Black Pigs Research Articles

Correlation between fat accumulation and fecal microbiota in crossbred pigs.

Backfat thickness (BF) is an important indicator of fat deposition capacity and lean meat rate in pigs and is very important in porcine genetics and breeding. Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on fat deposition of livestock animals. To investigate the relationship between the pig gut microbiome and BF, 20 low-BF (L-BF) and 20 high-BF (H-BF) pigs were selected as two groups from Yunong Black pigs in the present study. Fecal samples from pigs were analyzed for microbial diversity, composition, and predicted functionality using 16S rRNA gene sequencing. The results showed that there were significant differences in microbial β diversity between the two groups. LEfSe analysis revealed a number of bacterial features being differentially enriched in either L-BF or H-BF pigs. Spearman correlation analysis identified the abundance of Oscillospira, Peptococcus, and Bulleidia were significantly positive correlations with BF (P < 0.05), while Sutterella and Bifidobacterium were significantly negatively correlated with BF (P < 0.05). Importantly, the bacteria significantly positively correlated with BF mainly belong to Clostridium, which can ferment host-indigestible plant polysaccharides into short-chain fatty acid (SCFA) and promote fat synthesis and deposition. Predictive functional analysis indicated that the pathway abundance of cell motility and glycan biosynthesis were significantly widespread in the microbiota of the H-BF group. The results of this study will be useful for the development of microbial biomarkers for predicting and improving porcine BF, as well as for the investigation of targets for dietary strategies.

Innate Immune Response Analysis in Meniscus Xenotransplantation Using Normal and Triple Knockout Jeju Native Pigs.

Although allogenic meniscus grafting can be immunologically safe, it causes immune rejection due to an imbalanced tissue supply between donor and recipient. Pigs are anatomically and physiologically similar to adult humans and are, therefore, considered to be advantageous xenotransplantation models. However, immune rejection caused by genetic difference damages the donor tissue and can sometimes cause sudden death. Immune rejection is caused by genes; porcine GGTA1, CMAH, and B4GLANT2 are the most common. In this study, we evaluated immune cells infiltrating the pig meniscus transplanted subcutaneously into BALB/c mice bred for three weeks. We compared the biocompatibility of normal Jeju native black pig (JNP) meniscus with that of triple knockout (TKO) JNP meniscus (α-gal epitope, N-glycolylneuraminic acid (Neu5Gc), and Sd (a) epitope knockout using CRISPR-Cas 9). Mast cells, eosinophils, neutrophils, and macrophages were found to have infiltrated the transplant boundary in the sham (without transplantation), normal (normal JNP), and test (TKO JNP) samples after immunohistochemical analysis. When compared to normal and sham groups, TKO was lower. Cytokine levels did not differ significantly between normal and test groups. Because chronic rejection can occur after meniscus transplantation associated with immune cell infiltration, we propose studies with multiple genetic editing to prevent immune rejection.

Using Machine Learning to Identify Biomarkers Affecting Fat Deposition in Pigs by Integrating Multisource Transcriptome Information

Fat deposition in pigs is not only closely related to pig production efficiency and pork quality but also an ideal model for human obesity. Transcriptome sequencing is widely used to study fat deposition. However, due to small sample sizes, high false positive rates, and poor consistency of results from different studies, new strategies are urgently needed. Machine learning, a new analysis method, can effectively fit complex data and accurately identify samples and genes. In this study, 36 samples of adipose tissue, muscle tissue, and liver tissue were collected from Songliao black pigs and Landrace pigs, and the mRNA of all the samples was sequenced. In addition, we collected transcriptome data for 64 samples in the GEO database from four different sources. After standardization and imputation of missing values in the data set comprising 100 samples, traditional differential expression analysis was carried out, and different numbers of expressed genes were selected as features for the training model of eight machine learning methods. In the 1000 replications of fourfold cross validation with 100 samples, AdaBoost performed best, with an average prediction accuracy greater than 93% and the highest mean area under the curve in predicting the high- and low-fat content groups among the eight ML methods. According to their performance-based ranks inferred by AdaBoost, 12 genes related to fat deposition were identified; among them, FASN and APOD were specifically expressed in adipose tissue, and APOA1 was specifically expressed in the liver, which could be important candidate biomarkers affecting fat deposition.

Managing genetic diversity in pig populations: implications of optimal contribution selection in the Black Slavonian pig

Implications of optimal contribution selection for litter size in the Black Slavonian pig were analysed using 23,882 litter records from 6764 sows. To obtain population parameters, pedigree analysis was performed for 7367 animals. The average inbreeding coefficient was 2.87%, the average inbreeding rate was 1.96%, and the effective population size was 25.52. The average maximum number of generations traced back was 4.12 and the average number of full generations was 1.17. Selection candidates were chosen using the following criteria: animals had no culling date in the record; animals had sufficient pedigree depth and an estimated breeding value. Using these criteria, 8 boars among 24 and 386 sows among 2028 were defined as selection candidates. Two scenarios were tested. The first scenario was based on the application of the traditional optimal contribution selection with the maximisation of genetic gain and restricting the mean kinship in the offspring accounting also for breeding values. The second scenario was based on minimising inbreeding by restricting the average kinship of the population. In the first scenario, different kinship constraints between candidates resulted in changing the number of selected animals and changed the average breeding values such that the number of selected candidates increased when the kinship constraint was stronger, with a simultaneous decrease in breeding values. The second scenario resulted in increased inbreeding when the additional weight on genetic gain was added. The results of the study showed that the use of optimal contribution selection in Black Slavonian is possible, however, with additional efforts to improve pedigree and data quality. HIGHLIGHTS Genetic diversity analysis and application of optimal contribution selection in the Black Slavonian pig were analysed using pedigree. Results indicate a recent loss of genetic variability in the Black Slavonian pig. Optimal contribution selection enabled simultaneous genetic improvement and achieving conservation goals.

Processed Meat Characteristics between Commercial Duroc-Sired and Heritage Breed Large Black Pigs.

This study examined the meat processing characteristics between Duroc-sired (DS) and heritage breed Large Black (LB) pigs fed high forage (FIB) or commercial diets (CON). Fifty pigs (DS, n = 25; LB, n = 25) were used in a 2 × 2 factorial design with breed and diet as fixed effects. Processing traits were measured for fresh bellies, bacon slices, and sausage patties. Results showed that DS bellies were longer (p < 0.001) but thinner (p = 0.026). CON bellies were longer (p = 0.005) and thicker (p < 0.001). LB bellies had decreased lean area (p < 0.001) and processing yield (p = 0.001). DS patties were lighter (L*, p < 0.001) and less red (a*, p < 0.001). LB had increased belly firmness (p = 0.053). The CON diet resulted in better particle definition (p = 0.010) in patties as well as a larger slice area (p = 0.048) in bacon slices. A breed × diet interaction was observed for lipid oxidation (p = 0.001). The findings provided novel insight into the comparison between these breeds and diets. While LB pork may have niche market value, the integration of this breed into commercial bacon processing has limitations in composition that need to be further evaluated to improve the product desirability.

Identification of Body Size Determination Related Candidate Genes in Domestic Pig Using Genome-Wide Selection Signal Analysis.

Simple SummaryIn this study, the pairwise fixation index (FST) and π ratio (case/control) genetic parameters were used to identify the genes that influence the body size of pigs and analyze the genetic basis of pig body size formation. The results of candidate gene (CG) annotation showed that a series of CGs (MSTN, LTBP4, PDPK1, PKMYT1, ASS1, and STAT6) was enriched into the gene ontology terms. Moreover, molecular pathways, such as the PI3K-Akt, HIF-1, and AMPK signaling pathways, were verified to be related to body development. These findings will help us further understand the genetic basis of animal body-size determination.This study aimed to identify the genes related to the body size of pigs by conducting genome-wide selection analysis (GWSA). We performed a GWSA scan on 50 pigs belonging to four small-bodied pig populations (Diannan small-eared pig, Bama Xiang pig, Wuzhishan pig, and Jeju black pig from South Korea) and 124 large-bodied pigs. We used the genetic parameters of the pairwise fixation index (FST) and π ratio (case/control) to screen candidate genome regions and genes related to body size. The results revealed 47,339,509 high-quality SNPs obtained from 174 individuals, while 280 interacting candidate regions were obtained from the top 1% signal windows of both parameters, along with 187 genes (e.g., ADCK4, AMDHD2, ASPN, ASS1, and ATP6V0C). The results of the candidate gene (CG) annotation showed that a series of CGs (e.g., MSTN, LTBP4, PDPK1, PKMYT1, ASS1, and STAT6) was enriched into the gene ontology terms. Moreover, molecular pathways, such as the PI3K-Akt, HIF-1, and AMPK signaling pathways, were verified to be related to body development. Overall, we identified a series of key genes that may be closely related to the body size of pigs, further elucidating the heredity basis of body shape determination in pigs and providing a theoretical reference for molecular breeding.

Genome-wide association study revealed ABCD4 on SSC7 and GREB1L and MIB1 on SSC6 as crucial candidate genes for rib number in Beijing Black pigs.

As one of the few animals with variation in the number of rib pairs (RIB), the pig is a good model to study the mechanism of RIB regulation. Quantitative trait loci (QTL) for porcine RIB are present on Sus scrofa chromosome 7 (SSC7). Although several candidate genes exist in this QTL region on SSC7, the causal gene has yet to be verified. Beijing Black pig with 14-17 RIB is a good population for candidate gene mining and 1104 individuals were genotyped using the Illumina Porcine 50K BeadChip. A total of 14 SNPs from 95.49 to 97.78Mb on SSC7 showed genome-wide significant association with RIB. On SSC7, a locuszoom plot using pairwise linkage disequilibrium displayed the narrowest linkage region encompassing only two genes, ABCD4 and VRTN. In mice, a transcriptome expression profile was obtained using three embryos at E9.5 (the critical period for rib formation). ABCD4 was highly expressed, but no expression of VRTN was detected. On SSC6, there were four genome-wide significant SNPs from 106.42 to 106.92Mb associated with RIB. GREB1L and MIB1, in this region, were regarded as novel candidate genes. These results revealed a crucial candidate causal gene on SSC7 and novel genes on SSC6 for rib number and provided interesting new insights into its genetic basis.

Effects of Rose Hip (Rosa canina L.) Extract as a Natural Ingredient on the Nutritional Composition, Oxidative Stability and Sensory Attributes of Raw and Cooked Pork Patties from Majorcan Black Pig Breed under Retail Conditions

Effects of Rose Hip (Rosa canina L.) Extract as a Natural Ingredient on the Nutritional Composition, Oxidative Stability and Sensory Attributes of Raw and Cooked Pork Patties from Majorcan Black Pig Breed under Retail Conditions

Characteristics of Mycoplasma hyopneumoniae Strain ES-2 Isolated From Chinese Native Black Pig Lungs.

Mycoplasma hyopneumoniae is the primary pathogen of swine enzootic pneumonia and causes great economic losses to the swine industry worldwide. In China, M. hyopneumoniae seriously hinders the healthy development of the native black pigs. To prevent and treat porcine respiratory disease caused by M. hyopneumoniae, the characteristics of M. hyopneumoniae strain ES-2 isolated from Chinese native black pig lungs with gross lesions at post-mortem were studied for the first time in this study. Strain ES-2 cell was round or oval cells and most sensitive to kanamycin. The diameters of most strain ES-2 cells ranged from 0.4 to 1.0 μm with maximum viability of 1010 CCU/ml. Experimental challenge of animals with strain ES-2 showed respiratory disease could be reproduced, with pneumonic lung lesions evident. Comparative genomics analysis identified that 2 genes are specific to pathogenic M. hyopneumoniae strains, which may be predicted to be a molecular marker. These findings suggest that the study on the characteristics of M. hyopneumoniae strain ES-2 will guide the rapid and accurate drug use in the clinic, and develop a theoretical foundation for accurately diagnosing and treating the infection caused by pathogenic M. hyopneumoniae.

Effects of sweet potato vine silage supplementation on growth performance, nutrient digestibility, and intestinal health in finishing pigs

We investigated the effects of sweet potato vine silage (SPVS) supplementation on the growth performance, apparent digestibility and gut health of finishing pigs. 180 Bali Black pigs (Berkshire × Licha Black, with body weight of 74.54 ± 3.32 kg) were assigned to three groups: basal diet (Ctrl), Ctrl supplemented with 2.5% SPVS (Lspvs) and 5.0% SPVS (Hspvs). Animals were slaughtered after nine weeks of feeding. The results indicated that dietary SPVS supplementation improved average daily food intake and average daily gain. However, SPVS treatment decreased the apparent digestibility. Activities of antioxidant enzymes including total superoxide dismutase, total antioxidant capacity, glutathione peroxidase and catalase in the intestines of the Lspvs group were markedly upregulated. Concentrations of IL-1β and IL-6 were decreased and secretory immunoglobulin A was increased in Lspvs group. A significant increase (P &amp;lt; 0.05) of ileum diamine oxidase in Lspvs group was observed. The ileum villus height/crypt depth in the Hspvs group was significantly reduced. The ratio of Firmicutes to Bacteroidetes in the caecum contents of pigs was reduced, and the abundance of Lactobacillus was significantly increased. Specifically, Hspvs treatment markedly reduced the abundances of Proteobacteria. Collectively, these results suggest that dietary supplementation with SPVS is capable of improving growth performance, immune function and intestinal health by promoting the balance of the intestinal microbiota.

Comparison of the meat quality and fatty acid profile of muscles in finishing Xiangcun Black pigs fed varied dietary energy levels.

To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs, 400 Xiangcun Black pigs (BW = 79.55 ± 4.77 kg) were randomly assigned to 5 treatments with varied calculated digestive energy (DE) at 3,050, 3,100, 3,150, 3,200 and 3,250 kcal/kg, respectively. Each treatment had 8 replicates with 10 pigs per replicate. Meat quality, amino acid and fatty acid composition were tested in this study. No differences in average daily gain, average daily feed intake or feed-to-gain ratio (P > 0.05) were observed among dietary treatments. Glycogen concentrations of longissimus dorsi (LD) muscle in DE3150 was higher than those in other groups (P < 0.05). The crude fat concentration of biceps femoris (BF) muscle in DE3250 tended to be higher than that in DE3150 and DE3100 groups (P < 0.05). Pigs in DE3250 and DE3200 had higher fiber density and smaller cross-sectional area of BF muscle than those in DE3150 (P < 0.05). Pigs in DE3150 had the highest Cu concentration in LD muscle compared with those in DE3200, DE3250 (P < 0.05). The C16:1 proportion of LD muscle was lower (P < 0.01) and C20:1 was higher (P < 0.05) in DE3050 than that in the other dietary treatments. The C18:3n6 and C20:3n6 proportions of BF muscle in DE3150 were higher than those in DE 3050, DE3200 and DE3250 (P < 0.05). For LD muscle, mRNA expressions of type I and IIa MyHC in group DE3150 were higher than other treatments (P < 0.01). The LD muscle in DE3150 expressed higher PPARd than in other groups (P < 0.01). Pigs in DE3100 expressed higher FOX1 than in DE3200 and DE3250 (P < 0.05). Sterol-regulatory element binding proteins (SREBPa) mRNA expression decreased linearly when dietary energy level increased in BF muscle (P < 0.01). In conclusion, a 200 kcal/kg decrease in digestible energy for 4 consecutive weeks did not affect growth performance of Xiangcun Black pigs. Furthermore, LD and BF muscle respond differently to dietary energy level, and meat quality was improved by the medium energy level during the finishing phase.

Genetic Evaluation and Population Structure of Jiangsu Native Pigs in China Revealed by SINE Insertion Polymorphisms

Simple SummaryIn a previous study, 30 SINE-RIPs were applied for population genetic analysis in 7 Chinese miniature pig populations and approved effectively in the genetic distances and breed-relationships between these populations. There are abundant indigenous pigs famous across the world for their prolificacy in the Jiangsu Province of eastern China, such as Meishan, Erhualian. Since pork production relies on limited commercial breeds such as Landrace, Large White, and Duroc pigs, characterized by maximizing productivity in intensive production systems, these indigenous pigs are nowadays decrease sharply. The genetic characterizations of these resources are essential requirements for the development of conservation, selection, and sustainable utilizations. Therefore, SINE-RIPs were selected to evaluate the genetic variation and population structure of Jiangsu pig populations and the results may assist with the conservation and utilization of these native pig populations.Short interspersed nuclear elements (SINEs), one type of retrotransposon, are considered to be ideal molecular markers due to their wide distribution in the genome, high copy number, and high polymorphism. Preliminary studies have identified more than 35,000 SINE-retrotransposon insertion polymorphisms (RIPs) in the pig genome. In this study, 18 SINE-RIPs were used to evaluate the genetic variation and population structure of seven native pig populations and two crossbreeds in the Jiangsu Province of China. Two commercial pig breeds (Duroc and Large White) and one Italian native breed (Sicilian Black pig) were selected as the control. The results showed that all 18 SINE-RIPs were polymorphic among these pigs. The Jiangsu native pig populations (Erhualian, Fengjing, Middle Meishan, Mi, Shawutou, Small Meishan, and Huai) were shown to be more polymorphic than the crossbreeds (Sushan and Sujiang) and external breeds (Sicilian Black pig, Large White, and Duroc) based on the expected heterozygosity and polymorphic information content values. Some native pigs, including Small Meishan, Mi, Middle Meishan, and Erhualian, had a higher degree of inbreeding according to the FIS values. Based on the neighbor-joining tree, all of the Jiangsu native pig populations formed one branch, while the three external pig breeds formed the other branches, with the two crossbreeds containing more than 50% external pig ancestry. The Huai pigs were independent of the other Jiangsu native pigs but shared a common ancestor with Sujiang and Mi. The results provide a new perspective on the population structure of these native pig breeds and will assist with the conservation and utilization of Chinese native pigs.

Identifying Candidate Genes for Short Gestation Length Trait in Chinese Qingping Pigs by Whole-Genome Resequencing and RNA Sequencing.

Gestation length is a complex polygenic trait that affects pig fetal development. The Qingping (QP) pig, a Chinese native black pig breed, is characterized by short gestation length. However, the genetic architecture of short gestation length is still not clear. The present study aimed to explore the genetic architecture of short gestation length in QP pigs. In this study, selective sweep analyses were performed to detect selective sweep signatures for short gestation length traits between 100 QP pigs and 219 pigs from 15 other breeds. In addition, differentially expressed genes for the short gestation length between QP pigs and Large White pigs were detected by RNA sequencing. Comparing candidate genes from these methods with known genes for preterm birth in the database, we obtained 111 candidate genes that were known preterm birth genes. Prioritizing other candidate genes, 839 novel prioritized candidate genes were found to have significant functional similarity to preterm birth genes. In particular, we highlighted EGFR, which was the most prioritized novel candidate relative to preterm birth genes. Experimental validations in placental and porcine trophectoderm cells suggest that EGFR is highly expressed in the QP pigs with short gestation length and could regulate the NF-κΒ pathway and downstream expression of PTGS2. These findings comprehensively identified candidate genes for short gestation length trait at the genomic and transcriptomic levels. These candidate genes provide an important new resource for further investigation and genetic improvement of gestation length.

Modifying the Quality of Pig Carcasses, Meat, and Dry Fermented Sausage from Black Slavonian Pigs by Selecting the Final Body Weight and Nutrition.

A total of 96 Black Slavonian pigs were subjected to the research, in which they were split into 6 groups. Three groups (100, 120, and 130 kg) were fed a higher level (HL) of crude protein in fodder mixtures (CPFM), and three groups (100, 120, and 130 kg) were fed a lower level (LL) of CPFM. After the pigs were slaughtered, pig carcasses were dissected and the meat and halves quality indicators were determined. According to the influence of the final body weight (BW) and nutrition of pigs on the quality of their halves, meat, and dry fermented sausages (kulens), it was concluded that feeding an HL of CPFM increased the proportion of loin, belly rib part, and chin and increased the muscle tissue in the ham, loin, shoulder, neck, and belly rib parts. However, the chemical composition of the meat and the sensory properties of the kulen were not significantly affected by feeding the pigs an HL of CPFM. It was concluded that, by selecting the final BW and adjusting the feeding strategies for pigs, it is possible to modify the conformation and composition of pig carcasses and the quality of meat and kulens produced from the Black Slavonian pig, which is important because consumers prefer products with certain characteristics and of a standard quality and are ready to pay for them.

Genetic diversity and population structure of six autochthonous pig breeds from Croatia, Serbia, and Slovenia

BackgroundThe importance of local breeds as genetic reservoirs of valuable genetic variation is well established. Pig breeding in Central and South-Eastern Europe has a long tradition that led to the formation of several local pig breeds. In the present study, genetic diversity parameters were analysed in six autochthonous pig breeds from Slovenia, Croatia and Serbia (Banija spotted, Black Slavonian, Turopolje pig, Swallow-bellied Mangalitsa, Moravka and Krskopolje pig). Animals from each of these breeds were genotyped using microsatellites and single nucleotide polymorphisms (SNPs). The results obtained with these two marker systems and those based on pedigree data were compared. In addition, we estimated inbreeding levels based on the distribution of runs of homozygosity (ROH) and identified genomic regions under selection pressure using ROH islands and the integrated haplotype score (iHS).ResultsThe lowest heterozygosity values calculated from microsatellite and SNP data were observed in the Turopolje pig. The observed heterozygosity was higher than the expected heterozygosity in the Black Slavonian, Moravka and Turopolje pig. Both types of markers allowed us to distinguish clusters of individuals belonging to each breed. The analysis of admixture between breeds revealed potential gene flow between the Mangalitsa and Moravka, and between the Mangalitsa and Black Slavonian, but no introgression events were detected in the Banija spotted and Turopolje pig. The distribution of ROH across the genome was not uniform. Analysis of the ROH islands identified genomic regions with an extremely high frequency of shared ROH within the Swallow-bellied Mangalitsa, which harboured genes associated with cholesterol biosynthesis, fatty acid metabolism and daily weight gain. The iHS approach to detect signatures of selection revealed candidate regions containing genes with potential roles in reproduction traits and disease resistance.ConclusionsBased on the estimation of population parameters obtained from three data sets, we showed the existence of relationships among the six pig breeds analysed here. Analysis of the distribution of ROH allowed us to estimate the level of inbreeding and the extent of homozygous regions in these breeds. The iHS analysis revealed genomic regions potentially associated with phenotypic traits and allowed the detection of genomic regions under selection pressure.

Analysis of the Genetic Diversity and Family Structure of the Licha Black Pig Population on Jiaodong Peninsula, Shandong Province, China.

Simple SummaryThis study investigated the current conservation status, including the genetic diversity, the family structure, and inbreeding, of the Licha black pig population on Jiaodong Peninsula (Shandong Province, China). The results provide insights into the management and conservation of a local pig breed. Breeders are encouraged to utilize genomic data to improve mating schemes based on the family information obtained in this study, such as keeping an equivalent number of boars and sows in each family and selecting individuals with a kinship coefficient of less than 0.1 for mating.The Licha black pig, a popular indigenous Chinese pig breed, is known for its multi-vertebral trait and higher lean meat rate. Understanding the current conservation status, family structure, and degree of inbreeding of the Licha black pig population will be useful to maintain a sufficient level of genetic diversity in these animal resources. In the present study, the genetic diversity, population structure, and inbreeding coefficient of this conserved population were analyzed using SNP genotyping data from 209 Licha black pigs. Based on the genomic information, this population was divided into eight different families with boars. The effective population size (Ne), polymorphic marker ratio (PN), expected heterozygosity (He), and observed heterozygosity (Ho) of this population were 8.7, 0.827, 0.3576, and 0.3512, respectively. In addition, a total of 5976 runs of homozygosity (ROHs) were identified, and most of the ROHs (54.9%) were greater than 5 Mb. The genomic inbreeding coefficient of each individual was estimated based on ROHs (FROH) with an average inbreeding coefficient of 0.11 for the population. Five statistics (Ne, PN, Ho, He, and FROH) showed a decrease in the level of genetic diversity and a high degree of inbreeding in this population. Thus, special preservation programs need to be implemented in the future, such as introducing new individuals or improving the mating plan. Altogether, our study provides the first genomic overview of the genetic diversity and population structure of Licha black pigs, which will be useful for the management and long-term preservation of this breed.

Single-cell RNA-seq analysis of testicular somatic cell development in pigs

Spermatogenesis is the process by which diploid male germ cells propagate and differentiate into haploid flagellated spermatozoa. This highly complicated process is dependent on testicular somatic cells maturation. While the role of these somatic cells in spermatogenesis is relatively well established, knowledge about their development and maturation, particularly at the molecular level, is limited. In this study, we profiled the testicular single-cell transcriptomes of Guanzhong black pigs at the age of 7, 30, 60, 90, and 150 days. Five types of Sertoli cells, five types of Leydig cells, and four types of peritubular myoid cells were identified. Histological analysis revealed the changes in proliferation levels and marker gene expressions, and the prion-like protein gene (PRND) was identified as a novel marker for Sertoli cells. Additionally, integrated analyses of porcine and human datasets revealed similarities between human and pig testicular somatic cells. Overall, the data obtained in this study contribute to the understanding of testicular development in pigs as a model species.

Differences in Fatty Acid Profile and Physical-Chemical Composition of Slavonska slanina-Dry Cured Smoked Bacon Produced from Black Slavonian Pig and Modern Pigs.

Simple SummaryResearch on the products of local pig breeds is quite challenging as the populations are small, breeders are less educated and it is often difficult to design systematic research in various and usually different breeding conditions, compared to commercial breeds. In this study, we have analysed dry cured bacons, produced from the local Black Slavonian and modern breeds on the small home-made scale, and compared their physico-chemical properties and fatty acid profiles. Results have showed significant differences in chemical composition and fatty acid profiles between analysed pig breeds.The objective of this study was to compare the psysico-chemical composition and fatty acid (FFA) profile of traditional dry cured bacon Slavonska slanina, produced from the authentic Black Slavonian Pig (BP) and modern pigs (MP), using traditional homemade principles. The samples of Slavonska slanina produced from BP had a significantly (p < 0.05) higher fat content (78.32%) than the samples produced from MP (46.47%), while the samples produced from MP showed significantly higher (p < 0.05) protein and moisture content. The samples produced from BP also showed lower aw and salt content but higher pH. Determination of fatty acid composition was performed at the end of the production process. The composition of fatty acids with respect to the groups of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids was determined, as well as the ratios n-6/n-3 and PUFA/SFA. The results of fatty acid composition determination of Slavonska slanina produced from BP and MP show that oleic acid (C18: 1n9) is the most dominant fatty acid from the MUFA group (47.02 and 46.25%), the most common SFA acid was palmitic acid (C16: 0) (23.44 and 24.96%), and PUFA linoleic acid (C18: 2n-6c) (10.76 and 9.74%). The genotype had a significant (p < 0.05) effect on the SFA and USFA composition of Slavonska slanina. The ratios PUFA/SFA (0.34–0.28) and n-6/n-3 (31.84–27.34) for samples of Slavonska slanina produced from BP and MP are in concordance with previously published data for different dry cured meat products, and do not comply with the nutritionally recommended values of international health organizations (PUFA/SFA > 0.4 and n-6/n-3 < 4).

Population Genetic Structure and Selection Signature Analysis of Beijing Black Pig.

Beijing Black pig is an excellent cultivated black pig breed in China, with desirable body shape, tender meat quality and robust disease resistance. To explore the level of admixture and selection signatures of Beijing Black pigs, a total number of 90 individuals covering nine pig breeds were used in our study, including Beijing Black pig, Large White, Landrace, Duroc, Lantang pig, Luchuan pig, Mashen pig, Huainan pig and Min pig. These animals were resequenced with 18.19 folds mapped read depth on average. Generally, we found that Beijing Black pig was genetically closer to commercial pig breeds by population genetic structure and genetic diversity analysis, and was also affected by Chinese domestic breeds Huainan pig and Min pig. These results are consistent with the cross-breeding history of Beijing Black pig. Selection signal detections were performed on three pig breeds, Beijing Black pig, Duroc and Large White, using three complementary methods (FST, θπ, and XP-EHH). In total, 1,167 significant selected regions and 392 candidate genes were identified. Functional annotations were enriched to pathways related to immune processes and meat and lipid metabolism. Finally, potential candidate genes, influencing meat quality (GPHA2, EHD1, HNF1A, C12orf43, GLTP, TRPV4, MVK, and MMAB), reproduction (PPP2R5B and MAP9), and disease resistance (OASL, ANKRD13A, and GIT2), were further detected by gene annotation analysis. Our results advanced the understanding of the genetic mechanism behind artificial selection of Beijing Black pigs, and provided theoretical basis for the subsequent breeding and genetic research of this breed.

Improvement of Intramuscular Fat in longissimus Muscle of Finishing Thai Crossbred Black Pigs by Perilla Cake Supplementation in a Low-Lysine Diet.

This study was conducted to find out the effects of perilla cake (PC) supplementation in a low-lysine diet on Thai crossbred finishing pigs’ productivity, carcass and meat quality, and fatty acid composition. For six weeks, a total of 21 barrows of finishing pigs were fed with three dietary treatments (T1: basal diet, T2: 2.5 percent PC supplementation in a low-lysine diet, and T3: 4.5 percent PC supplementation in a low-lysine diet). The results show that the intramuscular fat and marbling score was significantly increased by T2 and T3. On the other hand, it was found that the boiling loss and shear force value were significantly decreased by T2 and T3 (p < 0.05). In a low-lysine diet, dietary PC supplementation caused a significant increase in malondialdehyde levels in meat (p < 0.05) compared with the basal diet. It was also shown that alpha-linolenic acid level in backfat and the longissimus thoracis et lumborum muscle was increased considerably by T2 and T3. Therefore, supplementing PC in a low-lysine diet may be an alternative strategy for improving the meat quality of late-phase pigs.