Detection and Characterization of Hepatitis E Virus in Domestic Pigs of Different Ages in Portugal

This study represents the primary hepatitis E virus (HEV) surveillance in domestic pigs in Portugal, five pig farms were investigated in 5 different Portuguese regions, ten faecal samples were collected at four different stages of the production. All faecal samples were tested for hepatitis E virus by real-time RT-PCR. At least one sample from each farms of all age groups tested positive for HEV. The prevalence in the pig herds varied from 10% to 30% and the mean prevalence was 32% in weaners, 20% in growers, 32% in fatteners and 4% in adult dry sows. Phylogenetic analysis of the detected HEV sequences indicated that the circulating virus strains belong under the genotype 3.     

浅析现代猪场不同猪群的饲养管理技术

对现代养猪场来说,后备母猪的健康水平是提高母猪生产力和使用寿命的保证;妊娠母猪的健康水平则直接关系到所产仔猪的健康水平和发育情况;哺乳母猪摄入的营养不仅要维持自身的生产需要还要满足哺育仔猪的需要;仔猪是现代养猪生产的基础,很大程度上关系到规模养殖场的经济效益.通过分析现代规模化养猪场特点,指出后备母猪、妊娠母猪、哺乳母...     

The 1997-1998 classical swine fever epidemic in The Netherlands--a survival analysis

The aim of this analysis was to characterise the temporal pattern of infection during the 1997/98 classical swine fever (CSF) epidemic in The Netherlands and hence identify and quantify risk factors for infection in different enterprise types and areas. Survival analysis and Cox proportional hazards regression were used to describe the epidemic. Substantial differences in temporal survival patterns (herd breakdown rate) were found between areas where different control policies operated. Factors with a significant influence on the infection hazard of individual herds included: sow numbers as a percentage of total sows and fatteners (HR = 3.38 for mixed herds (0.1–60% sows) vs. fattening herds (0% sows) and HR = 2.74 for breeding herds (60–100% sows) vs. fattening herds), the number of ‘transport contacts per month’ (>0.3 vs. <0.3; HR = 4.11), pig density (pigs/km²) in the area (HR_{1000 pigs} 1.48) and herd size (HR_{100 pigs} = 1.01).

Pre-emptive slaughter in an area appeared to be associated with lower subsequent disease levels. Higher frequency of transport contacts for welfare slaughter during the epidemic, however, well regulated and controlled, was associated with a substantially higher risk of becoming infected. The positive association of a higher pig density with CSF indicates the potential importance of local spread as a factor in disease transmission and emphasizes that dilution of the pig population can contribute to reduction in CSF occurrence. This analysis suggests however, that if pre-emptive slaughter can promptly be applied effectively in an area after initial diagnosis, pig density is then not a significant factor. Mixed and breeding herds had a higher probability of becoming infected than fattening herds, possibly due to different types and frequencies of inter-herd contacts. These contacts continue to some extent during the epidemic, despite the standstill of animal movements.     

Field experiments to evaluate the feasibility of eradication of Aujeszky's disease virus by different vaccination schedules.

In the present report, the extent of the reduction in Aujeszky's disease virus (ADV) dissemination achieved when pigs were intensively vaccinated with gI-deleted vaccines under field circumstances, was examined. On widely dispersed breeding-fattening farms, a gI-negative status was most rapidly obtained and the rate of new waves of infections was lowest when the attenuated Bartha strain was administered to both the sows and the fatteners. It was more difficult not only to reach but also to keep a gI-negative status on farms on which the sows were vaccinated with an inactivated vaccine and the fatteners with the attenuated Bartha strain or when the fattening pigs were not vaccinated at all. In a densely populated area, 9 of the 17 farms had gI-positive fatteners at the start of the intensive vaccination programme in which the attenuated Bartha strain was given to both the sows and the fatteners. Antibodies were not detected in the sera of the fatteners of each farm at some time during the experiments, but the fatteners on 7 of the 18 farms still showed antibodies against gI after 20 months of vaccination. At the end of the experiment, the percentage of fatteners with antibodies on these farms was markedly reduced compared with the percentage at the start of the experiment. Therefore, elimination of field virus may be feasible if intensive vaccination is carried out over a sufficiently long period of time. However, the high rate of reinfections experienced either due to reintroduction of the virus or to recrudescence should be a warning against too much optimism, particularly in regions with a dense swine population.     

Farm-level factors associated with above-average production on pig farms in Evia, Greece

The aim of this study was to identify farm-level factors associated with above-average production of pig farms in Evia, Greece. Cross-sectional data on pig farm characteristics and management, farmer characteristics, worming practices, anthelmintics used, and the parasite loads of 10 randomly selected boars, sows, weaners, and fatteners were collected from 28 pig enterprises in the Evian region of Greece (74% of the total number of pig enterprises in this region). Above-average productivity was defined as weaning 18 or more piglets per sow per year. A multivariate logistic regression model found that employing immigrant workers reduced the odds of a farm being an above-average producer (OR 0.016, 95% CI 0.001–0.27), while having a veterinarian select the anthelmintic strategy significantly increased the odds of a farm being an above-average producer (OR 10.24, 95% CI 0.78–135.13). None of the gastrointestinal parasites under investigation were significantly associated with above-average productivity. It is concluded that despite the fact that endoparasite load was not significantly associated with above-average production, a quantification of the impact of intestinal worms on pig productivity is needed to know how much control can be envisaged for gastrointestinal worms before reaching the threshold at which it is no longer physically or financially reasonable to continue pursuing control.     

母猪饲养管理与疾病预防

生猪养殖场的主要经济效益来源于母猪的生产力,如何挖掘母猪的生产潜力,做好母猪全阶段的饲养管理,是每个生猪养殖场需要解决的问题。该文主要论述后备母猪、妊娠母猪、哺乳母猪及空怀母猪的饲养管理要点及疾病的预防措施。     

Manure as a key resource within smallholder farming systems: Analysing farm-scale nutrient cycling efficiencies with the NUANCES framework

Smallholder farmers in Africa recognise the important role of manure in maintaining soil fertility. For smallholder farmers who use little fertiliser, efficient management of nutrients in manure is key for crop production. We describe a simple model to analyse the effect of manure management on the efficiency of mass and nutrient retention. We used on-farm data on manure excreted and manure management, experimental results, literature and fuzzy logic to model losses during manure storage. The model was used to analyse N cycling efficiency (NCE) within smallholder farms in western Kenya. Simulations showed that manure management during collection and storage had a large effect on the efficiency of C and nutrient retention. Differences in NCE between farmers of different wealth classes arose due to differences in resource endowment. For poorer farmers, large N losses occur at all stages of manure recycling. Urinary-N losses occurred on all farms but their impact on NCE for poor and medium-class farmers was larger due to the smaller amount of N recycled. With current management the poor farmer recovered < 1 kg N y^− 1 in composted manure from 15 kg N y^− 1 excreted. Improved manure storage had little effect on increasing overall NCE for the poor farmer due to large losses before storage. For the wealthier farmer improvement of manure storage increased NCE and allowed recycling of 30% of N excreted (ca. 30 kg N y^− 1) with small investment in infrastructure. Covering manure heaps with a polythene film reduced mass and N losses considerably. For the poor to increase overall NCE, investment in cattle housing and recycling of urinary-N is required. Increasing cattle numbers or improved feeding would have a larger effect on manure availability but this is constrained by feed scarcity and investment capacity. The absolute amounts of N recycled (1–6, 4–17 and 7–18 kg N y^− 1 for poor, medium and wealthier farmers) were small compared with maize N demand (> 50 kg N ha^− 1), but significant given the small farm sizes (0.1–1.1 ha). Although absolute amounts of N recycled with improved manure management may have little immediate impact on crop productivity, manure is often the only input available. Manure provides other nutrients for crops and maintains soil organic matter — both vital to guarantee efficient use of fertiliser N — which justifies the search for interventions to assist farmers make better use of manure.     

二元回交母猪的饲养管理策略

非洲猪瘟疫情发生后,母猪种源急剧减少,很多猪场将三元母猪作为种用,生猪产能得到恢复,但三元母猪留作种用的生产效率与二元母猪相比低20％左右.随着非洲猪瘟疫情常态化,猪场加强了生物安全体系建设,提升生产效率成为猪场的主要目标.二元回交母猪数量正在逐步上升,二元母猪取代生产性能差的三元母猪也将成为一种趋势.本文主要综述了二...     

Risk factors for stillbirth and foetal mummification in four Brazilian swine herds

The objective of this study was to identify the risk factors of stillbirth and foetal mummification in 565 farrowings of four commercial pig farms in Brazil. Stillborn piglets were observed in 31.3% of the litters and the stillborn risk was 5.6%. Mummified foetuses occurred in 42.1% of the litters and the mummification risk was 3.4%. The potential risk factors were included in multivariable logistic regression models as categories: herd (1–4); parity (1, 2–5 and >5); litter size (<10, 10–12 and >12 piglets); farrowing length (≤3 or >3 h); presence of mummified foetuses (yes or no); farrowing induction (yes or no); use of oxytocin (yes or no); use of vaginal palpation (yes or no); body condition score (<3, 3 and ≥4), and placental production index (PPI) (≤5 or >5) which was measured as the ratio of total foetal weight to total placental weight. Duration of farrowing and use of farrowing induction, oxytocin or vaginal palpation were not included in the model that investigated the risk factors of foetal mummification. Two models were used to investigate the risk factors of stillbirth, one with and the other without the inclusion of farrowing length. When compared to sows of parity 2–5, sows of parity >5 had 1.7- and 1.6-times higher odds (P < 0.05) for stillbirth in the models with and without the inclusion of farrowing length, respectively. In both models, sows with more than 12 piglets/litter had 3.6-times higher odds of stillbirth occurrence compared to sows with less than 10 piglets (P < 0.05). Sows with prolonged farrowing (>3 h) had 2.0-times higher odds of stillbirth occurrence than sows with short farrowing (P < 0.05). Sows with more than 12 piglets/litter had 14.5-times higher odds of mummification compared to sows with less than 10 piglets (P < 0.05). Sows of parities 1 and >5 had 3.5- and 2.0-times, respectively, higher odds of mummification in comparison to sows of parity 2–5 (P < 0.05). Sows with low PPI had 1.7-times higher odds of mummification compared to those with high PPI (P < 0.05). A large litter, a high-parity and a prolonged farrowing increased the risk of stillbirth. The probability of having a mummified foetus was increased in very young and older sows, when having a large litter and a litter with a less efficient placenta.     

Helminth infections in Danish organic swine herds

In nine organic swine herds, faecal excretion and pasture contamination by parasite eggs/larvae were studied in a period from March to October 1999. It was shown that the organic pigs were infected with Ascaris suum (28% of weaners, 33% of fatteners, 4% of sows), Trichuris suis (4% of weaners, 13% of fatteners, <1% of sows) and Oesophagostomum spp. (5% of weaners, 14% of fatteners, 20% of sows) whereas no infections with Hyostrongylus rubidus, Metastrongylus spp. or Strongyloides ransomi were detected. Moreover, no pigs showed clinical signs of infestations with scabies or lice. In the soil samples, very few Trichuris eggs were found throughout the season, whereas Ascaris eggs were found in 14% of the soil samples from sow pastures and in 35% from slaughter pig pastures, with the first infective eggs being recorded in July and the maximum number in August. Infective Oesophagostomum larvae were found in the grass samples in increasing numbers from May to October. Single herd cases of exceptionally high parasite infection levels are described in relation to herd management procedures.     

A swine integrator's perspective on nutrient management procedures

The goal of pork producers is to operate in a sustainable manner that includes among other requirements, environmental soundness, social acceptability, and profitability. Gains in efficiency have reduced nutrient by-products per pig, but competitive forces have led to specialization, larger farms, and concentrated areas of production that have resulted in new opportunities related to nutrient management. Available technology uses on-farm processing or storage facilities, and manure is applied to the land as an organic fertilizer. Knowledge of nutrient content of soils and crop uptake of nutrients is incorporated into manure application and crop removal plans to prevent either runoff or nutrient buildup on the land. This is to ensure water quality protection. Existing systems are adequate but lack flexibility, require effective management, may not have been incorporated into older farms, and do not offer obvious solutions to odor concerns. Cost-effective alternatives should address those needs. Advancement in nutrient management procedures will likely accelerate the ongoing changes in the structure of the swine industry.     

Characteristics of commercial pig farms in Great Britain and their use of antimicrobials

A mail survey of 1889 pig producers in Great Britain with more than 100 sows or more than 1000 pigs was carried out to investigate their use of antimicrobials and other health-related management practices. The response rate was 25.5 per cent. Antimicrobials were most commonly administered in feed. Depending on the production system, between 60 and 75 per cent of the farms had used antimicrobials in their weaner rations and 20 to 62 per cent had used them in their grower rations. Antimicrobial injections had been used on 59 per cent of the farms. The use of antimicrobials in pigs of different age groups was variously associated with the scale of production, membership of a quality assurance scheme, the use of vaccination and whether the farmer thought the farm environment could be improved. Half the respondents (49 per cent) indicated that they used growth promoters in their weaners, but fewer used these in their growers (45 per cent) and finishers (34 per cent). Although 63 per cent of the farmers felt that the continued use of antimicrobials for disease prevention was justified, only 21 per cent felt that their continued use as growth promoters was justified.     

Effectiveness of Cooperative Extension Manure Management Programs

Equine farms are increasing in number in many areas of the United States. Unlike traditional farming operations, equine farm managers may be less likely to use and are less connected to extension services. A manure management survey was mailed to 2000 New Jersey equine farms during the winter of 2006 to 2007; 472 surveys were returned (24% return rate). Respondents were asked from where they get manure management information; 27% received information from Rutgers Cooperative Extension, whereas 21% get information from a feed dealer, 6% from another retailer, 19% from the internet, 39% from magazines, 47% from other horse owners, and 25% from other sources. Veterinarians were not a variable in this survey; although they are a source of equine information, it is unclear how reliable a source they might be about manure management. They can play a role in manure management programs, particularly referral to other sources of information. Data were modeled to compare extension against all other sources and develop a prediction of where respondents receive information. This model had a predictive accuracy of 70.03% and R² of 0.08 (P > .10). This model showed that those receiving information from extension were likely to have 21 to 40 acres of pasture, were likely to spread manure on 6 to 10 acres, and likely to soil test regularly. Results indicate that cooperative extension was not the first or second information source for horse producers, although larger farms and those that soil tested on a regular basis were more likely to use extension services (P < .05).     

用生物经济模型对我国不同类型猪场的模拟研究——模型的构建和初步结果

根据我国当前养猪生产繁育体系,将我国集约化养猪生产概括为5类典型猪场,并利用农场模型的方法,构建了不同类型猪场的生物经济模型,并考虑了模型的生物学效率。模拟的600头母猪的商品猪场、猪苗场、杂种扩繁场、杜洛克育种场和长白（或大约克）育种场每年总利润分别为56.01、12.99、100.53、134.09和164.10万元,净能利用效率分别为27.69、32.98、28.25、28.32和28.48 MJ/kg。模型还输出了不同类型猪场的成本结构、收入组成和生产综合指标。对模型的敏感度分析表明,模型对不同市场形势、生产水平和管理措施变化的反应是灵敏的。     

关于三元母猪种用价值和改善措施的探讨

非洲猪瘟背景下,猪场面临两大难题,一是安全问题,二是种源问题。通过不断提升生物安全等级能够有效保障猪场安全,但种源问题却一时难以解决。在这种特殊背景下,部分猪场开始大胆创新的将三元母猪作为种源进行生产。但是,国内外关于三元母猪种用的资料文献几乎没有,无法形成有效的借鉴。一时之间,关于三元母猪究竟有没有种用价值和如何提高其种用价值成为养猪业的热门话题。文章从三元母猪种用价值、种用劣势和改善措施三个方面进行深入剖析和探讨,旨在为猪场了解和使用三元母猪提供参考。     

Worm control practices of pig farmers in Greece

Information concerning worm control practices of pig farmers in Greece was collected through a questionnaire survey by visiting farms and interviewing farmers. Questionnaires from 93 farmers were collected. The most commonly treated age groups of pigs were sows (87%), followed by fatteners (59%) and weaners (57%). Most of the farmers treated their sows twice per year (78%). The preferred method for calculating anthelmintic dosages was visual estimation (77%) of an average body weight (97%). Drug administration was by mixing anthelmintics with 1-day ration (97%) in two doses with an interval of 4-5 days (94%). The most commonly used group of anthelmintic was benzimidazoles and probenzimidazoles (37-46%), followed by avermectins (7-14%) and tetrahydropyrimidines (8-14%). Febantel was the most commonly used individual drug (34-40%), followed by ivermectin (7-14%) and pyrantel (9-14%). A small number of pig farmers used more than one group of anthelmintics (1-4%) or individual drug (2-6%) in the same year. The majority of the farmers (60%) used the same anthelmintic group for 3 or more years. When gilts/sows or boars were brought, 55% of the pig farmers did not treat with an anthelmintic. Most of the farmers evaluated the efficacy of an anthelmintic by inspecting the general appearance of the pigs or by inspecting for the presence of worms expelled in the faeces after treatment. Planning of the anthelmintic treatment strategy for most of the farms was the responsibility of veterinarians. However, most of the farmers considered the magnitude of worm infection in their own farm as insignificant.     

Individual and group antimicrobial usage rates on 34 farrow-to-finish swine farms in Ontario, Canada

Antimicrobial drug-use was assessed on 34 farrow-to-finish operations that marketed at least 500 hogs/yr. These operations either did not use any antimicrobials or used narrow-spectrum or broad-spectrum antimicrobials in rations of post-weaning pigs. Total antimicrobial use was measured for two months after obtaining inventories and records of all antimicrobials used. The collection of empty medication bottles and inventories of drugs on hand was convenient for producers and useful for estimating or validating recorded treatment rates, particularly for antimicrobials that were used only in one class of pig. Treatment records, however, underestimated by approximately 35% the amounts used for 27/29 farm–antimicrobial combinations. Rates of individual-pig treatment varied from 0–24.1 pigs treated/1000 pig-days, with a median of 5.29. Most individual animal treatments were given to piglets and sows at parturition and penicillin was the most commonly used antimicrobial. Gentamicin was administered to suckling piglets on 19 of the farms.     

Simulated financial losses of classical swine fever epidemics in the Finnish pig production sector

Rapid structural change and concentration of pig production in regions with most intensive production has raised concerns about whether the risk of large-scale disease losses has increased in Finland. This paper examines the pig industry's losses due to classical swine fever (CSF) epidemics. The work is based on economic and epidemiological models providing insights to the consequences of epidemics to infected and uninfected farms, government and meat processing. The economic analysis was carried out by use of a sector model, which simulated the recovery of pig production, starting from the recognition of the disease in the country and ending at a steady-state market equilibrium about 12 years later. The model explicitly took into account profit-maximising behaviour of producers and the effects of decrease in export demand.

Epidemiological evidence suggests that under the current spatially diversified structure of Finnish pig farming and related industries, the probability of a severe disease epidemic counting dozens of infected farms is small. Even for epidemics considered large in Finland (5–33 infected farms) combined with a major reduction in export demand, the median loss was simulated to be only €19.2 million. The majority of these losses were due to loss of exports corresponding almost 20% of pig meat production in Finland. While the current structure of pig farming in Finland incurs higher production costs than the most intensive structures in Europe, it also seems to decrease the probability of ‘catastrophic’ economic losses. The results suggest that the response of export markets and the number of uninfected farms affected by preventive measures are critical to the magnitude of losses, as they can amplify losses even if only few farms become infected.     

2010年广西中小规模养猪户面临的问题调查分析

为了解广西中小规模养猪户面临的问题,以问卷形式对广西贵港、北海、玉林、柳州、南宁等地19个乡镇148个农户进行调查。结果显示20头母猪以上大户占75%,投入在5万元以上,从业多年,养猪是主要收入来源,户主多为中学文化水平,用工3～10人;5～20头母猪中户占17%,母猪在5头以下的小户占8%。大户对乳猪料认识好,用得多,占32%,但有50%的大户对价格比较敏感。农户饲养土杂猪的比例占60%,饲养快大猪占35%,纯土猪只有5%。大户的种猪多来自种猪场占25%,而小农户多数自己留种或在村里购买,占60%;对选种多数看外表占66%,15%的人会关注生产记录。普遍使用大猪场的精液,占80%。调查表明将中小规模养猪户并入产业链,统一规范管理,平衡合作农户的计酬,形成一站式服务是中小规模养猪户的发展趋势。     

浅谈非洲猪瘟背景下的后备母猪初配标准和改善措施

非洲猪瘟进入我国已2年有余,目前全国生猪产能已经恢复到非瘟发生前的88％以上.但是,猪场在快速恢复产能过程中诸多问题会对猪场生产成绩造成持续影响,例如如何确立后备母猪初配标准,亟待建立和规范.文章从后备母猪初配标准的重要性、关键指标和改善措施3个方面进行深入剖析和探讨,旨在为猪场建立最佳的后备母猪初配条件提供参考.