Porcine Health Management最新文献

Background: Magnolia officinalis is a medicinal herb known for its pharmacological properties and as a potential natural feed additive. We aimed to assess the effects of dietary Magnolia officinalis extract (MOE) on the growth performance and immune function of piglets, and explored the potential of MOE as a natural alternative to antibiotics for piglet nutrition during weaning.

Results: Compared with the basal diet group (CK), the MOE diet significantly increased average daily feed intake and reduced diarrhea incidence and serum interleukin-6 (IL-6) levels. Compared with 0.1% MOE group, the 0.05% MOE group had lower diarrhea rates, eosinophils (EOS) count, EOS' percentage, and serum interleukin-4 levels. Compared with CK, 0.05% MOE supplementation in the diet could reduce the diarrhea incidence and the thymus index by elevating the levels of transforming growth factor-β (TGF-β) and interleukin-10 (IL-10) in the serum, jejunum, and ileum. Compared with the basal diet group, 0.05% MOE supplementation upregulated the mRNA expressions of IL-10 and TGF-β1 in the jejunum and ileum (P < 0.05) and those of IL-10, interleukin-1β (IL-1β), and interferon-γ (IFN-γ) in the thymus (P < 0.05). Moreover, 0.05% MOE increased the levels of butyric, isobutyric, isovaleric, and valeric acids in the colon.

Conclusions: MOE supplementation could modulate the immune status of animals, lower production costs, and contribute to more sustainable and ethical pig farming practices by promoting healthier growth and reducing disease susceptibility. Our findings offer a sustainable solution to antibiotic use in animal farming, addressing concerns about antibiotic resistance and food safety.

Background: Glässer's disease, caused by Glaesserella parasuis (G. parasuis), is a widespread bacterial infection in swine that leads to significant economic losses. G. parasuis, a member of the normal microbiota within the Pasteurellaceae family, exhibits horizontal resistance gene exchange and intracellular invasion capabilities, increasing the risk of developing resistant isolates. Accurate antimicrobial therapy is essential for controlling Glässer's disease. The production systems for exotic crossbred pigs and Taiwan black pigs differ considerably. To inform Glässer disease control and monitor antimicrobial resistance, we assessed the antimicrobial susceptibilities of G. parasuis isolates, analyzed them using normalized resistance interpretation (NRI), and compared findings between the two production systems.

Results: A total of 154 G. parasuis isolates from 106 exotic crossbred pig herds and 48 Taiwan black pig herds were tested against 16 antimicrobial agents between 2015 and 2020. Due to the absence of specific breakpoints for G. parasuis, NRI was utilized to define non-wild-type (non-WT) populations based on minimum inhibitory concentration (MIC) distributions. Non-WT subpopulations of isolates for amoxicillin, ampicillin, ceftiofur, gentamicin, kanamycin, and tiamulin were observed. The highest MIC₉₀ (the concentration at which 90% of isolates were inhibited) was > 256 µg/mL for several antimicrobials, including gentamicin, kanamycin, lincomycin, lincospectin, spectinomycin, and tylosin. In contrast, the lowest MIC₉₀ was observed for ceftiofur (0.5 µg/mL). The MIC values for cephalothin were significantly higher in exotic crossbred pigs than in Taiwan black pigs (p = 0.0016). Conversely, MIC values for florfenicol were significantly higher in Taiwan black pigs than in exotic crossbred pigs (p = 0.003).

Conclusions: This study provides the susceptibility profile of G. parasuis isolates for both exotic crossbred pigs and Taiwan black pigs in Taiwan and highlights potential antimicrobial resistance for aminocyclitol, aminoglycosides, beta-lactams, lincosamides, macrolides, and pleuromulin. Ceftiofur, cephalothin, doxycycline, and florfenicol could be most suitable for treating early-stage Glässer's disease. Nonetheless, increased attention should be paid to the responsible use of antimicrobials in light of the growing threat of antimicrobial resistance.

The combined, intradermal application of multiple vaccines against key diseases in swine offers many benefits, including reduced time and labor costs, and improved animal welfare due to fewer injections and manipulations. This study investigated the efficacy of a newly developed intradermal combination vaccine for Porcine circovirus 2 (PCV2) and Mycoplasma hyopneumoniae (M hyo) (PCV M Hyo ID vaccine) in swine. The vaccine was evaluated for its efficacy against PCV2 and M hyo infection and its concurrent mixed use with Lawsonia intracellularis (LI) and non-mixed use with Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines. The findings demonstrated that the PCV M Hyo ID combination vaccine is efficacious against PCV2 and M hyo infection. Furthermore, the new PCV M Hyo ID combination vaccine can also be administered simultaneously and at the same anatomical location after mixing with LI ID vaccine, and next to PRRS ID vaccine, to efficiently protect pigs from all four major diseases in swine. The efficacy with the combination of vaccines was equivalent to that of the single vaccines.

Background: Pain in pigs needs to be managed and treated to the benefit of individual pigs. It is imperative for veterinarians and farmers to assure that pigs do not suffer from unnecessary pain that can be relieved. This review focusses on pain related to spontaneously occurring diseases and injuries since this topic is often neglected. The aim is to identify ways to accelerate knowledge and evidence in this area to prevent painful conditions in pigs in the future.

Methods: A scoping review was conducted with results from a search of the electronic databases VetSearch and CABI Rxiv. The findings of selected publications are narratively synthesized and reported orienting on the PRISMA ScR guideline.

Results: The results emphasize that pigs experience pain due to spontaneously occurring diseases and injuries, but systematic knowledge about this topic is scarce. More research is especially needed for rare diseases (such as UTIs). Moreover, research conducted about the topic pain in pigs should involve standardized protocols to document, analyse and share results on pain detection beyond a projects' timeframe. The findings of this review suggest that such a protocol would comprise validated pain identification measures over time and in relation to administered pain treatment.

Conclusion: The results of this study invite veterinary practitioners to reconsider in each pig patient whether pain and related indicators are present, how to handle the situation and document the process to ensure the welfare of individual compromised pigs.

Background: Pigs can suffer from pain due to spontaneously occurring diseases, wounds, injuries, trauma, and physiological conditions such as the farrowing process; however, this pain is often neglected. To increase knowledge and awareness about this phenomenon, the current article presents a scoping review of basic and new approaches for identifying, evaluating, and treating pain in pigs.

Methods: A scoping review was conducted with results from a search of the electronic database VetSearch and CABI. With regard to eligibility criteria, 49 out of 725 publications between 2015 and the end of March 2023 were included. The findings are narratively synthesized and reported orienting on the PRISMA ScR guideline.

Results: The results of this review showed that practitioners need to consider pain not only as a sign of a disease but also as a critical aspect of welfare. If both the symptoms of pain and the underlying reasons remain unassessed, the longevity and prosperity of pigs may be at risk. In this respect, veterinarians are obliged to know about intricacies of pain and pain mechanisms and to provide adequate treatment for their patients.

Conclusion: It is pivotal to increase knowledge about pain mechanisms, the reasons for heterogeneity in behavioural signs of pain, and methods for evaluating whether a pig is experiencing pain. This article will help practitioners update their knowledge of this topic and discuss the implications for everyday practice.

Background: Mycoplasma (M.) hyopharyngis, M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae can all be transiently present in the swine tonsils without causing any clinical signs or lesions. M. hyopharyngis is considered a commensal bacterium, however, our knowledge about its prevalence and pathogenic capabilities is lacking. M. hyopneumoniae, M. hyorhinis and M. hyosynoviae are widespread pathogens, responsible for significant economic losses. M. hyopneumoniae is known as the causative agent of porcine enzootic pneumonia, while M. hyorhinis and M. hyosynoviae are associated with arthritis and polyserositis. The objective of this study was to evaluate the detection rates of these mycoplasmas in Central-Eastern Europe (Croatia, the Czech Republic, Hungary, and Slovakia) through a cross-sectional investigation. In parallel, a novel quantitative polymerase chain reaction (qPCR) assay was designed targeting M. hyopharyngis to facilitate the identification of this bacterium.

Results: Tonsils of 15 animals per herd were sampled from six-month-old fattening pigs, and a total of 150 herds were examined. Tonsils form each herd were divided into three pools, each comprising five tonsils. The samples were submitted for species-specific TaqMan assay and isolation. M. hyopharyngis was identified in 92.67% (139/150, 95% confidence interval: 87.35-95.86%) of the stocks, with successful isolation from 20 herds. Besides, M. hyopneumoniae was detected in 51.33% (77/150, 95% confidence interval: 43.40-59.19%) of the stocks. Additionally, M. hyorhinis was identified in all herds (100.00%; 150/150, 95% confidence interval: 97.50-100.00%) by qPCR examination and was successfully isolated from 107 stocks. Regarding the occurrence of M. hyosynoviae, 88.00% (132/150, 95% confidence interval: 81.83-92.27) of the herds showed positive PCR results, and the pathogen was successfully isolated in 122 cases. Moreover, the newly developed M. hyopharyngis qPCR assay proved to be a reliable and sensitive method.

Conclusions: This study determined the detection rates of several porcine mycoplasmas (M. hyopharyngis, M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae) in fattening pigs in Central-Eastern Europe. Additionally, the developed M. hyopharyngis qPCR assay may facilitate future prevalence studies and diagnostic procedures concerning this neglected bacterium.

Background: In 2020, a highly virulent PRRSV-1 strain emerged in Spain and rapidly spread across the country. The purpose of the present study was to test in a piglet model whether a commercial PRRSV-1 modified live vaccine was able to confer protection against strain R1, a representative of the emerging clade. For that purpose, two groups of 26 piglets were either vaccinated intradermally or kept as controls; 42 days later, half of the animals in each group were intranasally challenged with the R1 strain. Then, animals were followed to assess the development of clinical signs (until 14 days post-challenge), lung lesions (10- and 35-days post-challenge), weight gains, viremia and nasal shedding and the immune response (anti PRRS virus nucleoprotein antibodies) by ELISA and virus specific-interferon-γ secreting cells by ELISPOT).

Results: Challenge of naïve pigs resulted in high fever (up to 41.9 °C), lethargy and severely retarded growth (0.748 kg/day). In contrast, vaccinated/challenged pigs had less fever and for a shorter period, lower clinical scores and a higher average daily weight gain (0.940 kg/day), comparable to the unchallenged animals. At 10 days-post challenge, in naïve animals on average 49.1% of the lung was pneumonic (range 8-81%) while in vaccinated animals the average was 15.7% (4-41%). Duration of viremia was reduced in vaccinated animals and after 14 days post-challenge, most were negative by RT-qPCR. In contrast, 50% of the naïve/challenged pigs remained viremic at 35 days post-challenge. Vaccination induced rapid seroconversion and challenge of naïve animals resulted in 100% of ELISA-positive pigs by day 14 post-challenge. Regarding the development of IFN-γ responses, for vaccinated animals the frequencies increased until day 35 post-vaccination. After challenge, in vaccinated pigs, the peak of the R1-specific IFN-γ response was reached at 14 days and then the viremia ceased, although nasal shedding persisted in some vaccinated animals.

Conclusions: In the present trial, vaccination resulted in improved clinical course, better weight gain and reduced viremia. At the peak of the infection, lung lesions were reduced in most animals although some individuals still had extensive pneumonia. In summary, vaccination was shown to provide partial but significant protection against the highly virulent R1 strain.

Background: The benefits of porcine reproductive and respiratory syndrome (PRRS) modified live virus vaccines (MLV) have been largely proven, however, the safety of these vaccines is questioned since vaccine strains can revert to virulence due to random mutations or recombination events. Reversion to virulence has been previously described for PRRSV-2 MLVs and recently for PRRSV-1 MLV after recombination. This case report describes the introduction of a PRRSV-1 strain derived from a MLV associated with an outbreak of reproductive disorder in a 1000-sow farrow-to-wean farm in France.

Case presentation: In January 2023, unusual fever and lethargy in sows, and premature farrowings were reported in a farm that was regularly controlled as PRRS stable, through mass vaccination of the sows. PRRSV-1 was detected by PCR in sows and suckling piglet samples. Sequencing of ORF5, ORF7, and whole genome (WGS) was performed. Time-to-baseline production and total production losses were calculated using statistical process control methods. ORF5 and ORF7 nucleotide sequences indicated that the strain isolated from the clinical samples was differentiable from the DV MLV strain used in the farm (94.1% and 95.9% respectively) but closely related to the VP-046 Bis MLV strain which was never used (99.0% and 99.2% respectively). WGS of the farm PRRSV strain confirmed the high nucleotide identity percentage with the VP-046 Bis MLV strain (98.6%) over the entire genome and no recombination events was detected with MLV strains authorized in France. After different investigations aiming to identify the source of contamination, we were able to detect a closely related strain (99.46% of identity with the case farm strain across the entire genome) in a wean-to-finish farm located 400 m further. It took 17 batches (34 weeks) to recover the baseline production of piglets after implementation of a PRRSV stabilization protocol, which represented a total loss of 812 weaned piglets.

Conclusion: This is the first case report of a PRRSV-1 MLV which might have reverted to virulence in France and has caused substantial economic losses.

Background: Atypical porcine pestivirus (APPeV), also known as Pestivirus scrofae, is a member of the Pestivirus genus within the Flaviviridae family. Experimental infections have directly linked APPeV to congenital tremor (CT) type A-II in congenitally infected piglets born to challenged sows. Here, we report the assessment of the prevalence of APPeV in Hungarian pig herds and the influence of different sample types on detection rates.

Results: Altogether, 2650 blood serum, 198 oral fluid and 163 processing fluid samples were obtained via a systemic approach from 26 Hungarian farms and one Slovakian farm. The samples originated from different age groups and were analyzed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The estimated prevalence of APPeV was determined to be 66.67% in the sampled farms, indicating the widespread distribution of the virus within Hungary. Within the positive farms, APPeV genetic material was detected in the serum (21%), processing fluid (57%), and oral fluid (72%) samples. Notably, in some farms, the presence of APPeV was confirmed in only specific sample types, and five farms had APPeV in all three sample types. Age group analysis revealed that 10-week-old animals had the highest positivity rate in their blood serum (27%), whereas 20-week-old animals presented the highest rate in their oral fluid samples (59%). Processing fluid and oral fluid samples proved to be valuable for noninvasive diagnostic matrices, allowing for efficient population-level virus detection. We determined the partial NS2-3 coding region of 15 Hungarian strains and a Slovakian strain, and our phylogenetic analysis revealed that very similar strains can be found on different farms.

Conclusion: In conclusion, our study provides insights into APPeV prevalence in Hungarian pig herds, emphasizing the importance of different sample types for accurate diagnostics. These findings contribute to our understanding of the virus's distribution across different age groups.

Background: Streptococcus suis (S. suis) infections are responsible for a large disease burden in piglets during the nursery phase, compromising animal welfare and increasing antibiotic use. The immune gap caused by decreased maternal-derived antibodies (MDA) and insufficient levels or functionality of acquired antibodies in weaned pigs could play a role in the increased susceptibility to S. suis infections. To better understand this, two studies were performed. Study I evaluated the associations between sow antibodies in colostrum and serum, birth parameters (e.g., birth weight, colostrum intake and piglet growth) and the levels of S. suis-specific (serotypes 2 and 9) antibodies in one-day-old piglets from four farms. Subsequently, study II used one of these farms to evaluate S. suis-specific and total antibody kinetics in piglets (10 litters with 6 selected piglets per litter, total n = 60) from birth until 10 weeks of age. Additionally, tonsil swabs from sows and piglets were taken to evaluate the S. suis tonsillar carrier status (serotypes 2 and 9) before and after weaning.

Results: High variability in serum and colostrum antibody levels was observed between and within the four farms (study I). In study II, there was a decrease in S. suis-specific MDA after 24 h of age, with the lowest level occurring at approximately 18/19 days of age. Afterwards, there was an increase in specific antibodies, most likely due to acquired immunity. Colostrum intake, birth weight and 24-h weight gain after birth were important parameters that were positively associated with S. suis antibody levels in piglets after birth but also affected these antibody levels at a later age. All the piglet tonsils were colonized with S. suis serotype 9 before weaning, while the prevalence of serotype 2 increased after weaning.

Conclusions: Total Ig against S. suis in serum declined after birth and the lowest level was detected just before weaning. Farmers and veterinarians should focus on piglets with low birth weights and late-born piglets because these parameters reduce both the S. suis-specific MDA preweaning and the specific antibodies acquired postweaning. Colostrum intake and 24 h-weight gain also affect the level of S. suis specific antibodies on day 1.