Piglet Mortality Research Articles

Effect of season on weaned piglet mortality during transport greater than 8h under Canadian conditions.

North American swine producers commonly transport piglets away from sow farms at weaning. However, limited information on factors associated with piglet mortality during these transports is available. The objectives of this study were to identify transport characteristics that were associated with the occurrence of in-transit mortality (≥1 piglet found dead on arrival) and/or associated with increased rates of in-transit mortality using records of weaned piglet transport voluntarily provided by Canadian swine companies. Following cleaning and validation, records of 810 long duration (>8 h to <28 h) weaned piglet (min.: 4.2, max.: 7.7 kg) transports conducted between 2016 and 2017 by four companies were available to investigate risk factors for the occurrence of in-transit mortality. Transports originated in Ontario, Saskatchewan, or Alberta and 30% of transports had one or more mortality events recorded. Season of transport was significant in the final logistic regression model; the odds of a transport having mortality occur was greater during the winter (December, January, February) compared to the spring (March, April, May) (OR=1.8; 95% CI: 1.13-2.96; P = 0.013), summer (June, July, August) (OR= 2.1; 95% CI: 1.28-3.34; P = 0.003) and fall (September, October, November) (OR=2.2; 95% CI: 1.36-3.62; P = 0.001), with no differences observed between the other seasons. Additionally, records from 755 long duration weaned piglet (min.: 4.2, max.: 7.9 kg) transports conducted between 2014 and 2017 by a single company was used to identify risk factors for increased rates of in-transit mortality. Transports originated in Saskatchewan or Alberta and 44.9% of transports had one or more mortality events recorded with in-transit mortality rates ranging from 0.00% to 6.16%. Season of transport was again significant in the final negative binomial regression model. The rate of piglet death in-transit was increased in all seasons compared to the summer with winter transport having the highest predicted rate of in-transit mortality. Transports conducted during the winter had a rate of in-transit mortality nearly five times greater compared to transports conducted during the summer (IRR= 4.94; 95% CI: 3.11-7.87; P = 0.000) and approximately three times greater compared to transports conducted during the fall (IRR=2.7; 95% CI: 1.73-4.30; P = 0.000) and spring (IRR=3.1; 95% CI: 1.96-4.99; P = 0.000). These results suggest that winter transport in Western Canada is an area of opportunity to reduce in-transit mortality during long duration weaned piglet transport. Research investigating transport practices that may mitigate the effects of extreme cold (e.g., space allowance, bedding provision) would be useful for informing specific recommendations for this age group.

Effectiveness of gilt acclimatization - improvement procedures in a farm with recurrent outbreaks of porcine epidemic diarrhea.

Porcine epidemic diarrhea (PED) is a severe infectious disease that causes very high mortality in newborn piglets up to 2-3 weeks age. The main cause of repeated outbreaks of PED in infected farms is the continuing circulation of the PED virus (PEDV). Improper gilt management, including inappropriate gut feedback, commingling, and inadequate immunization, causes a prolonged virus circulation in breeding herds. Moreover, insufficient transfer of passive immunity through the colostrum to newborn piglets can also increase infection risk. Therefore, a gilt management program that controls infection should focus on infection monitoring and acclimatization. We investigated the source of recurrent PEDV outbreaks and examined how the effect of immunization methods, specifically using gut feedback mechanism and vaccination, can reduce PEDV circulation and improve immune responses in replacement gilts. The study site was a segregated commercial production farm with endemic PEDV. The acclimatization methods included gut feedback and vaccination. This longitudinal study evaluated two strategies of gilt acclimatization against PEDV: Program 1 (routine farm management) and Program 2 (early feedback program and all-in-all-out system). Levels of PED RNA in fecal samples were measured using quantitative reverse transcription-polymerase chain reaction, and the PEDV S gene was sequenced. Porcine epidemic diarrhea-specific immune responses were assessed using enzyme-linked immunosorbent assay and the serum neutralization test. Porcine epidemic diarrhea outbreaks occurred in the farrowing, nursery, and finishing units and farrowed litters 5-10 days old were symptomatic of PED. Phylogenetic analyses of the S gene showed PEDV sequence divergence between PEDV field strains and vaccine strain, which may contribute to periodic outbreaks and continued persistence of PEDV in the farm. After gut feedback and acclimatization, replacement gilts from Program 1 continued to shed PEDV before being introduced to sow herds, while those from Program 2 did not shed PEDV before being introduced to sow herds. However, the components of the immune response against PEDV in serum samples, including specific immunoglobulin (Ig)G, specific IgA, and neutralizing antibodies were lower in gilts of Program 2 than those in Program 1. We speculate that implementing the appropriate gilt acclimatization program can control PEDV circulation in farm. However, the acclimatization methods in Program 2 did not induce a strong and adequate immune response in replacement gilts. Therefore, maternal immunity levels and the degree of protection against PEDV require further study.

Genome-scale CRISPR screen identifies TRIM2 and SLC35A1 associated with porcine epidemic diarrhoea virus infection

Porcine epidemic diarrhoea (PED) caused by the porcine epidemic diarrhoea virus (PEDV) is the most devastating disease in the global pig industry due to its high mortality rate in piglets. The host factors critical for PEDV replication are poorly understood. Here, we designed a pooled African green monkey genome-scale CRISPR/Cas9 knockout (VeroCKO) library containing 75,608 single guide RNAs targeting 18,993 protein-coding genes. Subsequently, we use the VeroCKO library to identify key host factors facilitating PEDV infection in Vero E6 cells. Several previously unreported genes associated with PEDV infection are highly enriched post-PEDV selection. We discovered that knocking out the tripartite motif 2 (TRIM2) and the solute carrier family 35 member A1 (SLC35A1) inhibited PEDV replication. Virtual screening and molecular docking approaches showed that chem-80,048,685 (M2) s ignificantly inhibited PEDV attachment and late replication by impeding SLC35A1. Furthermore, we found that knocking out SLC35A1 in Vero E6 cells upregulated a disintegrin and metalloprotease protein-17 (ADAM17) by splicing porcine aminopeptidase N (pAPN) and angiotensin-converting enzyme 2 (ACE2) ectodomains to reduce PEDV-infection in a CMP-Sialic Acid (CMP-SA) cell entry-independent manner. These findings provide a new perspective for a better understanding of host-pathogen interactions and new therapeutic targets for PEDV infection.

Preparation and immunogenicity evaluation of mRNA vaccine against porcine epidemic diarrhea

Porcine epidemic diarrhea (PED) is a highly contagious disease that causes high mortality in suckling piglets. Although several licensed inactivated and live attenuated vaccines were widely used, the infection rate remains high due to unsatisfactory protective efficacy. In this study, mRNA vaccine candidates against PED were prepared, and their immunogenicity was evaluated in mice and pregnant sows. The mRNA PED vaccine based on heterodimer of viral receptor binding region (RBD) showed good immunogenicity. It elicited robust humoral and cellular immune responses in mice, and the neutralizing antibody titer reached 1:300 after a single vaccination. Furthermore, it induced neutralizing antibody level similar to that of the inactivated vaccine in pregnant sows. This study developed a new design of PED vaccine based on the mRNA-RBD strategy and demonstrated the potential for clinical application.

Genetic and phenotypic time trends of litter size, piglet mortality, and birth weight in pigs

IntroductionLitter size in pigs has increased steadily since 1990. Because of unfavorable genetic correlations with piglet mortality, breeding goals should include survival traits next to litter size. Unbalanced breeding programs that neglect this requirement have produced increased mortality levels, attracting negative public attention. Balanced breeding does not have this disadvantage, but the general public is largely unaware of this.MethodsWe present long-term time trends as realized in commercial breeding. The data includes (i) phenotypes of litter size, piglet birth weight, and piglet mortality, as used in routine breeding value estimation; and (ii) the genomic Best Linear Unbiased Prediction (gBLUP) estimated breeding values thus obtained. Piglet mortality (2001–2022) and birth weight (2009–2022) phenotypes were related to litter size by recording year. Estimated breeding values (EBVs) for the mortality traits were regressed on those for litter size by birth year (2012–2022).ResultsAverage litter size is very weakly correlated to the mortality (R2 ≤ 0.06) and birth weight (0.07 ≤ R2 ≤ 0.26) traits, and those correlations are unfavorable (antagonistic) within each year. However, all traits analyzed here show favorable simultaneous phenotypic and genetic trends over time: the antagonisms are neutralized by balanced breeding. Above the annual mean litter size level, farrowing and lactation mortality rates increased with increasing litter size in every year (unfavorable), but the annual intercepts and the slopes decreased from 2001 to 2022 (favorable). Average litter birth weight decreased with litter size in every year (unfavorable), but the annual intercepts increased and the slopes decreased from 2009 to 2022 (favorable). The within-litter birth weight variation coefficient increased with litter size in every year (unfavorable), but the annual intercepts decreased from 2009 to 2022 (favorable). The proportion of low birth weights (i.e.,&amp;lt; 0.9 kg) for a given litter size is decreasing over time, and the critical birth weight level (below which lactation mortality increases strongly) is clearly population dependent and changes over time too.DiscussionThe increases in litter size and piglet survival rates due to balanced breeding policies lead to reduced total numbers of dead piglets (i.e., per country, per year) coinciding with a certain pig production volume (i.e., with a certain total number of weaned piglets).

A descriptive study of weaned piglet transport practices in Alberta, Ontario, and Saskatchewan, Canada between 2014 and 2018.

Canadian transport practices for shipments of newly weaned piglets are not well-described despite documentation requirements for those conducting the movement of these animals. The objective of this study was to describe the characteristics of weaned piglet transport events that occurred between 2014 and 2018 using records provided by five Canadian swine companies. Following cleaning and validation, the dataset included records from 6203 transport events involving the transport of approximately 6.9 million piglets (5.7kg, 4.1-7.9kg) from 62 origin sites in Alberta, Ontario, or Saskatchewan, Canada. This represents approximately 4.7% of the piglets estimated to have been weaned in Canada between 2014 and 2018, and 1.7% of sow farms in Canada according to 2016 National census data. Most transport events ended at farms in Canada (71.3%), while the remaining delivered piglets to one of eight American states. The predominant trailer types used were Straightdeck (51.4%) and Potbelly (36.6%), but this did not reflect the number of piglets transported as Potbelly trailers have greater load capacity. Transport events most frequently involved loading piglets from one origin barn and delivering them to a single destination barn (78.1%). Only transport events involving export to the United States picked up piglets from, or delivered them to, more than one farm site. Most transport events had very short trip distances (median distance: 48.0km; IQR: 497.0), but a marked range was observed (1.8-2931.2km). Average daily temperature data matched to the transport records by origin and destination location demonstrated ambient environmental conditions during these transport events ranged from -30.3-28.7°C. Overall, less than 10% of transport events had mortality occur. Comparable with other observational studies documenting weaned piglet mortality, the average in-transit mortality rate observed over the multiple seasons, companies, trip distances, and other characteristics in this dataset was 0.027%. However, instances of mortality over 1% did sporadically occur and could translate to considerable losses given the large load sizes common for piglets of this age and size (median load size: 1105 piglets; IQR: 1036 piglets). These data provide a better understanding of the interconnectedness of the Canadian swine industry as well as common transport practices which may inform future research on disease transmission in swine transport networks, or piglet welfare during transport. Additionally, variables that were not present in this dataset that would further strengthen these types of investigations are highlighted (e.g., space allowance).

Porcine epidemic diarrhea viruses from Vietnam: isolation, characterization, and neutralizing activity

Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death, with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were propagated successfully in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene showed that all 3 isolates belong to genogroup 2b, which is closely related to other prevalent Asian strains. A comparison of the amino acid sequence revealed a 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013–2015, suggesting that field PED viruses (PEDVs) are evolving continuously. Experiments in animals showed that the antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log2) of neutralizing antibodies against the homologous strain and a relatively moderate level of neutralizing antibodies against the field isolates. This finding would be helpful in selecting a PEDV strain for vaccine development.

A Customized Novel Blocking ELISA for Detection of Bat-Origin Swine Acute Diarrhea Syndrome Coronavirus Infection.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly discovered emerging alphacoronavirus. SADS-CoV shares over 90% genome sequence identity with bat alphacoronavirus HKU2. SADS-CoV was associated with severe diarrhea and high mortality rates in piglets. Accurate serological diagnosis of SADS-CoV infection is key in managing the emerging SADS-CoV. However, thus far there have been no effective antibody-based diagnostic tests for diagnose of SADS-CoV exposure. Here, monoclonal antibody (MAb) 6E8 against SADS-CoV N protein accurately recognized SADS-CoV infection. Then, MAb 6E8 was utilized as a blocking antibody to develop blocking ELISA (bELISA). We customized the rN coating antigen with concentration 0.25 μg/mL. According to receiver operator characteristic curve analysis, the cutoff value of the bELISA was determined as 38.19% when the max Youden index was 0.955, and specificity was 100%, and sensitivity was 95.5%. Specificity testing showed that there was no cross-reactivity with other serum positive swine enteric coronaviruses, such as porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), porcine rotavirus (PoRV), and porcine sapelovirus (PSV). In conclusion, we customized a novel and high-quality blocking ELISA for detection of SADS-CoV infection, and the current bELISA will be linked to a clinical and epidemiological assessment of SADS-CoV infection. IMPORTANCE SADS-CoV was reported to be of high potential for dissemination among various of host species. Accurate serological diagnosis of SADS-CoV infection is key in managing the emerging SADS-CoV. However, thus far there have been no effective antibody-based diagnostic tests for diagnose of SADS-CoV exposure. We customed a novel and high-quality bELISA assay for detection of SADS-CoV N protein antibodies, and the current bELISA will be linked to a clinical and epidemiological assessment of SADS-CoV infection.

Physiology and management of the peri-parturient sow in the context of changing production conditions.

Genetic selection has resulted in a considerable increase in litter size, paralleled by an increase in farrowing duration and perinatal mortality. This paper describes some of the physiological changes around farrowing, and how genetic trends and sow management interact with these. Compromised farrowing can be related to nutritional management, or to housing conditions and handling of periparturient sows. Transition diets for example, can be formulated to support calcium homeostasis and alleviate constipation. The opportunity to expression natural behaviours and minimising stress around farrowing can further optimise farrowing conditions and reduce piglet mortality. Loose farrowing systems are part of the answer to the challenges around farrowing, however, current systems do not perform consistently. In conclusion, increased farrowing duration and increased perinatal mortality may to some extent be inevitably related to trends in pig production, however, they can be improved by nutritional measures, housing conditions and farrowing management.

A note on sows' behaviour towards humans during lactation in farrowing pens with short-term fixation and its effects on piglet mortality

The objective of this study was to determine a relationship between sows’ aggressive behaviour towards humans in farrowing pens with space to move freely and its reproductive outcome. A total of 215 crossbred (Large White x Landrace) sows were included in the research. All sows were housed in farrowing pens with movable crates whereby the crate was closed for five days around farrowing. To measure the sows’ behaviour towards a stockperson, the reaction on being separated from her piglets when handled were scored in week 1 and week 4 of lactation in a separation test. Each sow was scored between 1 (not aggressive) and 5 (extremely aggressive). In addition, reproductive performance was documented as piglets born alive, their birth and weaning weight, piglet losses and piglet losses due to crushing. The majority of the sows showed no aggressive behaviour (scores 1 and 2) in both tests (86.7%). However, sows reacted significant more aggressively in week 1 (16.7%) than in week 4 (10.0%; p < 0.05). The sows’ aggression towards the stockperson had a significant influence on piglet losses. Regardless of whether the sows were aggressive only in week 1 or week 4 or at both times, the aggressive sows (scores 3 to 5) lost significantly more piglets than the sows classified as non-aggressive (scores 1 and 2) (20.1% ± 2.83 vs. 14.1% ± 0.89; p < 0.05). Furthermore, aggressive sows tended to crush more piglets compared to non-aggressive sows (8.91% ± 1.98 vs. 5.59% ± 0.63; p = 0.08). These results indicate that aggressive behaviour of sows towards humans cannot be considered equivalent to good maternal behaviour of sows.

HSPA5 Promotes Attachment and Internalization of Porcine Epidemic Diarrhea Virus through Interaction with the Spike Protein and the Endo-/Lysosomal Pathway.

Porcine epidemic diarrhea virus (PEDV) has caused huge economic losses to the global pig industry. The swine enteric coronavirus spike (S) protein recognizes various cell surface molecules to regulate viral infection. In this study, we identified 211 host membrane proteins related to the S1 protein by pulldown combined with liquid-chromatography tandem mass spectrometry (LC-MS/MS) analysis. Among these, heat shock protein family A member 5 (HSPA5) was identified through screening as having a specific interaction with the PEDV S protein, and positive regulation of PEDV infection was validated by knockdown and overexpression tests. Further studies verified the role of HSPA5 in viral attachment and internalization. In addition, we found that HSPA5 interacts with S proteins through its nucleotide-binding structural domain (NBD) and that polyclonal antibodies can block viral infection. In detail, HSPA5 was found to be involved in viral trafficking via the endo-/lysosomal pathway. Inhibition of HSPA5 activity during internalization would reduce the subcellular colocalization of PEDV with lysosomes in the endo-/lysosomal pathway. Together, these findings show that HSPA5 is a novel PEDV potential target for the creation of therapeutic drugs. IMPORTANCE PEDV infection causes severe piglet mortality and threatens the global pig industry. However, the complex invasion mechanism of PEDV makes its prevention and control difficult. Here, we determined that HSPA5 is a novel target for PEDV which interacts with its S protein and is involved in viral attachment and internalization, influencing its transport via the endo-/lysosomal pathway. Our work extends knowledge about the relationship between the PEDV S and host proteins and provides a new therapeutic target against PEDV infection.

Selecting the optimal strategies when using nurse sows for supernumerous piglets.

Hyper-prolific sows frequently do not have a sufficient number of functional teats for their piglets to nurse which has led to the use of nurse sows to manage these surplus piglets. This review discusses strategies for using nurse sows and factors that influence preweaning survival and weight gain of their litters, as well as those that affect their subsequent rebreeding performance. Rearing piglets using a nurse sow can be as successful as piglets reared with their biological mother and is thus a powerful management tool to decrease preweaning piglet mortality. Selecting a young sow as nurse sow is beneficial for piglet survival; however, piglets nursing first parity sows often have a lower daily weight gain than piglets nursing multiparous sows. A litter of uniform surplus piglets is preferably handled using the two-step nurse sow strategy. A consequence of nonuniform litters will most likely be an increased mortality and decreased weaning weight among the smallest piglets within a litter. The subsequent fertility of nurse sows is not compromised. There is an increased risk of lactational oestrus when using nurse sows leading to an increased weaning-to-oestrus interval; however, litter size in nurse sows is identical or even moderately higher in the subsequent parity compared with nonnurse sows.

Administration of ketoprofen in postpartum sows to control the incidence of post-parturient disorders and improve piglet survival rate.

Inflammation and pain management in postpartum hyperprolific sows is currently an important animal welfare issue in the swine industry. The present study investigates effects of ketoprofen treatment on the incidence of post-parturient disorders, feed intake, colostrum yield, piglet colostrum intake, colostrum immunoglobulin G (IgG) and piglet mortality rate during the first 3 days of postnatal life. In total, 61 Danish Landrace×Yorkshire crossbred sows and their offspring (n = 833) were included in the experiment. The sows were randomly distributed into two groups: i) control (n = 31), sows were treated with tolfenamic acid 2 mg per kg for 2 days postpartum; ii) ketoprofen (n = 30), sows were treated with ketoprofen 3 mg per kg for 2 days postpartum. The farrowing process of the sows was monitored for 24 h daily, and data associated with farrowing were collected. Piglet colostrum intake, sow colostrum yield and colostrum IgG were determined. During the first 3 days postpartum, the incidence of sows that had fever did not differ between control and ketoprofen groups (51.6% and 56.7%, respectively, p = 0.692). Piglet colostrum intake did not differ between control and ketoprofen groups (p = 0.736). However, the proportions of piglets that had inadequate colostrum intake were 71.3%, 22.6%, and 5.4% in those with birth weights of <1.0 kg, 1.0 to 1.29 kg, and ≥1.30 kg, respectively (p<0.001). The piglet mortality rate did not differ between control and ketoprofen groups (p = 0.808). Administration of ketoprofen in postpartum sows for 2 days can control the evidence of post-parturient disorders in sows as effectively as the use of tolfenamic acid. No deleterious effect of ketoprofen was detected on sow colostrum yield, piglet colostrum intake and piglet mortality. Therefore, ketoprofen can be recommended as an alternative anti-inflammatory drug used in postpartum sows.

Epidemiological and genetic characterization of porcine epidemic diarrhea virus in the Mekong Delta, Vietnam, from 2015 to 2017.

Porcine epidemic diarrhea (PED) virus (PEDV) is a highly contagious virus. PED was first identified in 2008 and has greatly affected the Vietnamese pig production economy. The aim of this study was to investigate the epidemiological and genetic characteristics of PEDV in piglet herds in the Mekong Delta, Vietnam. Diarrheal stool and intestinal samples from 2262 piglets from 191 herds in five provinces were collected to test for the presence of PEDV. Ten PEDV strains were randomly selected for sequencing, and four genes encoding PEDV structural proteins were analyzed. The rates of herds and samples positive for PEDV were 27.23% and 27.72%, respectively. In positive herds, the morbidity and mortality of PEDV-positive piglets were 97.97% and 79.06%, respectively, with most of the infected piglets under 7 days of age. Phylogenetic analysis showed that the 10 PEDV strains from this study clustered with genotype G2 strains from Vietnam and neighboring countries. Many amino acid substitutions were identified in important antigenic regions in the spike protein of the 10 strains when compared to four PEDV vaccine strains. This study provides novel insights into the epidemiology and genetic diversity of circulating PEDV strains, which could facilitate the development of an appropriate and proactive strategy for controlling PED.

A Candidate Antigen of the Recombinant Membrane Protein Derived from the Porcine Deltacoronavirus Synthetic Gene to Detect Seropositive Pigs.

Porcine deltacoronavirus (PDCoV) is an emergent swine coronavirus which infects cells from the small intestine and induces watery diarrhea, vomiting and dehydration, causing mortality in piglets (>40%). The aim of this study was to evaluate the antigenicity and immunogenicity of the recombinant membrane protein (M) of PDCoV (rM-PDCoV), which was developed from a synthetic gene obtained after an in silico analysis with a group of 138 GenBank sequences. A 3D model and phylogenetic analysis confirmed the highly conserved M protein structure. Therefore, the synthetic gene was successfully cloned in a pETSUMO vector and transformed in E. coli BL21 (DE3). The rM-PDCoV was confirmed by SDS-PAGE and Western blot with ~37.7 kDa. The rM-PDCoV immunogenicity was evaluated in immunized (BLAB/c) mice and iELISA. The data showed increased antibodies from 7 days until 28 days (p < 0.001). The rM-PDCoV antigenicity was analyzed using pig sera samples from three states located in "El Bajío" Mexico and positive sera were determined. Our results show that PDCoV has continued circulating on pig farms in Mexico since the first report in 2019; therefore, the impact of PDCoV on the swine industry could be higher than reported in other studies.

Effect of tolfenamic acid in postpartum gilts and the performance of their piglets

Postpartum dysgalactia syndrome (PPDS) is a common disorder affecting sows in intensive production systems. In most cases, hypogalactia is not clearly identified and assumes a subclinical aspect. Therefore, the present study aimed to evaluate the effect of a nonsteroidal anti-inflammatory drug (NSAID) based on tolfenamic acid as a prophylactic treatment for PPDS and the performance of suckling piglets. Gilts (n = 319) were randomly divided into two groups: a tolfenamic acid group (n = 157) and a control (n = 162). The tolfenamic acid group received a single intramuscular injection (1 ml/20 kg of 4% tolfenamic acid) after farrowing, whereas the control group received no treatment. The occurrence of PPDS was confirmed. All piglets (n = 4,466) were weighed at 1, 4, and 18 days of age. All litters were evaluated for weight gain, the occurrence of diarrhea, and mortality between 4 and 18 days of age. PPDS variables were analyzed using logistic regression. Piglet weights were analyzed based on covariance while considering the effects of initial weight and the presence of diarrhea. Tolfenamic acid had no significant effect on the incidence of PPDS. The tolfenamic acid group had a 0.41% lower piglet mortality rate until 18 days of age. Tolfenamic acid administered prophylactically to gilts after farrowing reduced piglet mortality during lactation and promoted weight gain.

Review on diseases and health management of poultry and swine

Poultry and swine production play an important role in countries' socioeconomic development by providing proteins that support food and nutrition security. However, several infectious and non-infectious diseases hinder the production of swine and poultry. Therefore, this review aim to provide highlight of the common disease and health management of poultry and swine. Poultry production has suffered from different pathogenic microorganisms that cause devastating economic losses in poultry industries worldwide. Poultry can be infected with common diseases like endoparasites, ectoparasites, infectious bronchitis, Marek's disease, fowl cholera, salmonellosis, infectious coryza, fowl pox, avian encephalomyelitis, etc. Health management is a system of preventive medicine that considers the whole poultry farms and the total influences, including social, with respect to relationships with others in the flock, psychological, and environmental factors that affect health. Swine production can be destructed by the influence of infectious diseases, which include Mycoplasma Hyopneumoniae, Actinobacillus pleuropneumoniae, Porcine Reproductive and Respiratory Syndrome Virus, Trichinella spp., Toxoplasma gondii, Salmonella spp., Campylobacter, and Leprospira. This all causes respiratory problems, leg problems, reproductive disorders, gastrointestinal problems, claw and skin problems, parasitic infections, and piglet mortality. Endoparasites and ectoparasites are regarded as the most significant constraints for welfare and health, as well as economic loss, in swine production, particularly during the post-weaning period. However, health management of swine production can reduce the effect of disease and optimize their productivity. Herd health management practices include vaccination, genetic improvement, and observation for all animals’ clinical signs, record keeping, detection and treatment of injury, sanitation, disease, pest control, and animal handlers. Generally, disease has a great risk to the health of poultry and swine animals that causes a decrement in their production. Therefore, the health management on poultry and swine farms should have to be strictly measured and further studies need to be conducted to solve the major problem of economic loss of production.

Hypericum japonicum extract inhibited porcine epidemic diarrhea virus in vitro and in vivo.

Porcine epidemic diarrhea virus (PEDV) infection causes lethal watery diarrhea and high mortality in neonatal piglets, leading to huge economic losses in the global swine industry. Currently, the existing commercial vaccines cannot fully control PEDV, so it is urgent to develop effective antiviral agents to complement vaccine therapy. In the present study, we investigated the antiviral effect of Hypericum japonicum extract (HJ) against PEDV in vivo and in vitro. In in vitro assays, HJ could directly inactivate PEDV strains; moreover, it inhibited the proliferation of PEDV strains in Vero or IPI-FX cells at its non-cytotoxic concentrations. Time of addition assays revealed that HJ mainly inhibited PEDV at the later stages of the viral life cycle. In in vivo, compared with the model group, HJ could reduce the viral titers in the intestines of infected piglets, and improve their intestinal pathological, indicating that HJ could protect the newborn piglets from highly pathogenic PEDV variant infection. Furthermore, this effect may be related to the fact that HJ can not only directly inhibit viruses, but also regulate the structure of intestinal microbiota. In conclusion, our results indicate that Hypericum japonicum could inhibit PEDV replication in vitro and in vivo and might possess the potential to develop as the anti-PEDV drug.

Porcine Epidemic Diarrhea Virus Replication in Human Intestinal Cells Reveals Potential Susceptibility to Cross-Species Infection.

Various coronaviruses have emerged as a result of cross-species transmission among humans and domestic animals. Porcine epidemic diarrhea virus (PEDV; family Coronaviridae, genus Alphacoronavirus) causes acute diarrhea, vomiting, dehydration, and high mortality in neonatal piglets. Porcine small intestinal epithelial cells (IPEC-J2 cells) can be used as target cells for PEDV infection. However, the origin of PEDV in pigs, the host range, and cross-species infection of PEDV remain unclear. To determine whether PEDV has the ability to infect human cells in vitro, human small intestinal epithelial cells (FHs 74 Int cells) were inoculated with PEDV LJX and PEDV CV777 strains. The results indicated that PEDV LJX, but not PEDV CV777, could infect FHs 74 Int cells. Furthermore, we observed M gene mRNA transcripts and N protein expression in infected FHs 74 Int cells. A one-step growth curve showed that the highest viral titer of PEDV occurred at 12 h post infection. Viral particles in vacuoles were observed in FHs 74 Int cells at 24 h post infection. The results proved that human small intestinal epithelial cells are susceptible to PEDV infection, suggesting the possibility of cross-species transmission of PEDV.

Changes in intestinal morphology, number of mucus-producing cells and expression of coronavirus receptors APN, DPP4, ACE2 and TMPRSS2 in pigs with aging

Porcine enteric viral infections cause high morbidity and mortality in young piglets (<3 weeks). Later, these rates decrease with age. This age-dependent infectivity remains largely unexplored. This study investigated the changes in intestinal morphology, number of mucus-producing cells and expression level of coronavirus receptors in three age groups of pigs. Villus height and crypt depth increased with age from 3 days to 3 months in duodenum and ileum but not in mid-jejunum, where the villus height decreased from 580 µm at 3 days to 430 µm at 3 months. Enterocyte length-to-width ratio increased from 3 days to 3 months in all intestinal regions. The number of mucus-producing cells increased with age in the intestinal villi and crypts. The Brunner’s glands of the duodenum contained the highest concentration of mucus-producing cells. The expression of coronavirus receptor APN was highest in the small intestinal villi at all ages. DPP4 expression slightly decreased over time in jejunum and ileum; it was highest in the ileal villi of 3-day-old piglets (70.2% of cells). ACE2 and TMPRSS2 positive cells increased with age in jejunal and ileal crypts and were particularly dominant in the ileal crypts (> 45% of cells). Except for the expression of DPP4 in the jejunum and ileum of young pigs, the expression pattern of the selected coronavirus receptors was very different and not correlated with the age-dependent susceptibility to viral infections. In contrast, the number of mucus-producing cells increased over time and may play an essential role in protecting enteric mucosae against intestinal viruses.