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PubMed2001

Molecular phylogenetics relationship between six Chinese native pig breeds and three Swedish pig breeds from mitochondrial DNA.

Mitochondrial DNA genetic polymorphisms were used to evaluate the relationship between 6 Chinese indigenous pig breeds and 3 Swedish domestic pig breeds. A total of 440 bp of the control region and 798 bp of cytochrome b (cyt b) gene of mtDNA were determined from 140 pigs of 9 different breeds. The results of phylogenetics analysis showed that 6 Chinese native pig breeds originated from the Asian wild boar. The pairwise nucleotide sequences divergence suggested that they might occur about 413,000-875,000 years before present (YBP) between Chinese native pig breeds and European wild boar, and approximately 7,500-15,600 YBP between Chinese native pig breeds and Asian wild boar. Three Swedish pig breeds are present both European clade and Asian clade, which is due to the documented introgression of Chinese pig breeds into European domestic pig breeds 2 thousand years ago or during early 18th century.

Animals↗

PubMed2000

Analysis of diversity and genetic relationships between four Chinese indigenous pig breeds and one Australian commercial pig breed.

The genetic diversities and relationships of four Chinese indigenous pig breeds and one Australian commercial pig breed have been evaluated using 27 microsatellites recommended by the International Society of Animal Genetics (ISAG) and the Food and Agriculture Organization (FAO). The allele frequencies, effective numbers of alleles and the polymorphic information content have been calculated. Nei's standard genetic distances have been used to construct a UPGMA dendrogram, which has been evaluated by the Bootstrap test. The utility of microsatellites for evaluating genetic diversity of pigs is discussed.

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PubMedDate not supplied

Genetic variation and relationships of eighteen Chinese indigenous pig breeds.

Chinese indigenous pig breeds are recognized as an invaluable component of the world's pig genetic resources and are divided traditionally into six types. Twenty-six microsatellite markers recommended by the FAO (Food and Agriculture Organization) and ISAG (International Society of Animal Genetics) were employed to analyze the genetic diversity of 18 Chinese indigenous pig breeds with 1001 individuals representing five types, and three commercial breeds with 184 individuals. The observed heterozygosity, unbiased expected heterozygosity and the observed and effective number of alleles were used to estimate the genetic variation of each indigenous breed. The unbiased expected heterozygosity ranged between 0.700 (Mashen) and 0.876 (Guanling), which implies that there is an abundant genetic variation stored in Chinese indigenous pig breeds. Breed differentiation was shown by fixation indices (FIT, FIS, and FST). The FST per locus varied from 0.019 (S0090) to 0.170 (SW951), and the average FST of all loci was 0.077, which means that most of the genetic variation was kept within breeds and only a little of the genetic variation exists between populations. The Neighbor-Joining tree was constructed based on the Nei DA (1978) distances and one large cluster with all local breeds but the Mashen breed, was obtained. Four smaller sub-clusters were also found, which included two to four breeds each. These results, however, did not completely agree with the traditional type of classification. A Neighbor-Joining dendrogram of individuals was established from the distance of -ln(proportions of shared alleles); 92.14% of the individuals were clustered with their own breeds, which implies that this method is useful for breed demarcation. This extensive research on pig genetic diversity in China indicates that these 18 Chinese indigenous breeds may have one common ancestor, helps us to better understand the relative distinctiveness of pig genetic resources, and will assist in developing a national plan for the conservation and utilization of Chinese indigenous pig breeds.

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PubMed1982

[Preliminary communication. Applicability of the Welsh breed in Dutch pig breeding].

An experimental cross-breeding scheme using Welsh Pigs in the 'Gemert District' integrated group is described in this preliminary communication. This experiment was carried out to examine whether it would be possible to produce F1 sows (Welsh x Dutch Landrace), the longevity of which was superior to that of the current Great Yorkshire (GY) crossed with the Dutch Landrace (NL) when the Welsh breed was used, unaccompanied by any loss of performance among the offspring. F1 animals having Welsh blood included a larger proportion of halothane-positive pigs than did the GY x NL cross-bred animals. In addition, animals crossed with those of the Welsh breed showed increased back-fat depth. However, this would appear to be of minor importance as these F1 animals, mated with GY boars, produced fattening piglets, the carcass qualities of which were equivalent to those GY x (GY x NL) animals. The growth rates of animals having Welsh blood would seem to be even more satisfactory. A definite conclusion regarding longevity cannot be reached at this stage as the findings concerning the majority of animals were recorded up to and including the third litter. The studies are being continued in order ultimately to arrive at more definite and more justified conclusions.

Animals↗

PubMed1985

Systemic malacoplakia in a breeding pig.

An adult breeding pig had multiple disseminated lesions in several organs of the thoracic and abdominal cavities. Histopathologically, the lesions consisted of accumulated histiocytic cells with a few giant cells and a mild infiltration of lymphocytes and plasma cells associated with concentric laminated spherical Michaelis-Gutmann bodies which stained strongly with haematoxylin and varied in diameter. The histological features of the lesions were similar to those of malacoplakia reported in man. The present case seems to be unique because the characteristic lesions were found in many organs including kidneys, liver, spleen, lungs, gall bladder, small intestine and several lymph nodes. The possibility of the haematogenous spread of malacoplakia was suggested by the frequent formation of the lesions in perivascular areas. The present case should be described as "systemic malacoplakia in a breeding pig".

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PubMed2003

Genetic diversity of microsatellite loci in fifty-six Chinese native pig breeds.

The genetic diversity of fifty-six indigenous pig breeds in China, and three introduced pig breeds (Duroc, Landrace and Large White) was surveyed using twenty-seven microsatellites recommended by the International Society for Animal Genetics (IS-AG) and Food and Agriculture Organization (FAO). By means of the allele frequencies, mean heterozygosity, effective number of alleles, estimator of gene differentiation, polymorphism information content, genetic distance and dendrogram analysis, the genetic variability and population structure of native pig breeds were estimated. Genetic variabilities within native pig breeds are as follows: Effective number of alleles vary from 2.12 to 9.03, from 0.44 to 0.87 for mean heterozygosity, from 0.39 to 0.86 for polymorphism information content. Nei's genetic distance and Nei's standard genetic distance were estimated and used to construct UPGMA and NJ dendrograms, which were evaluated by the bootstrap test. Fifty-six Chinese indigenous pig breeds were clustered into twelve groups based on the dendrogram. Compared with the classification in Pig Breeds in China, I, II and III groups in the study are equivalent to North-China type, IV group basically accords with Lower-Changjiang River Basin type, V, VI, VII, VIII and IX groups quite correspond with Central-China type, X and XI group largely correspond to South-China type, the last group, XII is equal to South-west type at large. Suggestions that the conservation farms together with conservation areas are appropriate methods for the preservation of native pig breeds in our country were proposed. The results could provide basic molecular data for the research on the germplasm characteristics of local breeds in our country and scientific basis for the conservation and utilization of those breeds.

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PubMed2002

[Studies of population genetic relationships among 24 Chinese and exotic pig breeds using AFLP analysis].

A total of 12 AFLP primer combinations were used to detect genetic variation of pooled DNA in a sample of 19 Chinese native pig breeds, 1 cultivated pig breed and 4 European and American pig breeds. The genetic similarity coefficient of 24 pig beeds was calculated from AFLP data, UPGMA cluster analysis was also performed. The 12 primer combinations generated more than 1000 bands, of which 208 bands were polymorphic, 17.3 polymorphic markers were detected by one primer combination on the average. Thirteen putative breed specific bands were produced in the pooled DNA of 8 pig breeds. The cultivated pig breed and 4 exotic pig breeds were clustere into one group, while 19 Chinese native pig breeds were gathered into the other group in the UPGMA tree. The result indicated that AFLP analysis had high assay efficiency index (Ai) and provided a valuable tool for assaying genetic diversity and breed characterization in pigs. Chinese native pig breeds and exotic pig breeds show remarkable genetic differentiation, which had farther genetic relationships. Nanchang White pig and Large White pig, Yushan Black pig and Yanshan Black pig had intimate genetic relationships with each other respectively, which were consistent with its breeding history, geographical distribution and RAPD analysis results. In addition, the reasons for cluster results of some pig breeds from AFLP data were not consistent with morphology, geographical distribution and existing classification were discussed.

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PubMed2006

Comparison of Vietnamese and European pig breeds using microsatellites.

This study characterized autochthonous pig breeds of Vietnam and compared them with breeds from other regions. A total of 343 animals were considered from 5 indigenous pig breeds of Vietnam (Muong Khuong, Co, Meo, Tap Na, and Mong Cai), 2 exotic breeds kept in Vietnam (Landrace and Yorkshire), 3 European commercial breeds (German Land-race, Piétrain, and Large White), the Chinese breed Meishan, and the European Wild Boar. Each individual was genotyped for 20 selected polymorphic microsatellite loci. The Vietnamese autochthonous breeds showed higher degrees of polymorphism, allelic diversity, and heterozygosity than the other pig breeds. Also, large genetic diversity was observed across the area of distribution, with village-specific subpopulations, which led to significant inbreeding coefficients. As expected, genetic distances showed large differences among European-based, Chinese, and Vietnamese indigenous breeds and reflected the geographical distribution of breeds. In comparison with the European breeds, the Vietnamese indigenous pig breeds harbored a considerable amount of genetic diversity and, therefore, will be of significance for livestock bioconservation.

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PubMed2003

Research on the genetic variations of a1-fucosytransferase (FUT1) gene in 26 pig breeds.

Enterotoxigenic Escherichia coli F18(ECF18) is a main pathogen that causes edema disease and post-weaning diarrhoea in piglets, and al-fucosytransferase (FUT1) gene has been identified as a candidate gene for controlling the expression of the receptor for ECF18 bacteria. The genetic variations at position 307 nucleotide in open reading frame of FUT1 gene in 26 pig breeds (total 1458 individuals) from 5 western commercial pig breeds and 21 Chinese native pig breeds were investigated by PCR-RFLP. The results showed that the genetic polymorphisms of the FUT1 locus were only detected in 5 western pig breeds and the Chinese Lingao pig breed, 5 western pig breeds possessed 3 different genotypes, and Lingao pig breed had two susceptible genotypes GG and AG, while all the other 20 Chinese native pig breeds only presented the susceptible genotype GG. The results indicated that if M307G-A point mutation in the coding region of FUT1 gene was the key factor determining the expression of the ECF18 receptor, most of Chinese native pig breeds were absent of the genetic background on the resistance to ECF18 bacteria. In this case, it was inferred that the resistance gene to ECF18 might be originated from western pig breeds. In addition, it is of great importance for the conservation of Lingao pig breed as it is the only found Chinese native pig breed possessing resistance M307A allele in FUT1 gene. Generally, compared with exotic pig breeds, Chinese native pig breeds have stronger resistance to edema disease and post-weaning diarrhoea in piglets. The results suggested that further study should be done to identify and characterize putative QTL (quantitative trait locus) or/and the functional gene responsible for the resistance to ECF18 in Chinese native pig breeds.

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PubMed1998

Genetic diversity of Yunnan local pig breeds inferred from blood protein electrophoresis.

Protein electrophoresis was used to examine the blood protein polymorphism in Yunnan local pig breeds, i.e., the Saba pig, Dahe pig, and Diannan small-ear pig breeds. Of 38 genetic loci surveyed, 9 were found to be polymorphic. The percentage of polymorphic loci (P) varies from 0.1875 to 0.2121, and the mean individual heterozygosity (H) varies from 0.0712 to 0.1027 in three pig breeds. The results indicate that blood protein polymorphism in Yunnan pig breeds is high. Yunnan local pig breeds have a wealth of genetic diversity at the level of blood proteins.

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PubMed2005

[Effect study of white locus (I) on coat color inheritance in Chinese native pig breeds].

The classical White (I) locus is one of the important pig coat color hereditable loci,which is homologous to KIT gene. In this study,PCR-RFLP and PCR-SSCP analysis were commanded on the Intron 17 and 18 nucleotide sequences of KIT gene. The tested results showed that the substitution mutation (G-->A) of Intron 17 was found in white pigs, including Wuzhishan pigs (white), Landrace and Large White,and its genotype (AB) frequency was 1.1 and 0.8 respectively. The genotype frequency was uniformly 0 in the other native pig breeds. Similarly,the deleted mutation (AGTT) of Intron 18 was also found in the same white pigs,its genotype (,AA) frequency was 1.1 and 0.93 separately,while in the other native pig breeds was 0. Accordingly it was considered that KIT gene was an important factor regulating the white coat color genotype, and the classical I locus (KIT gene) was epistatic to the other genetic coat color loci. On the other hand,although the native pig breed Rongchang Pig is similar to Landrace and Large White in phenotype (white coat color), the mutation status found in them was absolutely distinct. So it is presumed that the coat color genetic system of Chinese native pig breeds was different from that of imported breeds.

Animals↗

PubMed2005

The phylogeny of Chinese indigenous pig breeds inferred from microsatellite markers.

A genetic study of 32 local Chinese, three foreign pig breeds [Duroc (DU), Landrace and Yorkshire], and two types of wild boar (Hainan and Dongbei wild boar) based on 34 microsatellite loci was carried out to clarify the phylogeny of Chinese indigenous pig breeds. The allele frequencies, effective numbers of alleles, and the average heterozygosity within populations were calculated. The results showed that the genetic variability of the Lingao pig was the largest, while the Jiaxing pig was the lowest. The greatest distance between domestic pigs was found between Shanggao and DU pig and the shortest was found between Wuzhishan and Lingao pig, respectively. A neighbour-joining tree constructed from Modified Cavalli-Sforza genetic distances divided Chinese pigs into two clusters; four subclusters were also identified. Our results only partly agree with the traditional types of classification and also provide a new relationship among Chinese local pig breeds. Our data also confirmed that Chinese pig breeds have a different origin from European/American breeds and can be utilized in programmes that aim to maintain Chinese indigenous pig breeds.

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PubMed2006

Comparison of prenatal muscle tissue expression profiles of two pig breeds differing in muscle characteristics.

The objective of this study was to compare purebred Duroc and Pietrain prenatal muscle tissue transcriptome expression levels at different stages of prenatal development to gain insight into the differences in muscle tissue development in these pig breeds. Commercial western pig breeds have been selected for muscle growth for the past 2 decades. Pig breeds differ for their muscle phenotypes (i.e., myofiber numbers and myofiber types). Duroc and Pietrain pig breeds are extremes; Duroc pigs have redder muscle fiber types with more intramuscular fat, and Pietrain pigs have faster-growing and whiter muscle fiber types. Pietrain pigs are more muscular than Duroc pigs, whereas Duroc pigs are fatter than Pietrain pigs. The genomic background underlying these breed-specific differences is poorly known. Myogenesis is a complex exclusive prenatal process involving proliferation and differentiation (i.e., fusion) of precursor cells called myoblasts. We investigated the difference in the prenatal muscle-specific transcriptome profiles of Duroc and Pietrain pigs using microarray technology. The microarray contained more than 500 genes affecting myogenesis, energy metabolism, muscle structural genes, and other genes from a porcine muscle cDNA library. The results indicated that the expression of the myogenesis-related genes was greater in early Duroc embryos than in early Pietrain embryos (14 to 49 d of gestation), whereas the opposite was found in late embryos (63 to 91 d of gestation). These findings suggest that the myogenesis process is more intense in early Duroc embryos than in Pietrain embryos but that myogenesis is more intense in late Pietrain fetuses than in Duroc fetuses. Transcriptomes of muscle structural genes followed that pattern. The energy metabolism genes were expressed at a higher level in prenatal Pietrain pigs than in prenatal Duroc pigs, except for d 35, when the opposite situation was found. Fatty acid metabolism genes were expressed at a higher level in early (14 to 49 d of gestation) Duroc embryos than in Pietrain embryos. Better understanding of the genomic regulation of tissue formation leads to improved knowledge of the genome under selection and may lead to directed breed-specific changes in the future.

Animals↗

PubMed1978

[Aujeszky's disease. Studies on the possibility of differentiating between contaminated pig-breeding farms and farms on which the pigs have been inoculated with the Bartha vaccine (author's transl)].

The serological studies reported in the present paper were done on forty-one pig-breeding farms contaminated with Aujeszky's disease and four farms that were free from this disease and on which fifty per cent of the animals had been inoculated with the Bartha vaccine. The serological studies were based on the serum neutralization test (SN test). On contaminated farms, the majority of the animals present at the time of outbreak of the disease were serologically positive. Comparison of the serological findings on farms on which there had been outbreaks of the disease from two to seven and from seven to twelve months previously, showed that there was hardly any difference in titre levels between the two groups. Of twenty-eight breeding boars used for service at the time of the outbreak, twenty-one per cent were serologically negative. Serological studies in breeding gilts showed that virulent virus was only transmitted up to two months after the outbreak of the disease.

Animals↗

PubMed1999

[Preliminary evaluation of xenotransplantation and utilization of native pig breeds in China].

OBJECTIVE: To evaluate the general situation of the native pig breeds and the relative present study conditions for better development of xenotransplantation in China. METHODS: By comparing the profits between the pigs and the non-human primates as the potential donors for xenotransplantation and emphasizing the source of the pigs as the organ donors from the transplantation studies, we analyzed the possible values of the native pig breeds as the donors. RESULTS: As one of the richest resources in the world, the species variation and relative genetic stability of Chinese native pig breeds could be the very valuable resources for xenotransplantation study and utilization. As a reverse, the xenotransplantation could provide opportunity for more economically and environmentally utilization of the pigs besides as the meat supply. CONCLUSION: As a very valuable and potential resource of organ donor, the native pig breeds of China might be noticed by the xenotransplantation colleagues in the world. It is necessary, to keep the balance among the risk vs. benefit and the protection vs. utilization of this valuable resource.

Animals↗

PubMed2006

Seasonal infertility in Kenyan pig breeding units.

Reproductive performance of 12 Kenyan pig breeding units (56-299 sows per unit) of similar feeding, genetics and health status were evaluated from October 2003 to October 2004 during hot and cooler periods. Sows during cooler months of the year (April to October, average temperature between 08:00 and 17:00: 25.2 +/- 2.2 degrees C) had shorter (P < 0.01) weaning to service intervals (7.9 +/- 2.2 days vs. 12.7 +/- 2.7 days, respectively), less (P < 0.01) regular returns to service (5.7 +/- 1.9% vs. 9.9 +/- 1.9%, respectively), higher (P < 0.01) farrowing rates (80.1 +/- 4.4% vs. 70.8 +/- 3.8%, respectively), and larger born (10.0 +/- 1.1 vs 9.1 +/- 1.7, P < 0.05) and weaned litter sizes (9.2 +/- 1.2 vs. 8.0 + 1.3, P < 0.05) compared with the time periods of high ambient temperature (November to March, between 08:00 and 17:00: 37.2 +/- 3.3 degrees C). It was concluded that a high ambient temperature is a risk factor for reproductive performance in pig breeding units.

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PubMed2005

Genetic structure of pig breeds from Korea and China using microsatellite loci analysis.

To understand molecular genetic characteristics of Korean pigs, the genetic relationships of nine pig breeds including two Korean pigs (Korean native pig and Korean wild pig), three Chinese pigs (Min pig, Xiang pig, and Wuzhishan pig), and four European breeds (Berkshire, Duroc, Landrace, and Yorkshire) were characterized from a 16-microsatellite loci analysis. The mean heterozygosity within breeds ranged from 0.494 to 0.703. Across multiple loci, significant deviation from Hardy-Weinberg equilibrium was observed in most pig breeds, except for two Chinese pigs (Min pig and Wuzhishan pig). This deviation was in the direction of heterozygote deficit. Across population loci, 36 of 144 significantly deviated (P < 0.05) from Hardy-Weinberg equilibrium. The mean FST, a measure of genetic divergence among subpopulations, of all loci indicated that 26.1% of total variation could be attributed to the breed difference. Relationship trees based on the Nei's DA genetic distance and scatter diagram from principal component analysis consistently displayed pronounced genetic differentiation among the Korean wild pig, Xiang pig, and Wuzhishan pig. Individual assignment test using a Bayesian method showed 100% success in assigning Korean and Chinese individual pigs into their correct breeds of origin and 100% exclusion success from all alternative reference populations at P < 0.001. These findings indicate that the Korean native pig has been experiencing progressive interbreeding with Western pig breeds after originating from a North China pig breed with a black coat color. Considering the close genetic relationship of Korean pigs to the Western breeds such as Berkshire and Landrace, our findings can be used as valuable genetic information for the preservation and further genetic improvement of the Korean native pig.

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PubMedDate not supplied

Genetic diversity of eleven European pig breeds.

A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall F(ST)= 0.27), and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

Journal Article↗