Glucocorticoid Regulates the Synthesis of Porcine Muscle Protein through m6A Modified Amino Acid Transporter SLC7A7.

The occurrence of stress is unavoidable in the process of livestock production, and prolonged stress will cause the decrease of livestock productivity. The stress response is mainly regulated by the hypothalamic-pituitary-adrenal axis (HPA axis), which produces a large amount of stress hormones, namely glucocorticoids (GCs), and generates a severe impact on the energy metabolism of the animal body. It is reported that m6A modification plays an important role in the regulation of stress response and also participates in the process of muscle growth and development. In this study, we explored the effect of GCs on the protein synthesis procession of porcine skeletal muscle cells (PSCs). We prove that dexamethasone affects the expression of SLC7A7, a main amino acid transporter for protein synthesis by affecting the level of m6A modification in PSCs. In addition, we find that SLC7A7 affects the level of PSC protein synthesis by regulating the conduction of the mTOR signaling pathway, which indicates that the reduction of SLC7A7 expression may alleviate the level of protein synthesis under stress conditions.

The Emerging Role of Zfp217 in Adipogenesis.

Zinc finger protein 217 (Zfp217), a member of the krüppel-type zinc finger protein family, plays diverse roles in cell differentiation and development of mammals. Despite extensive research on the functions of Zfp217 in cancer, pluripotency and reprogramming, its physiological roles in adipogenesis remain unknown. Our previous RNA sequencing data suggest the involvement of Zfp217 in adipogenesis. In this study, the potential function of Zfp217 in adipogenesis was investigated through bioinformatics analysis and a series of experiments. The expression of Zfp217 was found to be gradually upregulated during the adipogenic differentiation in C3H10T1/2 cells, which was consistent with that of the adipogenic marker gene Pparg2. Furthermore, there was a positive, significant relationship between Zfp217 expression and adipocyte differentiation. It was also observed that Zfp217 could not only trigger proliferative defect in C3H10T1/2 cells, but also interact with Ezh2 and suppress the downstream target genes of Ezh2. Besides, three microRNAs (miR-503-5p, miR-135a-5p and miR-19a-3p) which target Zfp217 were found to suppress the process of adipogenesis. This is the first report showing that Zfp217 has the capacity to regulate adipogenesis.

[Synthesis of Ultra-Uniform Gold Spherical Nanoparticles with Different Sizes and Their SERS Effects Study].

A series of ultra-uniform gold spherical nanoparticles with different sizes were synthesized using gold chloride acid as precursor, ascorbic acid as reductant and sodium citrate hydrate as surfactant. The prepared Au nanoparticles were characterized by scanning electron microscope (SEM) and UV-visible spectroscopy. The results showed that the absorption peak of UV-Vis spectroscopy red-shifted along with size increasing of the nanoparticles and finally appeared a quadrupole peak. To further explore the mechanism of surface enhanced Raman spectroscopy (SERS) effect and optimize the sensitivity, SERS on Au nanoparticles with different sizes were measured using Rhodamine 6G (R6G) as probe molecule. We found the SERS signals of R6G on the Au nanoaprtciles were highly size dependent. When the particles sizes are close to -120 nm, it will generate the highest enhancement, the enhancement factor is about 1.1 x 10(7). The 3D-FDTD simulation results correlated with the experimental data very well.

Effect of humic acid-modified attapulgite on polycyclic aromatic hydrocarbon adsorption and release from paddy soil into the overlying water in a rice-crab coculture paddy ecosystem and the underlying process.

Phenanthrene (Phe), a typical polycyclic aromatic hydrocarbon (PAH) pollutant, poses an enormous safety risk to rice-crab coculture (RC) paddy ecosystems. In this study, humic acid-modified purified attapulgite (HA-ATP) with a composite structure was successfully fabricated to adsorb PAHs released from paddy soil to overlying water in RC paddy ecosystems in Northeast China. The maximum crab bioturbation intensities for dissolved Phe and particulate Phe were 64.83nullng/L·(cm2·d) and 214.29nullng/L·(cm2·d), respectively. The highest concentration of dissolved Phe released from paddy soil to overlying water due to crab bioturbation reached 80.89nullng/L, while the corresponding concentration of particulate Phe reached 267.36nullng/L. The dissolved organic carbon (DOC) and total suspended solid (TSS) concentrations in overlying water increased correspondingly and were strongly correlated with dissolved Phe and particulate Phe concentrations, respectively (P < 0.05). When 6% HA-ATP was added to the surface layer of paddy soil, the efficiency of the adsorption of Phe release was 24.00%-36.38% for particulate Phe and 89.99%-91.91% for dissolved Phe. Because HA-ATP has a large adsorption pore size (11.33 nm) and surface area (82.41nullm2/g) as well as many HA functional groups, it provided multiple hydrophobic adsorption sites for dissolved Phe, which was conducive to competitive adsorption with DOC in the overlying water. In contrast to that adsorbed by DOC, the average proportion of dissolved Phe adsorbed by HA-ATP reached 90.55%, which reduced the dissolved Phe concentration in the overlying water. Furthermore, even though the particulate Phe was resuspended by crab bioturbation, HA-ATP immobilized particulate Phe due to its capacity to inhibit desorption, which achieved the goal of reducing the Phe concentration in the overlying water. This result was confirmed by research on the adsorption-desorption characteristics of HA-ATP. This research provides an environmentally friendly in situ remediation method for reducing agricultural environmental risks and improving rice crop quality.

Molecular characterization and association analysis of porcine adipose triglyceride lipase (PNPLA2) gene.

The adipose triglyceride lipase (PNPLA2, also known as ATGL) is a novel triacylglycerol (TG) lipase which specifically removes the first fatty acid from the triglyceride molecule generating free fatty acid and diglyceride (DG) in mammalian cells. Here we describe the molecular characterization of the porcine ATGL gene. The full-length cDNA sequence contains a 1,461 bp open reading frame encoding a protein of 486 amino acids with a calculated molecular mass of 53.2 kDa and an isoelectric point of 7.90. The porcine ATGL protein shares high identity with other mammalian ATGL. The ATGL gene contains 9 coding exons, spans approximately 6 kb. The porcine ATGL mRNA was expressed predominantly in backfat, mildly in muscle, small intestine and heart, and almost absent in liver, spleen, lung, stomach, kidney and ovary. Statistical analysis showed the ATGL gene polymorphism (G/A(392)) was different between Chinese indigenous and introduced commercial western pig breeds, and was highly associated with almost all the fat deposition and carcass traits, including subcutaneous fat thickness, viscera adipose tissue, lean percentage, loin eye traits and even rib numbers.

cDNA cloning and characterization of 5' upstream promoter region of porcine mef2c gene.

The myocyte enhancer factor 2C (MEF2C) is a member of the MEF2 family of transcription factors, involved in skeletal muscle development. In this study we report the cDNA sequence and isolate the 5' upstream region of the mef2c gene from porcine genomic DNA using PCR-based GenomeWalker. The open reading frame of porcine mef2c cDNA covers 1,392 bases, encoding 464 amino acids, which show 94% identity with human MEF2C at the level of the primary protein structure. Annear the C terminus of mef2c, a 96-nt sequence appear to represent alternatively spliced transcripts was present in some cDNAs and absent in the other. No typical TATA, GC box or CAAT box binding site was found in porcine mef2c 5' upstream region, whereas some potential binding sites for MyoD (E-box), MEF2 and MBF1 were present in the proximal upstream region. Transfection of the mef2c 5' upstream region with EGFP into cos7 cells demonstrated that the region from -162 to +115 bp immediately 5' of the exon 1 was sufficient to direct strong EGFP protein expression. Co-transfection assays demonstrated that MBF1 bound the mef2c promoter and inhibited mef2c expression. These results may be useful for elucidating the regulation mechanisms of mef2c, which interacts with other factors to regulate target genes.

Glucocorticoid Receptor Alpha Targets SLC2A4 to Regulate Protein Synthesis and Breakdown in Porcine Skeletal Muscle Cells.

In the presence of stress, the hypothalamic-pituitary-adrenal (HPA) axis activity can be enhanced to promote the secretion of a large amount of glucocorticoids (GCs), which play an important role in the anabolism and catabolism of skeletal muscle. When the endogenous and exogenous glucocorticoids are deficient or excessive, the body will produce stress-related resistance and change the protein metabolism. In this study, we investigated the effect of GC receptor GRα on protein breakdown and synthesis in porcine skeletal muscle cells (PSCs). Overexpression of GRα was shown to increase the expression of protein degradation-related genes, while knockdown of GRα decreased the expression of these genes. Additionally, we found a relationship between GRα and solute carrier family 2 member 4 (SLC2A4), SLC2A4 expression level increases when stress occurs, suggesting that increasing SLC2A4 expression can partially alleviate stress-induced damage, and we found that there is a combination between them via luciferase reporter assays, which still needs to be confirmed in further studies.

Recombinant PBD-1 (porcine beta-defensin 1) expressed in the milk by transplanting transgenic mES-like-derived cells into mouse mammary gland.

ES (embryonic stem)-derived cells have been investigated in many animal models of severe injury and degenerative disease. However, few studies have examined the ability of ES-derived cells to improve functional outcome following partially damaged breast and also the modification of mammary tissue to produce costly proteins. This study investigates the feasibility of implanting mES-dK (mouse ES-derived keratinocytes-like) cells stably transfected with a mammary gland special expression vector for the PBD-1 (porcine beta-defensin 1) in developing mammary glands. Our aim was to assess the ability of cell grafting to improve functional outcome following partial damage of the breast, also on the breast modification mammary tissue in mice for the production of PBD-1 protein secreted in the milk. Our results showed that the ratios of the surviving cells labelled with the myoepithelial or luminal cell markers, EMA (epithelial membrane antigen) and CALLA, were 41.7 +/- 15.2% and 28.4 +/- 9.6%, respectively, which revealed that transplanted mES-dK cells survived, integrated in vivo and differentiated into myoepithelial or luminal cells. In addition, Western blot analysis showed that 37.5% (3 out of 8) female transplanted mice had PBD-1 expression in their milk and reached 0.4998, 0.5229 and 0.5195 microg/ml, respectively.

Molecular characterization, expression profile and association analysis with carcass traits of porcine LCAT gene.

The lecithin cholesterol acyltransferase gene (LCAT) plays an important role in lipoprotein metabolism, especially in the process termed 'reverse cholesterol transport'. In this study, we obtained the 1,434 bp mRNA sequence of porcine LCAT including the full coding region and encoding a protein of 472 amino acids. The sequence was deposited into the GenBank under the accession no. EU717835. The genomic sequence of this gene which contains six exons and five introns, is 3,712 bp in length (GQ379050). Bioinformatic analysis of the 5' regulatory region has revealed that some transcription factor Sp1, AP-1, AP-2 and NF-kappaB were represented in this region. Tissue expression analysis showed that the porcine LCAT gene is ubiquitously expressed in all examined tissues. Phylogenetic tree was constructed by aligning the amino acid sequences of different species. Moreover, we found a single nucleotide polymorphism (SNP, C/G266) in intron 1 of the LCAT gene and association analysis showed that it was significantly associated with ratio of lean to fat (P < 0.05), caul fat weight (P < 0.01), leaf fat weight (P < 0.05), carcass length (P < 0.05) and bone percentage (P < 0.05). Our study will lay the groundwork for the further investigations on the detailed physiological function of LCAT in pig models.

[Polymorphism in exon 2 of pig FIT1 gene and its association with fat-deposition-related traits].

In pig industry, fat deposition related traits such as back fat thickness and fat rate are of great economic importance. Thus, research on genes related with fat deposition can offer many useful values theoretically and practically. Gene FIT1 (Fat-inducing transcript 1) plays an important role in packaging lipid droplets. Here, we used FIT1 gene as the candidate gene for fat deposition. Sequence comparison revealed that an insertion/deletion mutation occurred at 590~595 bp of the second exon. We then carried out PCR-SSCP analysis followed by association analysis in F2 "Large white xMeishan" resource family. In all the individuals tested, all Meishan pigs possessed the insertion, which was designated allele A, while most Large white pigs possessed the deletion and was named as allele B. Association analysis in F2 resource family showed that this site was highly associated with fat percentage (FP), 6-7 rib fat thickness (RFT), buttock fat thickness (BFT), leaf fat weigh (LFW), total internal fat weigh (TFW), and internal fat rate (IFR) (Plt;0.01). These results indicated that FIT1 gene may have some important values for application. Further and deep research is necessary for revealing more information on this gene in order to provide a new marker for molecular marker-assisted selection breeding.

CapsCarcino: A novel sparse data deep learning tool for predicting carcinogens.

Determining chemical carcinogenicity in the early stages of drug discovery is fundamentally important to prevent the adverse effect of carcinogens on human health. There has been a recent surge of interest in developing computational approaches to predict chemical carcinogenicity. However, the predictive power of many existing approaches is limited, and there is plenty of room for improvement. Here, we develop a new deep learning architecture, termed CapsCarcino, to distinguish between carcinogens and noncarcinogens. CapsCarcino is constructed based on a dynamic routing algorithm that requires less data, extracts more comprehensive information, and does not require feature selection. We find that CapsCarcino provides a significantly improved predictive and generalization ability over, and outperforms five other machine learning models. Specifically, the best model of CapsCarcino achieves an accuracy of 85.0% on an external validation dataset. In addition, we discover that the enhanced predictive capability of CapsCarcino over that of the other methods is robust and can be achieved using sparse datasets. Training on merely 20% of the dataset, CapsCarcino performs comparably to the other methods based on the full training dataset. Further mechanism analysis indicates that CapsCarcino could efficiently learn the characteristics of carcinogens even if structural alerts are insufficiently represented. The results indicate that CapsCarcino should be helpful for carcinogen risk assessment.

Dose distribution of brachytherapy for locally advanced (stage IIB) cervical cancer.

PURPOSE: The aim of the study was to compare the dose distributions of combined intracavitary and interstitial (IC/IS) brachytherapy with 3-catheter IC brachytherapy in treating locally advanced (stage IIB) cervical cancer. METHODS AND MATERIALS: In total, 46 patients were included, each with stage IIB cervical cancer, local lesion sizes ≥5 cm, and tumors that had not regressed after 45 Gy/25 F external intensity-modulated radiotherapy. To identify the dosimetric advantage of delivering a local boost to high-risk (HR)-cervix in IC/IS, patients were divided into two groups: IC/IS and IC/IS + HR-cervix. The differences in dosimetric parameters were compared between the two groups. Comparisons were then made between the parameters of the four planning methods: IC (Point A), IC (three dimensional [3D]), IC/IS, and IC/IS + HR-cervix. RESULTS: In patients with IC/IS implants, the relative uterine tandem dwell time was significantly extended in the IC/IS + HR-cervix group, and the V150 and V200 volumes of HR-cervix were increased (all p < 0.001), whereas the D90 and D100 values of the IC/IS + HR-cervix group were lower than those in the IC/IS group. In pairwise comparisons, HR-cervix V150 and V200 values were lowest in the IC/IS group, followed by the IC (3D), IC/IS + HR-cervix, and IC (Point A) groups. All differences were statistically significant (p < 0.05), with the exception of IC/IS vs. IC (3D). CONCLUSIONS: When treating locally advanced cervical cancer (stage IIB, local residual volume ≥5 cm after external radiotherapy), the IC/IS + HR-cervix optimization method can meet the HR clinical target volume D90 dose requirement, normal tissue dose limits, and can escalate doses to local areas of the cervix.

Composting swine carcasses with nitrogen transformation microbial strains: Succession of microbial community and nitrogen functional genes.

In this study, nitrogen transformation strains, including three ammonium transformation strains, one nitrite strain and one nitrogen fixer, were inoculated at different swine carcass composting stages to regulate the nitrogen transformation and control the nitrogen loss. The final total nitrogen content was significantly increased (p < 0.01). The bacterial communities were assessed by amplicon sequencing and association analysis. Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes were the four most dominant phyla.,Brevibacterium, Streptomyces and Ochrobactrum had a significant (p < 0.05) and positive correlation with total nitrogen and ammonium nitrogen content in both groups. The quantitative results of nitrogen transformation genes showed that ammonification, nitrification, denitrification and nitrogen fixation were simultaneously present in the composting process of swine carcasses, with the latter two accounting for a higher proportion. The ammonium transformation strains significantly (p < 0.05) strengthened nitrogen fixation and remarkably (p < 0.01) weakened nitrification and denitrification, which, however, were notably (p < 0.05) enhanced by the nitrite strain and nitrogen fixer. In this research, the inoculated strains changed the bacterial structure by regulating the abundance and activity of the highly connected taxa, which facilitated the growth of nitrogen transformation bacteria and regulated the balance/symbiosis of nitrogen transformation processes to accelerate the accumulation of nitrogen.

Logistic regression analysis of the related factors in discarded semen of boars in Southern China.

This study aimed to investigate factors affecting the discarded semen of boars. A total of 176,368 ejaculates of boars from nine AI centers were collected from January 2013 to May 2016 in Southern China. The criteria for determining whether their semen was abnormal included cytoplasmic droplets, coiling tail, sperm agglutination, impurity, poor motility, oligozoospermia, necrozoospermia, azoospermia, and hemospermia. The cause of discarded semen was evaluated with a Chi-square test, and the effects of housing type, breed, age at collection, season identified in the northern hemisphere, and age at herd entry of the discarded semen of boars were analyzed with a logistic regression model. Results indicated the proportion of the discarded semen (PDS) in the nine AI centers was 13.09%. Chi-square test showed the greatest PDS among all causes was found in semen discarded due to cytoplasmic droplets (31.60%), followed by impurity (25.96%), sperm agglutination (20.31%), coiling tail (17.72%), oligozoospermia (10.86%), and others (6.78%; P < 0.0001). Logistic regression analysis revealed the PDS was affected by all these five factors (P < 0.0001). The PDS of boars raised individually in stalls was greater than that of boars raised individually in pens (OR: 1.657; 95% CI: 1.607 to 1.709). The PDSs of Duroc boars (OR: 1.130; 95% CI: 1.093 to 1.167) and Yorkshire boars (OR: 1.432; 95% CI: 1.380 to 1.486) were greater than that of Landrace boars. The PDSs of adult boars (aged from 13 to 24 mo, from 25 to 36 mo, and more than 37 mo with OR: 0.800, 0.941, and 0.838, respectively; 95% CI: 0.771 to 0.831, 0.902 to 0.983, and 0.790 to 0.889, respectively) were lower than those of young boars (aged less than 12 mo). The PDSs of semen collected in summer (OR: 1.367; 95% CI: 1.314 to 1.422), autumn (OR: 1.185; 95% CI: 1.138 to 1.234), and winter (OR: 1.159; 95% CI: 1.115 to 1.206) were greater than those of semen obtained in spring. The PDSs of boars introduced at ages of 5-7 mo (OR: 1.432; 95% CI: 1.380 to 1.486) and 10-12 mo (OR: 1.432; 95% CI: 1.380 to 1.486) were greater than those of boars introduced at an age of 8 and 9 mo. In conclusion, logistic regression analysis reveals discarded semen is affected by housing type, breed, age at collection, season, and age at herd entry. More importantly, cytoplasmic droplets is the primary reason for discarding boar semen, and 8 months at herd entry is the most suitable age for boar introduction.

Long-term culture of keratinocyte-like cells derived from mouse embryonic stem cells.

A number of epithelial lineages have been derived from mouse embryonic stem cells during the past decades, but the long lasting culture has never been reported. In this paper, we report when mouse embryonic stem cells were dispersed into small clumps containing approximately 50 to 100 cells and grown on mitotically inactivated mouse embryonic fibroblast feeder layers for up to 10 d to form epithelial-like colonies. Through subsequent cultivation without mouse embryonic fibroblast feeder layers, a serially subcultured keratinocyte-like cell lineage was established under these conditions. Pan cytokeratin, cytokeratin 14, and cytokeratin 18 were observed in these proliferating cells using immunocytochemistry and flow cytometry. E-cadherin, Involucrin, and keratin mRNAs were determined by a semi-quantitative and a quantitative real time reverse transcription-polymerase chain reaction (RT-PCR). These results confirmed the establishment of a keratinocyte-like cell lineage derived from mouse embryonic stem cells. In this paper also, we describe a method by which mouse embryonic stem cells can be differentiated into cells with some characteristics of epidermal keratinocytes and kept these cells in long-term culture. Potential applications of this method are the in vitro differentiation of cells of interest from embryonic stem (ES) cells of mice during embryonic development and the production of genetically modified epidermal keratinocytes that could be used as temporary wound dressing or as carriers of genes of interest in gene therapeutic treatments or better understanding the mechanisms for epithelial differentiation of embryonic stem cells.

Association of MYF5 and MYOD1 gene polymorphisms and meat quality traits in Large White x Meishan F2 pig populations.

MYF5 and MYOD1 belong to the myogenic regulatory factor (MRF) gene family. They code for the basic helix-loop-helix transcription factors that play key regulatory roles in the initiation and development of skeletal muscle and the maintenance of its phenotype. In this work three single nucleotide polymorphisms (SNPs) in porcine MYF5 and one in porcine MYOD1 were detected in three pig breeds (Large White, Landrace, and Meishan) by means of a PCR-RFLP protocol. Analysis of the association of meat quality traits with the four polymorphisms in a series of three Large White x Meishan F2 populations, totaling 399 pigs, found: (1) MYF5 exon 1 Hsp92II polymorphism causing a Met --> Leu substitution was associated with intramuscular fat content (P = 0.04) and water moisture content (P = 0.0001) in the longissimus dorsi; (2) MYF5 exon 2 MspI polymorphism and an intron 1 HaeIII polymorphism, which were completely linked, were significantly associated with longissimus dorsi pH (P < 0.05); (3) MYOD1 intron 1 DdeI polymorphism was not significantly associated with any meat quality traits tested. Among these genetic variants (a novel SNP and three identified SNPs), our data suggested that the novel SNP of the MYF5 gene within exon 1 is valuable for pig breeding.

Analysis of influencing factors of boar claw lesion and lameness.

This study aimed to investigate the factors affecting boar claw lesions and lameness. A total of 1299 boars were examined for claw lesions and lameness, including 788 boars reared in individual pens with solid concreted floor (IPS) and 511 boars raised in individual stalls with slatted floor (ISS). Flooring type showed significant impacts on all claw lesion types (P < 0.01). Except for swelling ankle, boar age had significant effects on all other claw lesion types (P < 0.01). In addition, only heel overgrowth and erosion, cracked wall horizontal, heel-sole crack, dew claws, and toes were significantly related to boar breeds (P < 0.05). Furthermore, IPS lame boars had higher prevalence of lameness in the hind limb (P < 0.05), whereas in ISS lame boars, there were no significant differences in prevalence of lameness between the fore and hind limbs (P > 0.05). Boar lameness was moderately correlated with swelling ankle (Φ = 0.5571). In conclusion, claw lesions can be influenced by flooring type, boar age and breed, and could serve as a predictor for boar lameness.

Quantitative trait loci for carcass traits on pig chromosomes 4, 6, 7, 8 and 13.

For 22 carcass traits, we identified 16 QTLs (based on data for pig resource population no. 214, including 180 F2 hybrids of 3 Yorkshire boars and 8 Meishan sows) and mapped them with the use of 39 microsatellite marker loci on chromosomes 4, 6, 7, 8 and 13. Five QTLs were highly significant (P < or = 0.01 at chromosome level): for skin weight (on chromosome 7 at SW1856 and on chromosome 13 at SW1495), skin percentage (on chromosome 7 between SW2155 and SW1856 and on chromosome 13 between SW1495 and SW520), and ratio of leg and butt to carcass (on chromosome 4 at SW1996). The remaining 11 QTLs were significant (P < or = 0.05 at chromosome level): for backfat thickness at shoulder, loin eye width, loin eye height, fat meat weight, lean meat weight, skin weight, bone weight, skin percentage, fat meat percentage, and ratio of lean meat to fat meat. The proportion of phenotypic variance explained by these QTLs ranged from 0.06% (QTL for loin eye width on chromosome 8 between SW1037 and SW1953) to 18.04% (QTL for ratio of lean meat to fat meat on chromosome 7 between SW252 and SW581). Seven of the QTLs reported here are novel.

Linear model analysis of the influencing factors of boar longevity in Southern China.

This study aimed to investigate the factors influencing the boar herd life month (BHLM) in Southern China. A total of 1630 records of culling boars from nine artificial insemination centers were collected from January 2013 to May 2016. A logistic regression model and two linear models were used to analyze the effects of breed, housing type, age at herd entry, and seed stock herd on boar removal reason and BHLM, respectively. Boar breed and the age at herd entry had significant effects on the removal reasons (P < 0.001). Results of the two linear models (with or without removal reason including) showed boars raised individually in stalls exhibited shorter BHLM than those raised in pens (P < 0.001). Boars aged 5 and 6 months at herd entry (44.6%) showed shorter BHLM than those aged 8 and 9 months at herd entry (P < 0.05). Approximately 95% boars were culled for different reasons other than old age, and the BHLM of these boars was at least 12.3 months longer than that of boars culled for other reasons (P < 0.001). In conclusion, abnormal elimination in boars is serious and it had a negative effect on boar BHLM. Boar removal reason and BHLM can be affected by breed, housing type, and seed stock herd. Importantly, 8 months is suggested as the most suitable age for boar introduction.

Dietary n-6:n-3 ratio and Vitamin E improve motility characteristics in association with membrane properties of boar spermatozoa.

This study was aimed to evaluate the effects of dietary n-6:n-3 ratio and Vitamin E on the membrane properties and motility characteristics of spermatozoa in boars. Forty Duroc boars were randomly distributed in a 2 × 2 factorial design with two n-6:n-3 ratios (14.4 and 6.6) and two Vitamin E levels (200 and 400 mg kg-1 ). During 16 weeks of treatment, fresh semen was collected at weeks 0, 8, 12, and 16 for measurements of motility characteristics, contents of fatty acids, membrane properties (membrane fluidity and membrane integrity), and lipid peroxidation of the spermatozoa. The semen was diluted in Beltsville Thawing Solution (BTS) extender and stored at 17°C, and the sperm motility was assessed at 12, 36, 72, and 120 h of storage. The 6.6 n-6:n-3 dietary ratio increased the contents of n-3 polyunsaturated fatty acids (PUFAs) and docosahexaenoic acid (DHA) and improved the membrane integrity and membrane fluidity of the spermatozoa, resulting in notably increased total motility, sperm progressive motility, and velocity parameters of fresh semen. Feeding diet with Vitamin E (400 mg kg-1 ) prevented sperm lipid peroxidation, and resulted in higher total motility and sperm progressive motility in fresh and liquid stored semen. In conclusion, the adjustment of n-6:n-3 ratio (6.6) and supply of Vitamin E (400 mg kg-1 ) successfully improved sperm motility characteristics and thus may be beneficial to the fertility of boars, which might be due to the modification of the physical and functional properties of spermatozoa membrane in response to dietary supplementation.