Korean Native Pigs Research Articles

Effects of natural resistance-associated macrophage protein 1 and toll-like receptor 2 gene polymorphisms on post-weaning piglet survivability

Predicting resistance or susceptibility to infectious diseases on the basis of the genotypes of animals regarding disease or immune related genes could be important in animal production. We evaluated the potential influence of the genetic polymorphisms of four immune related genes, porcine beta defensin 4, interferon-induced GTP-binding protein Mx1, natural resistance-associated macrophage protein 1 (Nramp1), and Toll-like receptor 2 (TLR2) on post-weaning piglet survivability in farms. We selected a single SNP that satisfied the criteria of non-synonymous substitutions and the minor allele frequency >0.1 from each gene, and performed PCR–RFLP. Distributions of allele and genotype frequencies of the SNPs were, in general, significantly different among the five breeds (Berkshire, Yorkshire, Duroc, Landrace, and Korean native pigs. Initially, 371 randomly collected Yorkshire × Landrace F1 piglets consisting of post-weaning survival (n = 185) and non-survival groups (n = 186) were genotyped for the selected SNPs. For the Nramp1 and TLR2 SNPs, genotype frequencies were significantly different between the two groups (P < 0.05). To confirm the results, additional animals that were collected in a different time-period were genotyped for the Nramp1 (n = 390) and TLR2 (n = 240) SNPs. The results using the combined samples (n = 761) were consistent with the initial analysis (P < 0.01), suggesting that the genetic polymorphisms of Nramp1 and TLR2 affect post-weaning piglet survivability. The relative risks, i.e. odds ratios, between the beneficial and non-beneficial genotypes to piglet survivability were 4.88 and 29.65 for the Nramp1 and TLR2 SNPs, respectively.

재래흑돼지고기의 냉동저장기간 동안의 품질 및 항산화 특성 변화

본 연구는 150일간 냉동저장기간 중 재래흑돼지 등심과 뒷다리살의 품질변화와 항산화 특성을 알아보고자 실시하였다. pH 분석결과 등심의 경우 저장기간 동안 유의적으로 감소하였으나(p&#x3C;0.05), 뒷다리살은 일관된 경향을 보이지 않았다. 등심의 경우 L*값은 저장1일부터 120일 동안 유의적인 차이를 보이지 않았으나 뒷다리살의 경우 저장기간에 따라 유의적으로 감소하였다(p&#x3C;0.05). a*값의 경우 등심과 뒷다리살 모두 저장기간이 경과함에 따라 유의적으로 감소하였으며, b*값은 유의적으로 증가하였다(p&#x3C;0.05). 보수력 지수는 등심의 경우 저장 1일 32.80%에서 30일에 유의적으로 감소하여(p&#x3C;0.05) 저장 150일까지 26.42%로 유지됨을 나타내었다. 등심과 뒷다리살의 총균수는 각각 4.88, 5.16 Log CFU/g을 나타내었고, 저장 30일에 유의적으로 감소하였다(p&#x3C;0.05). 냉동 저장 중 재래흑돼지 등심과 뒷다리살 각각의 2-thiobarbituric acid reaction substance 값은 0.057-0.069, 0.052-0.087 mg MDA/kg meat의 범위를 보였으나, 저장 150일까지 유의적인 차이는 없었다. 등심과 뒷다리살의 volatile basic nitrogen값은 각각 15.13-16.55, 16.05-16.23 mg%의 범위를 나타내었다. 등심과 뒷다리살의 항산화 활성인 oxygen radical absorbance capacity과 carnosine함량을 분석한 결과 냉동저장 150일 동안 유의적으로 감소하였다(p&#x3C;0.05). 본 연구 결과, 재래흑돼지 등심과 뒷다리살의 냉동저장 중 식육의 품질은 다소 감소하는 경향은 있었지만 큰 변화는 없었다. 하지만, 항산화 활성과 항산화 기능을 갖는 di-peptide인 carnosine은 냉동저장 150일 동안 유의적으로 감소하였음을 나타내었다(p&#x3C;0.05). This study was carried out to evaluate changes in the meat quality and antioxidation activity in the loin and ham of Korean Native Black Pigs (KNBP) during frozen storage at &#x2212;18&#x2103; for 150 days. The pH value of the loin was decreased as storage days progressed, while the pH value of the ham showed no consistent changes with storage days. The lightness (L*) of the loin did not show any significant reduction until day 120, whereas L* of the ham was significantly declined throughout the storage period (p&#x3C;0.05). The redness (a*) values of the loin and ham were significantly decreased as storage progressed. The water holding capacity of the loin was decreased by day 30 and that value was maintained until the end of storage. The initial total numbers of microorganisms in the loin and ham were 4.88 and 5.16 Log CFU/g, respectively and these numbers were significantly decreased by day 30 (p&#x3C;0.05). The levels of 2-thiobarbituric acid reactive substances (a measurement of lipid oxidation) in the loin and ham ranged from 0.057-0.069 and 0.052-0.087 mg MDA/kg meat, respectively, until storage day 150. Volatile basic nitrogen values of the loin and ham ranged from 15.13-16.55 and 16.05-16.23 mg%. Oxygen radical absorbance capacities and carnosine contents of the loin and ham were significantly decreased during frozen storage for 3 months (p&#x3C;0.05). In summary, the meat quality of the loin and ham from KNBP was somewhat decreased during frozen storage. However, the levels of antioxidants and dipeptides with antioxidant activity were significantly decreased in pork loin and ham during frozen storage.

Effects of genetic variants for the swine FABP3, HMGA1, MC4R, IGF2, and FABP4 genes on fatty acid composition

This study aimed to verify genetic relationships between fatty acid composition (FAC) and genotypes of several genes (FABP3, HMGA1, MC4R, IGF2, and FABP4) using pig breeds. The effects of genetic variations on FAC of the longissimus muscle were statistically significant with additive and dominance effects. The polymorphisms of FABP3 and IGF2 had the largest effects on stearic (C18:0, P=0.009) and γ-linoleic (C18:3n6, P=0.039) acids, respectively, whereas HMGA1 and FABP4 did not show significances. The analysis revealed that MC4R was significantly associated with palmitoleic acid (C16:ln7) and MUFA. Allele frequencies of the genes examined in this analysis were significantly skewed or fixed in the Korean native pig (KNP), whereas the allele frequencies of the crossbreds tended to fall between those of the purebreds except that HMGA1 and FABP4 had approximately the same allele frequencies with Duroc and KNP, respectively. The polymorphisms found in this study could be used as genetic markers in breeding programs to simultaneously change proportions of fatty acids in muscle tissues.

Whole-genome resequencing analyses of five pig breeds, including Korean wild and native, and three European origin breeds.

Pigs have been one of the most important sources of meat for humans, and their productivity has been substantially improved by recent strong selection. Here, we present whole-genome resequencing analyses of 55 pigs of five breeds representing Korean native pigs, wild boar and three European origin breeds. 1,673.1 Gb of sequence reads were mapped to the Swine reference assembly, covering ∼99.2% of the reference genome, at an average of ∼11.7-fold coverage. We detected 20,123,573 single-nucleotide polymorphisms (SNPs), of which 25.5% were novel. We extracted 35,458 of non-synonymous SNPs in 9,904 genes, which may contribute to traits of interest. The whole SNP sets were further used to access the population structures of the breeds, using multiple methodologies, including phylogenetic, similarity matrix, and population structure analysis. They showed clear population clusters with respect to each breed. Furthermore, we scanned the whole genomes to identify signatures of selection throughout the genome. The result revealed several promising loci that might underlie economically important traits in pigs, such as the CLDN1 and TWIST1 genes. These discoveries provide useful genomic information for further study of the discrete genetic mechanisms associated with economically important traits in pigs.

Production of Cloned Korean Native Pig by Somatic Cell Nuclear Transfer.

The Korean native pig (KNP) have been considered as animal models for animal biotechnology research because of their relatively small body size and their presumably highly inbred status due to the closed breeding program. However, little is reported about the use of KNP for animal biotechnology researches. This study was performed to establish the somatic cell nuclear transfer (SCNT) protocol for the production of swine leukocyte antigens (SLA) homotype-defined SCNT KNP. The ear fibroblast cells originated from KNP were cultured and used as donor cell. After thawing, the donor cells were cultured for 1 hour with 15 μM roscovitine prior to the nuclear transfer. The numbers of reconstructed and parthenogenetic embryos transferred were 98 ± 35.2 and 145 ± 11.2, respectively. The pregnancy and delivery rate were 3/5 (60%) and 2/5 (40%). One healthy SLA homotype-defined SCNT KNP was successfully generated. The recipient-based individual cloning efficiency ranged from 0.65 to 1.08%. Taken together, it can be postulated that the methodological establishment of the production of SLA homotype-defined cloned KNP can be applied to the generation of transgenic cloned KNP as model animals for human disease and xenotransplantation researches.

Association analyses of DNA polymorphisms in immune-related candidate genes GBP1, GBP2, CD163, and CD169 with porcine growth and meat quality traits

Genetic polymorphisms within immunity-related candidate genes in pigs have been identified to control variations in immune functions and/or disease resistance. It has become necessary to evaluate the effects of other genetic markers of economically important traits prior to introducing them into marker-assisted selection programs. In this study, polymorphisms of porcine genes coding Interferon-induced Gunylate binding protein 1 (GBP1), GBP2, CD163, and CD169 were investigated for their association with growth and meat quality traits in a Korean native pig breed -Yorkshire inter-crossed F2 pig population (KY-F2). KY-F2 animals (n=346) have been successfully used for linkage mapping to identify quantitative loci that control meat quality, growth, and immunity traits. In our results, polymorphisms in genes GBP1 and GBP2 showed association with pig growth rate as well as meat quality traits such as crude fat, drip loss, and meat color (yellowness) in the KY-F2 population. The polymorphism in gene CD163 only showed association with crude fat, as a meat quality trait. CD169 gene was associated with pork tenderness. In conclusion, four immune-related genetic markers were validated for their association with growth and meat quality traits to gauge their potential use in a swine selection program. The results warrant further studies in other commercial pig populations.

Effects of 7 SNPs on growth and meat quality traits in F1crossbred of Korean native pig × Duroc

The study was designed to investigate genetic associations of single nucleotide polymorphism (7 SNPs located on 7 selected candidate genes) with growth and meat quality of F1 Korean native pig × Duroc. Selected SNP sets (7) of 86 F1 crossbred pig samples were genotyped by PCR-RFLP. The association analysis revealed that SNPs on MC4R, PGK2 and CTSD genes were significantly associated with body weight. Average daily gain at 2 weeks (ADG2) showed significant associations with SNPs on MC4R and PGK2. On the other hand, ADG10 showed associations only with SNP on MC4R. In addition, backfat thickness and pH value also exhibited significant associations with the SNPs on MC4R, TNNI1, CTSK, CTSZ, and PGK2 genes. Therefore, we concluded that a significant association exists between economic traits and SNPs located on 7 genes. However, further studies seem mandatory to establish the possibility that SNP markers tested here could be used as potential genetic markers for the crossbred Korean native pigs.

Length polymorphism in OGT between Korean native pig, Chinese Meishan, and the Western pig breeds.

BackgroundThe Korean native pig (KNP) is generally thought to have come from northern China to the Korean peninsula approximately 2000 years ago. KNP pigs were at the brink of extinction in the 1980s, since then efforts have been made to restore the breed by bringing together the remaining stocks in South Korea. As a result, KNP was registered as a breed in 2006. To find additional breed-specific markers that are distinct among pig breeds, variations in O-linked N-acetylglucosamine transferase (OGT) were investigated. OGT is located on chromosome X and catalyzes the post-translational addition of a single O-linked-β-N-acetylglucosamine to target proteins.FindingsLength polymorphism in the intron 20 of OGT was identified. The intron 20 of OGT from Duroc, Landrace, and Yorkshire breeds was 281-bp longer than that from either KNP or Chinese Meishan pigs. The difference between the Western pig breeds (BB genotype) and KNP or Meishan pigs (AA genotype) was due to an inserted 276-bp element and the 5-bp ACTTG.ConclusionsThe polymorphism in OGT identified in this study may be used as an additional marker for determining the breed of origin among Meishan and the Western pig breeds. The length polymorphism suggests that the locus near OGT is not fixed in KNP. This marker would be relevant in determining the breed of origin in crossbred pigs between KNP pigs with known genotypes and the Western pig breeds with BB genotypes, thus confirming the contribution of the X chromosome from each breed.

Genome-wide QTL analysis of meat quality-related traits in a large F2 intercross between Landrace and Korean native pigs.

BackgroundWe conducted a genome-wide linkage analysis to identify quantitative trait loci (QTL) that influence meat quality-related traits in a large F2 intercross between Landrace and Korean native pigs. Thirteen meat quality-related traits of the m. longissimus lumborum et thoracis were measured in more than 830 F2 progeny. All these animals were genotyped with 173 microsatellite markers located throughout the pig genome, and the GridQTL program based on the least squares regression model was used to perform the QTL analysis.ResultsWe identified 23 genome-wide significant QTL in eight chromosome regions (SSC1, 2, 6, 7, 9, 12, 13, and 16) (SSC for Sus Scrofa) and detected 51 suggestive QTL in the 17 chromosome regions. QTL that affect 10 meat quality traits were detected on SSC12 and were highly significant at the genome-wide level. In particular, the QTL with the largest effect affected crude fat percentage and explained 22.5% of the phenotypic variance (F-ratio = 278.0 under the additive model, nominal P = 5.5 × 10−55). Interestingly, the QTL on SSC12 that influenced meat quality traits showed an obvious trend for co-localization.ConclusionsOur results confirm several previously reported QTL. In addition, we identified novel QTL for meat quality traits, which together with the associated positional candidate genes improve the knowledge on the genetic structure that underlies genetic variation for meat quality traits in pigs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-014-0080-6) contains supplementary material, which is available to authorized users.

Characterization and phylogenetic analysis of the swine leukocyte antigen 3 gene from Korean native pigs.

We investigated the phylogenetic relationships between pig breeds, compared the genetic similarity between humans and pigs, and provided basic genetic information on Korean native pigs (KNPs), using genetic variants of the swine leukocyte antigen 3 (SLA-3) gene. Primers were based on sequences from GenBank (accession Nos. AF464010 and AF464009). Polymerase chain reaction analysis amplified approximately 1727 bp of segments, which contained 1086 bp of coding regions and 641 bp of the 3'- and 5'-untranslated regions. Bacterial artificial chromosome clones of miniature pigs were used for sequencing the SLA-3 genomic region, which was 3114 bp in total length, including the coding (1086 bp) and non-coding (2028 bp) regions. Sequence analysis detected 53 single nucleotide polymorphisms (SNPs), based on a minor allele frequency greater than 0.01, which is low compared with other pig breeds, and the results suggest that there is low genetic variability in KNPs. Comparative analysis revealed that humans possess approximately three times more genetic variation than do pigs. Approximately 71% of SNPs in exons 2 and 3 were detected in KNPs, and exon 5 in humans is a highly polymorphic region. Newly identified sequences of SLA-3 using KNPs were submitted to GenBank (accession No. DQ992512-18). Cluster analysis revealed that KNPs were grouped according to three major alleles: SLA-3*0502 (DQ992518), SLA-3*0302 (DQ992513 and DQ992516), and SLA-3*0303 (DQ992512, DQ992514, DQ992515, and DQ992517). Alignments revealed that humans have a relatively close genetic relationship with pigs and chimpanzees. The information provided by this study may be useful in KNP management.

Genome-wide detection and characterization of positive selection in Korean Native Black Pig from Jeju Island.

BackgroundIn the 1980s, Korean native black pigs from Jeju Island (Jeju black pigs) served as representative sample of Korean native black pigs, and efforts were made to help the species rebound from the brink of extinction, which occurred as a result of the introduction of Western pig breeds. Geographical separation of Jeju Island from the Korean peninsula has allowed Jeju black pigs not only to acquire unique characteristics but also to retain merits of rare Korean native black pigs.ResultsTo further analyze the Jeju black pig genome, we performed whole-genome re-sequencing (average read depth of 14×) of 8 Jeju black pig and 6 Korean pigs (which live on the Korean peninsula) to compare and identify putative signatures of positive selection in Jeju black pig, the true and pure Korean native black pigs. The candidate genes potentially under positive selection in Jeju black pig support previous reports of high marbling score, rare occurrence of pale, soft, exudative (PSE) meat, but low growth rate and carcass weight compared to Western breeds.ConclusionsSeveral candidate genes potentially under positive selection were involved in fatty acid transport and may have contributed to the unique characteristics of meat quality in JBP. Jeju black pigs can offer a unique opportunity to investigate the true genetic resource of once endangered Korean native black pigs. Further genome-wide analyses of Jeju black pigs on a larger population scale are required in order to define a conservation strategy and improvement of native pig resources.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-014-0160-1) contains supplementary material, which is available to authorized users.

두록과 교잡돈(두록×재래돼지)의 도체 및 육질 특성과 지방산 조성 비교

This study was conducted to develop new crossbred pig using Korean native pig and Duroc. Fifteen pigs of pure Duroc (D) and 26 crossbred gilts (15 of DK1 and 11 of DK2) were reared until 195 ± 5 days old, then slaughtered at local slaughterhouse. Pork loin was gathered and vacuum packed from left carcass after 24 h of slaughter to analyze meat quality traits, such as color, pH, water holding capacity (WHC), cooking loss and shear force (SF), and free fatty acid composition. Live weight and carcass weight of Duroc and DK1 were 119.1±8.7 / 82.91±6.1kg and 116.3±6.3 / 80.91±4.4 kg, respectively, and it was significantly higher than those of DK2 (104.7±8.4 / 71.36±5.7 kg) (p 0.05). DK1 showed the highest monounsaturated fatty acids (MUFAs) contents of 51.45±2.0% and DK2 showed the highest polyunsaturated fatty acids (PUFAs) contents of 8.98±1.4%, however there was no significantly difference in PUFA/SFA ratio between pig groups (p>0.05). Duroc and DK2 contain significantly higher amount of linoleic (7.99±1.2 and 8.11±1.3%, respectively) and linolenic acid (0.43±0.1 and 0.44±0.1%, respectively) than DK1, and DK1 contains significantly higher amount of oleic acid (47.32±1.8%) than others (p<0.05).

A whole genomic scan to detect selection signatures between Berkshire and Korean native pig breeds.

BackgroundScanning of the genome for selection signatures between breeds may play important role in understanding the underlie causes for observable phenotypic variations. The discovery of high density single nucleotide polymorphisms (SNPs) provide a useful starting point to perform genome–wide scan in pig populations in order to identify loci/candidate genes underlie phenotypic variation in pig breeds and facilitate genetic improvement programs. However, prior to this study genomic region under selection in commercially selected Berkshire and Korean native pig breeds has never been detected using high density SNP markers. To this end, we have genotyped 45 animals using Porcine SNP60 chip to detect selection signatures in the genome of the two breeds by using the FST approach.ResultsIn the comparison of Berkshire and KNP breeds using the FDIST approach, a total of 1108 outlier loci (3.48%) were significantly different from zero at 99% confidence level with 870 of the outlier SNPs displaying high level of genetic differentiation (FST ≥0.490). The identified candidate genes were involved in a wide array of biological processes and molecular functions. Results revealed that 19 candidate genes were enriched in phosphate metabolism (GO: 0006796; ADCK1, ACYP1, CAMK2D, CDK13, CDK13, ERN1, GALK2, INPP1; MAK, MAP2K5, MAP3K1, MAPK14, P14KB, PIK3C3, PRKC1, PTPRK, RNASEL, THBS1, BRAF, VRK1). We have identified a set of candidate genes under selection and have known to be involved in growth, size and pork quality (CART, AGL, CF7L2, MAP2K5, DLK1, GLI3, CA3 and MC3R), ear morphology and size (HMGA2 and SOX5) stress response (ATF2, MSRB3, TMTC3 and SCAF8) and immune response ( HCST and RYR1).ConclusionsSome of the genes may be used to facilitate genetic improvement programs. Our results also provide insights for better understanding of the process and influence of breed development on the pattern of genetic variations.Electronic supplementary materialThe online version of this article (doi:10.1186/2055-0391-56-23) contains supplementary material, which is available to authorized users.

Effect of ascorbic acid 2-glucoside supplementation on sperm characteristics during semen cryopreservation in Korean native pig

Effect of ascorbic acid 2-glucoside supplementation on sperm characteristics during semen cryopreservation in Korean native pig

Estimation of Growth Curve Parameters for Evaluation of Growth Characteristics of Purebred Korean Native Pigs and Crossbred between Korean Native Sows and Duroc Boars

Estimation of Growth Curve Parameters for Evaluation of Growth Characteristics of Purebred Korean Native Pigs and Crossbred between Korean Native Sows and Duroc Boars

Genetic Structure of and Evidence for Admixture between Western and Korean Native Pig Breeds Revealed by Single Nucleotide Polymorphisms.

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 (FST) 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 r2 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.

Genome-wide association analysis to identify SNP markers affecting teat numbers in an F2 intercross population between Landrace and Korean native pigs.

Most reproductive traits have low heritability and are greatly affected by environmental factors. Teat number and litter size are traits related to the reproduction ability of pigs. To identify quantitative trait loci (QTLs)for teat number traits, a genome-wide association study (GWAS) was conducted using an F2 intercross between Landrace and Korean native pigs. Genotype analysis was performed using the porcine SNP 60K beadchip. The GWAS was performed using a mixed-effects model and linear regression approach. When a genome-wide threshold was determined using the Bonferroni method (P=1.61×10(-6)), 38 single nucleotide polymorphism (SNP) markers in pig chromosome 7(SSC7) were significantly associated with three teat number traits (total teat number, left teat number, and right teat number). Among these, SNPs in 5 genes (HDDC3, LOC100156276, LOC100155863, ANPEP, SCAMP2) were selected for further study based primarily on their statistical significance. A significant association was detected in SCAMP2 g.25280 G>A for total teat number (P=2.0×10(-12)), HDDC3 g.1319 G>A SNP for left teat number (P=2.3×10(-7)), and SCAMP2 g.14198 G>A for right teat number (P=4.7×10(-12)). These results provide valuable information about the selective breeding for desirable teat numbers in pigs.

Effect of Particular Breed on the Chemical Composition, Texture, Color, and Sensorial Characteristics of Dry-cured Ham.

The present study demonstrates the impact of specific breed on the characteristics of dry-cured ham. Eighty thighs from Korean native pig (KNP), crossbreed (Landrace×Yorkshire)♀×Duroc♂ (LYD), Berkshire (Ber), and Duroc (Du) pig breeds (n = 10 for each breed) were used for processing of dry-cured ham. The thighs were salted with 6% NaCl (w/w) and 100 ppm NaNO2, and total processing time was 413 days. The effects of breed on the physicochemical composition, texture, color and sensory characteristics were assessed on the biceps femoris muscle of the hams. The results revealed that the highest weight loss was found in the dry-cured ham of LYD breed and the lowest weight loss was found in Ber dry-cured ham. The KNP dry-cured ham contain higher intramuscular fat level than other breed hams (p<0.05). It was observed that the dry-cured ham made from KNP breed had the lowest water activity value and highest salt content, while the LYD dry-cure ham had higher total volatile basic nitrogen content than the Ber and Du hams (p<0.05). Zinc, iron and total monounsaturated fatty acids levels were higher in KNP ham while polyunsaturated fatty acids levels were higher in Du ham when compared to other breed hams (p<0.05). Additionally, the KNP dry-cured ham possessed higher Commission International de l’Eclairage (CIE) a* value, while the Du dry-cured ham had higher L*, CIE b* and hue angle values (p<0.05). Furthermore, breed significantly affected the sensory attributes of dry-cured hams with higher scores for color, aroma and taste found in KNP dry-cured ham as compared to other breed hams (p<0.05). The overall outcome of the study is that the breed has a potential effect on the specific chemical composition, texture, color and sensorial properties of dry-cured hams. These data could be useful for meat processors to select the suitable breeds for economical manufacturing of high quality dry-cured hams.

Effects of crossbreeding and gender on the carcass traits and meat quality of korean native black pig and duroc crossbred.

This study was conducted to observe the effects of crossbreeding and gender on the carcass traits and meat quality of Korean Native Black Pig (KNP) and KNP×Duroc crossbred (KNP×D). A total of 50 pigs comprising seven KNP barrows, eight KNP gilts, twenty KNP×D barrows and fifteen KNP×D gilts were used in this study. Animals were reared in the same housing condition with same feed diet for six months prior to slaughter. After an overnight chilling, the carcasses were graded, and samples of Musculus longissimus dorsi were obtained for meat quality analysis. The slaughter and carcass weights and dressing percentage of KNP×D were higher (p<0.001) than those of KNP. The slaughter and carcass weights and backfat thickness of barrows were higher (p<0.01) than those of gilts. There were no significant difference in carcass conformation and quality grade between KNP and KNP×D as well as barrow and gilt. Fat content of KNP×D was higher (p<0.001) than that of KNP. Fat content of barrow was higher (p<0.001) than that of gilt. There was interaction between crossbreeding and gender on the fat content. KNP gilt showed higher fat content than KNP barrow whereas KNP×D barrow showed higher fat content than KNP×D gilt. Lightness, redness, yellowness, chroma and hue angle values and color preference of meat of KNP×D were lower (p<0.001) than those of KNP. Redness, yellowness and chroma values of meat of barrow were lower (p<0.05) than those of gilt. It is concluded that crossbreeding KNP with Duroc increases carcass productivity and meat fat but decreases meat color values and preference. Crossbreeding of KNP with Duroc produces a better fat deposition in meat of barrows than in gilts.

Identification of genomic regions associated with piglet survival and mortality

One of the major problems in the modern pig industry is infectious disease. Susceptibility to infectious diseases is influenced by both constitutional (e.g. genotype, age, gender, and reproductive status) and environmental factors (e.g. nutrition, management, infections, and other forms of stress). Genetic variations within individual animals or herds can cause differences in the execution of immune functions against infectious agents in domestic pigs. The objectives of the present study were to identify genetic factor(s) responsible for piglet survival and mortality under commercial field conditions with infectious diseases as well as determine QTL regions for immune capacity in a pig reference family. Sex ratio was examined between normal grown and presumed dead groups of F2 animals generated by Korean native pigs (KNP) and Yorkshire (YS) breeds. The ratio of males was significantly higher in the presumed dead group than in the normal grown group. In order to study genetic factors associated with presumed mortality under disease outbreak, allelic frequencies of 239 single nucleotide polymorphisms (SNPs) were compared between normal grown and presumed dead groups. Exactly 22 SNPs showed significant differences in their allelic frequencies between the two groups, and four of them were validated with another commercial population divided by normal and emaciated pigs. Furthermore, the relationships between 239 SNPs and immune-related traits were studied. These results demonstrate that identification of genetic components of animal immune systems and susceptibility to infectious diseases is possible and will be useful to improve disease resistance in individuals as well as in breeding programs.