Pig Feces Research Articles

85 The influence of supplementing isolated or intact structural fiber on the physicochemical properties of digesta and fecal consistency of nursery pigs

Abstract In human nutrition, functional fiber refers to isolated non-digestible carbohydrates with physiological roles, while structural fiber pertains to those that are intrinsic and intact in plants. Increasing dietary fiber in post-weaning pig diets has been shown to improve gastrointestinal health and alter fecal consistency. However, minimal research has been conducted on the role of supplementing isolated functional or structural fiber that are chemically insoluble in nursery diets. The experimental objective was to evaluate the effect of functional or structural insoluble fiber supplementation on the physicochemical properties of digesta and feces during the nursery period. A total of 256 newly weaned pigs were randomly assigned to one of four treatments across two replications with 4 pigs per pen and 16 pens per treatment for a 35-d study. The average initial pig body weight (BW) was 5.13 ± 0.65 kg and same sex pens were used and balanced across treatments. Dietary treatments consisted of a control nursery diet (PC), PC with 3% soy hulls (NC), PC with 2% isolated lignocellulose (ISO), and PC with 2% structural lignocellulose (STR). Treatments were fed across phase 1 (d 0-7) and phase 2 (d 7-21) diets, and a common diet was fed in phase 3 (d 21-35). On d 7, 14, 21, 28, and 35, fresh fecal samples were collected to determine water binding capacity (WBC), water swelling capacity (WSC), and fecal dry matter (DM). Fecal scores were also evaluated using a predefined scale (1 = solid; 4 = liquid). On d 21, one pig per pen closest to the mean BW was necropsied, and ileal, cecal, and colonic digesta were collected. Continuous data were analyzed as a linear mixed model (PROC MIXED) with treatment, sex, and period as fixed effects, replicate as a random effect, and initial BW as a covariate where appropriate. Fecal scores were analyzed using a multinomial model in PROC GENMOD and FREQ. Pigs fed ISO and STR tended to have greater fecal DM (24.1%, 24.6%, 25.4%, and 26.29% for PC, NC, ISO, and STR, respectively; P = 0.071). There was a greater proportion of solid and semi-solid feces in pigs fed ISO (P = 0.039). Fecal WBC was greatest in pigs fed PC, with NC and ISO performing intermediately, and STR having the least (2.66, 2.55, 2.50, and 2.39 mL/g of DM for PC, NC, ISO, and STR, respectively; P = 0.071). Fecal WSC increased with time (P < 0.001), but there was no impact of treatment (P = 0.983). Ileal digesta pH was decreased in NC and STR, relative to PC and ISO, (P = 0.007). There tended to be a similar response for cecal pH (P = 0.092). Pigs fed PC tended to have the greatest colonic WBC (P = 0.058). Collectively, supplementing isolated or structural lignocellulose can alter the physicochemical properties of nursery pig feces.

PSII-12 Dose-dependent effects of supplemental benzoic acid on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs

Abstract The objective of this study was to determine the effects of supplemental benzoic acid (BA) at 0.5% to 2.5% in diets on nitrogen (N) utilization, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen barrows with an initial body weight of 56.2 kg (standard deviation = 2.6) were individually housed in metabolism crates. The animals were allocated to a replicated 6 × 4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per dietary treatment. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.0%, 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% BA at the expense of corn starch. Each period consisted of a 4-d adaptation period and a 24-h collection period for slurry followed by a 4-d collection period for feces and urine. On d 5, feces and urine were collected for 24 h, and the feces and urine were mixed in a ratio of fecal weight to urine weight at the end of the collection to obtain slurry samples. The apparent total tract digestibility of N tended to linearly increase (P = 0.071) and the daily digested N linearly increased (P < 0.05) with increasing BA supplementation. In contrast, the urinary N output and retained N were not affected by inclusion of BA. The urinary and slurry pH were quadratically decreased (P < 0.05) with increasing BA supplementation. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (P < 0.05) and isovalerate concentration tended to linearly decrease (P = 0.099) by supplemental BA. In the slurry samples, the concentrations of isovalerate and skatole decrease linearly (P < 0.05), and butyrate concentration tended to linearly decrease (P = 0.054) by supplemental BA. In conclusion, supplemental benzoic acid has the potential to improve the N digestibility in a dose-dependent manner for pigs. In addition, increasing benzoic acid supplementation decreased urinary pH, slurry pH, and concentrations of some odorous compounds in pig feces and slurry.

Seroprevalence and Phylogenetic Characterization of Hepatitis E Virus (Paslahepevirus balayani) in Guinean Pig Population.

Background: Hepatitis E virus (HEV) is transmitted by the fecal route, usually through contaminated water in humans and/or infected animals, especially pigs. The objective of this study was to evaluate the level of anti-HEV antibodies in a panel of pig sera and to identify HEV in pig feces in farms. Methodology: The presence of HEV antibodies was tested by an in-house ELISA and a commercial ELISA IDvet. HEV genome was assessed by nested RT-PCR, and then, genotype was identified by sequencing (MinION Nanopore technology). Results: In 2017-2019, the 43% seroprevalence found in Forest Guinea was significantly higher than the 7% found in the Lower region (p < 0.01). Presence of HEV genotype 3c was demonstrated during a secondary study in the Lower region (Conakry) in 2022. Conclusion: The presence of HEV-3c in pigs calls for an evaluation of seroprevalence in human populations and for a HEV genotype human circulation check. Contribution Heading: This study is the first report, to our knowledge, of seroprevalence and characterization of HEV infection in pigs in Guinea.

Genetic- and fiber-diet-mediated changes in virulence factors in pig colon contents and feces and their driving factors.

Virulence factors (VFs) are key factors for microorganisms to establish defense mechanisms in the host and enhance their pathogenic potential. However, the spectrum of virulence factors in pig colon and feces, as well as the influence of dietary and genetic factors on them, remains unreported. In this study, we firstly revealed the diversity, abundance and distribution characteristics of VFs in the colonic contents of different breeds of pigs (Taoyuan, Xiangcun and Duroc pig) fed with different fiber levels by using a metagenomic analysis. The analysis resulted in the identification of 1,236 virulence factors, which could be grouped into 16 virulence features. Among these, Taoyuan pigs exhibited significantly higher levels of virulence factors compared to Duroc pigs. The high-fiber diet significantly reduced the abundance of certain virulence factor categories, including iron uptake systems (FbpABC, HitABC) and Ig protease categories in the colon, along with a noteworthy decrease in the relative abundance of plasmid categories in mobile genetic elements (MGEs). Further we examined VFs in feces using absolute quantification. The results showed that high-fiber diets reduce fecal excretion of VFs and that this effect is strongly influenced by MGEs and short-chain fatty acids (SCFAs). In vitro fermentation experiments confirmed that acetic acid (AA) led to a decrease in the relative abundance of VFs (p < 0.1). In conclusion, our findings reveal for the first time how fiber diet and genetic factors affect the distribution of VFs in pig colon contents and feces and their driving factors. This information provides valuable reference data to further improve food safety and animal health.

Dissemination of antibiotic resistance genes from aboveground sources to groundwater in livestock farms

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are prevalent in various environments on livestock farms, including livestock waste, soil, and groundwater. Contamination of groundwater by ARB and ARGs in livestock farms is a growing concern as it may have potentially huge risks to human health. However, the source of groundwater-borne ARB and ARGs in animal farms remains largely unknown. In this study, different types of samples including groundwater and its potential contamination sources from aboveground (pig feces, wastewater, and soil) from both working and abandoned swine feedlots in southern China were collected and subjected to metagenomic sequencing and ARB isolation. The source tracking based on metagenomic analysis revealed that 56–95 % of ARGs in groundwater was attributable to aboveground sources. Using metagenomic assembly, we found that 45 ARGs predominantly conferring resistance to aminoglycosides, sulfonamides, and tetracyclines could be transferred from the aboveground sources to groundwater, mostly through plasmid-mediated horizontal gene transfer. Furthermore, the full-length nucleotide sequences of sul1, tetA, and TEM-1 detected in ARB isolates exhibited the close evolutionary relationships between aboveground sources and groundwater. Some isolated strains of antibiotic-resistant Pseudomonas spp. from aboveground sources and groundwater had the high similarity (average nucleotide identity > 99 %). Notably, the groundwater-borne ARGs were identified as mainly carried by bacterial pathogens, potentially posing risks to human and animal health. Overall, this study underscores the dissemination of ARGs from aboveground sources to groundwater in animal farms and associated risks.

Cryptosporidium and associated risk factors in local breeds of pigs kept in Donga Local Government Area Taraba State, Nigeria

Cryptosporidium, an enteric protozoan parasite, poses economic losses in animal production and has zoonotic potential. This study aimed to determine the prevalence of cryptosporidium and associated risk factors in local pig breeds within Donga Local Government Area of Taraba State, Nigeria. A cross-sectional study was conducted, and a total of 384 faecal samples were collected from pigs in eight sampling sites. The samples were examined using the modified Ziehl-Neelsen staining technique.The results showed an overall prevalence of 27.9% (107/384) for cryptosporidium oocysts. The prevalence was significantly higher in pre-weaned piglets (64%) compared to post-weaned (26.9%) and adult pigs (24.14%). Female pigs had a significantly higher prevalence (49.21%) than males (17.4%), and diarrhoeic pigs had a significantly higher prevalence (55.2%) than non-diarrhoeic (22.9%). The prevalence was higher in the rainy season (42.4%) than in the dry season (10.3%).The detection of Cryptosporidium spp. oocysts in the faeces of pigs suggests that these animals may serve as potential reservoirs and shedders of this protozoan parasite, contaminating the environment and serving as a source of infection to other animals and humans. Adequate personal and environmental hygiene, along with prompt veterinary care, should be intensified.

Dispersion of antimicrobial resistant bacteria in pig farms and in the surrounding environment

BackgroundAntimicrobial resistance has been identified as a major threat to global health. The pig food chain is considered an important source of antimicrobial resistance genes (ARGs). However, there is still a lack of knowledge on the dispersion of ARGs in pig production system, including the external environment.ResultsIn the present study, we longitudinally followed one swine farm located in Italy from the weaning phase to the slaughterhouse to comprehensively assess the diversity of ARGs, their diffusion, and the bacteria associated with them. We obtained shotgun metagenomic sequences from 294 samples, including pig feces, farm environment, soil around the farm, wastewater, and slaughterhouse environment. We identified a total of 530 species-level genome bins (SGBs), which allowed us to assess the dispersion of microorganisms and their associated ARGs in the farm system. We identified 309 SGBs being shared between the animals gut microbiome, the internal and external farm environments. Specifically, these SGBs were characterized by a diverse and complex resistome, with ARGs active against 18 different classes of antibiotic compounds, well matching antibiotic use in the pig food chain in Europe.ConclusionsCollectively, our results highlight the urgency to implement more effective countermeasures to limit the dispersion of ARGs in the pig food systems and the relevance of metagenomics-based approaches to monitor the spread of ARGs for the safety of the farm working environment and the surrounding ecosystems.

Performance evaluation and application of host-specific Bacteroidales and mitochondrial DNA markers to identify sources of fecal contamination in river water in Japan

Microbial source tracking (MST) using host-specific Bacteroidales and mitochondrial DNA (mtDNA) markers is an efficient tool to identify the sources of fecal contamination in environmental water. This study evaluated and updated the previously reported performances of seven host-specific Bacteroidales markers (three human-, two cattle-, and two pig-specific). Additionally, the performance of a cattle-specific Bovine mtDNA and a pig-specific Swine mtDNA marker were evaluated and then applied to MST of river water samples collected in Yamanashi Prefecture, Japan. We collected 48 fecal-source samples, including raw sewage, secondary-treated sewage, an effluent of a domestic wastewater treatment tank, pig feces, pig wastewater, and cattle feces, which were quantitatively analyzed using host-specific Bacteroidales and mtDNA markers. BacHum and gyrB markers (human-specific), BacR and Bovine mtDNA markers (cattle-specific), and Pig2Bac and Swine mtDNA markers (pig-specific) were judged the best-performing markers. Then, these selected markers were applied to MST to identify the sources of fecal contamination in 59 river water samples collected at 21 sites. Of them, 20 (95%), 21 (100%), and 16 (76%) sites were positive for at least one human, cattle, and pig marker, respectively, indicating the need for immediate action and monitoring to control fecal pollution.

Liquid fertilizers produced by microwave-assisted acid hydrolysis of livestock and poultry wastes and their effects on hot pepper cultivation.

Liquid fertilizers (LFs) produced by microwave-assisted acid hydrolysis of livestock and poultry wastes were applied to potted hot pepper (Capsicum annuum L.) to evaluate their potential to be used as amino acid LFs. A preliminary experiment was conducted to determine the optimum acid-hydrolysis conditions for producing LFs from a mixture of pig hair and faeces (P) and another mixture of chicken feathers and faeces (C). Two LFs were produced under the optimum acid-hydrolysis conditions (acidification by sulphuric acid (7.5 mol L-1) in a microwave (200 W) for 90 minutes), and a commercial amino acid LF (Guo Guang (GG)) was used for comparison. P, C and GG fertilizers were tested in potted hot pepper cultivation at two doses, whereas no fertilizer application served as the control (CK). P and C fertilizers significantly increased the fruit yield compared with GG fertilizer, particularly at the higher dose. Moreover, the treatments improved the fruit vitamin C and soluble sugar contents in the order of C > P > GG compared with CK. These results could be attributed to more types of amino acids in C fertilizer than in P and GG fertilizers. The results also indicated that the prepared fertilizers could significantly increase the shoot and root dry weight, soil available nitrogen and phosphorus contents and nitrogen, phosphorus, and potassium (NPK) uptake by plants compared with CK. In conclusion, microwave-assisted acid hydrolysis could effectively convert unusable wastes into valuable fertilizers comparable or even superior to commercial fertilizers.

The Fecal Redox Potential in Healthy and Diarrheal Pigs and Their Correlation with Microbiota.

The redox potential plays a critical role in sustaining the stability of gut microbiota. This study measured the fecal redox potential in healthy and diarrheal pigs using direct and dilution methods and investigated their correlation with microbiota. The results showed that the fluctuations in the redox potential of healthy pig feces were consistent using two different methods and the two methods are equivalent based on an equivalence test. The redox potential was positively correlated with the number of fungi and negatively related to the total bacteria. The relative or absolute abundances of many bacteria at the phyla and genus levels were associated with redox potential. In diarrheal pigs, the potentiometric trends of the two methods demonstrated an opposing pattern and the correlation with total bacteria was reversed. Precipitously elevated redox potential was detected post-diarrhea using dilution methods. The absolute abundance of Escherichia-Shigella and Fuurnierella was positively correlated with redox potential, while both relative and absolute abundances of Limosilactobacillus were positively correlated. These results suggest that both methods are suitable for detecting gut redox potential in healthy pigs, while the dilution method is more suitable for diarrheal pigs. The findings on the correlation of Limosilactobacillus, Prevotella, and Escherichia-Shigella with redox potential offer novel insights for targeted modulation of intestinal health.

Candidatus Methanosphaera massiliense sp. nov., a methanogenic archaeal species found in a human fecal sample and prevalent in pigs and red kangaroos.

Methanosphaera stadtmanae was the sole Methanosphaera representative to be cultured and detected by molecular methods in the human gut microbiota, further associated with digestive and respiratory diseases, leaving unknown the actual diversity of human-associated Methanosphaera species. Here, a novel Methanosphaera species, Candidatus Methanosphaera massiliense (Ca. M. massiliense) sp. nov. was isolated by culture using a hydrogen- and carbon dioxide-free medium from one human feces sample. Ca. M. massiliense is a non-motile, 850 nm Gram-positive coccus autofluorescent at 420 nm. Whole-genome sequencing yielded a 29.7% GC content, gapless 1,785,773 bp genome sequence with an 84.5% coding ratio, encoding for alcohol and aldehyde dehydrogenases promoting the growth of Ca. M. massiliense without hydrogen. Screening additional mammal and human feces using a specific genome sequence-derived DNA-polymerase RT-PCR system yielded a prevalence of 22% in pigs, 12% in red kangaroos, and no detection in 149 other human samples. This study, extending the diversity of Methanosphaera in human microbiota, questions the zoonotic sources of Ca. M. massiliense and possible transfer between hosts.IMPORTANCEMethanogens are constant inhabitants in the human gut microbiota in which Methanosphaera stadtmanae was the only cultivated Methanosphaera representative. We grew Candidatus Methanosphaera massiliense sp. nov. from one human feces sample in a novel culture medium under a nitrogen atmosphere. Systematic research for methanogens in human and animal fecal samples detected Ca. M. massiliense in pig and red kangaroo feces, raising the possibility of its zoonotic acquisition. Host specificity, source of acquisition, and adaptation of methanogens should be further investigated.

Metagenomic insights into isolable bacterial communities and antimicrobial resistance in airborne dust from pig farms.

This study aims to investigate bacterial communities and antimicrobial resistance (AMR) in airborne dust from pig farms. Airborne dust, pig feces and feed were collected from nine pig farms in Thailand. Airborne dust samples were collected from upwind and downwind (25 meters from pig house), and inside (in the middle of the pig house) of the selected pig house. Pig feces and feed samples were individually collected from the pen floor and feed trough from the same pig house where airborne dust was collected. A direct total bacteria count on each sampling plate was conducted and averaged. The ESKAPE pathogens together with Escherichia coli, Salmonella, and Streptococcus were examined. A total of 163 bacterial isolates were collected and tested for MICs. Pooled bacteria from the inside airborne dust samples were analyzed using Metagenomic Sequencing. The highest bacterial concentration (1.9-11.2 × 103 CFU/m3) was found inside pig houses. Staphylococcus (n = 37) and Enterococcus (n = 36) were most frequent bacterial species. Salmonella (n = 3) were exclusively isolated from feed and feces. Target bacteria showed a variety of resistance phenotypes, and the same bacterial species with the same resistance phenotype were found in airborne dust, feed and fecal from each farm. Metagenomic Sequencing analysis revealed 1,652 bacterial species across all pig farms, of which the predominant bacterial phylum was Bacillota. One hundred fifty-nine AMR genes of 12 different antibiotic classes were identified, with aminoglycoside resistance genes (24%) being the most prevalent. A total of 251 different plasmids were discovered, and the same plasmid was detected in multiple farms. In conclusion, the phenotypic and metagenomic results demonstrated that airborne dust from pig farms contained a diverse array of bacterial species and genes encoding resistance to a range of clinically important antimicrobial agents, indicating the significant role in the spread of AMR bacterial pathogens with potential hazards to human health. Policy measurements to address AMR in airborne dust from livestock farms are mandatory.

Multi-omics analysis of gut microbiota and metabolites reveals contrasting profiles in domestic pigs and wild boars across urban environments.

The gut microbiota plays a crucial role in host health and metabolism. This study explores the differences in gut microbiota and metabolites between domestic pigs (DP) and wild boars (WB) in urban environments. We analyzed gut microbial composition, metabolic profiles, virome composition, antibiotic resistance genes (ARGs), and human pathogenic bacteria (HPB) in both DP and WB. Our results revealed that DP exhibited a higher Firmicutes/Bacteroidetes ratio and were enriched in bacterial genera associated with domestication and modern feeding practices. Metabolomic analysis showed distinct profiles, with WB significantly enriched in the Pantothenate and CoA biosynthesis pathway, highlighting dietary and environmental influences on host metabolism. Additionally, DP had a distinct gut virome composition, particularly enriched in lytic phages of the Chaseviridae family. ARG analysis indicated a higher abundance of tetracycline resistance genes in DP, likely due to antibiotic use in pig farms. Furthermore, variations in HPB composition underscored potential health risks associated with contact with pig feces. These findings provide valuable insights into the microbial ecology of domestic pigs and wild boars, emphasizing the importance of these comparisons in identifying zoonotic pathogen transmission pathways and managing antibiotic resistance. Continued research in this area is essential for developing effective strategies to mitigate public health risks and promote sustainable livestock management practices.

Genomic characterization and probiotic potential of lactic acid bacteria isolated from feces of guinea pig (Cavia porcellus).

Presently, there exists a growing interest in mitigating the utilization of antibiotics in response to the challenges emanating from their usage in livestock. A viable alternative strategy encompasses the introduction of live microorganisms recognized as probiotics, exerting advantageous impacts on the immune system and nutritional aspects of the host animals. Native lactic acid bacteria, inherently possessing specific properties and adaptive capabilities tailored to each animal, are deemed optimal contenders for probiotic advancement. In the current investigation, microorganisms exhibiting probiotic potential were isolated, characterized, and identified from the fecal samples of guinea pigs (Cavia porcellus) belonging to the Peruvian breed. The lactic acid bacteria isolated on Man, Rogosa, and Sharpe agar underwent Gram staining, catalase testing, proteolytic, amylolytic, and cellulolytic activity assays, low pH tolerance assessment, hemolytic evaluation, antagonism against Salmonella sp., determination of autoaggregation and coaggregation capacity, and genotypic characterization through sequencing of the 16S rRNA gene. A total of 33 lactic acid bacteria were isolated from the feces of 30 guinea pigs, also 10 isolates were selected based on Gram staining and catalase testing. All strains exhibited proteolytic activity, while only one demonstrated amylolytic capability, and none displayed cellulase activity. These bacteria showed higher tolerance to pH 5.0 and, to a lesser extent, to pH 4.0. Furthermore, they exhibited antagonistic activity against Salmonella sp. Only two bacteria demonstrated hemolytic activity, and were subsequently excluded from further evaluations. Subsequent assessments revealed autoaggregation capacities ranging from 4.55% to 23.19%, with a lesser degree of coaggregation with Salmonella sp. ranging from 3.53% to 8.94% for the remaining eight bacterial isolates. Based on these comprehensive tests, five bacteria with notable probiotic potential were identified by molecular assays as Leuconostoc citreum, Enterococcus gallinarum, Exiguobacterium sp., and Lactococcus lactis. The identified bacteria stand out as promising probiotic candidates, deserving further assessment in Peruvian breed guinea pigs. This exploration aims to enhance production outcomes while mitigating the adverse effects induced by pathogenic microorganisms.

The sub-MIC selective window decreases along the digestive tract: determination of the minimal selective concentration of oxytetracycline in sterilised intestinal contents.

The administration of antibiotics can expose the digestive microbiota of humans and animals to sub-inhibitory concentrations, potentially favouring the selection of resistant bacteria. The minimal selective concentration (MSC) is a key indicator to understand this process. The MSC is defined as the lowest concentration of an antibiotic that promotes the growth of a resistant strain over a susceptible isogenic strain. It represents the lower limit of the sub-minimal inhibitory concentration (MIC) selective window, where resistant mutants can be selected. Previous studies focused on determining the MSC under standard culture conditions, whereas our research aimed to determine the MSC in a model that approximates in vivo conditions. We investigated the MSC of oxytetracycline (OTC) in Mueller-Hinton broth (MHB) and sterilised intestinal contents (SIC) from the jejunum, caecum and rectum (faeces) of pigs, using two isogenic strains of Escherichia coli (one susceptible and one resistant to OTC). Additionally, the MIC of OTC against the susceptible strain was determined to assess the upper limit of the sub-MIC selective window. Our study took a novel approach, and the results indicated that MIC and MSC values were lower in MHB than in SIC. In the latter, these values varied depending on the intestinal segment, with distal compartments exhibiting higher MIC and MSC values. Moreover, the sub-MIC selective window of OTC in SIC narrowed from the jejunum to the rectum, with a significantly closer MSC to MIC in faecal SIC. The results suggest that OTC binds to digestive contents, reducing the fraction of free OTC. However, binding alone does not fully explain our results, and interactions between bacteria and intestinal contents may play a role. Furthermore, our findings provide initial estimates of low concentrations facilitating resistance selection in the gut. Finally, this research enhances the understanding of antimicrobial resistance selection, emphasising the intricate interplay between antibiotics and intestinal content composition in assessing the risk of resistance development in the gut.

Diversity of Fecal Indicator Enterococci among Different Hosts: Importance to Water Contamination Source Tracking.

Enterococcus spp. are common bacteria present in the intestinal tracts of animals and are used as fecal indicators in aquatic environments. On the other hand, enterococci are also known as opportunistic pathogens. Elucidating their composition in the intestinal tracts of domestic animals can assist in estimating the sources of fecal contamination in aquatic environments. However, information on the species and composition of enterococci in animal hosts (except humans) is still lacking. In this study, enterococci were isolated from the feces of cattle, pigs, birds, and humans using selective media. Enterococcal species were identified using mass spectrometry technology, and each host was characterized by diversity and cluster analysis. The most dominant species were E. hirae in cattle, E. faecium in birds, and E. faecalis in pigs and humans. Cattle had the highest alpha diversity, with high interindividual and livestock farm diversity. The dominant enterococcal species in pigs and humans were identical, and cluster analysis showed that the majority of the two hosts' species clustered together.

Molecular Characterization and Phylogenetic Analysis of Hepatitis E Virus (HEV) Strains from Pigs Farmed in Eight European Countries between 2020 and 2022

In high-income countries, the hepatitis E virus (HEV) is considered an emerging threat causing autochthonous acute hepatitis in humans, with an increased number of reported cases over the last 10 years and related increased burden of chronic hepatitis in immunocompromised and transplant patients. Pigs are the main reservoir of the HEV-3 genotype, which is the most common in Europe, and can be transmitted to humans through the consumption of raw and undercooked pork products. Extensive sequencing revealed the existence of several HEV-3 subtypes in both humans and pigs, confirming a broad heterogeneity of the virus, with some subtypes, such as 3e, 3f, and 3c, which are predominant in Europe. In this study, 291 HEV sequences were obtained from pig feces sampled in more than 74 farms located in Austria, Bulgaria, Czech Republic, Germany, Italy, Poland, the United Kingdom, as well as an unknown number of farms in Netherlands. Of the 99 nonidentical sequences (99/291), 90 were assigned to seven established HEV-3 subtypes: 3a, 3c, 3e, 3f, 3g (here named 3g-like), 3i, and 3l (named 3l-like), already described in Europe, while nine sequences of HEV-3 could not be assigned to any existing subtype (here named 3 ∗ ). The 3e subtype was the most common, detected in six out of eight countries, followed by 3f and 3c, which were also present in several countries; 3g-like, 3i, and 3l-like subtypes showed only a limited circulation. The distribution of frequently (3e, 3f, and 3c) and rarely (3g-like, 3i, and 3l-like) detected HEV-3 subtypes in pigs was correlated with their detection rates in human patients in Europe. The results from this study confirm the wide circulation of several HEV-3 strains in European pigs and confirm that sequencing is needed to monitor the different strains and to identify possible zoonotic transmission paths.

Effects of microbial deodorizer on pig feces fermentation and the underlying deodorizing mechanism

Microbial deodorization is a novel strategy for reducing odor in livestock and poultry feces. Herein, 12 strains of ammonia (NH3) and 15 hydrogen sulfide (H2S) removing bacteria were obtained with a removal efficiency of 65.20–79.80% and 34.90–79.70%, respectively. A novel bacteria deodorant named MIX (Bacillus zhangzhouensis, Bacillus altitudinis, and Acinetobacter pittii at a ratio of 1:1:2) were obtained. MIX can shorten the temperature rising stage by 2 days and prolong the thermophilic stage by 4 days. The ability of MIX to remove NH3, H2S, and volatile fatty acids (VFAs) and the underlying removal mechanism were analyzed during pig feces fermentation. MIX can significantly reduce the concentrations of NH3 and H2S by 41.82% and 66.35% and increase the concentrations of NO3−–N and SO42− by 7.80% and 8.83% (P < 0.05), respectively, on the 25th day. Moreover, the concentrations of acetic, propionate, iso-valerate, and valerate were significantly reduced. The dominant bacteria communities at the phylum level were Firmicutes, Proteobacteria, Bacteroidetes, and Spirochaetes. B. zhangzhouensis and B. altitudinis could convert NH4+–N to NO3−–N, and A. pittii could transfer H2S to SO42−. This study revealed that bacteria deodorant can reduce the concentrations of NH3, H2S, and VFAs in pig feces and increase those of NH4+, NO3−, and SO42− and has excellent potential in deodorizing livestock and poultry feces composting.

Lactobacillus-driven feed fermentation regulates microbiota metabolism and reduces odor emission from the feces of pigs.

Our present study showed that dietary supplementation with feed fermented by Lactobacillus could promote the growth performance of pigs, regulate the microbiota, and inhibit the growth of harmful bacteria. It could prevent the accumulation of toxic substances and reduce odor emission from pig feces, thereby reducing environmental pollution. In addition, one key triumph of the present study was the isolation of Weissella cibaria ZWC030, and the strain could inhibit the production of skatole in vitro in our present results.

Probiotic complex supplementation to growing pig’s diet enhances daily growth and reduces fecal gas emission

A total of 180 growing pigs (Duroc × Landrace × Yorkshire) with an initial body weight (BW) of 23.58 ± 0.8 kg were used in this experiment. According to initial BW and sex, pigs were randomly allotted three dietary treatments, 12 replicates (pen) per treatment, and five pigs per pen. The three dietary treatments were basal diet (CON) and basal diet supplemented with either 0.1% Bacillus and Saccharomyce s spp.-based probiotics complex (BS1) or 0.2% probiotics complex (BS2). The whole experiment lasted 42 days. The results showed that the BW of pigs fed the BS1 diet was significantly higher than those fed the CON diet on day 42 ( P &lt; 0.05). The average daily gain (ADG) of pigs receiving BS1 and BS2 diets was higher than those fed CON diet during days 21–42, whereas during the overall experiment period ADG ( P &lt; 0.05) was higher in only BS1 compared with CON group. The NH3 and H2S emissions on day 42 were reduced from the feces of pigs fed probiotic complex-supplemented diets. Therefore, adding 0.1% probiotic complex to the late-phase diet of growing pigs can more effectively improve BW and daily gain and reduce harmful gas emissions.