Swine Research Articles

First Report of Porcine Parvovirus 2 (PPV2) in Pigs from Colombia Associated with Porcine Reproductive Failure (PRF) and Porcine Respiratory Disease Complex (PRDC)

Pigs are affected by various parvoviruses (PPVs); eight have been reported to date (PPV1–PPV8). Porcine parvovirus 1 is considered a primary agent of porcine reproductive failure (PRF), while it is unknown whether other PPVs impact porcine health. Recently, the presence of PPV2 has been confirmed in the lung, either as a single agent or in the form of coinfection with other respiratory; therefore, it has been proposed as a potential participant in the porcine respiratory disease complex (PRDC). In the present study, the presence of PPV2 alone and coinfection with other viruses (PCV2, PCV3, and PRRSV) was evaluated in lung samples obtained from pigs with respiratory signs (respiratory group: RG) (n = 146) and stillborn lungs (stillborn group: SG) (n = 19) from 82 farms in the five regions with the highest swine production in Colombia. The overall PPV2 prevalence was 37.6% (62/165), with the highest proportion mainly detected in grow-finisher pigs (62.5%), while its herd prevalence was 51.2% (42/82). The most prevalent virus was PRRSV in both groups, while PPV2 alone was found only in the RG group. The most common dual coinfection in the RG and SG was PCV2/PRRSV (17.8% and 10.5%), while the most frequent coinfections involving PPV2 in the RG were PPV2/PCV2 (7.5%) and PPV2/PRRSV (4%) and PPV2/PCV2 (5.3%) in the SG. The most common triple coinfection was PPV2/PCV2/PRRSV at 15% in the RG and 21% in the SG, while quadruple coinfection PVV2/PCV2/PCV3/PRRSV was detected only in the RG (5.5%). Histopathological evaluation of 21 PPV2-positive lungs showed variable degrees of histiocytic or lymphohistiocytic interstitial pneumonia (9%) in the RG, while no significant changes were observed in SG; in addition, neutrophilic bronchopneumonia was observed in 73.7% if cases evaluated. In situ hybridization-RNAScope® confirmed the presence of PPV2 within pulmonary lesions in 2/19 RG pigs, while no in situ detection was observed in the SG pigs. The phylogenetic evaluation of seven PPV2 sequences detected in Colombia was compared with another 102 reported sequences, indicating that the Colombian strains are located in clade 2. Our results confirm the presence of PPV2 in pigs with PRDC alone and pigs coinfected with PCV2, PCV3, and PRRSV. Likewise, its presence alone or in coinfection in stillbirths suggests that PPV2 is also involved in PRF.

Molecular detection of Toxoplasma gondii in domestic and wild guinea pigs (Cavia spp.) from the Marangani district in Cuzco, Peru

Toxoplasmosis is a foodborne disease caused by the protozoan Toxoplasma gondii, and transmitted to humans by eating raw or undercooked meat, mainly. Poultry, beef, and pork are the main meats consumed in Peru; despite this, guinea pig meat is also widely consumed. For this reason, the objective of this study was to molecularly detect T. gondii in domestic and wild guinea pigs from the Marangani district in Cuzco, Peru, and identify some risk factors associated with this pathogen. DNA was extracted from the brain tissue samples of guinea pigs (30 domestic and 30 wild), and PCR protocols were used to amplify the internal transcribed spacer (ITS-1) region and a 529 bp fragment from the T. gondii genome. T. gondii DNA was detected in 14 (23.3%) guinea pigs. T. gondii frequency was 33.3% in domestic guinea pigs and 13.3% in wild guinea pigs. Our results demonstrated that guinea pigs represent an important source for T. gondii infection in human populations in this locality.

Natural selection on feralization genes contributed to the invasive spread of wild pigs throughout the United States.

Despite a long presence in the contiguous United States (US), the distribution of invasive wild pigs (Sus scrofa × domesticus) has expanded rapidly since the 1980s, suggesting a more recent evolutionary shift towards greater invasiveness. Contemporary populations of wild pigs represent exoferal hybrid descendants of domestic pigs and European wild boar, with such hybridization expected to enrich genetic diversity and increase the adaptive potential of populations. Our objective was to characterize how genetic enrichment through hybridization increases the invasiveness of populations by identifying signals of selection and the ancestral origins of selected loci. Our study focused on invasive wild pigs within Great Smoky Mountains National Park, which represents a hybrid population descendent from the admixture of established populations of feral pigs and an introduction of European wild boar to North America. Accordingly, we genotyped 881 wild pigs with multiple high-density single-nucleotide polymorphism (SNP) arrays. We found 233 markers under putative selection spread over 79 regions across 16 out of 18 autosomes, which contained genes involved in traits affecting feralization. Among these, genes were found to be related to skull formation and neurogenesis, with two genes, TYRP1 and TYR, also encoding for crucial melanogenesis enzymes. The most common haplotypes associated with regions under selection for the Great Smoky Mountains population were also common among other populations throughout the region, indicating a key role of putatively selective variants in the fitness of invasive populations. Interestingly, many of these haplotypes were absent among European wild boar reference genotypes, indicating feralization through genetic adaptation.

Social influence and attention bias in free-ranging domestic pigs: Effects of demonstrator rank and friendship

Pigs, as highly social animals, form stable hierarchies and different relationships to other members of their group. Pigs, mostly of very young ages, have been shown to use social learning to gather information about food locations and even extractive foraging techniques from various types of sources. The present study aims to investigate whether also adult pigs, living in a long-term stable kin-based sounder, use information of their group mates and, more specifically, whether this is based on their mates' rank or their relationship with them. The dominance order of 20 female semi-naturally housed Kune Kune pigs (aged between five to seven years) was established with dyadic hierarchy tests, where two pigs competed against each other over a monopolizable food source. Their affiliative relationships (i.e. friendships) towards each other were assessed based on observations during their daily lives. After finding suitable demonstrator dyads, differing in rank and/or relationship quality to the respective observer, six rounds of two-choice tests were conducted. Prior to each two-choice test, two demonstrators were positioned on each side of the observer and were allowed to feed from a trough with an assigned olfactory cue that provided additional information in the subsequent test. After two minutes, the observer pig was allowed to enter a test room and was given the choice between two food bowls, which were marked with the olfactory cues connected to the respective demonstrators. Results indicate that sows, irrespective of their own rank, preferred to pay attention to the relatively lower-ranking demonstrator during the exposure phase, possibly due to avoidance of the relatively higher-ranking demonstrator. Furthermore, the observers with higher sociability preferred to pay more attention to the demonstrators with whom they had better friendships. In the two-choice test, we found no significant effect of demonstrator rank or friendship. However, a left side bias in more sociable observers may point towards at least some social effects. Overall, the study provided evidence that not only dominance, but also socio-positive relationships between individuals affect the behaviour of domestic pigs.

The shelf life of pork depends on its quality and microbial and non-microbial meat destructors

This work aimed to establish the maximum shelf life of pork of different quality classes depending on the action of non-microbial and microbial destructors. To achieve this goal, samples were taken from the longest back muscles of domestic and industrial pig carcasses. Depending on the results of organoleptic research, pork was divided into three quality classes: 1) NOR (close to optimal quality indicators), 2) PSE (pale, soft, exudative), and 3) DFD (dark, firm, dry). After that, each of the samples was divided into 1 equal parts and placed for storage in a refrigerator (t = 3 ± 1 °C). Each day, one part of the samples was used for laboratory research. The purpose of laboratory research was to establish the freshness of meat by determining the reaction to peroxidase, amino-ammonia nitrogen, reaction to ammonia with Nessler's reagent, and the content of short-chain fatty acids. In addition, the level of MAFAnM was determined. The results of laboratory studies showed that the fastest signs of spoilage were registered in pork, with signs of PSE obtained after the slaughter of pigs on small farms. The first signs of deterioration appeared already on the sixth day of storage. The second fastest spoilage rate (on the eighth day) was meat samples of the PSE quality class taken from pigs of industrial origin. At the same time, the highest increase in microbial contamination during storage was registered in meat samples of industrial origin with signs of DFD. We found that the microbial contamination of pork depends not only on the initial contamination at the production site but also on the quality class of the meat. On the 12th day of pork storage, only NOR-class meat samples of industrial origin remained fresh. Comparing meat samples of the same quality classes, asserting a shorter shelf life and a higher risk of meat products obtained due to domestic origin and backyard slaughter of pigs is possible. The main reason is a combination of factors, the main of which are the impossibility of observing proper hygienic conditions for animal slaughter, poor bleeding, unbalanced diet, and others.

Exploring bacterial diversity and antimicrobial resistance gene on a southern Brazilian swine farm

The bacterial composition of and the circulation of antimicrobial resistance genes (ARGs) in waste from Brazilian swine farms are still poorly understood. Considering that antimicrobial resistance (AMR) is one of the main threats to human, animal, and environmental health, the need to accurately assess the load of ARGs released into the environment is urgent. Therefore, this study aimed to characterize the microbiota in a swine farm in southern Brazil and the resistome in swine farm wastewater treated in a series of waste stabilization ponds (WSPs). Samples were collected from farm facilities and the surrounding environment, representing all levels of swine manure within the treatment system. Total metagenomic sequencing was performed on samples from WSPs, and 16S-rDNA sequencing was performed on all the collected samples. The results showed increased bacterial diversity in WSPs, characterized by the presence of Caldatribacteriota, Cloacimonadota, Desulfobacterota, Spirochaetota, Synergistota, and Verrucomicrobiota. Furthermore, resistance genes to tetracyclines, lincosamides, macrolides, rifamycin, phenicol, and genes conferring multidrug resistance were detected in WSPs samples. Interestingly, the most abundant ARG was linG, which confers resistance to the lincosamides. Notably, genes conferring macrolide (mphG and mefC) and rifamycin (rpoB_RIF) resistance appeared in greater numbers in the late WSPs. These drugs are among the high-priority antibiotic classes for human health. Moreover, certain mobile genetic elements (MGEs) were identified in the samples, notably tnpA, which was found in high abundance. These elements are of particular concern due to their potential to facilitate the dissemination of ARGs among bacteria. In summary, the results indicate that, in the studied farm, the swine manure treatment system could not eliminate ARGs and MGEs. Our results validate concerns about Brazil's swine production system. The misuse and overuse of antimicrobials during animal production must be avoided to mitigate AMR.

Comparison of the effectiveness and efficiency of the grid and link search methods to recover scattered skeletal remains

The grid and link search methods are used to recover scattered skeletal remains. Neither have not been compared robustly and clear guidelines for the link method have not been sufficiently developed. The study aimed to compare the effectiveness and efficiency of both methods and propose guidelines for the link method. The scattering patterns of two scavengers of forensic relevance—slender mongooses (Galerella sanguinea) and black-backed jackals (Canis mesomelas)—were recreated using four pig skeletons (Sus scrofa domesticus). Two groups (n = 6 each) were assigned a different method to recover the scattered remains. The length of the search and when each bone was located for each scatter pattern was recorded for each group and scatter pattern. A Likert scale questionnaire assessed participants’ perceptions of their assigned method. A paired t-test (p = 0.005) compared the efficiency of each method and the questionnaire answers. Both methods were effective, recovering 100% of all remains. The link method was more efficient for both scatter patterns, despite there being no statistical significance (jackal: p = 0.089; mongoose: p = 0.464). Participants indicated favorable views for both methods; however, the link method scored significantly more favorably (p = 0.01) for efficiency. Specific guidelines were developed for the use of the link method. The link method is suggested for the recovery of scattered remains in forensic contexts, especially when the scavenger, its behavior, and scattering pattern is known or suspected.

African swine fever: implications for the Italian pork trade.

In early 2022, the confirmed presence of African swine fever (ASF) circulating in wild boars in mainland Italy and subsequently found in domestic pigs led to several changes regarding the export of pork and pork products to countries outside the European Union (non-EU). The sector suffered the complete and immediate closure of the markets of some countries, often without the measure being communicated in the forms stipulated by international agreements. Indeed, compliance with the current EU regulations does not guarantee the possibility of exporting to non-EU countries. Knowledge of the animal health status requirements of the country (Italy in this case) is essential for food business operators (FBOs) wishing to enter markets outside the EU according to the 'Agreement on the Application of Sanitary and Phytosanitary Measures'. In cases where a sanitary protocol and a model of an official certificate with the importing country exist, the market is officially accessible according to the agreed sanitary requirements. Where no agreement exists, requirements are detailed in the 'import permit' issued to individual FBOs or may be known by directly accessing national regulations through the client/importer. Therefore, the purpose of this work is to briefly outline the conditions imposed by the main non-EU countries for pork products, especially in light of the new epidemiological situation created by the spread of the ASF into a country previously free of the disease.

African swine fever virus MGF505-6R attenuates type I interferon production by targeting STING for degradation.

African swine fever (ASF) is an acute hemorrhagic and devastating infectious disease affecting domestic pigs and wild boars. It is caused by the African swine fever virus (ASFV), which is characterized by genetic diversity and sophisticated immune evasion strategies. To facilitate infection, ASFV encodes multiple proteins to antagonize host innate immune responses, thereby contributing to viral virulence and pathogenicity. The molecular mechanisms employed by ASFV-encoded proteins to modulate host antiviral responses have not been comprehensively elucidated. In this study, it was observed that the ASFV MGF505-6R protein, a member of the multigene family 505 (MGF505), effectively suppressed the activation of the interferon-beta (IFN-β) promoter, leading to reduced mRNA levels of antiviral genes. Additional evidence has revealed that MGF505-6R antagonizes the cGAS-STING signaling pathway by interacting with the stimulator of interferon genes (STING) for degradation in the autophagy-lysosomal pathway. The domain mapping revealed that the N-terminal region (1-260aa) of MGF505-6R is the primary domain responsible for interacting with STING, while the CTT domain of STING is crucial for its interaction with MGF505-6R. Furthermore, MGF505-6R also inhibits the activation of STING by reducing the K63-linked polyubiquitination of STING, leading to the disruption of STING oligomerization and TANK binding kinase 1 (TBK1) recruitment, thereby impairing the phosphorylation and nuclear translocation of interferon regulatory factor 3 (IRF3). Collectively, our study elucidates a novel strategy developed by ASFV MGF505-6R to counteract host innate immune responses. This discovery may offer valuable insights for further exploration of ASFV immune evasion mechanisms and antiviral strategies.

Hourly Feeding Regime of Modern Genetics Lactating Sows: Enhancing Productive Performance, Welfare, and Piglet Growth in Smart Farm-Based Systems

Effective management of lactating sows significantly influences various aspects of swine production. This study compared the impact of an hourly feeding regime and a five-times-daily feeding regime on the productive performance, body condition, and welfare of lactating sows, as well as on the growth performance of their offspring. Twenty-eight lactating sows (Landrace × Yorkshire) were divided into two groups: Group 1 was fed five times a day, and Group 2 was fed according to an hourly regime. The data were analyzed using independent-samples T-tests and the Mann–Whitney U test using Statistical Analysis System (SAS, 2011, Version 9.3) software. An hourly feeding regime positively affected (p < 0.05) sows’ feed intake and body condition, significantly reducing the days from the weaning-to-estrus interval. Group 1 exhibited significantly higher (p < 0.05) reductions in backfat thickness (BFT) and body condition score (BCS) during the weaning period compared to Group 2. Additionally, significant differences (p < 0.05) were observed in regard to sow body weight loss, feed intake, piglet livability and mortality rate at weaning, sow index, and calculated milk yield. Feeding sows according to an hourly regime positively impacted their productive performance compared to those fed five times daily. No significant differences (p > 0.05) were recorded in regard to the total number of piglets born, live births, mummified piglets, stillbirths, piglet mortality, litter size at weaning, and sow feed conversion ratio (FCR). However, the number of piglets weaned per sow per year (PSY) was numerically higher in Group 2 (p > 0.05). The piglets from Group 2 had significantly higher (p < 0.05) weaning weights and exhibited lower feed intake, greater weight gain, improved average daily gain, and greater litter size weight gain than those from Group 1. Statistically, sows from Group 2 exhibited a higher frequency of standing (p < 0.05), which potentially contributed to the reduction in shoulder skin lesions in sows (p > 0.05). In conclusion, an hourly feeding regime could optimize sow productive performance, body condition, milk yield, welfare, and piglet growth in swine production.

Nutritional value of meat from selected neotropical reptiles

This is the second part of a two-part review. The first part focused on the nutritive value of meat and meat products of selected neo-tropical mammals with the potential for domestication. The objective of this current review was to investigate the nutritional qualities and carcass traits of selected neotropical reptiles compared to domestic species, focusing on the spectacled caiman, iguana, tegu, and yellow anaconda. Carcass weight analysis revealed that the spectacled caiman and male iguana were efficient converters of live weight to edible carcass weight, with higher yields than other reptiles. Among domestic species, pigs and chickens showed higher carcass yields compared to cattle and lamb. Moisture content in reptile meat was generally higher than in domestic animals, impacting texture and juiciness. Protein content was lower in reptiles but still contributed to daily requirements, while fat content, though generally lower in reptiles, could impact flavor and tenderness. Cholesterol levels were lower in reptiles, particularly the yellow anaconda, making them potentially healthier options for those with cardiovascular concerns. Fatty acid composition analysis indicated varying levels of saturated, monounsaturated, and polyunsaturated fatty acids, with potential cardiovascular health benefits in reptile meats. Amino acid content, though lower in reptiles compared to domestic species, provided essential building blocks for various physiological functions. Overall, the study highlighted the nutritional value and potential health benefits of including neotropical reptile meat in the human diet, especially as alternative protein sources.

Integrated Proteomics Analysis of Baseline Protein Expression in Pig Tissues.

The availability of an increasingly large amount of public proteomics data sets presents an opportunity for performing combined analyses to generate comprehensive organism-wide protein expression maps across different organisms and biological conditions. Sus scrofa, a domestic pig, is a model organism relevant for food production and for human biomedical research. Here, we reanalyzed 14 public proteomics data sets from the PRIDE database coming from pig tissues to assess baseline (without any biological perturbation) protein abundance in 14 organs, encompassing a total of 20 healthy tissues from 128 samples. The analysis involved the quantification of protein abundance in 599 mass spectrometry runs. We compared protein expression patterns among different pig organs and examined the distribution of proteins across these organs. Then, we studied how protein abundances were compared across different data sets and studied the tissue specificity of the detected proteins. Of particular interest, we conducted a comparative analysis of protein expression between pig and human tissues, revealing a high degree of correlation in protein expression among orthologs, particularly in brain, kidney, heart, and liver samples. We have integrated the protein expression results into the Expression Atlas resource for easy access and visualization of the protein expression data individually or alongside gene expression data.

Experimental inoculation of pigs with monkeypox virus results in productive infection and transmission to sentinels

ABSTRACT Monkeypox virus (MPXV) is a re-emerging zoonotic poxvirus responsible for producing skin lesions in humans. Endemic in sub-Saharan Africa, the 2022 outbreak with a clade IIb strain has resulted in ongoing sustained transmission of the virus worldwide. MPXV has a relatively wide host range, with infections reported in rodent and non-human primate species. However, the susceptibility of many domestic livestock species remains unknown. Here, we report on a susceptibility/transmission study in domestic pigs that were experimentally inoculated with a 2022 MPXV clade IIb isolate or served as sentinel contact control animals. Several principal-infected and sentinel contact control pigs developed minor lesions near the lips and nose starting at 12 through 18 days post-challenge (DPC). No virus was isolated and no viral DNA was detected from the lesions; however, MPXV antigen was detected by IHC in tissue from a pustule of a principal infected pig. Viral DNA and infectious virus were detected in nasal and oral swabs up to 14 DPC, with peak titers observed at 7 DPC. Viral DNA was also detected in nasal tissues or skin collected from two principal-infected animals at 7 DPC post-mortem. Furthermore, all principal-infected and sentinel control animals enrolled in the study seroconverted. In conclusion, we provide the first evidence that domestic pigs are susceptible to experimental MPXV infection and can transmit the virus to contact animals.

Pharmacokinetics of oral clonazepam in growing commercial pigs (Sus scrofa domestica).

Clonazepam causes sedation and psychomotor impairment in people. Due to similarities between people and swine in response to benzodiazepines, clonazepam may represent a viable option to produce mild-to-moderate tranquillization in pigs. The objective of this study was to determine the pharmacokinetic profile of a single oral dose (0.5 mg/kg) of clonazepam in eight healthy, growing commercial cross pigs. Serial plasma samples were collected at baseline and up to 96 h after administration. Plasma concentrations were quantified using reverse-phase high-performance liquid chromatography, and compartment models were fit to time-concentration data. A one-compartment first-order model best fits the data. Maximum plasma concentration was 99.5 ng/mL, and time to maximum concentration was 3.4 h. Elimination half-life was 7.3 h, mean residence time 7.4 h, and apparent volume of distribution 5.7 L/kg. Achieved plasma concentrations exceeded those associated with psychomotor impairment in people although pharmacodynamic effects have not been investigated in pigs. A simulated oral regimen consisting of 0.35 mg/kg administered every 8 h to pigs would achieve plasma concentrations above 32 ng/mL which are shown to produce psychomotor impairment in people. Further studies to test the clinical efficacy of these dosages in commercial and miniature pigs are warranted.

307 Awardee Talk: Effects of dietary valerate glycerides on weanling piglet diarrhea and immunity

Abstract The use of various feed additives for their non-nutrient, immunomodulatory qualities is under investigation for application in swine production, especially during the post-weaning period. Butyrate (C4) is a known modulator of intestinal physiology, produced endogenously by commensal microbes and found in other organic sources. However, the understanding of the role of valerate (C5) as a feed additive for pigs has not been well-evaluated. Two experiments were conducted utilizing glycerides of butyrate or valerate as feed additives for weanling piglets under enterotoxigenic Escherichia coli (ETEC) infection conditions. In both experiments, daily diarrhea scores were recorded to monitor the frequency of diarrhea. The first pilot experiment utilized 20 weanling piglets (21 to 24 d of age) housed individually and assigned to either control diet, or control diet supplemented with 0.10% butyrate glycerides or 0.10% valerate glycerides. This experiment also aimed to establish a coinfection disease model, administering two strains of ETEC at a dose of 0.5 × 109 CFU/1.5 mL for each strain after a 7-d adaptation period (F4 and F18; two highly prevalent strains in swine production). Overall, piglets had significantly (P < 0.05) decreased frequency of diarrhea in either treatment group compared with control, suggesting similar modulatory effects by dietary valerate glycerides and butyrate glycerides. In addition, pigs fed valerate glycerides tended (P = 0.061) to have less neutrophils and had significantly (P < 0.05) less serum TNF-α on d 4 post-inoculation (PI). Moving forward, a full-scale experiment was performed using 60 weanling piglets (21 to 24 d of age) to further investigate the effect of dietary valerate glycerides on piglet health under ETEC F18 infection conditions. Treatments included nursery basal diet (control), 0.075% or 0.10% monovalerin, or 0.1% trivalerin added to control. Pigs fed 0.1% trivalerin exhibited significantly (P < 0.05) reduced frequency of diarrhea and fecal shedding of ETEC F18. Serum samples were collected throughout the experimental period and six replicate pigs per treatment group were sacrificed on d 7 PI to collect intestinal samples for morphological analysis and intestinal mucosa RT-qPCR analysis. Pigs fed trivalerin had reduced (P < 0.05) serum TNF-α on d 0 before inoculation and d 6 PI compared with pigs in control. The mRNA expression of TNFA in ileal mucosa from pigs fed 0.1% monovalerin tended (P < 0.10) to be lower compared with control. In addition, ZO1 mRNA expression tended (P < 0.10) to be increased in jejunal mucosa from pigs fed 0.1% trivalerin. Overall, the second experiment indicated that dietary supplementation of valerate glycerides reduced diarrhea and fecal shedding of ETEC F18 in piglets infected with ETEC. In conclusion, both experiments provide evidence in support of supplementing 0.075 or 0.10% valerate glycerides could enhance disease resistance of weanling piglets experiencing ETEC-associated diarrhea.

32 Overview over methionine metabolism: Implications in swine nutrition and health

Abstract Methionine (Met) can be referred to as a functional amino acid (AA) because besides serving as a building block for protein bio-syntheses, it also performs many other biochemical and physiological functions in swine body, simply due to its unique chemical structure and cellular metabolism. As a sulfur-containing AA (SAA), a Met molecule, as its name indicates, contains a methyl group covalently bonded to a sulfur atom via a thioether bond. In terms of its functions, first of all, Met is the initiator for virtually all protein bio-syntheses. Secondly, Met can be easily oxidized to a sulfoxide via a covalent modification, and the resulting Met sulfoxide can be readily reduced back to Met. In the case of protein-bound Met, both Met and cysteine (Cys) residues are most susceptible to oxidation and this nature can protect many proteins from oxidative damages. The biochemical metabolism of Met involves transmethylation, remethylation, transsulfuration, and transamination pathways. The initial step of transmethylation is generation of S-adenosylmethionine (SAM) which is an essential methyl donor in a myriad of metabolic events that include the methylation of DNA, RNA, proteins, phospholipids, and some small molecules. These various methylations dictate the replicational, transcriptional and translational fidelities, mismatch repair, chromatin modelling, epigenetic modification, imprinting, as well as detoxification of xenobiotics, which are all topics of great interest and importance in swine health and production performance. SAM is also a key metabolite to produce homocysteine which can be remethylated back to Met via the remethylation pathway (known as methyl cycle). The transsulfuration pathway firstly converts homocysteine to cystathionine via a condensation with serine, and then cystathionine is cleaved to Cys plus α-ketobutyrate and ammonia. Transsulfuration pathway is irreversible, and that is why Met is an indispensable AA whose deficiency cannot be remedied by Cys, whereas Cys is dispensable when more Met is provided. Because of this metabolic interconversion between Met and Cys in the body, these two are generally grouped together as SAA (Met + Cys) in swine nutrition practice. That said, when tissue Met concentration is too great, Met can be catabolized via its transamination pathway which is minor and SAM-independent. Met toxicity is mainly caused by methanethiol and H2S, two major toxic metabolites in the transamination pathway. Synthesized from Met, a myriad of proteins and peptides are involved in the functioning of immune system for maintaining animal health. For example, SAM is also a precursor for synthesis of polyamines which can enhance immune cell proliferation during an immune challenge. Cys and its derivatives (e.g., glutathione and taurine), in addition to their antioxidative capacity, can ameliorate inflammation during an immune response. In short, Met is a unique SAA that has numerous indispensable biological functions for supporting swine health and production performance.

PSIII-16 Effects of dietary corn origin (U.S., Argentina, and Brazil) on pig growth performance

Abstract Corn is an important global commodity. Understanding its nutritional value and practically utilizing different corn sources and varieties in swine diets is important to U.S. corn and swine production. Globally, the U.S. “dent” corn variety is presumed to be of lesser quality compared with “harder” flint-type corn (the preferred varieties in Argentina and Brazil) due to differences in whole kernel structure when shipped long distances. In fact, official work from the US Grains Council indicates that US corn produces more ethanol per bushel when compared with flint-type varieties of corn. This indicates a greater concentration of starch in US corn and increased starch content should mean a greater quantity of energy and nutrients. Therefore, swine producers globally benefit from understanding the feeding value of different varieties and origins of corn. The objective of this study was to assess the performance of pigs fed corn from three exporting countries: U.S., Argentina (ARG), and Brazil (BRZ). Two similar studies were conducted comparing the effect of 3 corn sources on late nursery pig growth performance. Study 1 used 96 nursery pigs [body weight (BW) = 8.8 ± 1.7 kg] split between 24 pens and study 2 used 114 nursery pigs (8.0 ± 1.3 kg) split between 24 pens. Three experimental diets were formulated with corn sources from: 1) U.S.; 2) ARG; and, 3) BRZ. The U.S. corn diet was considered the control diet and was balanced to meet or exceed all nutrient requirements for the pigs. The U.S. corn was replaced with ARG corn and BRZ corn on a kg for kg basis in the diets. Pigs were assigned in a randomized block design based on initial body weights (BW) and sex. Feed and water were offered ad libitum over a 28-d period, pig BW and feed disappearance were measured each week. Average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency [gain to feed ratio (G:F)] were determined after weeks 1, 2, and 4. Performance data were analyzed using PROC MIXED procedure in SAS considering dietary treatment as a main effect and pen as experimental unit. There were no significant differences (P > 0.05) in BW, ADFI, ADG, and feed efficiency between the three corn sources throughout all weeks and the overall 28 d. Overall performance values for the three treatments were: US corn ADG (0.66 kg), ADFI (0.91 kg), and G:F (0.72): Argentina corn, ADG (0.65 kg), ADFI (0.92), and G:F (0.70); and Brazil corn, ADG (0.65), ADFI (0.92), and G:F (0.71). In conclusion, the value of US corn is similar in nutrient content and nutritional quality as demonstrated by equivalent performance in nursery pigs. The aesthetics of whole kernels are not indicative of feeding value to swine.

292 Effects of feeding mycotoxins-contaminated feed with a mitigation strategy on growth performance and health status in weaned pigs

Abstract Various types and levels of mycotoxins are present in feed ingredients, thus negatively impacting swine health and productivity. Appropriate sampling and frequent testing of feed ingredients are recommended to assess the risk of mycotoxins in feed and to determine mitigation strategies for mycotoxin control. However, monitoring plans do not guarantee feed will be free of mycotoxins, so in-feed mitigation strategies are implemented to minimize production losses. The objective of this study was to investigate the efficacy of a mycotoxin mitigation product (MultiSHIELD, modified clinoptilolite-based product) on growth performance and health status of weaned pigs under dietary challenges with various types and levels of mycotoxins commonly found in feed. The presence of mycotoxins was confirmed in the ground corn, which was obtained from the Midwestern United States and then used in a standard corn and soybean meal-based diet for three dietary treatments. Treatments were as follows: 1) control diet containing mycotoxins without mitigation (fumonisins B1 at 390, 454, and 527 ppb; zearalenone at 727, 846, and 982 ppb; deoxynivalenol at 671, 781, and 907 ppb in N1, N2, and N3 diets, respectively), 2) control diet with 0.15% of MultiSHIELD as mitigation level 1, and 3) control diet with 0.3% of MultiSHIELD as mitigation level 2. A total of 912 weaned pigs were allotted to 1 of 3 dietary treatments (19 pigs per pen and 16 replicates per treatment) in a randomized complete block design with the initial body weight (as blocking. The results revealed that mycotoxin mitigation, regardless of the mitigation levels, had decreased removal rate (P < 0.01), incidence of injectable medication treatments (P = 0.01), ear necrosis (P = 0.27), and scours (P = 0.18) compared with control. Overall, pigs fed mycotoxin mitigation treatment diets had heavier pen weight (P = 0.06) than those fed the control diet due to fewer removals. The results also demonstrated a significant improvement of economic parameters (i.e., income over feed cost per pen; P = 0.01) for pigs fed diets with MultiSHIELD, regardless of the inclusion level, than pigs fed control diet. In conclusion, poor swine productivity was observed due to the presence of mycotoxins in feed, and the inclusion of MultiSHIELD in feed under the mycotoxin challenge delivers a positive impact on health and economic performance of nursery pigs.

83 Effect of stocking density on F1 gilt reproductive performance

Abstract Replacement females are the future of a farm, and their development can impact production. Currently, replacement gilts are housed in many different environments. Stocking density of replacement females is one factor that varies across production systems. Therefore, the objective of this study was to evaluate the effect of different stocking densities on replacement gilt reproductive performance. At 10 wk of age, DNA L241 females (n = 824; DNA Genetics, Columbus, NE) were randomly allotted to finishing pens with 3 different stocking densities. Each stocking density consisted of 12 pens of 0.71 m2 (n = 360), 0.93 m2 (n = 264), and 1.25 m2 (n = 204). Heat detection started at 20 wk of age with fence line exposure for 2 wk at 15 minutes per pen. Within pen boar exposure occurred from 22 to 31 wk of age for a minimum of 10 min per pen. Starting at 20 wk of age, females that exhibited red and swollen vulvas or standing estrus were recorded. Body weight, backfat, and loin depth measurements were collected at estrus detection. A blood progesterone assay was performed on all females at 24 wk of age. Further blood progesterone assays were performed at 27, 29 and 31 wk of age on any female for which progesterone was not detected on previous assays. Females were mated on their 2nd estrus if they were at least 136 kg or on their first estrus if they were over 145 kg. Body weight was recorded at the time of mating. For females that cycled by 31 wk, females in the 0.71 m2 treatment cycled significantly earlier than the 0.93 m2 treatment, 147 vs 153 d post-weaning respectively (P < 0.05). No difference was detected in age at mating; however, gilts in the 0.71 m2 treatment were 5.9 kg and 8.2 kg lighter than the 0.93 and 1.25 m2 treatments respectively (P < 0.01). At 31 wk of age 60% of the 0.71 m2, 71% of the 0.93 m2, and 77% of the 1.25 m2 treatments had cycled according to visual heat detection. However, according to the progesterone assay, at 31 wk of age 75% of 0.71 m2, 81% of the 0.93 m2, and 84% of the 1.25 m2 had cycled. The accuracy of visual heat detection compared with progesterone assay were 79.4% for 0.71 m2, 77.3% for 0.93 m2, and 85.8% for 1.25 m2 treatments. Overall, the 1.25 m2 treatment resulted in heavier females at mating, a greater rate of females cycling, and a more accurate detection of females cycling than the 0.71 m2 treatment. Swine producers can improve the percentage of females detected in estrus and mated in the desired period by providing additional rearing space during gilt development.

37 Key learnings from the improving pig survivability project

Abstract The Improving Pig Survivability Project has completed 5 yr encompassing research, education, and extension with the goal of reducing overall mortality in the U.S. commercial swine industry. The project is funded by National Pork Board and Foundation for Food and Agriculture Research, and continues through 2026. Team members represent institutions including Iowa State University, Kansas State University, and Purdue University. The project is guided by an advisory board consisting of US swine producers and allied industry partners. Research efforts seek to identify factors contributing to swine mortality in commercial production, and to develop strategies and information that can be utilized to reduce mortality and maximize pig survivability. Key economic findings include the first publicly available economic tool for swine producers to input their specific production information and costs, creating a farm level specific cost of mortality for both the breeding herd and post-weaning to market. Key strategies found to reduce sow mortality include: understanding late gestation body condition as thin sows in late gestation are more likely to prolapse compared with normal or overweight sows; Early intervention to monitor and treat lameness resulted in 25.4% relative reduction in annualized sow mortality in commercial settings tested; Feeding sows four 1.5-pound meals reduced farrowing assistance and reduced piglet deaths compared with ad libitum intake for 3 to 5 d before farrowing; perineal score, genetics, and microbiome risk factors for pelvic organ prolapse were identified. Key strategies found to reduce pre-weaning mortality include: colostrum should be 300 to 350 g per piglet, and a milky cheese addition during enrichment period. Key strategies found to reduce wean to finish mortality include: whole-herd analysis of 2,568 WTF closeouts revealed sow farm parameters associated with improved livability were sow farm health status and productivity associated with lower WTF mortality; Increased mortality was associated with Streptococcus suis, Glaeserella parasuis, PRRSv, Mycoplasma hyopneumoniae and PEDv; early maturing duroc sired pigs had reduced stress, greater feed intake, decreased % losing body weight post weaning, and greater gain during the nursery period; enrichment cubes to pigs post-weaning reduced the percentage losing body weight after weaning; feeding large pellet creep feed in lactation improved nursery pig growth and decreased fallout rates; mat feeding reduced mortality and removals; sensory attractant powder before and after weaning reduced percentage that lost body weight the first 3 d after weaning, and linoleic:linolenic acid ratio can impact gilt growth and the use of lower energy diets appears to reduce joint inflammation. In addition to grant funding, 22 additional projects were supported by in-kind industry donations/partnerships worth over $1.6 million. Resources generated are available in peer-reviewed publications, factsheets (English and Spanish), short informational videos, and podcasts (PigX). Project outcomes are available at the Improving Pig Surviability website (www.piglivability.org).