Accurate models and nutritional strategies for specific oxidative stress factors: Does the dose matter in swine production?

Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.

Establishment of an indirect immunofluorescence assay for the detection of African swine fever virus antibodies

African swine fever(ASF)continues to cause enormous economic loss to the global pig industry.Since there is no safe and effective vaccine,accurate and timely diagnosis of ASF is essential to implement control measures.Indirect immunofluorescence assay(IFA)is a gold standard serological method recommended by the World Organization for Animal Health(WOAH).In this study,we used primary fetal kidney cells to establish a wild boar cell line(BK2258)that supported the efficient replication of ASF virus(ASFV)SD/DY-I/21 and showed visible cytopathic effect(CPE).Moreover,using BK2258,we established a sensitive and specific IFA for ASFV antibody detection.To standardize and evaluate the performance of this assay,we used serum samples from pigs infected with the low virulent genotype I SD/DY-I/21 and genotype II HLJ/HRB1/20,and immunized with the vaccine candidate HLJ/18-7GD,field samples,and negative serum samples.The IFA reacted with the ASFV-positive sera and displayed bright fluorescence foci.There was no non-specific green fluorescence due to cellular senescence or other cell damage-causing factors.Compared to a commercial indirect enzyme-linked immunosorbent assay(iELISA),ASFV antibodies were detected 1–4 days earlier using our IFA.The detection limits of the IFA and iELISA for the same ASFV-antibody positive serum samples were 1:25,600 and 1:6,400,respectively,indicating that the IFA is more sensitive than iELISA.The newly established IFA was highly specific and did not cross-react with sera positive for six other important porcine pathogens(i.e.,Classical swine fever virus(CSFV),Porcine reproductive and respiratory syndrome virus(PRRSV),Porcme circovirus type 2(PCV2),Pseudorabies virus(PRV),Foot-and-Mouth disease virus type O(FMDV/O),and Porcine epidemic diarrhea virus(PEDV)).This study thus provides a sensitive,specific,and reliable detection method that is suitable for the serological diagnosis of ASF.

Characterization of three African swine fever viruses from diferent clinical settings revealed a potential attenuation mechanism

African swine fever(ASF)is an acute and fatal hemorrhagic disease in domestic pigs and wild boars caused by African swine fever virus(ASFV)that currently threatens the pig industry worldwide.Since the 2018 ASF outbreak in China,ASFV has evolved and caused diverse clinical manifestations,such as chronic and asymptomatic infections.Therefore,it is important to understand the molecular mechanisms underlying ASFV attenuation in the feld.Here,we isolated three ASFVs from one diseased and two asymptomatic pigs by using primary porcine alveolar macrophages(PAMs)from both domestic pigs and Bama minipigs.The three ASFVs exhibited similar phenotypes in cell culture,includ‑ing cytopathic efects(CPEs),hemadsorptions(HADs),viral protein expressions and growth curves.Genome sequenc‑ing revealed that all three ASFVs were genotype II strains.Genomic comparisons suggested that the disruption of the viral genes MGF360 and MGF110,rather than EP402R and EP153R,is likely involved in the potential attenuation of ASFV via the upregulation of innate immune responses.

Advances in research on the efcacy of traditional Chinese herbal medicine in combating African swine fever

African swine fever(ASF)is a highly contagious disease of domestic and wild pigs caused by African swine fever virus(ASFV).The mortality rate associated with ASF is remarkably high,almost approaching 100%.Since the introduction of ASF into China in 2018,its rapid spread has caused marked economic losses in the country’s swine industry.To date,there are no safe and efective commercial vaccines or antiviral drugs against ASF;thus,there is an urgent need to develop novel prevention and control strategies.Traditional Chinese medicine(TCM),which comprises various herbs that are abundant in various potential functional components,holds great promise for the prevention and control of ASF.Here,we provide a comprehensive review of the advancements in TCM and the efects of its compound formulas against ASF,including the antiviral abilities,immunoregulatory activities,and practical application of these formulas for the prevention and control of ASF.We specifcally examined the potential and constraints of natural product-derived extracts and TCM formulas in combating ASFV.This review aims to ofer insights and ideas for the holistic management and containment of ASF.

Development and application of a SYBR Green I fuorescent PCR assay for the diferentiation of genotypes I and II African swine fever viruses

African swine fever(ASF)is a highly fatal hemorrhagic disease afecting domestic pigs caused by African swine fever virus(ASFV).Genetic analysis of ASFV isolates to date has identifed 24 geographically related genotypes with various subgroups,but only genotype I and II ASFVs have been reported outside Africa.ASFV genotype II and genotype I viruses were reported in China in 2018 and 2021,respectively.In this study,unique and highly conserved noncoding regions were found between MGF_505-9R and MGF_505-10R in the 188 genomes of ASFV genotypes I and II.A pair of primers was designed on the basis of this region.By optimizing the reaction system and conditions,a SYBR Green I fuorescence PCR assay that can distinguish between ASFV genotypes I and II was established,and the sensitivity,reproducibility and specifcity were evaluated.The detection limit was 1 TCID_(50)/0.1 mL for both genotypes,with no cross-reactivity observed with other common pig pathogens.The intra-and interbatch variation coefcients were both less than 1.2%.Clinical sample detection analysis revealed 47 positive cases out of 100,including 3 for genotype I and 44 for genotype II,aligning with results from the WOAH-recommended and national standard methods.The method developed in this study allows for the diferentiation of ASFV genotypes I and II without the need for genome sequencing,ofering a convenient and rapid approach for ASFV detection and genotype identifcation.

Call for Papers:Special issue“African Swine Fever”

African swine fever(ASF)is one of the most devastating diseasesin pigs and is caused by the ASF virus(ASFV).Since its firstdiscovery in 1921 in Kenya,ASFV has spread from Africa to otherparts of the world,causing severe economic losses to the porkindustry.Scientists have studied ASF for over 100 years,and manygovernments have tried to eradicate the disease.Nonetheless,approaches to effectively control ASF are still lacking.In recent years,ASF outbreaks have been reported in China,Belgium,Germany,Italyand many other Asian and European countries.Studies on this diseasehave gained new popularity.Under this background,we are organizingthe special issue“African swine fever”to collect the most recentknowledgeon this disease.

Call for Papers:Special issue“African Swine Fever”

African swine fever(ASF)is one of the most devastating diseases in pigs and is caused by the ASF virus(ASFV).Since its first discovery in 1921 in Kenya,ASFV has spread from Africa to other parts of the world,causing severe economic losses to the pork ASFV industry.Scientists have studied ASF for over 100 years,and many governments have tried to eradicate the disease.Nonetheless,approaches to effectively control ASF are still lacking.

Current research progress on the viral immune evasion mechanisms of African swine fever virus

African swine fever(ASF),caused by the ASF virus(ASFV),is an acute,severe,and highly contagious infectious disease in domestic pigs and wild boars.Domestic pigs infected with a virulent ASFV strain can have morbidity and mortality rates of up to 100%.The epidemic of ASF has caused serious economic losses to the global pig industry.Currently,there is no safe and efective vaccine or specifc drug for treating ASF.Therefore,ASFV still poses a great threat to pig factories.ASFV is a double-stranded DNA virus with a complex icosahedral multilayer structure.The ASFV genome contains 150-170 open reading frames(ORFs)that encode 150-200 proteins.Some ASFV-encoded proteins are involved in virus invasion,genome replication,DNA repair,and virion formation.Some ASFV proteins execute immunomodulatory functions by regulating the host antiviral innate immune response.Accumulating studies have shown that the immunomodulatory functions of ASFV genes are closely related to the virulence and pathogenicity of ASFV isolates.This review summarizes the research advances on ASFV immune evasion mechanisms in African swine fever patients and provides new insights for developing attenuated live vaccine candidates to prevent and control ASF.

Application of traditional Chinese herbal medicine in the prevention and treatment of swine viral infectious diseases

This study aims to explore the current application status and development prospects of Chinese herbal medicine in preventing and treating swine viral infectious diseases over the past five years.By adopting the method of literature review,we collect,organize,and analyze relevant research literature,with the goal of summarizing and summarizing the research progress in this field.Through research,we found that swine infectious diseases have caused serious economic losses in the breeding industry and that some diseases cannot be fully protected by using vaccines.Therefore,we need new means to prevent diseases.The use of Chinese herbal medicine for the prevention and treatment of related diseases has become a reliable means.This study first briefly introduces the common infectious diseases of pigs and the risks and challenges faced by prevention and treatment,then reads the literature comparing the treatment with Western medicine and traditional Chinese medicine,proving the reliability of traditional Chinese medicine treatment and the unique advantages of Chinese herbal medicine.Afterwards,we summarized the literature on the prevention and treatment of related swine diseases with Chinese herbal medicine in the past five years,and finally made a summary and outlook,hoping to provide ideas for relevant researchers and workers.

A Review on Tibetan Swine(a)——Carcass,Meat Quality,Basic Nutrition Component,Amino Acids,Fatty Acids,Inosine Monophosphate and Muscle Fiber

In this review, the carcass, meat quality, internal organs, basic nutrition component, amino acids （AAs）, fatty acids, inosine monophosphate （IMP） and mus- cle fiber of Tibetan swine were summarized for the first time. The formation mecha- nism of excellent features was analyzed from the aspects of physiological traits, ge- ographical environments and constraint reasons. Thereby, the outstanding features of Tibetan swine could be extended continuously, and the poor characteristics should be improved in the future.

The Lapinized Chinese Strain Vaccine Against Classical Swine Fever Virus:A Retrospective Review Spanning Half A Century

Classical swine fever （CSF）, a list A disease of Office International des Epizooties, is caused by classical swine fever virus （CSFV） belonging to the Flaviviridae family. The well-known lapinized Chinese strain of CSFV, also known as C-strain, was developed in China in the mid-1950s. In the past half a century, the vaccine has been proved to be safe and immunogenic in pigs of essentially any age. It is of high efficacy, providing immunized animals with broad-spectrum, sometimes lifelong, protection, which is contributed by both cell-mediated immunity and humoral immunity, against essentially all genotypes or subgenotypes of the virus. The maternal antibodies derived from immunized sows can confer solid protection of their offspring from disease; however, they have been proved to inhibit the successful active immunization of C-strain vaccine. The complete genomes of C-strain and dozens of established or field strains have been sequenced and annotated. Recently, the reverse genetics system of C-strain has been developed, resulting in several C- strain-derived candidate marker vaccines. Many countries manage to control or even eradicate CSF with the aid of mass vaccination with C-strain. in spite of these efforts, the eradication of the disease worldwide remains a big challenge and needs to go a long way, and provably still resorts to genetically modified C-strain vaccine. The authors present an overview of the characteristics of the vaccine, which has stood the test of half a century.

A multiplex real-time PCR assay for simultaneous detection of classical swine fever virus,African swine fever virus,and atypical porcine pestivirus

With the implementation of the C-strain vaccine,classical swine fever(CSF) has been under control in China,which is currently in a chronic atypical epidemic situation.African swine fever(ASF) emerged in China in 2018 and spread quickly across the country.It is presently occurring sporadically due to the lack of commercial vaccines and farmers’ increased awareness of biosafety.Atypical porcine pestivirus(APPV) was first detected in Guangdong Province,China,in 2016,which mainly harms piglets and has a local epidemic situation in southern China.These three diseases have similar clinical symptoms in pig herds,which cause considerable losses to the pig industry.They are difficult to be distinguished only by clinical diagnosis.Therefore,developing an early and accurate simultaneous detection and differential diagnosis of the diseases induced by these viruses is essential.In this study,three pairs of specific primers and Taq-man probes were designed from highly conserved genomic regions of CSFV(5’ UTR),African swine fever virus(ASFV)(B646L),and APPV(5’ UTR),followed by the optimization of reaction conditions to establish a multiplex real-time PCR detection assay.The results showed that the method did not cross-react with other swine pathogens(porcine circovirus type 2(PCV2),porcine reproductive and respiratory syndrome virus(PRRSV),foot-and-mouth disease virus(FMDV),pseudorabies virus(PRV),porcine parvovirus(PPV),and bovine viral diarrhea virus BVDV).The sensitivity results showed that CSFV,ASFV,and APPV could be detected as low as 1 copy μL–1;the repeatability results showed that the intra-assay and interassay coefficient of variation of ASFV,CSFV,and APPV was less than 1%.Twenty-two virus samples were detected by the multiplex real-time PCR,compared with national standard diagnostic and patented method assay for CSF(GB/T 27540–2011),ASF(GB/T 18648–2020),and APPV(CN108611442A),respectively.The sensitivity of this triple real-time PCR for CSFV,ASFV,and APPV was almost the same,and the compliance results were the same(100%).A total of 451 clinical samples were detected,and the results showed that the positive rates of CSFV,ASFV,and APPV were 0.22% (1/451),1.3%(6/451),and 0%(0/451),respectively.This assay provides a valuale tool for rapid detection and accurate diagnosis of CSFV,ASFV,and APPV.

Effects of Integrated Chinese Herbs and Western Medicine on Swine Toxoplasmosis

[ Objective] To evaluate the efficacy of integrated Chinese herbs and western medicine on the treatment of swine toxoplasmosis, in order to increase cure rate and lower recurrence rate. [ Method] Pigs artificially infected by Toxoplasma gondii were treated with compound suffonamide and a self-designed Chinese herbs formula, and the quantities of toxoplasma in ascites were determined. Animal regression experiment was per- formed after mice were inoculated with pathological samples of the pigs infected with toxoplasma. After treatment with integrated Chinese herbs and western medicine, the clinical manifestations of pigs were observed and the level of circulating antigen （CAg） in sera was detected. Curative effect indexes of integrated Chinese herbs and western medicine-treated group were compared with that of Chinese herbs-treated group, western medi- cine-treated group and positive control group. [ Result] All the toxoplasma trophozoites were killed by integrated and westem medicine. Regression expedment results showed that toxoplasma appeared only in one mouse that was inoculated with brain of pig. The treated pigs had nonsignificant clinical symptoms; the peak of serum CAg was lower than that of the positive control group and CAg turned negative faster than that of Chinese herbs-treated group, westem medicine-treated group, and positive control group. [ Conclusion] The integrated Chinese herbs and western medicine has good effect on the treatment of swine toxoplasmosis.

Study on Environmental and Economic Benefits of Rice and Wheat Rotation with Swine Manure-Straw Returning

[Objective] The aim was to investigate the application effect of swine manure-straw returning and to determine the best mode. [Method] A field experiment under rice and wheat rotation with different swine manure-straw treatments was con- ducted to study the growth characters and output of rice and wheat, calculate the economic benefit and carbon dioxide emission reduction, and analyze the best mode of swine manure applying-straw returning. [Result] The swine manure-straw returning was conducive to the growth of crop, the highest outputs of rice and wheat were on the treatment of ＂30% swine manure and 20% straw and 50% chemical fertiliz- er＂, they were 7 874.57 and 6 427.00 kg/hm^2, and saved cost about 5 146.35 Yuan/hm^2, increased input 5 312.56 and 3 931.93 Yuan/hm^2, the greenhouse gas e- mission reduction was 1.30 t/hm^2 （calculated according to carbon dioxide on a dry basis）. [Conclusion] The treatment of ＂30% swine manure and 20% straw and 50% chemical fertilizer＂ was the best mode of swine manure-straw returning.

Cloning and Sequence Analysis on IGF-1 Gene of Hubei White Swine

[Objective] The study aimed at cloning and analyzing the insulin-like growth factor-1 （IGF-1） gene from liver of Hubei white swine. [Method] The total RNA was extracted by using Trizol from the liver of Hubei white swine and used as template to amplify IGF-1 gene cDNA by RT-PCR. The cDNA product was cloned into pCRII vector, screened with blue-white colonies, digested with double enzymes and sequenced. [Result] The sequencing result indicated that the IGF-1 gene consisted of 607 nucleotides, containing 5＇-untranslated region at nucleotides 1-145, a complete ORF at nucleotides 146-538 encoding 130 amino acids, and 3＇-untranslated region at nucleotides 539-607. It shared 100% homology with the porcine IGF-1 gene reported by Muller et al. [Conclusion] The successful cloning and sequencing of the Hubei white swine IGF-1 gene confirmed that IGF-I gene was highly conserved, which provided technical basis for the use of transgenic technology for breeding of Hubei white swine.

Bioinformatics Analysis on MSTN Gene of Swine

[Objective] The aim was to make bioinformatics analysis on MSTN gene in swine. [Method] In the research, coding sequences （CDS） of MSTN gene in swine, rat, mouse, dog, sheep, goat, cattle, chimpanzee, human, horse, chicken and zebra fish were loaded to Megalign of DNAstar for analysis of phyletic evolution. In addi- tion, we also made analysis on basic information, restriction map, secondary struc- ture of coding protein, signal peptide, transmembrane domain and protein subcellular localization. [Result] Closely related to rat, mouse, dog, sheep, goat, cattle, chim- panzee, human and horse, MSTN genes in swine included many enzyme cutting sites and the encoding protein was unstable in hydrophobicity. The molecular weight was 42 791.3 u, isoelectric point was 6.98, and the gene included 375 amino acid residues. In addition, the secondary structure of protein contained 20.53% of c^-Helix, 4% of 15-Turn, 53.07% of Coil, 22.4% of extenden strand and one transmembrane domain. The extracellular protein was probably being signal peptide. [Conclusion] The research provided references for further study on MSTN genes of swine.

Swine Wastewater Treatment with Struvite Precipitation Technology

[Objective] This study aimed to determine the optimal technical parameters for the swine wastewater treatment by struvite precipitation. [Method] Central composite design （CCD） and response surface method （RSM） were employed to study the effects of struvite precipitation on removing the ammonia nitrogen in the swine wastewater. Quadratic model was developed to describe the mathematical relationships between the investigated factors of pH value, reaction time, magnesium to nitrogen molar ratio （Mg/P）, nitrogen to phosphorus molar ratio （N/P）, the investigated indicators of NH 4 -N removal efficiency and residual PO 4 3 -P concentration. Contour overlay plot was proposed to predict the optimal experimental conditions with the NNH 4 -N removal efficiency of 75% and residual PO 4 3-P concentration of 3.0 mg/L as the desired values. [Result] At pH of 10.0, mixing time of 30 min, Mg/N of 1.11, N/P of 1.14, the NH 4 -N removal efficiency （Y 1 ） was the maximum of 79.0% , and the residual PO 4 3-P concentration （Y 2 ） at this time was 0.35 mg/L. The verification test of the optimal conditions proved that the verification data and model predictions agreed well. [Conclusion] The optimized parameters for the chemical struvite precipitation used to treat swine wastewater with central composite experimental design and response surface method are scientific, rational and efficient.

不变与变:从“SARS”到“Swine Influenza”的中文译名谈起

SARS与Swine Influenza为发生在本世纪初的两场重大传染疾病,其中SARS的中文译名一直未变,译为"非典";Swine Influenza则从开始的"猪流感"更名为"甲型H1N1流感"。本文尝试从翻译与传播的视角探讨这两种疾病中文译名的不变与变,分析背后的原因,并提出SARS中文译名的改进译法。

一株猪流感病毒A/swine/Shanghai/01/2019(H1N1)的分离鉴定及遗传进化分析

为鉴定上海地区猪流感病毒的流行株及其分子生物学特征,本研究从上海地区养殖场采集疑似流感症状的猪咽拭子样品40份,采用套式PCR结合鸡胚分离鉴定方法,从中分离到1株H1N1亚型猪流感病毒(SIV),命名为A/swine/Shanghai/01/2019(H1N1)。经全基因组测定和遗传进化分析结果显示该分离株的8个基因节段与欧亚类禽H1N1 SIV同源性最高,其PB2、PB1、PA基因节段可能来源于A/swine/Jiangsu/49/2012(H1N1)病毒,NA、NP和M基因节段可能来源于A/swine/Shanghai/3/2014(H1N1)病毒。该分离病毒的HA蛋白裂解位点为PSIQSR↓GLFGAI,为低致病性流感病毒的分子特征。该分离株NA蛋白未出现与神经氨酸酶抑制剂相关的氨基酸突变,M2蛋白S31N突变表明该病毒可能对金刚烷胺类药物具有一定的耐药性。PA蛋白224S和PB2蛋白701N突变提示该分离株对哺乳动物的适应性增强,可能导致其致病性增强,需要加强对此类SIV的监测。结合近年来的监测表明,上海地区猪群中H1N1亚型SIV持续存在,需要持续跟踪监测SIV变异趋势。本研究为防控猪流感提供实验依据。

A review of the effects of dietary organic acids fed to swine

Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters （AGP） has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are （3-4 weeks age） exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb＇s cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.