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 antioxid...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.展开更多
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...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.展开更多
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 ...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.展开更多
Africanswinefever(ASF),causedbythe African swine fever virus (ASFV), is an acute, hemorrhagic, and contagious disease of domestic pigs and wild boars.The disease is notifiable and listed by the World Organization for ...Africanswinefever(ASF),causedbythe African swine fever virus (ASFV), is an acute, hemorrhagic, and contagious disease of domestic pigs and wild boars.The disease is notifiable and listed by the World Organization for Animal Health (WOAH)(Wang N et al. 2019).展开更多
Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological re...Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans.As a result,functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.Comparatively,large r,more clinically relevant models have not been as well studied.To achieve similar locomotor testing standardization in larger animals,the models must be accessible to a wide array of researchers.Non-human primates are the most relevant animal model fo r translational research,however ethical and financial barriers limit their accessibility.This review focuses on swine,sheep,and goats as large animal alternatives for transitional studies between rodents and non-human primates.The objective of this review is to compare motor testing and data collection methods used in swine,sheep,and goats to encourage testing standardization in these larger animal models.The PubMed database was analyzed by searching combinations of swine,sheep,and goats,neurologic injuries,and functional assessments.Findings were categorized by animal model,data collection method,and assessment design.Swine and sheep were used in the majority of the studies,while only two studies were found using goats.The functional assessments included open pen analysis,treadmill walking,and guided free walking.Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software.Overall,swine and sheep were well-suited for a variety of assessment designs,with treadmill walking and guided free walking offering the most consistency across multiple trials.Data collection methods varied,but image-based gait analysis software provided the most robust analysis.Future studies should be conducted to standardize functional testing methods after neurologic impairment in large animals.展开更多
African swine fever(ASF) was first discovered and reported in East Africa in 1921 and it has been listed as a notifiable animal disease by the World Organization for Animal Health(WOAH) due to the high morbidity and m...African swine fever(ASF) was first discovered and reported in East Africa in 1921 and it has been listed as a notifiable animal disease by the World Organization for Animal Health(WOAH) due to the high morbidity and mortality(WOAH 2019). African swine fever virus(ASFV) can persist in pig farm environments, carcasses, and various pig products(Petrini et al. 2019). ASF has caused significant economic losses to the pig industry since its outbreak in China in 2018(Zhao et al. 2019).展开更多
This paper aims to optimize the culling compensation policy from a micro perspective through scenario simulation.Based on an investigation of 273 pig farms in eight regions,four typical pig farms were constructed acco...This paper aims to optimize the culling compensation policy from a micro perspective through scenario simulation.Based on an investigation of 273 pig farms in eight regions,four typical pig farms were constructed according to farm size and breeding mode,representing the swine producers in China.Besides,a decision objective function of pig farms facing suspected African swine fever(ASF)outbreaks was constructed.This study used a mathematical programming model to design and simulate scenarios based on compensation standards and local implementation levels,aiming to incentivize pig farms to report epidemics.The results show that the optimal decisions on epidemic reports differed among typical farms and by herd daily age.The results suggest the following adjustments for optimizing culling compensation policies:(1)to set culling compensation standards based on the market value and(2)to maintain a high level of epidemic surveillance capability in the animal husbandry and veterinary sector.展开更多
Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluati...Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluating intramuscular fat in live animals. Together with other genetic improvement tools, ultrasound technology will offer seedstock producers the opportunity to select for improved IMF in potential breeding stock replacements and hence speed genetic progress for the improvement of this trait. After three generations of selection for IMF using real-time ultrasound in an Iowa State University study, the average EBV for select line pigs is 0.83% greater than for control line pigs. Selection for IMF has, however, resulted in slightly more backfat and less loin muscle area, and a trend toward more days to 114 kg in the select line compared to the control line. Carcass evaluation of a sample of pigs from each litter indicated a similar increase in IMF, increase in backfat, and reduction in loin muscle area for select line pigs. No differences were found for Hunter L* color, Minolta reflectance, and ultimate pH.展开更多
Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance,lean gain and lipid accretion.It is closely linked with energy metabolism,as the oxidation of carbon-c...Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance,lean gain and lipid accretion.It is closely linked with energy metabolism,as the oxidation of carbon-containing components in the feed drive all metabolic processes.While much is known about nutrient utilization and tissue metabolism,blending these subjects into a discussion on feed efficiency has proven to be difficult.For example,while increasing dietary energy concentration will almost certainly increase feed efficiency,the correlation between dietary energy concentration and feed efficiency is surprisingly low.This is likely due to the plethora of non-dietary factors that impact feed efficiency,such as the environment and health as well as individual variation in maintenance requirements,body composition and body weight.Nonetheless,a deeper understanding of feed efficiency is critical at many levels.To individual farms,it impacts profitability.To the pork industry,it represents its competitive position against other protein sources.To food economists,it means less demand on global feed resources.There are environmental and other societal implications as well.Interestingly,feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed.This review will explain why this arithmetic calculation,as simple as it initially seems,and as universally applied as it is in science and commerce,can often be misleading due to errors inherent in recording of both weight gain and feed intake.This review discusses the importance of feed efficiency,the manner in which it can be measured and reported,its basis in biology and approaches to its improvement.It concludes with a summary of findings and recommendations for future efforts.展开更多
Meeting the increasing demands for high-quality pork protein requires not only improved diets but also biotechnology-based breeding to generate swine with desired production traits.Biotechnology can be classified as t...Meeting the increasing demands for high-quality pork protein requires not only improved diets but also biotechnology-based breeding to generate swine with desired production traits.Biotechnology can be classified as the cloning of animals with identical genetic composition or genetic engineering(via recombinant DNA technology and gene editing)to produce genetically modified animals or microorganisms.Cloning helps to conserve species and breeds,particularly those with excellent biological and economical traits.Recombinant DNA technology combines genetic materials from multiple sources into single cells to generate proteins.Gene(genome)editing involves the deletion,insertion or silencing of genes to produce:(a)genetically modified pigs with important production traits;or(b)microorganisms without an ability to resist antimicrobial substances.Current gene-editing tools include the use of zinc finger nuclease(ZFN),transcription activator-like effector nuclease(TALEN),or clustered regularly interspaced short palindromic repeats-associated nuclease-9(CRISPR/Cas9)as editors.ZFN,TALEN,or CRISPR/Cas9 components are delivered into target cells through transfection(lipid-based agents,electroporation,nucleofection,or microinjection)or bacteriophages,depending on cell type and plasmid.Compared to the ZFN and TALEN,CRISPR/Cas9 offers greater ease of design and greater flexibility in genetic engineering,but has a higher frequency of off-target effects.To date,genetically modified pigs have been generated to express bovine growth hormone,bacterial phytase,fungal carbohydrases,plant and C.elagan fatty acid desaturases,and uncoupling protein-1;and to lack myostatin,α-1,3-galactosyltransferase,or CD163(a cellular receptor for the"blue ear disease"virus).Biotechnology holds promise in improving the efficiency of swine production and developing alternatives to antibiotics in the future.展开更多
Objective To study the audition and inner ear structure in a normal swine model.Methods Auditory brainstem responses(ABRs) were determined in swine at 1 day and 1 month after birth.The form of the cochlea and hair cel...Objective To study the audition and inner ear structure in a normal swine model.Methods Auditory brainstem responses(ABRs) were determined in swine at 1 day and 1 month after birth.The form of the cochlea and hair cells were examined under a scanning electron microscope and on cochlear slices.Results ABR thresholds at 1 day and 1 month post-birth were between 40 and 50 dB SPL.The latencies of waves I,III and V in 1 day old swine were 1.97 ± 0.13,3.01± 0.16 and 4.26±0.20 ms,respectively.At 1 month,the lantancies of waves I,III and V were 2.01 ± 0.05,3.11±0.08 and 4.65 ± 0.14 ms,respectively,slightly longer than those at 1 day,although not statistically significant(p>0.05).The swine cochlea was constituted of 3 and a half turns and the cochlear hair cells lined up in four rows.Hair cell cilia in the apical turn were longer than those in other turns.Conclusions The swine cochlea is mature at the time of birth.Swine ABR thresholds are slightly higher than humans and rats.Swine appears to be a precocial animal species.展开更多
BACKGROUND:Gastric lavage(GL)is one of the most critical early therapies for acute paraquat(PQ)poisoning;however,details of the treatment protocol remain to be established.METHODS:A rapid quantitative method involving...BACKGROUND:Gastric lavage(GL)is one of the most critical early therapies for acute paraquat(PQ)poisoning;however,details of the treatment protocol remain to be established.METHODS:A rapid quantitative method involving sodium dithionite testing was developed.It was validated for the determination of the PQ concentrations in gastric juice and eluate samples from a swine acute PQ poisoning model with early or delay GL,or without.The vital signs,laboratory testing,and PQ plasma concentrations were collected for therapeutic effect evaluation.RESULTS:The reaction conditions of the test were optimized for two types of samples.Early GL at one hour(H1)could improve the signs and symptoms after acute PQ poisoning at 24 hours(H24).In contrast,GL at 6 hours(H6)could only partially relieve the vital signs.The H1 GL group effectively reduced the peak of the plasma PQ concentration.In addition,the PQ concentrations in the plasma and the gastric juice were significantly decreased in both the GL groups as compared to the untreated group at H24.Moreover,there was no significant difference in the washing efficiencies calculated from the total eluates between the two GL groups.However,the washing efficiency of the first 10 L eluate is superior to that of the additional 10 L eluate.CONCLUSION:GL only at early stage may it benefit PQ poisoning in an animal model.The currently used 20 L GL volume may need to be reduced in view of the low washing efficiency in the later 10 L eluate.The rapid quantitative method can be used for gastric juice sample and has a certain value for clinical GL practices.展开更多
Background:The ongoing African swine fever virus(ASFv)epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority.It has been recent...Background:The ongoing African swine fever virus(ASFv)epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority.It has been recently identified that feed and feed ingredients,along with drinking water,can serve as transmission vehicles and might facilitate transboundary spread of ASFv.Thus,it is important to test the antiviral activity of regulatory compatible,antiviral feed additives that might inhibit ASFv infectivity in feed.One promising group of feed additive candidates includes medium-chain fatty acids(MCFA)and monoglyceride derivatives,which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria.Results:The antiviral activities of selected MCFA,namely caprylic,capric,and lauric acids,and a related monoglyceride,glycerol monolaurate(GML),to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments.Antiviral assays showed that all tested MCFA and GML inhibit ASFv.GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms.Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min,as determined by infectious viral titer measurements.Enzyme-linked immunosorbent assay(ELISA)experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein,which likely relates to protein conformational changes arising from viral membrane disruption.Conclusion:Together,the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed,which may help to curb disease transmission.展开更多
基金supported by Guangzhou Science and Technology Planning Project(2023A04J0131)Special fund for scientific innovation strategyconstruction of high level Academy of Agriculture Science(R2020PY-JG009,R2022PY-QY007,202106TD)+2 种基金China Agriculture Research System-CARS-35the Project of Swine Innovation Team in Guangdong Modern Agricultural Research System(2022KJ126)Special Fund for Rural Revitalization Strategy of Guangdong(2023TS-3),China。
文摘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.
基金supported by the National Key R&D Program of China(2019YFE0107300 and 2021YFD1800101)the Applied Technology Research and Development Project of Heilongjiang Province,China(GA19B301)the Central Public-interest Scientific Institution Basal Research Fund,China(1610302022003)。
文摘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.
基金supported by the National Natural Science Foundation of China (31872484) to Zhang Qianyithe Non-profit Key Program of Veterinary Drug Industry from China Institute of Veterinary Drug Control (GY202011) to Xia Yingju。
文摘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.
基金supported by the National Key R&D Program of China (2021 YF D1800101 and 2019YFE0107300)the Applied Technology Research and Development Project of Heilongjiang Province, China (GA19B301)the Central Public-Interest Scientific Institution Basal Research Fund, China (1610302022003)。
文摘Africanswinefever(ASF),causedbythe African swine fever virus (ASFV), is an acute, hemorrhagic, and contagious disease of domestic pigs and wild boars.The disease is notifiable and listed by the World Organization for Animal Health (WOAH)(Wang N et al. 2019).
文摘Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans.As a result,functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.Comparatively,large r,more clinically relevant models have not been as well studied.To achieve similar locomotor testing standardization in larger animals,the models must be accessible to a wide array of researchers.Non-human primates are the most relevant animal model fo r translational research,however ethical and financial barriers limit their accessibility.This review focuses on swine,sheep,and goats as large animal alternatives for transitional studies between rodents and non-human primates.The objective of this review is to compare motor testing and data collection methods used in swine,sheep,and goats to encourage testing standardization in these larger animal models.The PubMed database was analyzed by searching combinations of swine,sheep,and goats,neurologic injuries,and functional assessments.Findings were categorized by animal model,data collection method,and assessment design.Swine and sheep were used in the majority of the studies,while only two studies were found using goats.The functional assessments included open pen analysis,treadmill walking,and guided free walking.Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software.Overall,swine and sheep were well-suited for a variety of assessment designs,with treadmill walking and guided free walking offering the most consistency across multiple trials.Data collection methods varied,but image-based gait analysis software provided the most robust analysis.Future studies should be conducted to standardize functional testing methods after neurologic impairment in large animals.
基金supported by the National Key Research and Development Program of China (2021YFC2600305 and 2021YFD1801405)。
文摘African swine fever(ASF) was first discovered and reported in East Africa in 1921 and it has been listed as a notifiable animal disease by the World Organization for Animal Health(WOAH) due to the high morbidity and mortality(WOAH 2019). African swine fever virus(ASFV) can persist in pig farm environments, carcasses, and various pig products(Petrini et al. 2019). ASF has caused significant economic losses to the pig industry since its outbreak in China in 2018(Zhao et al. 2019).
基金supported by the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(10-IAED-RC-06-2022)。
文摘This paper aims to optimize the culling compensation policy from a micro perspective through scenario simulation.Based on an investigation of 273 pig farms in eight regions,four typical pig farms were constructed according to farm size and breeding mode,representing the swine producers in China.Besides,a decision objective function of pig farms facing suspected African swine fever(ASF)outbreaks was constructed.This study used a mathematical programming model to design and simulate scenarios based on compensation standards and local implementation levels,aiming to incentivize pig farms to report epidemics.The results show that the optimal decisions on epidemic reports differed among typical farms and by herd daily age.The results suggest the following adjustments for optimizing culling compensation policies:(1)to set culling compensation standards based on the market value and(2)to maintain a high level of epidemic surveillance capability in the animal husbandry and veterinary sector.
文摘Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluating intramuscular fat in live animals. Together with other genetic improvement tools, ultrasound technology will offer seedstock producers the opportunity to select for improved IMF in potential breeding stock replacements and hence speed genetic progress for the improvement of this trait. After three generations of selection for IMF using real-time ultrasound in an Iowa State University study, the average EBV for select line pigs is 0.83% greater than for control line pigs. Selection for IMF has, however, resulted in slightly more backfat and less loin muscle area, and a trend toward more days to 114 kg in the select line compared to the control line. Carcass evaluation of a sample of pigs from each litter indicated a similar increase in IMF, increase in backfat, and reduction in loin muscle area for select line pigs. No differences were found for Hunter L* color, Minolta reflectance, and ultimate pH.
文摘Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance,lean gain and lipid accretion.It is closely linked with energy metabolism,as the oxidation of carbon-containing components in the feed drive all metabolic processes.While much is known about nutrient utilization and tissue metabolism,blending these subjects into a discussion on feed efficiency has proven to be difficult.For example,while increasing dietary energy concentration will almost certainly increase feed efficiency,the correlation between dietary energy concentration and feed efficiency is surprisingly low.This is likely due to the plethora of non-dietary factors that impact feed efficiency,such as the environment and health as well as individual variation in maintenance requirements,body composition and body weight.Nonetheless,a deeper understanding of feed efficiency is critical at many levels.To individual farms,it impacts profitability.To the pork industry,it represents its competitive position against other protein sources.To food economists,it means less demand on global feed resources.There are environmental and other societal implications as well.Interestingly,feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed.This review will explain why this arithmetic calculation,as simple as it initially seems,and as universally applied as it is in science and commerce,can often be misleading due to errors inherent in recording of both weight gain and feed intake.This review discusses the importance of feed efficiency,the manner in which it can be measured and reported,its basis in biology and approaches to its improvement.It concludes with a summary of findings and recommendations for future efforts.
基金supported by Agriculture and Food Research Initiative Competitive Grants(2014–67015-21770,2015–67015-23276,2016–67015-24958,and 2018–505706-95720)from the USDA National Institute of Food and Agriculture,and Texas A&M Agri Life Research(H-8200)
文摘Meeting the increasing demands for high-quality pork protein requires not only improved diets but also biotechnology-based breeding to generate swine with desired production traits.Biotechnology can be classified as the cloning of animals with identical genetic composition or genetic engineering(via recombinant DNA technology and gene editing)to produce genetically modified animals or microorganisms.Cloning helps to conserve species and breeds,particularly those with excellent biological and economical traits.Recombinant DNA technology combines genetic materials from multiple sources into single cells to generate proteins.Gene(genome)editing involves the deletion,insertion or silencing of genes to produce:(a)genetically modified pigs with important production traits;or(b)microorganisms without an ability to resist antimicrobial substances.Current gene-editing tools include the use of zinc finger nuclease(ZFN),transcription activator-like effector nuclease(TALEN),or clustered regularly interspaced short palindromic repeats-associated nuclease-9(CRISPR/Cas9)as editors.ZFN,TALEN,or CRISPR/Cas9 components are delivered into target cells through transfection(lipid-based agents,electroporation,nucleofection,or microinjection)or bacteriophages,depending on cell type and plasmid.Compared to the ZFN and TALEN,CRISPR/Cas9 offers greater ease of design and greater flexibility in genetic engineering,but has a higher frequency of off-target effects.To date,genetically modified pigs have been generated to express bovine growth hormone,bacterial phytase,fungal carbohydrases,plant and C.elagan fatty acid desaturases,and uncoupling protein-1;and to lack myostatin,α-1,3-galactosyltransferase,or CD163(a cellular receptor for the"blue ear disease"virus).Biotechnology holds promise in improving the efficiency of swine production and developing alternatives to antibiotics in the future.
基金supported by a Natural Science Foundation of China(NSFC) grant to 863: 2007AA02Z150 general program Natioual natural scienle foundation of China:30871398Key proiects in the national science & technology pillar program during me elevench five year plan period:2008BAI50B08,key profram of Natural Scievne foundation of China:30730040
文摘Objective To study the audition and inner ear structure in a normal swine model.Methods Auditory brainstem responses(ABRs) were determined in swine at 1 day and 1 month after birth.The form of the cochlea and hair cells were examined under a scanning electron microscope and on cochlear slices.Results ABR thresholds at 1 day and 1 month post-birth were between 40 and 50 dB SPL.The latencies of waves I,III and V in 1 day old swine were 1.97 ± 0.13,3.01± 0.16 and 4.26±0.20 ms,respectively.At 1 month,the lantancies of waves I,III and V were 2.01 ± 0.05,3.11±0.08 and 4.65 ± 0.14 ms,respectively,slightly longer than those at 1 day,although not statistically significant(p>0.05).The swine cochlea was constituted of 3 and a half turns and the cochlear hair cells lined up in four rows.Hair cell cilia in the apical turn were longer than those in other turns.Conclusions The swine cochlea is mature at the time of birth.Swine ABR thresholds are slightly higher than humans and rats.Swine appears to be a precocial animal species.
基金Natural Science Found of Jiangsu Province(BK20171500,16KJB320003)Program for Key disease of Jiangsu Province Science and Technology Department(BL2014088)+1 种基金Program for Innovative Medical Research Team of Jiangsu Province(CXTDA2017007)Jiangsu Province’s key provincial talents program(QNRC2016597).
文摘BACKGROUND:Gastric lavage(GL)is one of the most critical early therapies for acute paraquat(PQ)poisoning;however,details of the treatment protocol remain to be established.METHODS:A rapid quantitative method involving sodium dithionite testing was developed.It was validated for the determination of the PQ concentrations in gastric juice and eluate samples from a swine acute PQ poisoning model with early or delay GL,or without.The vital signs,laboratory testing,and PQ plasma concentrations were collected for therapeutic effect evaluation.RESULTS:The reaction conditions of the test were optimized for two types of samples.Early GL at one hour(H1)could improve the signs and symptoms after acute PQ poisoning at 24 hours(H24).In contrast,GL at 6 hours(H6)could only partially relieve the vital signs.The H1 GL group effectively reduced the peak of the plasma PQ concentration.In addition,the PQ concentrations in the plasma and the gastric juice were significantly decreased in both the GL groups as compared to the untreated group at H24.Moreover,there was no significant difference in the washing efficiencies calculated from the total eluates between the two GL groups.However,the washing efficiency of the first 10 L eluate is superior to that of the additional 10 L eluate.CONCLUSION:GL only at early stage may it benefit PQ poisoning in an animal model.The currently used 20 L GL volume may need to be reduced in view of the low washing efficiency in the later 10 L eluate.The rapid quantitative method can be used for gastric juice sample and has a certain value for clinical GL practices.
基金Natural Biologics Inc.provided funding to conduct the experiments in this study.J.A.J.acknowledges additional funding support from the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2020R1C1C1004385).
文摘Background:The ongoing African swine fever virus(ASFv)epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority.It has been recently identified that feed and feed ingredients,along with drinking water,can serve as transmission vehicles and might facilitate transboundary spread of ASFv.Thus,it is important to test the antiviral activity of regulatory compatible,antiviral feed additives that might inhibit ASFv infectivity in feed.One promising group of feed additive candidates includes medium-chain fatty acids(MCFA)and monoglyceride derivatives,which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria.Results:The antiviral activities of selected MCFA,namely caprylic,capric,and lauric acids,and a related monoglyceride,glycerol monolaurate(GML),to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments.Antiviral assays showed that all tested MCFA and GML inhibit ASFv.GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms.Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min,as determined by infectious viral titer measurements.Enzyme-linked immunosorbent assay(ELISA)experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein,which likely relates to protein conformational changes arising from viral membrane disruption.Conclusion:Together,the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed,which may help to curb disease transmission.
