Three novel simple sequence repeats (SSRs) identified by MALDI-TOF-MS method were associated with backfat in pig.

Backfat trait is an important economic trait and highly heritable, but difficult to evaluate. Thus, it is of great significance to explore optimal backfat thickness of pigs by using marker-assisted selection (MAS) to speed up its breeding process and improve economic efficiency. This study aimed to investigate the relationship between genetic variations (e.g., SSRs) and backfat of Qinghai Bamei pigs using MALDI-TOF Mass Spectrometry (MALDI-TOF-MS). Herein, five alternative SSR loci (namely V1, V2, V3, V4 and V5) were selected for subsequent detection. The results suggested that 3 (141-, 143- and 145-), 3 (128-, 130- and 132-), 2 (160- and 162-), 2 (136- and 139-) and 3 (170-, 184- and 192-) alleles of V1, V2, V3, V4 and V5 were found, respectively. Subsequent analysis showed that there was linkage equilibrium among five SSRs and Hap19 (13.1%) (141-/132-/160-/139-/192-) had the highest haplotype frequency. Among these five SSR loci, V1, V2 and V3 loci were significantly associated to the backfat of Qinghai Bamei sows. These findings enriched the study of SSRs in Qinghai Bamei pigs, and (AC)n (Chr15:85485851-85485995), (AC)n (Chr10:52724583-52724713) and (TG)n (Chr4:90732644-90732802) could be utilized as the candidate locus for MAS in pig industry.HIGHLIGHTSFive novel SSR loci was identified in pigs through MALDI-TOF MS.V1, V2 and V3 loci was were significantly associated to the backfat of pigs.

Fine mapping of a major QTL qPA7-1 for low hydrocyanic acid content in sorghum-sudangrass hybrid.

The purpose of this study was to study the genetic mechanism of low hydrocyanic acid (HCN) content. The segregation of HCN content trait in fresh stems and leaves was determined in the sorghum (Sorghum bicolor (L.) Moench)-sudangrass (Sorghum sudanense (Piper) Stapf) hybrid F2 population (N = 1200), also used to detect a quantitative trait locus (QTL) for HCN content. Our hypothesis was that the additive effect of QTL was negative, showing that QTL was associated with low HCN. In the present research, a total of 11 simple sequence repeats (SSR) polymorphic primers were screened, and four SSR markers associated with low HCN content were developed based on the bulked segregant analysis method. A high-resolution genetic linkage group of the previously known qPA7-1 locus of the low HCN trait was constructed by analyzing different populations, families, and recombinants. Then, the QTL qPA7-1 of sorghum-sudangrass hybrid was fine-mapped to a 203.6 kb region between markers SORBI4G4-120 and SORBI4G4-680, and seven candidate genes for low HCN were predicted in this region based on sequence comparison with the sorghum reference genome. According to gene annotation, the candidate genes related to low HCN content may be different from those involved in the known regulation mode of sorghum dhurrin biosynthesis and metabolism.

Identification of three new microsatellites and their effects on body measurement traits in pigs using time of flight-mass spectrometry (TOF-MS).

The body status of livestock affects their physiological function and productive performances. Microsatellites, one of the most used DNA markers, have been found to be associated with pig productive traits. However, their identifications and effects on body measurement traits of the Chinese Qinghai Bamei pig still uncovered. According to our previous sequencing data, in this study, three novel microsatellites were found in this breed. Using time of flight-mass spectrometry (TOF-MS) method, these microsatellites were further identified in a large Bamei pig population. TOF-MS spectra showed that there are three microsatellites loci, named P1, P2 and P3. These microsatellites were linkage equilibrium based on the values of D' and r2 tests. Association results demonstrated that P1 locus was associated with the body length, body height and chest width and the beneficial genotype was 150-/150-bp (p < 0.05); and P2 locus was associated with the body height (p < 0.05), and the 145-/145-bp, 145-/147-bp and 145-/149-bp were claimed as favorable genotypes and 145-bp allele was considered as the favorable allele. These findings suggested that P1 and P2 microsatellites might be considered as the candidate genetic markers to select pigs with superior body sizes, especially in local breed.

Over-expression of miR-125a-5p inhibits proliferation in C2C12 myoblasts by targeting E2F3.

MicroRNAs (miRNAs) are a class of small non-coding RNAs of 20-25 nucleotides in length. It has been shown that miRNAs play important roles in the proliferation of many types of cells, including myoblasts. In this study, we used real-time quantitative polymerase chain reaction, western blotting, EdU, flow cytometry, and CCK-8 assay to explore the role of miR-125a-5p during the proliferation of C2C12 myoblasts. It was found that the expression of miR-125a-5p was decreased during C2C12 myoblast proliferation. Over-expression of miR-125a-5p inhibited C2C12 myoblast proliferation as indicated by EdU staining, flow cytometry, and CCK8 assay. It was also found that miR-125a-5p could negatively regulate E2F3 expression at posttranscriptional level, via a specific target site in the 3' untranslated region. Knockdown of E2F3 showed a similar inhibitory effect on C2C12 myoblast proliferation. Thus, our findings suggest that miR-125a-5p may act as a negative regulator of C2C12 myoblast proliferation by targeting E2F3.

MiR-15a/b promote adipogenesis in porcine pre-adipocyte via repressing FoxO1.

Diabetes and many other metabolism syndromes are closely related to obesity. To reveal the underlying mechanism of fat deposition, an increasing number of studies are focusing on the functions of miRNAs during adipocytes development. Previous studies have proved that miR-15a/b play important roles in multiple physiological processes; however, their functions during adipogenesis remain unclear. To reveal this, we detected the expression profiles of miR-15a/b during adipogenesis in porcine pre-adipocyte, and found that their expression levels increased in the early stage of adipocyte differentiation and dropped after day 4. Moreover, over-expression of miR-15a/b in porcine pre-adipocytes promoted adipocyte differentiation and lipid accumulation. Target genes of miR-15a/b were predicted and examined, which revealed that Forkhead box protein O1 (FoxO1) is the target gene of miR-15a/b. The inhibition of FoxO1 expression level caused by miR-15a/b over-expression had a positive effect on adipogenesis. Thus, we conclude that miR-15a/b promote adipogenesis in porcine pre-adipocyte via repressing FoxO1.

MicroRNA-199a-5p affects porcine preadipocyte proliferation and differentiation.

MicroRNAs (miRNAs), a class of small non-coding RNAs, have emerged as novel and potent regulators of adipogenesis. However, few miRNAs have been fully investigated in porcine adipogenesis, given the fact that pig is not only an apropos model of human obesity research, but also a staple meat source of human diet. In this study, we showed that miRNA-199a-5p is highly expressed in porcine subcutaneous fat deposits compared to several other tissue types and organs measured alongside. Overexpression of miR-199a-5p in porcine preadipocytes significantly promoted cell proliferation while attenuating the lipid deposition in porcine adipocytes. By target gene prediction and experimental validation, we demonstrated that caveolin-1 (Cav-1) may be a bona fide target of miR-199a-5p in porcine adipocytes, accounting for some of miR-199a-5p's functions. Taken together, our data established a role of miR-199a-5p in porcine preadipocyte proliferation and differentiation, which is at least partially played by downregulating Cav-1.

Identification and Analysis of Genes Related to Testicular Size in 14-Day-Old Piglets.

The RNA-Seq technology was used to screen the key genes that affect the early development of the testes of Duroc × Landrace × Yorkshire piglets, to determine the regulatory pathway and provide reference for subsequent reproductive performance research, breeding, and other production practices. This study selected 14-day-old Duroc × Landrace × Yorkshire piglets as the trial animals. Testes from piglets with similar weights and no pathological changes were divided into small testis (ST) and large testis (LT) groups, and the RNA-Seq screening of differentially expressed genes (DEGs) was performed to find candidate genes and regulatory pathways related to early testicular development. The results show that 570 DEGs were found in the ST and LT groups, with 281 upregulated and 289 downregulated. The DEGs were mainly enriched on 47 gene ontology (GO) functional items. The Kyoto encyclopedia of genes and genotypes (KEGG) enrichment analysis found that there were 44 significantly enriched KEGG signal pathways, and the regulation of testicular development mainly focused on the arachidonic acid metabolism, Wnt signaling pathway and GnRH secretion pathways. The PTGES, SFRP1, SPP1, PLA2G4E, KCNJ5, PTGS2, and HCN1 genes were found to be as closely related to the testicular development of these Duroc × Landrace × Yorkshire piglets, and the differential gene expression was consistent with the real-time quantitative reverse transcription PCR (real-time qRT-PCR) validation results. This study was validated by high-throughput sequencing analysis and real-time qRT-PCR, and showed that the PTGES, SFRP1, SPP1, PLA2G4E, KCNJ5, PTGS2, and HCN1 genes may be involved in the regulation of germ cell development, spermatogenesis and semen traits. These should be further studied as candidate genes for early testicular development and reproductive trait regulation in boars.

Ovine KRT81 Variants and Their Influence on Selected Wool Traits of Commercial Value.

Keratins are the main structural protein components of wool fibres, and variation in them and their genes (KRTs) is thought to influence wool structure and characteristics. The PCR-single strand conformation polymorphism technique has been used previously to investigate genetic variation in selected coding and intron regions of the type II sheep keratin gene KRT81, but no variation was identified. In this study, we used the same technique to explore the 5' untranslated region of KRT81 and detected three sequence variants (A, B and C) that contain four single nucleotide polymorphisms. Among the 389 Merino × Southdown cross sheep investigated, variant B was linked to a reduction in clean fleece weight, while C was associated with an increase in both greasy fleece weight and clean fleece weight. No discernible effects on staple length or mean-fibre-diameter-related traits were observed. These findings suggest that variation in ovine KRT81 might influence wool growth by changing the density of wool follicles in the skin, the density of individual fibres, or the area of the skin producing fibre, as opposed to changing the rate of extrusion of fibres or their diameter.

Overexpression of GPX2 gene regulates the development of porcine preadipocytes and skeletal muscle cells through MAPK signaling pathway.

Glutathione peroxidase 2 (GPX2) is a selenium-dependent enzyme and protects cells against oxidative damage. Recently, GPX2 has been identified as a candidate gene for backfat and feed efficiency in pigs. However, it is unclear whether GPX2 regulates the development of porcine preadipocytes and skeletal muscle cells. In this study, adenoviral gene transfer was used to overexpress GPX2. Our findings suggest that overexpression of GPX2 gene inhibited proliferation of porcine preadipocytes. And the process is accompanied by the reduction of the p-p38. GPX2 inhibited adipogenic differentiation and promoted lipid degradation, while ERK1/2 was reduced and p-p38 was increased. Proliferation of porcine skeletal muscle cells was induced after GPX2 overexpression, was accompanied by activation in JNK, ERK1/2, and p-p38. Overexpression methods confirmed that GPX2 has a promoting function in myoblastic differentiation. ERK1/2 pathway was activated and p38 was suppressed during the process. This study lays a foundation for the functional study of GPX2 and provides theoretical support for promoting subcutaneous fat reduction and muscle growth.

Effects of Probiotic-Fermented Feed on the Growth Profile, Immune Functions, and Intestinal Microbiota of Bamei Piglets.

Purebred Bamei piglets present problems, including slow growth, respiratory disease, and post-weaning stress. This study investigated the effects of Lactobacillus plantarum QP28-1- and Bacillus subtilis QB8-fermented feed supplementation on the growth performance, immunity, and intestinal microflora of Bamei piglets from Qinghai, China. A total of 48 purebred Bamei piglets (25 days; 6.8 ± 0.97 kg) were divided into the following four groups for a 28-day diet experiment: basal feed (CK); diet containing 10% Lactobacillus plantarum-fermented feed (L); diet containing 10% Bacillus subtilis-fermented feed (B); and diet containing a mixture of 5% Lactobacillus plantarum + 5% Bacillus subtilis-fermented feed (H). The daily weight gain and daily food intake of group H increased (p < 0.05), and the feed/weight gain ratios of the groups fed with fermented feed decreased more than that of the CK group. The levels of three immune factors, namely immunoglobulin (Ig)M, IgG, and interferon-γ, were higher (p < 0.05), whereas those of tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 were lower (p < 0.05) in the fermented feed groups than in the CK group. Total protein was higher (p < 0.05), while urea nitrogen, total cholesterol and triglycerides were lower (p < 0.05) in the mixed-fermented feed group than in the CK group. Analysis of the gut microbiota showed that the addition of fermented feed increased the α-diversity of the gut microbiota, increasing the abundances of probiotics including Lactobacillus, Muribaculaceae, Ruminococcaceae, Prevotellaceae, and Rikenellaceae. Additionally, correlation analysis demonstrated that several of these probiotic bacteria were closely related to serum immunity. In conclusion, fermented feed supplementation rebuilt the intestinal microbiota of Bamei piglets, thereby reducing the feed/weight ratio, improving feed intake, and enhancing immunity.

MiRNA-199a-3p regulates C2C12 myoblast differentiation through IGF-1/AKT/mTOR signal pathway.

MicroRNAs constitute a class of ~22-nucleotide non-coding RNAs. They modulate gene expression by associating with the 3' untranslated regions (3' UTRs) of messenger RNAs (mRNAs). Although multiple miRNAs are known to be regulated during myoblast differentiation, their individual roles in muscle development are still not fully understood. In this study, we showed that miR-199a-3p was highly expressed in skeletal muscle and was induced during C2C12 myoblasts differentiation. We also identified and confirmed several genes of the IGF-1/AKT/mTOR signal pathway, including IGF-1, mTOR, and RPS6KA6, as important cellular targets of miR-199a-3p in myoblasts. Overexpression of miR-199a-3p partially blocked C2C12 myoblast differentiation and the activation of AKT/mTOR signal pathway, while interference of miR-199a-3p by antisense oligonucleotides promoted C2C12 differentiation and myotube hypertrophy. Thus, our studies have established miR-199a-3p as a potential regulator of myogenesis through the suppression of IGF-1/AKT/mTOR signal pathway.

Investigation on Fermentation Characteristics and Microbial Communities of Wheat Straw Silage with Different Proportion Artemisia argyi.

Mycotoxins, secondary metabolites of fungi, are a major obstacle to the utilization of animal feed for various reasons. Wheat straw (WS) is hollow, and miscellaneous bacteria can easy attach to its surface; the secondary fermentation frequency after silage is high, and there is a risk of mycotoxin poisoning. In this study, a storage fermentation process was used to preserve and enhance fermentation quality in WS through the addition of Artemisia argyi (AA), which is an effective method to use WS resources and enhance aerobic stability. The storage fermentation of WS treated with AA had lower pH and mycotoxin (AFB1 and DON) values than the control due to rapid changes in microbial counts, especially in the 60% AA groups. Meanwhile, the addition of 60% AA improved anaerobic fermentation profiles, showing higher lactic acid contents, leading to increased efficiency of lactic acid fermentation. A background microbial dynamic study indicated that the addition of 60% AA improved the fermentation and aerobic exposure processes, decreased microbial richness, enriched Lactobacillus abundance, and reduced Enterobacter and Aspergillus abundances. In conclusion, 60% AA treatment could improve the quality by increase fermentation quality and improve the aerobic stability of WS silage by enhancing the dominance of desirable Lactobacillus, inhibiting the growth of undesirable microorganisms, especially fungi, and reducing the content of mycotoxins.

Effects of Lactic Acid Bacteria Reducing the Content of Harmful Fungi and Mycotoxins on the Quality of Mixed Fermented Feed.

The contamination of fermented feeds and foods with fungi and mycotoxins is a major food safety issue worldwide. Certain lactic acid bacteria (LAB), generally recognized as safe (GRAS) fermentation probiotics, are able to reduce microbial and mycotoxins contamination. In this study, Lactiplantibacillus (L.) plantarum Q1-2 and L. salivarius Q27-2 with antifungal properties were screened as inoculants for mixed fermenting feed, and the fermentation and nutritional qualities, microbial community, and mycotoxins of mixed fermented feed were analyzed at different fermentation periods (1, 3, 7, 15, and 30 days, respectively). The findings indicated that the utilization of Q1-2 and Q27-2 strains in fermenting feed led to a decrease in pH and an increase in lactic acid concentration and the proportion of Lactiplantibacillus, while effectively restraining the proliferation of undesirable microorganisms. In particular, Q1-2 reduced the relative abundance of fungi including Fusarium and Aspergillus. Compared to the control group, the Q1-2 and Q27-2 groups reduced aflatoxin B1 by 34.17% and 16.57%, and deoxynivalenol by up to 90.61% and 51.03%. In short, these two LAB inoculants could reduce the contents of aflatoxin B1 and deoxynivalenol to the limited content levels stipulated by the Chinese National Standard GB 13078-2017. These findings suggest that the LAB strains of Q1-2 and Q27-2 have potential applications in the feed industry for the mitigation of mycotoxin pollution, thereby enhancing the quality of animal feed.

Enhancing the In-Plane Behavior of a Hybrid Timber Frame-Mud and Stone Infill Wall Using PP Band Mesh on One Side.

Traditional village dwellings in China consisting of timber frames with mud and stone infill walls represent an important part of cultural heritage and civilization. Due to the lack of an effective link between the wood frame and the infill and the poor cohesiveness of clay, the masonry infill can collapse during an earthquake, whereas the wood frame suffers minimal damage. In this study, current retrofitting techniques for village buildings were investigated and discussed. A method using polypropylene (PP) band mesh and cement mortar to retrofit the timber frame with a mud and stone infill was proposed and the connection construction details were designed. In-plane static cyclic tests were conducted on two full-scale wood-stone hybrid walls reinforced on one side with different grid sizes of the PP band mesh. The failure behaviors of the reinforced and non-reinforced sides of the specimens were compared, and the failure mechanics and seismic capacity of the two specimens, i.e., the strength, stiffness, ductility, and energy dissipation, were investigated. The results were also compared with those of a previous frame with stone infill without pebbles and no reinforcement. The study indicated that the retrofitting method strengthened the integrity and lateral resistance of the hybrid structure and prevented the collapse of the stone infill of the reinforced surface in a plane earthquake. The grid size of the PP band mesh substantially affected the lateral performance of the reinforced specimens. The hybrid wall with the narrow PP band mesh grid (150 mm × 150 mm) had a higher lateral stiffness (79%) and lateral capacity (50%) than the wall with the wide grid (250 mm × 250 mm). However, the narrow PP band mesh resulted in a lower ductility of the wall than the wide PP band mesh. The involvement of pebbles in the stone infill led to collapses sooner and a weaker lateral resistance than in the structure without pebble infill.

Microbial community and fermentation characteristic of whole-crop wheat silage treated by lactic acid bacteria and Artemisia argyi during ensiling and aerobic exposure.

Whole-crop wheat silage (WCWS) is an excellent feed material for ruminants. However, microbial fermentation during silage production consumes valuable nutrients, decreasing the quality of silage. The main objective of this study was to assess how the addition of increasing amounts of Artemisia argyi (AA) affected fermentation quality, microbial composition, and mycotoxin production in whole-crop wheat at dough stage (WCWD) silage during ensiling to aerobic exposure compared with Lactiplantibacillus buchneri (LB). The addition of 20% AA, resulted in a lower pH and higher lactic acid content, was found in silage treated with 20% AA, and an obvious increase in the relative abundance of Lactobacillus was detected in silages treated with LB and 20% AA, respectively. Meanwhile, inoculation with 20% AA decreased the abundance of harmful microorganisms, including Acinetobacter, Enterobacter, and Aspergillus. It also reduced the contents of mycotoxins, Aflatoxin B1 (AFB1), and deoxynivalenol (DON) during ensiling and aerobic exposure. These results confirmed that WCWD treated with 20% AA could improve the fermentation quality and enhance the aerobic stability of silage.

Variation of Microbial Community and Fermentation Quality in Corn Silage Treated with Lactic Acid Bacteria and Artemisia argyi during Aerobic Exposure.

Silage, especially whole crop corn silage (WCCS), is an important part of ruminant diets, with its high moisture content and rich nutrient content, which can easily cause contamination by mold and their toxins, posing a great threat to ruminant production, food safety and human health. The objective of this study was to examine effects of lactic acid bacteria (LAB) Lactiplantibacillus (L.) plantarum subsp. plantarum ZA3 and Artemisia argyi (AA) on the fermentation characteristics, microbial community and mycotoxin of WCCS during 60 days (d) ensiling and subsequent 7 d aerobic exposure. The results showed that WCCS treated with LAB and AA both had lower pH value and ammonia nitrogen (NH3-N) contents, and higher lactic and acetic acids concentration compared with other groups after 60 d ensiling. In addition, for microbial communities, Acetobacter and Enterobacter were inhibited in all AA group, while higher abundance of Lactobacilli was maintained; besides, Candida, Pichia and Kazachstania abundances were decreased in both 6% and 12% AA groups. The content of five kinds of mycotoxins were all significantly lower after 7 d of aerobic exposure. As for the total flavonoid (TF), which is significantly higher in all AA treated groups, it was positively correlated with Paenibacillus, Weissella and Lactobacilli, and negatively with Acetobacter, Enterobacteria, Kazachstania and Pichia.

Bacteriocin-Producing Lactic Acid Bacteria Strains with Antimicrobial Activity Screened from Bamei Pig Feces.

Lactic acid bacteria (LAB), which are characterized by producing various functional metabolites, including antioxidants, organic acids, and antimicrobial compounds, are widely used in the food industry to improve gut health and prevent the growth of spoilage microorganisms. With the continual incidence of foodborne disease and advocacy of consumers for gut health, LAB have been designated as vital biopreservative agents in recent years. Therefore, LAB with excellent antimicrobial properties and environmental tolerance should be explored further. In this study, we focus on screening the LAB strains from a specialty pig (Bamei pig) feces of the Tibetan plateau region and determine their antimicrobial properties and environmental tolerance to evaluate their potential probiotic values. A total of 116 LAB strains were isolated, from which the LAB strain Qinghai (QP)28-1 was identified as Lactiplantibacillus (L.) plantarum subsp. plantarum using 16S rDNA sequencing and recA amplification, showing the best growth capacity, acid production capacities, environmental tolerance, hydrophobicity, antibiotic susceptibility, and bacteriocin production capacity. Furthermore, this strain inhibited the growth of multiple pathogens by producing organic acids and bacteriocin. These bacteriocin-encoding genes were identified using PCR amplification, including plnS, plnN, and plnW. In conclusion, bacteriocin-producing L. plantarum subsp. plantarum QP28-1 stands out among these 116 LAB strains, and was considered to be a promising strain used for LAB-related food fermentation. Moreover, this study provides a convenient, comprehensive, and shareable profile for screening of superior functional and bacteriocin-producing LAB strains, which can be used in the food industry.

Dynamics Changes of Microorganisms Community and Fermentation Quality in Soybean Meal Prepared with Lactic Acid Bacteria and Artemisia argyi through Fermentation and Aerobic Exposure Processes.

This study evaluated the effects of Lactiplantibacillus plantarum subsp. plantarum ZA3, Artemisia argyi and their combination, on the fermentation characteristics, microbial community, mycotoxins and crude flavonoids content of fermented soybean meal during fermentation (under anaerobic conditions) and aerobic exposure (under aerobic conditions). The results showed that ZA3, Artemisia argyi and ZA3+ Artemisia argyi groups had lower pH values and higher lactic acid concentrations compared with controls, and additives increased the abundance of Lactiplantibacillus and decreased those of Acetobacter and Enterobacter; in particular, Artemisia argyi and ZA3+ Artemisia argyi reduced the abundance of fungi, such as Aspergillus, Pichia, Fusarium, Cladosporium and Xeromyces. Meanwhile, the contents of mycotoxins were lower in treated groups, and even mycotoxins in the control were significantly reduced after 30 d (p < 0.05). Crude flavonoids that were correlated positively with Lactococcus and negatively with Bacillus, Aspergillus, Enterobacter and Kazachstania were significantly higher in the Artemisia argyi and ZA3+ Artemisia argyi groups (p < 0.05).

Analysis and Calculation of Stability Coefficients of Cross-Laminated Timber Axial Compression Member.

Cross-laminated timber (CLT) elements are becoming increasingly popular in multi-storey timber-based structures, which have long been built in many different countries. Various challenges are connected with constructions of this type. One such challenge is that of stabilizing the structure against vertical loads. However, the calculations of the stability bearing capacity of the CLT members in axial compression in the structural design remains unsolved in China. This study aims to determine the stability bearing capacity of the CLT members in axial compression and to propose the calculation method of the stability coefficient. First, the stability coefficient calculation theories in different national standards were analyzed, and then the stability bearing capacity of CLT elements with four slenderness ratios was investigated. Finally, based on the stability coefficient calculation formulae in the GB 50005-2017 standard and the regression method, the calculation method of the stability coefficient for CLT elements was proposed, and the values of the material parameters were determined. The result shows that the average deviation between fitting curve and calculated results of European and American standard is 5.43% and 3.73%, respectively, and the average deviation between the fitting curve and the actual test results was 8.15%. The stability coefficients calculation formulae could be used to predict the stability coefficients of CLT specimens with different slenderness ratios well.

A novel (ATC)n microsatellite locus is associated with litter size in an indigenous Chinese pig.

Simple sequence repeats (SSRs) are an important part of the genome and have become powerful auxiliary DNA markers in animal breeding using marker-assisted selection (MAS). Based on previous sequencing data of Qinghai Bamei pigs, a total of three novel candidate SSR loci were analysed in this study. Time-of-flight mass spectrometry (TOF-MS) was used for SSR genotyping, and association analyses between SSRs and the litter size of Qinghai Bamei sows was also performed. The results of genotyping showed that the (ATC)n -P1, (AC)n -P2 and (AC)n -P3 loci had 2, 3 and 18 genotypes, respectively; 2, 3 and 8 alleles were also identified at these loci. Except for the (AC)n -P2 locus, the polymorphism information content (PIC) values of other loci were greater than 0.25. Association analyses indicated that only the (ATC)n -P1 locus was significantly associated with the litter size of Qinghai Bamei sows (p = .047). Compared to 189-/189- genotype, individuals with the 189-/195- genotype had the senior litter size, which was 9.04 ± 0.21. Our results enrich the data on SSRs in Qinghai Bamei pigs and indicate that (ATC)n -P1 is a candidate locus for MAS in the pig industry.