. Faecal VFA concentrations were significantly affected by the pig breed. The proportion of acetate was higher in the Bama sows than in the other breeds. The real-time PCR analysis showed that 16S rRNA gene copies of total bacteria, Firmicutes and Bacteroidetes were significantly higher in the Bama sows compared to Xiaomeishan and Duroc sows. Both Meishan and Erhualian sows had higher numbers of total bacteria, Firmicutes, Bacteroidetes and sulphate-reducing bacteria as compared to Duroc sows. The results suggest that the pig breed affects the composition of gut microbiota. The microbial composition is different with different breeds, especially between overseas breeds (lean type) and Chinese breeds (relatively obese type).

• Genomics & Informatics
• /
• 제13권4호
• /
• pp.137-145
• /
• 2015

Selective sweep can cause genetic differentiation across populations, which allows for the identification of possible causative regions/genes underlying important traits. The pig has experienced a long history of allele frequency changes through artificial selection in the domestication process. We obtained an average of 329,482,871 sequence reads for 24 pigs from three pig breeds: Yorkshire (n = 5), Landrace (n = 13), and Duroc (n = 6). An average read depth of 11.7 was obtained using whole-genome resequencing on an Illumina HiSeq2000 platform. In this study, cross-population extended haplotype homozygosity and cross-population composite likelihood ratio tests were implemented to detect genes experiencing positive selection for the genome-wide resequencing data generated from three commercial pig breeds. In our results, 26, 7, and 14 genes from Yorkshire, Landrace, and Duroc, respectively were detected by two kinds of statistical tests. Significant evidence for positive selection was identified on genes ST6GALNAC2 and EPHX1 in Yorkshire, PARK2 in Landrace, and BMP6, SLA-DQA1, and PRKG1 in Duroc. These genes are reportedly relevant to lactation, reproduction, meat quality, and growth traits. To understand how these single nucleotide polymorphisms (SNPs) related positive selection affect protein function, we analyzed the effect of non-synonymous SNPs. Three SNPs (rs324509622, rs80931851, and rs80937718) in the SLA-DQA1 gene were significant in the enrichment tests, indicating strong evidence for positive selection in Duroc. Our analyses identified genes under positive selection for lactation, reproduction, and meat-quality and growth traits in Yorkshire, Landrace, and Duroc, respectively.

• 한국축산식품학회지
• /
• 제21권3호
• /
• pp.183-191
• /
• 2001

Comparisons between the Korean native pig(KNP: 75kg of slaughter weight and 240 days of age) versus Landrace(110kg of slaughter and 180 days of age) in dressing and lean meat percentages, compositions of fatty acids and amino acids and sensory evaluations on longissimus muscle are as below. Compared with Landrace, KNP had smaller percentages in dressing and lean meat percentages and a smaller backfat thickness. In retail cuts, KNP had greater percentages in shoulder butt, belly and picnic shoulder and smaller percentages in spareribs, ham and loin muscle. The KNP had greater percentages in crude fat, palmitic(C16:0) and linolenic(C18:3) acids and smaller percentages in oleic(C18:1) and linoleic(C18:2) acids, but total cholesterol content and ratios of saturated and unsaturated fatty acids and essential fatty acids did not differ between the two breeds. In amino acid composition, KNP had a greater percentage in lysine, but smaller percentages in most other amino acids. The KNP had a greater a*(redness) value in longissimus muscle(LM) color and a greater L*(whiteness) value in attached backfat color. Moreover, sensory evaluations on cooked LM showed that KNP had greater flavor, tenderness and springiness, which resulted in a greater overall acceptability. In summary, KNP, compared with Landrace, had smaller dressing and lean meat percentages, a smaller backfat thickness, greater percentages in popular retail cuts, greater percentages in intramuscular fat and an $\omega$-3 component linolenic acid, with no difference in cholesterol content, which, altogether, is considered to be more beneficial for human health.

• Journal of Animal Science and Technology
• /
• 제47권1호
• /
• pp.91-98
• /
• 2005

Results of meat quality, physicochemical characteristics, fatty acid and amino acid composition of the Korean Native Black Pig(70 and 90 kg of slaughter weight; KNBP) versus Landrace(110kg of slaughter) are as below. Compared with Landrace, the KNBP exhibited a greater lean meat yield, with no difference in backfat thickness between Landrace and KNBP. There were no difference in chemical composition between Landrace and KNBP, but pH, and cooking loss in the KNBP were superior value than those of the Landrace. These results, KNBP were affected in sensory property and cooking yield. Amino acid content of KNBP and Landrace were significant differences between Landrace and KNBP. Except for the methionine, essential amino acid contents of KNBP had significantly higher than those of Landrace. In the change of fatty acid composition, the Landrace had significantly higher percentages of palmitic(l6: 0), stearic(18: 0) and linolenic(18: 3) acids than that of KNBP, but linoleic acid(l8: 2) was decreased.