Porcine Health Management最新文献

Background: Porcine circovirus 3 (PCV3) is a recently discovered swine pathogen associated with reproductive disease. To date, clinical problems linked to PCV3 have been described in intensive rearing pig farms. The present case describes an Iberian semi-outdoors sow farm affected by PCV3 reproductive disease.

Case presentation: The affected farm was composed of 420 self-replaced Iberian sows, working in 3-week batches (60 sows per batch). The farm was free from porcine reproductive and respiratory syndrome virus (PRRSV) and had been previously affected by porcine circovirus 2 (PCV2) reproductive disease, which was successfully managed through sow vaccination. In spring 2022, reproductive disease was noticed with a high increase in the number of mummified foetuses and stillborn piglets from gilts as the most remarkable finding; multiparous sows were not affected. A first analysis with pooled stillborn tissues ruled out most swine reproductive pathogens and revealed detection of PCV3. To further elucidate PCV3 implication in the reproductive disease, a complete post-mortem examination of stillborn and mummified foetuses from two affected litters was conducted. Pooled tissue samples yielded high PCV3 loads by quantitative PCR. Grossly, one (out of 5) stillborn had an enlarged, flaccid heart. Histopathological evaluation revealed PCV3 lesions consisting of lymphohistiocytic and systemic periarteritis (3/5). The grossly affected heart had lymphohistiocytic myocarditis with fibrosis and lymphohistiocytic endocarditis. By in situ hybridization, high amounts of PCV3 genome were observed within histological lesions. Moreover, immunohistochemistry against PRRSV and PCV2 resulted negative in the same tissues.

Conclusions: This is the first report of PCV3 reproductive disease in a semi-extensive production Iberian pig farm, affecting exclusively gilts. Moreover, this is the first description of grossly apparent myocarditis associated to PCV3 infection. Therefore, PCV3 should be considered within the differential diagnostic list of swine reproductive problems in non-intensive pig rearing production.

Background: Porcine ear necrosis (PEN) is characterized by dry crusts on the ear tip. The crusts often progress to moist and bloody lesions and may lead to partial loss of the ear tissue. The cause and pathophysiology of PEN are unknown. Skin infections, systemic infections, or ear biting have been suggested as a cause of PEN, but no proper evidence has been shown. The behavioural factor has not yet been investigated, therefore this study evaluated the importance of oral manipulations in the occurrence of PEN in nursery pigs. Three farms affected by PEN were visited weekly, and the prevalence and severity were recorded. Video recordings of the animals were performed, and the behaviour was evaluated. The presence of pathogens in the lesions and histological alterations were also analysed.

Results: The highest percentage of pigs with PEN lesions in the farms ranged between 58 and 93%, with most lesions being of mild to moderate severity. The first ear lesions occurred about 1-2 weeks after an increase in the number of ear manipulations in the pens. The frequency of the ear manipulations clearly changed over time, and the number of oral ear manipulation behaviour significantly differed (P < 0.05) between pigs in pens with high and low PEN prevalence. Increased ear manipulation behaviour was significantly related to a subsequent increase in PEN lesions (OR = 4.3; P < 0.001). Metagenomic investigation of lesion scrapings revealed a variety of pathogens mostly with low abundance, where microscopic alterations were found mainly in the epidermis.

Conclusions: Oral manipulation of the ear pinnae by pen mates was followed by the development of PEN lesions one to two weeks later. This suggests that the behaviour played an important role in the PEN lesions formation in the nursery pigs of the three farms. Bacteria found in PEN lesions most probably were secondary to initial external skin damage, but their relevance needs to be investigated further.

Background: Aggregated samples such as oral fluids (OFs) display an animal friendly and time and cost-efficient sample type for swine Influenza A virus (swIAV) monitoring. However, further molecular and biological characterization of swIAV is of particular significance. The reportedly inferior suitability of aggregated samples for subtyping of swIAV presents a major drawback compared to nasal swabs, still considered the most appropriate sample type for this purpose (Garrido-Mantilla et al. BMC Vet Res 15(1):61, 2019). In addition, the viral load in the original sample, storage conditions and characteristics of different swIAV strains might further compromise the eligibility of aggregated samples for molecular detection and subtyping. Therefore, the present study aimed to evaluate the suitability of stabilizing media to minimize the degradation of viral RNA and thus increase the detection and subtyping rate of swIAV by RT-qPCR in spiked OFs under different conditions (virus strain, storage temperature and viral load in the original sample) over a time span of 14 days.

Results: The use of stabilizing media in spiked OFs resulted in a significant higher probability to detect swIAV RNA compared to OFs without stabilizers (OR = 46.1, p < 0.001). In addition, swIAV degradation over time was significantly reduced in samples suspended with stabilizer (OR = 5.80, p < 0.001), in samples stored at 4 °C (OR = 2.53, p < 0.001) and in samples spiked with the avian derived H1N2 subtype (OR = 2.26, p < 0.01). No significant differences in swIAV RNA detection and degradation of swIAV RNA in spiked OFs over time were observed between the three different stabilizing media.

Conclusion: Addition of stabilizers and storage of samples under cooled conditions significantly improved detection and subtyping of swIAV in spiked OFs.

Background: Glutamine is a nonessential amino acid and the most abundant amino acid found in the seminal plasma and sperm-rich fraction of boar semen. Glutamine plays an important role in enhancing glutathione (GSH) synthesis. It acts as an effective antioxidant in semen and provides intracellular defense to sperm against oxidative stress. This study aimed to improve the quality of frozen-thawed boar semen by using glutamine supplementation in a short-term semen extender during the holding time at 17 °C before cryopreservation.

Results: The results indicate that the total motility, progressive motility, LIN, STR, and WOB were the highest in the 20 mM supplementation group at the 2 h timepoint after thawing. Thus, the optimal concentration for glutamine supplementation in short-term boar semen extender during the holding time at 17 °C was 20 mM. Interestingly, at all of the time points after thawing, 20 mM glutamine supplementation exhibited the highest level of sperm viability and membrane integrity when compared to the CONTROL (0 mM) and other experimental dilution groups. Moreover, the acrosome integrity, mitochondrial activity, and capacitation status (F pattern) were significantly greater in the 20 mM supplementation group than the other groups at the 2 h timepoint after thawing.

Conclusion: Supplementation of glutamine at a concentration of 20 mM in a short-term semen extender (Bio Pig^®) during the 17 °C holding time before cryopreservation, which had a standard freezing extender (9.0% glycerol and 1.9% Equex paste), could enhance the post-thaw sperm motility and quality parameters of cryopreservation.

Background: Three experiments were conducted separately to determine the optimum standardized ileal digestible (SID) valine (Val) to lysine (Lys) ratio for early finishing (Experiment 1, 40 to 75 kg bodyweight), finishing (Experiment 2, 75 to 100 kg bodyweight), and late finishing (Experiment 3, 100 to 130 kg bodyweight) pigs. Dietary SID Val: Lys ratios were designed at 0.61, 0.65, 0.69, 0.73, and 0.77. The optimal SID Val: Lys ratio was estimated by different regression models, including a quadratic polynomial model, a two-slope quadratic broken-line model, a curvilinear-plateau model, and a one-slope straight broken-line model.

Results: In Exp.1, a total of 550 early finishing pigs (initially 40.3 kg bodyweight) were used in a 38-day growth trial. Pigs consuming 0.61 dietary SID Val: Lys ratio had lower final bodyweight compared to those fed 0.69 in diets. Using regression models, the optimal dietary SID Val: Lys requirement for average daily gain (ADG) was between 0.63 and 0.68, and for feed to gain ratio (F: G) was between 0.62 and 0.68, respectively. In Exp.2, 525 finishing pigs (initially 76.4 kg) were used in a 26-day trial. Based on regression models, estimate of the required SID Val: Lys for ADG was between 0.65 and 0.71, and for F: G was between 0.64 and 0.70, respectively. In Exp.3, 640 late finishing pigs (102 kg bodyweight) were used in a 27-day trial. No significant improvement was found for performance parameters of pigs from 100 to 130 kg, while 0.73 SID Val: Lys ratio resulted in the highest ADG and the lowest F: G from a numerical point of view.

Conclusions: These findings indicated that the optimum SID Val: Lys requirement for pigs from 40 to 75 kg was between 0.62 and 0.68, and for pigs from 75 to 100 kg was estimated to be between 0.64 and 0.71, using different regression models.

Background: 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.

Results: 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).

Conclusions: 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.

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.

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Background: 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.

Results: 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.

Conclusions: 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.

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.