Wilfried Vahjen’s research while affiliated with MSD Animal Health, Germany and other places

Diet, especially the intake of dietary fibre, and weaning practices may influence pig wellbeing. This study assessed changes in salivary stress and immune markers in sows and their offspring fed either hay (HAY) or sugar beet pulp (SBP), either fine (F) or coarse (C), during gestation and lactation. The effect of weaning age (conventional-CW, late-LW) on these markers was also evaluated. Saliva was analysed for chromogranin A (CgA), cortisol, alpha-amylase, oxytocin, immunoglobulin A (IgA) and adenosine deaminase (ADA). CgA was higher at CW vs. LW in sows fed SBP-F (P=0.038). Alpha-amylase was higher in sows fed HAY-C at CW vs. LW (P=0.005) and in sows fed SBP-C at LW vs. CW (P=0.096). CgA and oxytocin were higher in sows fed SBP-F at CW vs. LW (P =0.038 and P =0.017, respectively). ADA was higher in sows fed SBP-C vs. HAY-C (P=0.035) at LW and at LW vs. CW in sows fed SBP-C (P=0.002). Piglet salivary CgA was higher at CW vs. LW in HAY-F (P=0.002) and SBP-F (P=0.031). Oxytocin was higher at CW vs. LW in piglets fed HAY-F (P=0.006). Piglet salivary IgA was higher in HAY-C vs. HAY-F at CW (P=0.010) and at LW vs. CW in piglets fed HAY-F (P=0.021). ADA was higher in piglets fed SBP-F vs. HAY-F (P=0.053) at CW and SBP-F vs. SBP-C (P=0.042) at LW. Dietary fibre type, weaning age and to a lesser extent grinding degree affect stress and immune markers in pigs. These findings highlight the impact of diet and weaning practice on pig welfare.

The microbiome undoubtedly plays a major role in stabilizing health and ensuring the highest possible related resilience against environmental stressors and infections. Pigs have distinctly developed microbiomes depending on age, husbandry, and diet. Furthermore, the microbial composition in the digestive tract differs depending on the localization. While the stomach and small intestine are largely dominated by lactic acid bacteria and enterobacteria, the spectrum in the large intestine changes significantly. In addition, there are also important differences between the mucosa-associated and the luminal microbiomes in different intestinal sections. Animal health is supported by a balanced colonization of microorganisms in the sense of eubiosis. Disturbances of the microbial ecological system are referred to as dysbiosis and can lead to an increased incidence of diarrheal diseases in particular as a result of infection with pathogens. An important factor in the control of the microbiome is the diet, in addition to the husbandry and genetics of the animals. A balanced diet formulation is an important basis; additionally, stabilization can be achieved by using feed additives. In this context, it is important to ensure that macronutrients are within nutritional recommendations, because protein, carbohydrates, fiber, and fats can influence the microbiome. Supplementation of minerals and feed additives also plays a major role. The latter have been studied very intensively in recent years; stabilizing effects are described for probiotics, prebiotics, synbiotics, organic acids, enzymes, and plant additives. High pharmacological concentrations of zinc oxide that were commonly used in the EU have been banned since 2022, so that the importance of alternative approaches became much greater. Improved knowledge of mechanisms, signaling pathways, and molecular interactions with the digestive tract and host organism is necessary to exploit the potential of the microbiome to stabilize animal health.

The swine gastrointestinal tract contains a great variety of microbes, forming a complex and dynamic ecosystem. Various internal and external factors (e.g. age, breed and diet) may influence its composition. This study aimed to investigate the gut microbial diversity of German Piétrain boars housed on different deep‐litter bedding materials (regional wood shavings, linen, hemp, spelt husks, and wood shavings) via 16S‐rDNA sequencing. Additionally, short‐chain fatty acids were analysed using gas chromatography. Fresh faecal samples ( n = 80) from 40 Piétrain boars were collected twice during the trial. Although it can be assumed that boars ingest bedding orally, no differences in the microbiome composition could be found. The main phyla were Firmicutes and Bacteroides . Acinetobacter was identified as a biomarker for sperm quality differences (total sperm motility) in breeding boars.

Reducing antibiotic use is one of the biggest challenges in pig farming, as antibiotics have been used for years to control typical problems such as newborn or post-weaning diarrhea. The pressure a one health approach has created on animal production regarding antimicrobial resistance is an opportunity to find other strategies against enterobacterial pathogens in suckling and weaned piglets. A farm-specific approach could have a good success due to the individual farm structures in Germany and other countries. In this study, non-metric multidimensional scaling, hierarchical clustering, and latent class analysis were used to determine the impact of antibiotic use on antibiotic resistance patterns and pathogen prevalence in 20 German pig farms. This may help to develop individualized health strategies. 802 fresh fecal samples were collected from sows and piglets from 20 piglet production and rearing farms at different production times (sows antepartum and postpartum, suckling piglets, weaned piglets). In addition, the use of antibiotics was recorded. DNA extracts were subjected to quantitative real-time qPCR with primers specific for antibiotic resistance genes (int1, sul1-3, dfrA1, mcr-1, blaCTX-M), and virulence factors of relevant bacteria (C. difficile, C. perfringens, Salmonella, Escherichia/Shigella/Hafnia, E. coli). Linear and logistic regression models were used to analyze the relationship between different antibiotics and the major genes contributing to the clustering of observations for the different animal groups. Clustering revealed different farm clusters for sows, suckling piglets, and weaned piglets, with the most remarkable diversity in antibiotic use among weaned piglets. Amoxicillin, lincomycin, and enrofloxacin were identified as the most probable cause of increased odds of the presence of relevant antibiotic resistance genes (mcr1, dfrA1, blaCTX-M). Still, direct effects of a specific antibiotic on its associated resistance gene were rare. Enrofloxacin and florfenicol favored the occurrence of C. difficile in sows. The E. coli fimbriae genes were less affected by antibiotic use in sows and piglets, but the F4 fimbriae gene could be associated with the integrase 1 gene in piglets. The results confirm that multidrug-resistant enterobacteria are widespread in German pig farms and give awareness of the impact of current antibiotic use while searching for alternative health strategies.

The present study aimed to investigate the effect of age, breed, and sex of broilers, as well as a probiotic or phytobiotic product on mucosal morphology, bacterial metabolites, and immune traits in the ileum of broilers. A total of 2,880 one-day-old male and female broiler chicks from two breeds (Ross308® and Cobb500®) were randomly assigned to 72 pens. Broilers were offered a wheat-soybean diet without (CO), or with either a probiotic (PO; 2.4 × 10⁹ CFU/kg of Bacillus subtilis DSM32324 and DSM32325 and B. amyloliquefaciens DSM25840) or a phytobiotic (PY; grape extract, 165 ppm procyanidin and 585 ppm polyphenols of the diet) product. The trial was conducted with a 3 × 2 × 2 factorial arrangement of diet, breed, and sex in a completely randomized design (6 replicate-pens per treatment). At day 7, 21, and 35, one chicken per pen was slaughtered for collecting ileal tissue to evaluate of histomorphology and mRNA expression, as well as ileal digesta to measure bacterial metabolites. Data were subjected to ANOVA (the main factors; age, diet, breed, and sex) and Four-Way ANOVA (interactions) using GLM procedure. Overall, the concentration of acetate and total short chain fatty acids reached the peak and lactate decreased to its lowest on day 21, but their concentrations at day 7 and 35 were similar (p > 0.05). Spermine, spermidine, and ammonia decreased after day 7, while putrescine and cadaverine increased after day 21 (p < 0.05). mRNA expression of cytokines, mucin 2 (MUC2) and claudin 5 (CLDN5) was similar; increased from day 7 to 21 and decreased afterward (p < 0.05). Villus height, crypt depth and villus surface area increased with age (p < 0.05). Acidic goblet cells (GC) number and density increased after day 21 (p < 0.05). Ross broilers showed higher D-lactate concentration and IFN-γ expression, while Cobb broilers had greater IL-4, IL-6 and TNF-α expression and higher total GC number (p < 0.05). Female displayed higher villus height and GC number and density (mixed and total GC) than male (p < 0.05). The effect of dietary treatment was not found on any investigated variables (p > 0.05). In conclusion, aging of broilers affected ileal histomorphology, cytokine expression, and barrier integrity, as well as bacterial activity. These observed impacts could be attributed to host-microbiota interaction and the direct effects of bacterial metabolites on intestinal cells and immune system.

Sow colostrum has been reported to protect the IPEC-J2 cells and piglet colon tissues from detrimental effect of Clostridioides difficile toxins. Since dietary fibre can influence the colostrum composition in sows, we hypothesised that it can also differentially affect the colostrum potential against C. difficile toxin-induced effects in IPEC-J2. IPEC-J2 were incubated with colostrum from sows fed either high-fermentable sugar beet pulp (SBP) or low-fermentable lignocellulose (LNC) fibres and in combination with the toxins and analysed by trans-epithelial electrical resistance (TEER) and cell viability using propidium iodide in flow cytometry. Toxins drastically decreased the integrity of IPEC-J2. Colostrum from the sows fed either SBP or LNC exerted protective effect against toxins on IPEC-J2 integrity and this effect was numerically superior in the SBP group. Differences in the percentages of TEER between different treatments were noted after 2 h (p = 0.043), 3 h (p = 0.017) and 4 h (p = 0.017) of incubation and a tendency for differences was noted after 5 h of incubation (p = 0.071). Colostrum from either SBP-or LNC-fed sows did not protect the IPEC-J2 from toxin-induced death. Colostrum of the sows fed either high-fermentable or low-fermentable fibres has a potential to protect IPEC-J2 from the loss of integrity, which may be important in protection from C. difficile-infection development in neonatal piglets. K E Y W O R D S lignocellulose, piglet, sugar beet pulp, TEER, viability

Beneficial effects of pro- and prebiotics in weanling piglets are of great interest in livestock production. Similarly, the use of specific vaccines is of interest as alternative to antibiotics to reduce post-weaning performance losses. The aim of this study was the assessment of the effect of a dual-strain probiotic (B. subtilis and B. licheniformis) and a prebiotic (fructo-oligosaccharides) as well as the additional vaccination with an autogenous inactivated Escherichia coli vaccine on the performance of newly weaned piglets after experimental infection with an enterotoxigenic Escherichia coli. Forty piglets at the age of 28 d were randomly allotted to one of five groups: non-challenged control (NC); challenged positive control (PC); challenged and vaccinated (CV); challenged and diet supplemented with pre- and probiotic mix (CM) and challenged, diet supplemented with pro- and prebiotic mix and vaccinated (CMV). Piglets of CV and CMV were vaccinated parenterally prior to the trial at the age of 17 d. Compared to NC, the experimental infection with E. coli resulted in a significant reduction of body weight gain in both vaccinated groups (p = 0.045), which was associated with an impaired gain to feed ratio (p = 0.012), but not feed intake. In contrast, piglets in the group supplemented with pro- and prebiotics (group CM) were able to maintain their weight and had an average daily gain, which was not significantly different from groups NC and PC. No differences regarding body weight gain, feed intake, gain to feed ratio and fecal score were observed between groups during the 3 rd and 4 th week of the trial. A significant impairment of fecal consistency and frequency of diarrhea was observed related to the oral challenge when comparing PC and NC treatments (p = 0.024). Neither vaccine, nor supplementation with pro- and prebiotics were able to significantly improve fecal consistency, nor did they have a positive effect on the prevalence of diarrhea. The results show no positive synergistic effect of the specific combination of vaccine and pre- and probiotics used in this trial on performance and diarrhea. The results show that the concept of a combination of a specific vaccination and a probiotic with a prebiotic needs further investigation. In the sense of avoiding the use of antibiotics, this seems to be an attractive approach.

Dietary fiber (DF) is receiving increasing attention, and its importance in pig nutrition is now acknowledged. Although DF for pigs was frowned upon for a long time because of reductions in energy intake and digestibility of other nutrients, it has become clear that feeding DF to pigs can affect their well-being and health. This review aims to summarize the state of knowledge of studies on DF in pigs, with an emphasis on the underlying mode of action, by considering research using DF in sows as well as suckling and weaned piglets, and fattening pigs. These studies indicate that DF can benefit the digestive tracts and the health of pigs, if certain conditions or restrictions are considered, such as concentration in the feed and fermentability. Besides the chemical composition and the impact on energy and nutrient digestibility, it is also necessary to evaluate the possible physical and physiologic effects on intestinal function and intestinal microbiota, to better understand the relation of DF to animal health and welfare. Future research should be designed to provide a better mechanistic understanding of the physiologic effects of DF in pigs.