Assessment of immunization procedures for foot-and-mouth disease in large-scale pig farms in China based on actual data and dynamics

Foot-and-mouth disease(FMD)is an acute,highly infectious and pathogenic animal disease.In recent years,with the rapid development of the swine breeding industry in China,pig farms have shown a trend of larger-scale development.Large-scale pig farms employ standardized management,a high level of automation,and a strict_system.However,these farms have a large trading volume,and increased transmission intensity of FMD is noted inside the farm.At present,the main control measure against FMD is pig vaccination.However,a standard for immunization procedures is not available,and currently adopted immunization procedures have not been effectively and systematically evaluated.Taking a typical large-scale pig farm in China as the research subject and considering the breeding pattern,piggery structure,age structure and immunization procedures,an individual-based state probability model is established to evaluate the effectiveness of the immune procedure.Based on numerical simulation,it is concluded that the optimal immunization program involves primary immunization at 40 days of age and secondary immunization at 80 days of age for commercial pigs.Breeding boars and breeding sows are immunized 4 times a year,and reserve pigs are immunized at 169 and 259 days of age.According to the theoretical analysis,the average control reproduction number of individuals under the optimal immunization procedure in the farm is 0.4927.In the absence of immunization,the average is 1.7498,indicating that the epidemic cannot be controlled without immunization procedures.

An Industrial Internet Platform for Massive Pig Farming (IIP4MPF)

Pig farming is becoming a key industry of China’s rural economy in recent years. The current pig farming is still relatively manual, lack of latest Information and Communication Technology (ICT) and scientific management methods. This paper proposes an industrial internet platform for massive pig farming, namely, IIP4MPF, which aims to leverage intelligent pig breeding, production rate and labor productivity with the use of artificial intelligence, the Internet of Things, and big data intelligence. We conducted requirement analysis for IIP4MPF using software engineering methods, designed the IIP4MPF system for an integrated solution to digital, interconnected, intelligent pig farming. The practice demonstrates that the IIP4MPF platform significantly improves pig farming industry in pig breeding and productivity.

Recycling of the Waste from Large-scale Pig Farms

The management mode, economic benefits and technology integration of large-scale pig breeding are superior to those of traditional pig breeding by scattered peasant households, and it has a significant agglomeration effect. However, the waste from large-scale pig farms are discharged in a concentrated manner, which aggravates environmental pollution and increases treatment difficulty, and improper disposal can lead to serious environmental problems. The main pollutants in the waste from large-scale pig farms are high-concentration organic pollutants, nitrogen and phosphorus. Meanwhile, they are also the main nutrients needed for the growth of plants, animals and microorganisms. By a series of key techniques, the waste from large-scale pig farms can be recycled as fertilizer, feed and energy.

Research on Influence Factors of Pig Farmers' Ecological Farming Behavior: Based on the TPB and SEM

China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.

Occurrence of antibiotics in typical pig farming and its wastewater treatment in Thailand

This study investigated antibiotics in pig feed and drinking water and their excretion together with manure and wastewater at a typical pig farm in Thailand.Among the 21 antibiotics analyzed,tetracyclines,macrolides,b-lactams,aminoglycosides,quinolones,sulfonamides,pleuromutilin,and florfenicol classes,were found as active ingredients in feed and drinking water and excreted together with pig wastes.Among them,doxycycline,tilmicosin,and amoxicillin were detected higher concentrations in wastewater(12.9e459.1 mg L^(-1)),sediment(0.074e0.62 mg kg^(-1)),and pig manure(0.45e4.1 mg kg^(-1)).During wastewater treatment,those major antibiotics were remaining in pond water and settled sludge up to 79.5 mg L-1 and 24.2 mg kg^(-1),respectively.The normalized excretion mass of total antibiotics was determined as 11.2 mg head-1 day-1,contributed mainly from doxycycline(5.9 mg head-1 day-1),tilmicosin(2.8 mg head-1 day-1),and amoxicillin(2.2 mg head-1 day-1).Based on total pig production in Thailand,the excreted mass of antibiotics was estimated at 79.3 tons year-1.

Aerial pollutants on a pig farm in peri-urban Beijing,China

The study was carried out to evaluate the airborne gases and suspended particulate matter concentrations in the pig barns of a commercial pig farm situated in the peri-urban area of Beijing,China.The measurements followed the natural pig life-stages namely:gestation,farrowing,weaning,and fattening.In order to accomplish these objectives,three different measurement devices were employed:(i)color diffusion tubes,(ii)a portable gas measuring device,and(iii)a dust measuring instrument.Due to the rotation of the devices in the different sampling places,the measurements were performed at different time periods during the months of the summer and winter season in Beijing.The pig farm had a capacity of 15000 pigs per year and the manurial system was identified as“gan qing fen”or dry cleaning of the manure.The main by-products generated by the farm were irrigation water and small-scale biogas production.High dust concentrations were identified in the pig barns,especially during the feeding and manure cleaning events inside the farrowing and weaning barns with slatted floors.Inhalable dust ranged from 0 mg/m3 to 12.45 mg/m3,while the allowable dust ranged from 0 mg/m3 to 9.62 mg/m3.Ammonia concentration ranged from 0 ppm to 20 ppm(1 ppm=1 cm3/m3),and the carbon dioxide concentration ranged from 300 ppm to 8000 ppm.The highest ammonia concentration was recorded in the fattening barn during the summer season,while the highest carbon dioxide concentration was reported in the weaning barn during the summer season.The results of this study were similar to the results of studies performed on pig farms under natural and mechanical ventilation systems.On the other hand,the problems encountered during the gas measurements on the pig farm were directly related to the inadequate housing layout due to the obstruction of windows,fans and air channels for indoor ventilation,and thus the measurement devices faced harsh working conditions.Therefore,it is recommended that the housing system should be improved with repaired windows and curtains especially for the winter season;similarly,the repair of the fans should be attempted in order to improve the ventilation,especially in the gestation barns.

Potential regulation of small RNAs on bacterial function activities in pig farm wastewater treatment plants

Small RNAs(sRNAs)are key players in the regulation of bacterial gene expression.However,the distribution and regulatory functions of sRNA in pig farm wastewater treatment plants(WWTPs)remains unknown.In this study,the wastewaters in anoxic and oxic tanks of the WWTPs were collected.The profiles of the community structure,mRNA expression,and sRNA expression of bacteria in pig farm wastewater were investigated using transcriptome sequencing and qPCR.This study demonstrated that there was a higher abundance of sRNA in the pig farm WWTPs and 52 sRNAs were detected.The sRNAs were mainly present in Proteobacteria and Firmicutes,including the potential human pathogenic bacteria(HPB)(Escherichia,Shigella,Bordetella and Morganella),crop pathogen(Pectobacterium)and denitrifying bacteria(Zobellella).And the sRNAs were involved in the bacterial functional activities such as translation,transcription,drug resistance,membrane transport and amino acid metabolism.In addition,most sRNAs had a higher abundance in anoxic tanks which contained a higher abundance of the genes associated with infectious diseases and drug resistance than that in oxic tanks.The results presented here show that in pig farm WWTPs,sRNA played an important role in bacterial function activities,especially the infectious diseases,drug resistance and denitrification,which can provide a new point of penetration for improving the pig farm WWTPs.

Farm-Scale Applicability of Three Covers (Peat, Polystyrene Balls and Synthetic Sheet Roof) to Reduce Ammonia Emissions from Pig Slurry Storage

Covering the slurry pit has been shown to be one of the best ways to reduce ammonia emissions (NH3) during manure management. Yet, few studies have been conducted at farm scale. We studied the feasibility of three cover materials (peat, polystyrene balls and synthetic sheet roof) to reduce ammonia (NH3) emissions during on-farm storage of pig slurry. The impact on greenhouse gas emissions, methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) of covering the slurry pit was also evaluated. Simultaneous field experiments were carried out using two similar pits at a farm with peat and polystyrene ball covers, which allowed direct comparison of the feasibility of the two covers to reduce gas emissions (measured using the dynamic chamber technique). Emissions from the third option (using a synthetic sheet roof) were estimated by measuring the concentrations in the headspace under the cover and the air leakage from the cover with a tracer gas (CO2). Results showed that the polystyrene balls cover reduced emissions of NH3 during storage by up to 80% whatever the season, but increased potential greenhouse gas emissions by 20% in summer. No consistent reduction was achieved with the peat cover even though some individual results seemed to indicate up to 25% reduction in ammonia emissions;moreover, there was a 30% increase in CH4 and CO2 emissions during the storage period. The use of a synthetic sheet roof enabled up to 90% reduction in NH3, CH4 and CO2 emissions whatever the season.

减少猪场臭气生成的饲粮配制技术与养殖技术研究进展

随着养殖规模和集约化程度的不断提高,养殖场产生的臭气严重危害人畜健康和周边生态环境,臭气污染问题备受关注。解决猪场臭气污染的重要途径之一是减少臭气物质产生,而改进饲粮技术和养殖技术是减少猪场臭气物质生成的关键技术措施。本文综述了猪场臭气组成及产生途径、猪场中关键致臭物质及筛选方法、有效减少臭气生成的饲粮技术和养殖技术,旨在为加强猪场臭气方面的基础研究及减排技术的推广提供参考,进一步推进养猪业的高质量发展。

关于我国种猪场猪肺炎支原体净化的思考

猪肺炎支原体是一种对生猪影响较大的细菌性病原体,往往可引起猪群发生慢性感染,且难以从猪群和猪场水平上清除,导致养猪业遭受巨大的经济损失。猪肺炎支原体净化在欧洲和北美已全面启动,且有成功案例,我国才刚刚启动。本文结合国外猪肺炎支原体净化方案的经验与我国生猪养殖特殊性的分析,提出分群体、分阶段的“三步法”净化建议,并对我国猪肺炎支原体的净化提出了展望。

规模化猪场粪污处理利用现状及案例分析

规模化猪场在养殖过程中会产生大量的粪污,如果不加以妥善处理与利用,将对环境和公共健康造成严重威胁。粪污处理与资源化利用成为实现养猪业可持续发展的关键环节。本文探讨了规模化猪场粪污的危害,介绍了规模化猪场粪污集中收集系统及目前规模化猪场在猪舍粪污处理中使用的尿泡粪和机械清粪2种清粪工艺,并详细讨论了生物发酵、厌氧消化、好氧处理等多种方法对固体粪污和液体污水的处理技术,以满足不同规模化养猪场的清粪需求。同时,探讨了规模化猪场种养结合生态循环利用和工业化深度处理2种主要的粪污处理利用模式。展望了未来科技创新对粪污处理与利用的推动作用,呼吁各方共同努力,以实现养猪企业的可持续发展、保障环境和人类健康的计划。本文为规模化养猪场选择粪污处理技术和利用模式提供了有益的参考,有助于环境保护和养猪业可持续发展。

藻菌共生体处理猪场沼液的参数优化研究

猪场沼液高色高浊、氮磷浓度高,采用藻菌共生体可同步高效去除碳氮磷、节能降耗、资源回收,符合新时代对污水处理的需求。从污染物去除、微生物生长等角度对光照强度、曝气量和藻菌接种比例这3个参数进行优选发现,曝气量对氮去除的影响最大,而3个参数对碳、磷去除的影响较小。经加权评价得出三因素排序:曝气量>光照强度>藻菌接种比例,最优参数组合:光照强度为550μmol/(m^(2)·s),曝气量为0.2 L/min,藻菌接种比例为1∶1。最优组的TP、COD、TN、NH_(4)^(+)-N分别为0.48、219.2、125.2、64 mg/L,TP、COD、TN、NH_(4)^(+)-N去除率分别为95.46%、88.58%、61.58%、80.21%。各组中藻菌絮体粒径均呈增大趋势,且随藻菌接种比例的增大而减小。

计算机视觉技术在规模化猪场应用的研究进展

作为人工智能的一个主要分支,计算机视觉技术在许多领域取得了很大的成就,其在规模化猪场中的应用将为猪场带来产业性的变革。计算机视觉技术可以大幅度减少规模化猪场中人员工作量,同时使猪场对生猪的相关判断更加准确。本文简述了规模化猪场的现状和计算机视觉技术,重点综述了计算机视觉技术在规模化猪场中对猪只的行为监测、疾病预测、情感状态分析、猪只判别、生产管理、生物安全和防疫以及企业的落地探索等方面的研究进展,以期为促进我国规模化猪场的现代化和智能化发展提供参考。

一例规模化猪场流行性腹泻病的诊断与防控风险分析

2022年2月4日,广西壮族自治区某规模化猪场妊娠母猪陆续出现水样腹泻、不吃或少吃料的临床症状,2022年2月6日,产房仔猪出现呕吐、水样腹泻,怕冷扎堆,脱水严重,且传播速度快。通过试剂盒快速检测和实验室检测,诊断为猪流行性腹泻病。针对检测结果对猪群进行紧急疫苗接种和药物治疗,并对此次疫情的发生和发展过程进行防控风险点分析,发现养猪场在生物安全方面存在较大的风险点,通过整改并采取严格的生物安全管理措施后,母猪群发病情况得到缓解,仔猪腹泻窝数下降,猪群趋于稳定,生产成绩逐步恢复。通过对此次案例的分析探讨,为规模化猪场对猪流行性腹泻病的发现和防控提供临床经验,同时增强对流行性腹泻病的风险预警意识,健全规模化猪场对流行性腹泻病的风险预警机制。

Driving factors of direct greenhouse gas emissions from China's pig industry from 1976 to 2016

Livestock cultivation is a significant source of greenhouse gas(GHG) emissions, accounting for 14.5% of the total anthropogenic emissions. China is responsible for a considerable share of the global livestock emissions, particularly caused by pork production. We used the Kaya identity and the logarithmic mean Divisia index(LMDI) to decompose the national annual GHG emissions from enteric fermentation and manure management in pig farming in China from 1976 to 2016. We decomposed the sources of the emissions into five driving factors:(1) technological progress(e.g., feed improvement);(2) structural adjustment in the livestock sector;(3) structural adjustment in agriculture;(4) affluence;and(5) population growth. The results showed that the net GHG emissions from the pig sector in China increased 16 million tons(Mt) of carbon dioxide equivalents(CO2 eq) during the study period. The decomposition analysis revealed that structural adjustment in agriculture, growing affluence, and population growth contributed to an increase of the GHG emissions of pork production by 23, 41, and 13 Mt CO2 eq, respectively. The technological progress and structural changes in animal husbandry mitigated emissions by –51 and –11 Mt CO2 eq, respectively. Further technological progress in pig production and optimizing the economic structures are critical for further reducing GHG emissions in China's pig industry. Our results highlight the dominant role of technological changes for emission reductions in the pig farming.

猪场粪污机械分离设备及效率分析

在研究猪场粪污(包括猪粪和猪粪厌氧消化液)理化特性的基础上,分析了常用的机械式猪场粪污分离设备的工作原理、结构特征、分离效率及优缺点等。筛网式分离机固定投资和运行费用低,但固体去除率较低且分离后的固体含水率较高,适用于猪场粪污的前处理;压滤式分离机结构简单、处理量大,分离后固体含水率低,但对猪场粪污进料浓度要求较高;沉降式离心机分离效率较高,对猪场粪污进料浓度适应性强,但其设备投资和能耗较高,在中小规模猪场难以推广。组合式机械分离方法可以有效提升固体去除率,降低分离后沼液的含固率。

猪场沼液还田对土壤和植物重金属含量的影响

还田消纳是猪场沼液资源化利用的主要方式。由于沼液中含有多种金属元素,过量浇灌会引发土壤重金属污染。目前,关于猪场沼液对耕地土壤和植物重金属污染特征的影响及其影响因子的研究还不够深入。在广西生猪养殖区,选取了4种不同耕地利用类型(叶菜类、果树类、饲草类、药草类)和14个样地,就不同沼液浇灌强度对土壤与植物重金属的影响规律及其影响因子进行研究。结果表明:在14个样地0~40 cm表层土壤中,重金属Cu、Zn、Cd的输入强度最大,且其含量和土壤pH变化和与沼液浇灌总量呈显著(p<0.05)正相关;在4种耕地类型中,杂交象草和空心菜的可食用部分Cu、Zn、Cd、Pb、Cr含量与沼液浇灌总量呈显著正相关;在沼液还田中,由于Cu、Zn的输入强度大,而植物对其的富集系数又较低,因此土壤中Cu、Zn积累较快;浇灌沼液对叶菜类和果树类的主要污染风险是Pb和Cd,而对杂交象草的污染风险较小。

围产期使用抗菌药物对PRRSV阳性猪场母猪和仔猪生产性能的影响

旨在评估围产期使用抗菌药物对猪繁殖与呼吸综合征病毒(PRRSV)阳性猪场母猪和仔猪生产性能的影响。从广西某规模化PRRSV阳性猪场挑选280头临产母猪随机分为5组,在其围产期分别用替米考星、泰妙菌素、多西环素和泰万菌素等兽医常用抗生素,对照组不使用抗菌药物。采集各组断奶仔猪前腔静脉血进行PRRSV核酸和抗体检测,以评估各药物对防控仔猪PRRSV感染的效果;统计各组断奶仔猪腹泻窝数及比率,以探究常用抗生素对仔猪腹泻的防控效果;统计各组断奶母猪的断配间隔及断奶7、10 d内发情配种率,统计各组仔猪的窝均断奶数、断奶存活率和断奶重等生产指标,以评估围产期常用抗生素使用对母猪和仔猪生产性能的影响并计算使用药物所带来的经济效益。结果表明:泰万菌素、替米考星组断奶仔猪PRRSV核酸阳性检出率为0%,且PRRSV抗体水平显著高于对照组;泰万菌素组仔猪的腹泻率低于其它用药组及对照组;相关生产指标统计显示,与其他组相比,泰万菌素组仔猪断奶存活率及断奶均重最高,母猪的断配间隔最短,窝均损失资产更低。综上,本研究评估了围产期使用兽医临床常用抗生素对PRRSV阳性猪场母猪和仔猪生产性能的影响,发现使用泰万菌素可以有效阻断PRRSV垂直传播,提升仔猪抗体水平,显著改善断奶仔猪腹泻率;使用泰万菌素显著提升了仔猪断奶存活率及断奶均重,缩短了母猪的断配间隔,降低了窝均损失资产。本研究的开展为规模化PRRSV阳性猪场的有效药物使用提供了重要试验数据和理论支持,为在PRRSV大流行背景下实现规模化猪场降本增效提供了必要的补充措施。