Porcine Health Management最新文献

{"title":"Early behavioral indicators of aberrant feces in newly-weaned piglets.","authors":"Vivian L Witjes, Fleur Veldkamp, Francisca C Velkers, Ingrid C de Jong, Ellen Meijer, Johanna M J Rebel, Jan A Stegeman, Tijs J Tobias","doi":"10.1186/s40813-024-00396-4","DOIUrl":"10.1186/s40813-024-00396-4","url":null,"abstract":"<p><strong>Background: </strong>Post-weaning diarrhea (PWD) is a frequently occurring health and welfare issue in weaned piglets. Behavioral changes indicating impaired health may be detectable before the onset of signs and could be useful to detect the development of PWD early, enabling targeted and timely interventions. Current algorithms enable automated behavioral classification on the group level, while PWD may not affect all piglets in one pen and individual level analysis may be required. Therefore, this study aimed to assess whether changes in pen activity or individual piglet behavior can be early indicators of the occurrence of PWD. During 3 replicated rounds, 72 piglets (Sus scrofa domestica, Landrace x Large White) weaned at 27 days of age, were housed in 4 pens with 6 piglets each. Individual fecal color and consistency were scored (0-5; ≥ 3 considered as aberrant feces) six times during the first two weeks post-weaning using rectal swabs. Additionally, using a similar scoring scale, feces on the pen floor were assessed daily. Two methods were applied for behavioral scoring. Individual behaviors (eating, drinking, standing, walking; n = 48) were scored manually and instantaneously with a five-minute interval from videos of the first two rounds, while pen activity (eating, drinking, moving; n = 12) was analyzed automatically and continuously using a commercially available algorithm from videos of all three rounds.</p><p><strong>Results: </strong>Piglets showing a relatively higher proportion of standing behavior one day before fecal scoring had increased odds of an aberrant fecal color score (odds ratio (OR): 4.8; 95% confidence interval (CI): 1.5-15.3). Furthermore, odds of aberrant colored feces increased in pens where piglets showed more moving activity two days before (OR: 6.14; 1.26 < 95%CI < 29.84), which was also found for fecal consistency (OR: 4.77; 95%CI: 1.1-21.6).</p><p><strong>Conclusions: </strong>Our results indicate that increased standing in individual piglets and an increased moving activity on the pen level may be important behavioral indicators of PWD before the onset of diarrhea. Further development of current algorithms that can identify behavioral abnormalities in groups, from the pen to the individual level, may therefore be a promising avenue for improved and targeted health and welfare monitoring.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11536707/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142583933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the role of riboflavin in swine well-being: a literature review.","authors":"Yauheni Shastak, Wolf Pelletier","doi":"10.1186/s40813-024-00399-1","DOIUrl":"10.1186/s40813-024-00399-1","url":null,"abstract":"<p><p>Riboflavin (vitamin B₂) is an essential B-vitamin crucial for the metabolism, development, and overall well-being of porcine species. As pig production intensifies, understanding the micronutrient needs of swine, particularly riboflavin, becomes increasingly vital. Riboflavin acts as a precursor for coenzymes involved in key redox reactions essential for energy production, growth, and immune regulation. Ariboflavinosis can disrupt metabolic functions, leading to impaired growth, reproductive issues, decreased feed efficiency, compromised immune function, ocular problems, and liver dysfunction. To ensure optimal growth and health, pig diets are consistently supplemented with riboflavin-enriched supplements. This review explores the diverse functions of riboflavin in swine metabolism, focusing on biochemical basics, metabolic pathways, riboflavin uptake and distribution, consequences of deficiency, and benefits of adequate intake. It emphasizes the need for optimized riboflavin supplementation strategies tailored to different production stages and environmental conditions. According to recommendations from four major breeding companies, the dietary riboflavin levels for swine are advised to range between 7.5 and 15 mg/kg for piglets, 3.5 to 8.0 mg/kg for finishing gilts and barrows, 4 to 10 mg/kg for gestating sows, and 5 to 10 mg/kg for lactating sows. Advances in precision nutrition, microbial production of riboflavin, and the development of functional feed additives are potential innovations to enhance swine health, growth performance, and sustainability. Comprehensive studies on the long-term effects of subclinical riboflavin deficiency and the broader health and welfare implications of supplementation are also needed. Addressing knowledge gaps and embracing future trends and innovations will be key to optimizing riboflavin supplementation and advancing the swine industry.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11526614/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142558586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and evaluation of a standardised sampling protocol to determine the effect of cleaning in the pig sty.","authors":"Lisa Dahlin, Ingrid Hansson, Nils Fall, Axel Sannö, Magdalena Jacobson","doi":"10.1186/s40813-024-00400-x","DOIUrl":"10.1186/s40813-024-00400-x","url":null,"abstract":"<p><strong>Background: </strong>All-in, all-out with strict hygienic routines is necessary in modern pig production. Furthermore, a standardised, validated method is needed to quantitatively control the effect of these hygiene protocols. This study aimed to establish a reproducible and reliable sampling method to assess cleaning of the pig pen.</p><p><strong>Methods: </strong>Sterilised pig faeces were mixed with indicator bacteria (i.e. Enterococcus hirae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) and spread out in a controlled environment. The retrieval rate of three different sampling methods were evaluated; swabbing by (i) a cloth and (ii) a sponge, analysed by standardised bacterial culture and counting of colony-forming units, and (iii) a cotton swab analysed by adenosine triphosphate (ATP) bioluminescence. Two time-points were evaluated during the study; after drying overnight and after manual scraping of the surfaces. To determine sample-to-sample variability, sampling by the cloth and the cotton swab was carried out after manual scraping and further, after high-pressure washing with cold water.</p><p><strong>Results: </strong>Sampling by the cloth and the sponge showed few differences in in the number of CFU obtained before and after the manual scraping (retrieval rate), whereas the swabs, measuring ATP bioluminescence, showed a very high retrieval rate. Sample-to-sample variability was low for all three methods.</p><p><strong>Conclusions: </strong>In conclusion, to sample pens for the presence of bacteria, the cloth was assessed as the preferable material, being cheap, easy, specific, and approachable, and with a low sample-to-sample variability. The ATP measurement could have potential for use when evaluating the cleaning of stables, however, threshold values for evaluating the cleaning of a pig sty needs to be developed.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11523895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear epitopes of PRRSV-1 envelope proteins ectodomains are not correlated with broad neutralization.","authors":"Jaime Castillo-Pérez, Francisco Javier Martínez-Lobo, Raquel Frómeta, José María Castro, Isabel Simarro, Cinta Prieto","doi":"10.1186/s40813-024-00393-7","DOIUrl":"10.1186/s40813-024-00393-7","url":null,"abstract":"<p><strong>Background: </strong>Neutralizing antibodies against PRRSV are capable of conferring protection against viral reinfection, but they tend to be strain specific and usually have poor cross-reactivity. Nonetheless, it has been described that there are individuals capable of efficiently neutralizing viruses of different origin, so it is expected that there are conserved neutralizing epitopes relevant for broad neutralization. However, although immunodominant regions and neutralizing epitopes have been described in different envelope proteins, their role in broad neutralization is unknown. The main objective of this study was to determine whether the linear epitopes existing in the ectodomains of PRRSV envelope proteins play a role in cross-neutralization.</p><p><strong>Results: </strong>A pepscan analysis was carried out using synthetic peptides against the ectodomains of PRRSV envelope proteins and PRRSV-hyperimmune sera of different cross-reactivity. The results obtained confirm the existence of antigenic regions in the ectodomains of the GP2, GP3, GP4 and GP5 that tend to be relatively conserved among different PRRSV isolates. Nonetheless, these antigenic regions have poor immunogenicity since they are only recognized by a limited number of sera. Furthermore, no differences were found between the reactivity of sera with broad cross-neutralization capacity and sera with poor heterologous neutralization activity, which indicate that linear epitopes existing in the ectodomains of PRRSV envelope proteins are not relevant for the development of broadly reactive neutralizing antibodies. Subsequently, some selected peptides were used in competition assays with the virus for binding to the cell receptors and in seroneutralization inhibition assays by incubation with hyperimmune sera. Firstly, some peptides that interfere with virus infectivity were identified in competition assays, but only in the case of one viral isolate, which points to the possible existence of a strain-dependent inhibition. However, the results of the seroneutralization inhibition assay indicate that, under the conditions of our study, none of the peptides used was capable of inhibiting virus neutralization by the hyperimmune sera.</p><p><strong>Conclusions: </strong>The results obtained indicate that the linear peptides analyzed in this study do not play a major role in the induction of broadly reactive neutralizing antibodies, which could probably depend on conformational neutralizing.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11492654/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142472923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case-control study on associations of hemorrhagic bowel syndrome in swine with feed characteristics and intestinal pathogens.","authors":"Fabienne Holenweger, Peter Spring, Negar Khayatzadeh, Andreas Hofer, Gertraud Schüpbach-Regula, Alexander Grahofer","doi":"10.1186/s40813-024-00397-3","DOIUrl":"https://doi.org/10.1186/s40813-024-00397-3","url":null,"abstract":"<p><p>Haemorrhagic bowel syndrome (HBS) is one of the most common causes of death in fattening pigs worldwide. The objective of this descriptive study was to systematically assess predictors or causal components for the appearance of HBS using case farms (mortality rate caused by HBS ≥ 1.5%) in comparison with control farms (mortality rate caused by HBS ≤ 0.25%), focusing on feed ingredients, feed quality and size, and gastrointestinal pathogens. The inclusion of sugar beet as a feed component in liquid feeding systems was found to be associated (p = 0.03) with farms identified as HBS cases. Another predictive or causal factor found for liquid feeding systems, but only for those using meal, was particle size. A higher percentage of small particles (< 2 mm) in the meal was associated with a higher risk of being an HBS case farm (p = 0.02), while no relevant association was detected for the use of pellets. Sugar beet in the diet was also associated with the incidence of HBS.The microbial quality of the feed in dry feeding systems, specifically the number of total aerobes at the first and last outlet tubes, was associated with a higher incidence of HBS (p = 0.03). Faecal sample analysis showed a difference (p < 0.05) in the prevalence of B. pilosicoli in the herd category (case vs. control herd). In this descriptive study, five predictive or causal factors were identified for an HBS farm with a mortality rate due to HBS ≥ 1.5%. These included the number of aerobes in dry matter samples from the first and last feeders, the particle diameter of the meal used in liquid feeding systems and sugar beet as a component of liquid feeding rations, and the presence of B. pilosicoli as an infectious agent at animal level. Relevant associations reinforce the findings of the previously published Swiss study that HBS is a multifactorial syndrome involving different aspects of pig production and cannot be attributed to a single cause. Further studies are needed to develop evidenced based causal models for HBS in swine.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11490042/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142472921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the individual stillborn rate from easy-to-collect sow data on farm: an application of the bayesian network model.","authors":"Charlotte Teixeira Costa, Gwenaël Boulbria, Christophe Dutertre, Céline Chevance, Théo Nicolazo, Valérie Normand, Justine Jeusselin, Arnaud Lebret","doi":"10.1186/s40813-024-00395-5","DOIUrl":"https://doi.org/10.1186/s40813-024-00395-5","url":null,"abstract":"<p><strong>Background: </strong>A high number of stillborn piglets has a negative impact on production and animal welfare. It is an important contributor to piglet mortality around farrowing and continues to rise with the increase of prolificacy. The objective of this study was to build a predictive model of the stillborn rate.</p><p><strong>Results: </strong>This study was performed on two farrow-to-finish farms and one farrow-to-wean farm located in Brittany, France. At each farm, the number of total born (TB), born alive (BA), stillborn piglets (S), the same data at the previous farrowing (TB_n- 1, BA_n- 1 and S_n- 1), backfat thickness just before farrowing and at previous weaning and parity rank were recorded in our dataset of 3686 farrowings. Bayesian networks were used as an integrated modelling approach to investigate risk factors associated with stillbirth using BayesiaLab^® software. Our results suggest the validity of a hybrid model to predict the percentage of stillborn piglets. Three significant risk factors were identified by the model: parity rank (percentage of total mutual information: MI = 64%), S_n- 1 (MI = 25%) and TB_n- 1 (MI = 11%). Additionally, backfat thickness just before farrowing was also identified for sows of parity five or more (MI = 0.4%). In practice, under optimal conditions (i.e., low parity rank, less than 8% of stillborn piglets, and a prolificacy lower than 14 piglets at the previous farrowing), our model predicted a stillborn rate almost halved, from 6.5% (mean risk of our dataset) to 3.5% for a sow at the next farrowing. In contrast, in older sows with a backfat thickness less than 15 mm, more than 15% of stillborn and a prolificacy greater than 18 piglets at the previous farrowing, the risk is multiplied by 2.5 from 6.5 to 15.7%.</p><p><strong>Conclusion: </strong>Our results highlight the impact of parity, previous prolificacy and stillborn rate on the probability of stillborn. Moreover, the importance of backfat thickness, especially in old sows, must be considered. This information can help farmers classify and manage sows according to their risk of giving birth to stillborn piglets.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11484292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142472922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serotype independent protection induced by a vaccine based on the IgM protease of Streptococcus suis and proposal for a new immunity-based classification system.","authors":"A A C Jacobs, A W F Grommen, S Badbanchi, A J van Hout, T J van Kasteren-Westerneng, L Garcia Morales, R Bron, R P A M Segers","doi":"10.1186/s40813-024-00398-2","DOIUrl":"https://doi.org/10.1186/s40813-024-00398-2","url":null,"abstract":"<p><p>The IgM protease (Ide_Ssuis gene; Gene ID 8153996) of Streptococcus suis is a putative virulence factor that has been shown to be a protective vaccine antigen for pigs (Seele et al. Vaccine 33:2207-12, 2015). To assess its potential as a cross-protective antigen, the amino acid variability among prevalent clinical isolates in various regions and among various serotypes was investigated. Multi-sequence alignment of full-length amino acid sequences of S. suis IgM protease, available in the public domain (status Jan-2022) supplemented with in-house sequences, i.e. a total of 1999 sequences, revealed that the IgM protease of S. suis clusters into three main evolutionary distinct branches: groups A, B and C. Group A, 82% of the sequences in the database, was associated with clinical isolates of various serotypes. Group B, 6% of the strains in the database, was associated with clinical isolates mainly in the EU and mainly belonging to serotype (st) 9. Group C, 12% of the strains in the database, was largely associated with healthy carrier isolates, i.e. nose or tonsil isolates of various serotypes but in particular with st9 and un-typable strains. Within the groups A, B and C, high levels of amino acid identity were observed (> 75%), whereas between groups A and B, the percentage amino acid identity was approximately 30% and between groups A and C approximately 55%. Experimental Escherichia coli expressed recombinant subunit vaccines based on the IgM protease group A sequence of st1 strain B10-99, st2 strain 10 or st7 strain 14009-1, induced serotype independent protection in pigs against challenge with all group A strains tested, i.e. strains of different parts of the phylogenetic tree and of different serotypes including st1, 2, 9 and 14. Protection was observed after vaccination of piglets at 3 and 5 weeks of age and subsequent challenge at 7 weeks but also after vaccination of gilts at 6 and 2 weeks before anticipated parturition and challenge of the offspring up to at least 8 weeks of age. No protection was observed against challenge with st9 strain SZ2000-6264 having group B IgM protease. A recombinant subunit vaccine based on the group B IgM protease sequence, also did not protect against challenge with the homologous group B st9 challenge strain. The results indicate that a vaccine based on a group A IgM protease induces protection against all S. suis strains that express the group A IgM protease. Depending on the geographical region such a vaccine is expected to protect against 60-100% of the virulent S. suis strains. Since the novel proposed IgM protease classification is highly relevant, a PCR was developed and validated, to be able to classify clinical isolates into IgM protease groups A, B and C and predict the cross-protection that can be expected from a group A based IgM protease vaccine.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11472559/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142472924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How do pig veterinarians view technology-assisted data utilisation for pig health and welfare management? A qualitative study in Spain, the Netherlands, and Ireland.","authors":"Xiao Zhou, Beatriz Garcia-Morante, Alison Burrell, Carla Correia-Gomes, Lucia Dieste-Pérez, Karlijn Eenink, Joaquim Segalés, Marina Sibila, Michael Siegrist, Tijs Tobias, Carles Vilalta, Angela Bearth","doi":"10.1186/s40813-024-00389-3","DOIUrl":"10.1186/s40813-024-00389-3","url":null,"abstract":"<p><strong>Background: </strong>Application of data-driven strategies may support veterinarians' decision-making, benefitting pig disease prevention and control. However, little is known about veterinarians' need for data utilisation to support their decision-making process. The current study used qualitative methods, specifically focus group discussions, to explore veterinarians' views on data utilisation and their need for data tools in relation to pig health and welfare management in Spain, the Netherlands, and Ireland.</p><p><strong>Results: </strong>Generally, veterinarians pointed out the potential benefits of using technology for pig health and welfare management, but data is not yet structurally available to support their decision-making. Veterinarians pointed out the challenge of collecting, recording, and accessing data in a consistent and timely manner. Besides, the reliability, standardisation, and the context of data were identified as important factors affecting the efficiency and effectiveness of data utilisation by veterinarians. A user-friendly, adaptable, and integrated data tool was regarded as potentially helpful for veterinarians' daily work and supporting their decision-making. Specifically, veterinarians, particularly independent veterinary practitioners, noted a need for easy access to pig information. Veterinarians such as those working for integrated companies, corporate veterinarians, and independent veterinary practitioners expressed their need for data tools that provide useful information to monitor pig health and welfare in real-time, to visualise the prevalence of endemic disease based on a shared report between farmers, veterinarians, and other professional parties, to support decision-making, and to receive early warnings for disease prevention and control.</p><p><strong>Conclusions: </strong>It is concluded that the management of pig health and welfare may benefit from data utilisation if the quality of data can be assured, the data tools can meet veterinarians' needs for decision-making, and the collaboration of sharing data and using data between farmers, veterinarians, and other professional parties can be enhanced. Nevertheless, several notable technical and institutional barriers still exist, which need to be overcome.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11468428/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oropharyngeal swab sampling for PRRSV detection in large-scale pig farms: a convenient and reliable method for mass sampling.","authors":"Mingyu Fan, Yang Li, Zhiqiang Hu, Lujie Bian, Weisheng Wu, Wei Liu, Meng Li, Xinglong Wang, Jing Ren, Lili Wu, Xiaowen Li","doi":"10.1186/s40813-024-00392-8","DOIUrl":"10.1186/s40813-024-00392-8","url":null,"abstract":"<p><strong>Background: </strong>Porcine reproductive and respiratory syndrome virus (PRRSV) has significant productivity and economic impacts in swine herds. Accurately determining the PRRSV status at the herd level is crucial for producers and veterinarians to implement strategies to control and eliminate the virus from infected herds. This study collected oropharyngeal swabs (OSs), nasal swabs (NSs), oral fluid swabs (OFs), rectal swabs (RSs), and serum samples continuously from PRRSV challenged pigs under experimental conditions and growing pigs under field conditions. Additionally, OSs and serum samples were collected from individual sows from 50 large-scale breeding farms, and the collection of OSs does not require the sows to be restrained. Ct values of PRRSV were detected in all samples using real-time reverse transcriptase-polymerase chain reaction (RT-qPCR).</p><p><strong>Results: </strong>In PRRSV challenged pigs, OSs showed a higher PRRSV-positive rate until the end of the observation period. The Ct values of OSs were significantly lower than those of NSs, OFs, and RSs at 2, 8, 12, 14 and 20 days post-challenge (DPC) (P < 0.05). For growing pigs, the positivity rate of PRRSV in OSs was higher than that in other sample types at 30, 70, and 110 days of age. In sows, 24,718 OSs and 6259 serum samples were collected, with PRRSV-positive rate in OSs (9.4%) being significantly higher than in serum (4.1%) (P < 0.05). However, the Ct values of PRRSV RNA in serum were significantly lower than those in OSs (P < 0.001).</p><p><strong>Conclusions: </strong>The OSs sample type yielded higher PRRSV-positive rates for longer periods compared to NSs, RSs, OFs and serum samples for PRRSV detection in infected pigs. Therefore, OSs has a good potential to be a convenient, practical, and reliable sample type for implementing mass sampling and testing of PRRSV in large-scale pig farms.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11465849/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection and quantification by molecular techniques of early infection by Lawsonia intracellularis in suckling piglets.","authors":"Víctor Rodriguez-Vega, Héctor Puente, Ana Carvajal, Lucía Pérez-Pérez, Samuel Gómez-Martínez, Fernando L Leite, Rocío García, Lola Abella, Héctor Argüello","doi":"10.1186/s40813-024-00394-6","DOIUrl":"https://doi.org/10.1186/s40813-024-00394-6","url":null,"abstract":"<p><strong>Background: </strong>Lawsonia intracellularis is the causative agent of Porcine Proliferative Enteropathy (PPE), one of the most prevalent pig enteric diseases worldwide, but with sparse information about early infections in suckling piglets in the epidemiology of PPE. With that aim, this study evaluates the prevalence of L. intracellularis in 3-week-old piglets by analysing ileal digesta content and mucosal scrapings from 383 pigs from 16 farms (aprox., 25 pigs/batch) by real-time qPCR and droplet digital PCR (ddPCR).</p><p><strong>Results: </strong>Forty-nine samples yielded a qPCR positive result. Eleven samples from eight farms were confirmed as positive with concentrations of L. intracellularis from 3.5 log₁₀ to 4.5 log₁₀ bacteria/g of sample. Another 16 samples, eight farms, were classified as low positive (2.07-2.38 log₁₀ bacteria/g) and 22 provided an uncertain result. Finally, 334 samples tested negative for L. intracellularis. At batch level, half of the farms included in the study had at least one positive sample and in 10 farms (62.5%) there was at least one low positive sample. The ddPCR was run in 50 of the 383 samples based on their PCR output (including low positive, uncertain and negative samples). Correlation analyses revealed a strong association between qPCR and the ddPCR results (ρ = 0.75; p < 0.001). The ddPCR allowed us to detect and confirm a positive result in the 19 samples classified as uncertain by the qPCR and detect L. intracellularis in 8 of 15 negatives by qPCR.</p><p><strong>Conclusions: </strong>The results of the study demonstrate that a number of piglets are already infected with L. intracellularis during the suckling period evidencing early infection in certain animals, adding information of PPE epidemiology and opening new research topics such as sow-piglet transmission. Study results also evidence the usefulness of a combination of qPCR and ddPCR to improve qPCR sensitivity but assuring high specificity.</p>","PeriodicalId":20352,"journal":{"name":"Porcine Health Management","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11459964/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142392668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}