Porcine Health Management最新文献

Background: Respiratory disease is an economically important disease in the swine industry. Housing air quality control is crucial for maintaining the respiratory health of pigs. However, maintaining air quality is a limitation of current housing systems. This study evaluated the growth and health parameters of pigs raised under different environmental conditions and identified key environmental variables that determine respiratory health. Eighty (Largewhite × Landrace) × Duroc crossed growing pigs (31.71 ± 0.53 kg) were equally distributed into two identical climate-controlled houses with distinct environmental conditions (CON = normal conditions and TRT = poor conditions). Two-sample tests were performed to compare the means of the groups, and a random forest algorithm was used to identify the importance scores of the environmental variables to respiratory health.

Results: Pigs in the TRT group were significantly exposed to high temperatures (28.44 vs 22.78 °C, p < 0.001), humidity (88.27 vs 61.86%, p < 0.001), CO₂ (2,739.93 vs 847.91 ppm, p < 0.001), NH₃ (20.53 vs 8.18 ppm, p < 0.001), and H₂S (14.28 vs 6.70 ppm, p < 0.001). Chronic exposure to these factors significantly reduced daily feed intake (1.82 vs 2.32 kg, p = 0.002), resulting in a significant reduction in average daily gain (0.72 vs 0.92 kg, p = 0.026), increased oxidative stress index (3.24 vs 1.43, p = 0.001), reduced cortisol levels (2.23 vs 4.07 mmol/L, p = 0.034), and deteriorated respiratory health status (74.41 vs 97.55, p < 0.001). Furthermore, a random forest model identified Min CO₂, Min NH₃, and Avg CO₂ as the best predictors of respiratory health, and CO₂ was strongly correlated with NH₃ and H₂S concentrations.

Conclusions: These findings emphasize the critical importance of proper environmental management in pig farming and suggest that regular monitoring and control of either CO₂ or NH₃, facilitated by environmental sensors and integration into intelligent systems, can serve as an effective strategy for improving respiratory health management in pigs.

Background: Salmonella is widespread in pig husbandry and pork is an important source for human salmonellosis. Surveillance programmes are conducted in many European countries and various management measures are implemented on farm level to control Salmonella. Piglet or maternal vaccination can reduce Salmonella shedding and lower the likelihood of piglet infection. Proper management of risk factors can help to maintain low infection pressure. The aim of the study was to evaluate the effect of sow vaccination and piglet vaccination on Salmonella seroprevalence at slaughter.

Results: Different vaccination strategies were evaluated for their effect on seroprevalences in nursery (serum) and slaughter pigs (meat juice) in a farrow-to-finish production chain tested positive for Salmonella Typhimurium (ST). Antibody levels of four piglet groups from one rearing farm and of pigs from four downstream fattening farms were measured by Salmonella LPS-ELISA in a longitudinal study (UNVAC: no vaccination against Salmonella; PIGVAC: piglets vaccinated twice with an attenuated Salmonella Cholerasuis (SC) live vaccine; SOWVAC-1: piglets born from sows vaccinated twice before farrowing with attenuated ST live vaccine; SOWVAC-2: Piglets from vaccinated sows (ST) which had been vaccinated twice already as a piglet (ST). Results revealed significantly lower ELISA optical density (OD) values (p < 0.05) and fewer serological positive piglets (OD > 40) from groups PIGVAC, SOWVAC-1 and SOWVAC-2 compared to group UNVAC at the end of rearing period. Summarizing results from pigs of all fattening farms revealed that pigs from group PIGVAC had significantly lower ELISA OD values in meat juice samples than all other groups (p < 0.05).

Conclusion: Piglet (SC) and sow vaccination (ST) led to significant reduction in detectable antibodies in a ST positive production chain and thus to reduced likelihood of infection during rearing. The results reflect that vaccination with a live attenuated SC vaccine resulted in cross-protection against ST without producing antibodies detectable by standard Salmonella LPS-ELISA. Summarizing all fattening farms, piglet vaccination reduced seroprevalence at the time of slaughter. In conclusion, sow and piglet vaccination with attenuated live vaccines against Salmonella are good instruments to reduce the infection pressure in the rearing period but need additional management measures to show effect on seroprevalence at slaughter.

Background: Glaesserella parasuis (G. parasuis) is the primary agent of Glässer's disease, significantly affecting nursery and early fattening piglets. Current prophylactic measures, mainly serovar-specific bacterins administered to sows, are limited by maternal immunity, which can interfere with active immunization in piglets. Subunit vaccines containing G. parasuis-specific antigenic molecules show promise but are not yet commercially available. Transferrin-binding proteins (Tbp), which enable G. parasuis to acquire iron in low-iron environments like mucosal surfaces, have been proposed as potential vaccine antigens. The mucosal administration of a TbpB-based subunit vaccine could provide a promising solution to overcome the limitations posed by maternal immunity, offering an effective approach to control the disease in weaning piglets. This study, conducted in two phases, primarily evaluates (days 0-45) the immunogenicity of a two-dose oral mucosal TbpB-based subunit vaccine (TbpB^Y167A) administered to colostrum-deprived piglets, and subsequently (days 45-52), its heterologous protection by challenging these piglets with four G. parasuis clinical isolates from different TbpB clusters (I, III) and serovars (SV1, SV4, SV5, SV7) recovered from Spanish pig farms.

Results: The oral mucosal administration of the two-dose TbpB-based vaccine induced a robust humoral immune response in immunized colostrum-deprived piglets, significantly increasing IgA and IgM concentration 15 days after the second dose (p < 0.01). Upon challenge with four G. parasuis clinical isolates, the vaccine demonstrated heterologous protection, markedly improving survival rates (OR: 8.45; CI 95%: 4.97-14.36) and significantly reducing clinical signs and lesions, regardless of the TbpB cluster and serovar. The vaccine reduced G. parasuis colonization in the respiratory tract (p < 0.0001) and G. parasuis systemic target tissues, like tarsus and carpus joints, liver, and brain (p < 0.05). Immunohistochemical analysis showed a lower macrophage count in different lung locations of immunized piglets (p < 0.0001).

Conclusions: This study demonstrates that oral mucosal administration of the TbpB^Y167A subunit vaccine in piglets provides effective heterologous protection against diverse virulent European G. parasuis field isolates, significantly reducing bacterial colonization and dissemination. This vaccine offers a promising alternative to traditional bacterins, overcoming limitations due to maternal immunity, and represents a strong candidate for universal vaccination against Glässer's disease.

Background: The herd age structure, i.e., distribution of sows within a farm based on their parity number, and its management are essential to optimizing farm reproductive efficiency. The objective of this study is to define different types of herd age structure using data from 623 Spanish commercial sow farms. Additionally, this study aims to determine which type of herd age structure can enhance reproductive efficiency at the farm level.

Results: Farms are classified into three groups according to the quadratic function fitted to the percentage of sows by parities. This classification unveils three types of herd structures: type 1 (HS1) exhibits a concave-downward trend, with a higher percentage of sows in intermediate parities (mean of 45.5% sows between the 3rd to 5th parity); type 2 (HS2) presents a trend curve that is close to a straight line, with a gradual decrease in the percentage of sows per parity (approximately 2% loss of sows census per parity); and type 3 (HS3) shows an upward concave trend curve, with an increase in the percentage of sows in later parities (19.0% of sows between 7th and ≥ 8th parity). Parametric tests assess productivity differences between the three types of herd structures (p < 0.01). HS1 farms have the best productive outcomes over a year, with 31.2 piglets weaned per sow and year (PWSY) and a farrowing rate of 87%, surpassing HS2 and HS3 farms (30.1 and 28.7 PWSY; 85.3% and 83.4% farrowing rates, respectively). HS1 also have the lowest percentage of sows returning to oestrus (11.8%) and the highest number of weaned piglets per litter (12.8), compared to HS2 (13.2% and 12.4 piglets weaned) and HS3 (15.1%, 11.9 piglets weaned). These differences show a medium effect size (η² between 0.06 to < 0.14).

Conclusions: This study shows the importance of herd age structure on sow-breeding farms as a factor of reproductive efficiency. The results endorse the proposed classification based on the curvature of the trend parabola obtained with the quadratic function to categorize herd structures into three groups. Additionally, these findings highlight the importance of considering the herd age structure in farm decision-making.

Background: Several surveys conducted at slaughter sites have highlighted that gastric lesions are a widespread issue in fattening pigs, mainly due to feeding regimes. Diets with small particle sizes and low fibre contents guarantee high digestibility and performance but generate more rapid stomach emptying with a negative effect on gastric mucosa integrity. Providing fattening pigs with fibrous materials (e.g., straw provided in racks) or coarse fibrous ingredients (e.g., coarse silages) reduced the presence of gastric ulcers. The present research compares a traditional corn-soy-based diet with an experimental diet where bran and a portion of corn meal was substituted with whole ear and whole plant corn silages at the maximum dosages permitted by new Protected Designation of Origin for Italian dry-cured ham (20 and 10% of DM, respectively). This study aimed to examine the impact of the inclusion of corn silages in the diet on the productive performance of heavy Italian pigs and their ability to mitigate gastric mucosa damage.

Results: The growth performances were satisfactory (750-800 g/d) given the advanced interval of growth of animals (from 120 to 180 kg). However, the inclusion of corn silages tended to reduce the growth rate by 5-6% due to the reduction of organic matter digestibility, without compromising the slaughter traits or the back-fat fatty acid profile. The experimental diet substantially affected both stomach development and mucosal integrity. The first consequence was an increase in stomach weight of approximately 6% (P < 0.01) but the most notable advantage of coarse feeding was a reduction in stomach damage severity, with a low number of cases with higher scores in animals fed coarse materials (P < 0.01).

Conclusions: The dietary inclusion of corn silages (30% of diet DM) decrease effectivelly the severity of stomach damage in finishing heavy pigs. Based on the feeding trial performances, the perspective of feeding heavy pigs corn silage should consider specific agronomic and harvesting techniques to improve digestibility and not reduce the growth rate.

Background: Umbilical outpouchings (UO) are common in Danish weaners. In slaughter pigs UOs consist of various pathological diagnoses; however, no studies have assessed the pathology in weaners from randomly selected herds, nor the agreement between clinical examination findings and post-mortem results. The primary objective was to estimate the prevalence of UO-related clinical findings in weaners before euthanasia and the pathologic macroscopic findings after euthanasia. A secondary objective was to assess the agreement between the size of the UO, the presence of ulcers, and the diagnosis before and after euthanasia. Pigs were selected for euthanasia and included in the study because the individual farmer believed the pigs were already unfit for transport, would not make it to slaughter, or would become unsellable.

Results: In total 214 weaners euthanized due to UOs were examined both clinically and post-mortem. Clinically 65.4% of the UOs were large (≥ 11 cm) and 52.3% were unreducible. In the autopsy 78.5% of the UOs were large, and 54.2% had ulcers on their UO. The most prevalent pathological diagnoses were hernia (36.4%), hernia combined with cysts/abscesses (30.8%), cysts (11.7%), and abscesses (11.2%). Adhesions were found in 32.7%, haemorrhage in 22.7%, incarcerated intestines in 8.9%, and connective tissue related to the UO in 51.9% of the pigs post-mortem. The agreement between the size of the UO in the clinical examination and post-mortem was good, as was the sensitivity and specificity for detecting ulcers in the clinical examination compared to post-mortem.

Conclusion: Hernias were the most common pathological diagnosis in weaners euthanized due to UOs, and many pigs had complications related to their UO such as ulcers, adhesions, haemorrhage, or incarcerated intestines-all conditions that could impact the pig's welfare. The presence of connective tissue in the UO in more than half of the pigs indicated that many of the UOs had been present for an extended period. Clinical identification of the umbilical ring is difficult, but the clinical examination is useful for determining the size of the UO and the presence or absence of an ulcer, both critical factors when assessing a pig's welfare and fitness for transport. Clinical examination, however, has limited value in determining the aetiology of UOs.

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.