Diet and microbiota-gut-brain axis in relation to tail biting in pigs: A review

Fewer culturable Lactobacillaceae species identified in faecal samples of pigs performing manipulative behaviour

Manipulative behaviour that consists of touching or close contact with ears or tails of pen mates is common in pigs and can become damaging. Manipulative behaviour was analysed from video recordings of 45-day-old pigs, and 15 manipulator-control pairs (n = 30) were formed. Controls neither received nor performed manipulative behaviour. Rectal faecal samples of manipulators and controls were compared. 16S PCR was used to identify Lactobacillaceae species and 16S amplicon sequencing to determine faecal microbiota composition. Seven culturable Lactobacillaceae species were identified in control pigs and four in manipulator pigs. Manipulators (p = 0.02) and females (p = 0.005) expressed higher Lactobacillus amylovorus, and a significant interaction was seen (sex * status: p = 0.005) with this sex difference being more marked in controls. Females (p = 0.08) and manipulator pigs (p = 0.07) tended to express higher total Lactobacillaceae. A tendency for an interaction was seen in Limosilactobacillus reuteri (sex * status: p = 0.09). Results suggest a link between observed low diversity in Lactobacillaceae and the development of manipulative behaviour.

Indicators of improved gestation housing of sows. Part I: Effects on behaviour, skin lesions, locomotion, and tear staining

Commercial gestation housing systems for sows generally fail to cater fully for their needs in terms of comfort or the ability to perform highly motivated behaviours, which can lead to chronic stress and an impairment to welfare. We compared a typical gestation system (CONTROL) with an IMPROVED one as regards oral stereotypies, aggressive behaviour, skin lesions, locomotion, and tear staining. Sows were mixed into 12 stable groups (six groups per treatment, 20 sows per group), 29 days post-service in pens with free-access, full-length individual feeding/lying stalls. CONTROL pens had fully slatted concrete floors, with two blocks of wood and two chains suspended in the group area. IMPROVED pens were the same but with rubber mats and a length of manila rope in each feeding stall, and straw provided in three racks in the group area. Direct observations of oral stereotypical (30 instantaneous scans per sow per day) and aggressive (all-occurrence sampling, 3 h per sow per day) behaviours were conducted 72 h post-mixing, in mid and late gestation. Skin lesions were counted 24 h and three weeks post-mixing, and in late gestation. Sows' locomotion (locomotory ability) was scored using a visual analogue scale in mid and late gestation. Right and left eye tear staining was scored in late gestation. Indications of better welfare in IMPROVED sows included performance of fewer oral stereotypies in mid and late gestation, and lower tear stain scores. These sows performed more aggression in late gestation, which was associated with access to enrichment, but skin lesion counts were not affected. Thus, the changes made in the IMPROVED treatment benefitted aspects of sow welfare.

Indicators of improved gestation housing of sows. Part II: Effects on physiological measures, reproductive performance and health of the offspring

Prenatal stress is the mechanism through which poor welfare of pregnant sows has detrimental effects on the health and resilience of their piglets. We compared two gestation housing systems (IMPROVED versus [conventional] CONTROL) in terms of sow stress and welfare indicators and sought to determine whether potential benefits to the sows would translate into improved offspring health. Sows were mixed into 12 stable groups (six groups per treatment, 20 sows per group) 29 days post-service in pens with free-access, full-length individual feeding/lying-stalls. CONTROL pens had fully slatted concrete floors, with two blocks of wood and two chains suspended in the group area. IMPROVED pens were the same but with rubber mats and manila rope in each stall, and straw provided in three racks in the group area. Saliva was collected from each sow on day 80 of pregnancy and analysed for haptoglobin. Hair cortisol was measured in late gestation. Sows' right and left eyes were scored for tear staining in mid lactation and at weaning. Numbers of piglets born alive, dead, mummified, and total born were recorded. Piglets were weighed and scored for vitality and intra-uterine growth restriction (IUGR) at birth. Presence of diarrhoea in farrowing pens was scored every second day throughout the suckling period. IMPROVED sows had lower haptoglobin levels and tear-stain scores during lactation. IMPROVED sows produced fewer mummified piglets, and these had significantly lower IUGR scores, and scored lower for diarrhoea than piglets of CONTROL sows. Hence, improving sow welfare during gestation improved the health and performance of their offspring.

Influence of body lesion severity on oxidative status and gut microbiota of weaned pigs

Body lesions in pigs are a common welfare concern, particularly during the weaning period. These lesions can lead to pain, infection, and impaired mobility, resulting in reduced growth performance and increased mortality. Moreover, weaning stress can affect gut microbiota, immune response and increase the oxidative stress of piglets during this transition period. It has been hypothesised that social stress and body lesions could contribute to affect the gut microbiota, physiological and immune response of piglets. The study aims to evaluate the impact of the body lesions due to social stress on microbial profile, immune response, and oxidative status of weaned piglets. Lesion score (LS) on skin, tail, ear, neck, middle trunk, and hind quarters was measured 1 week (28 days of age, T1) and 7 weeks postweaning (T2) on 45 tail-docked pigs according to the method suggested from the Walfer Quality® (2009) on a scale from 0 to 2. Based on the LS, at T1, piglets were classified as High LS (n = 16), when LS was >1 in at least two of the areas considered, or Low LS (n = 29). At T2, based on the same scoring system and to the LS observed at T1, piglets were divided into four groups: High to Low LS (H-L, n = 11), High to High LS (H-H, n = 5), Low to Low LS (L-L, n = 21) and Low to High LS (L-H, n = 8). Blood and faecal samples were collected at T1 and T2. At T1, pigs with a high LS had a lower biological antioxidant potential compared with the L group (P < 0.02). At T2, the L-H group had a lower Reactive Oxygen Metabolites concentration compared with the H-H group (P = 0.03) while the L-L group had a lower concentration of Immunoglobulin A compared with H-H and L-H groups (P = 0.02 and P = 0.04, respectively). At T1, piglets with high LS had a different microbiota compared to piglets with low LS (R² = 0.04, P < 0.01). Low LS pigs were characterised by a higher abundance of Firmicutes, Blautia, Eubacterium coprostanoligenes, Faecalibacterium, Megasphaera, Subdoligranulum (P.adj < 0.05), while pigs with high LS were characterised by higher abundance of Bacteroidota, Rikenellaceae RC9, Prevotellaceae UCG-003, uncultured-Lachnospiraceae and uncultured-Oscillospiraceae (P.adj < 0.05). At T2, the H-H group were characterised by Oscillospirales-UCG-010, H-L by Agatobachter and L-L by Alloprevotella (P.adj < 0.05). Overall, this study provides valuable insights into the relationship between body lesions, oxidative stress, and gut microbiota in weaned pigs.

Greek Pig Farmers' Perceptions and Experiences of Tail Biting and Tail Docking

Tail biting is both an important economic and a welfare problem. The primary preventive measure, almost on a routine basis throughout Europe, remains tail docking following a risk analysis. This study aimed to get insight on the perceptions of Greek pig farmers towards tail docking, intervention measures, and risk factors of tail biting, as well as opinions on pig welfare themes. Eighty-two farmers answered a questionnaire provided online and in printed form. In the case of a tail-biting outbreak, the most important intervention measure is the removal of the bitten pig (victim), while feed quality, air movements, and stocking density were ranked as the highest risk factors (p ≤ 0.05). Chains are the most common type of enrichment by 67% followed by plastic objects by 29.5%. Almost half of the farmers reported having no tail-biting problem on their farm, while 64.4% of the respondents have already tried at least once to raise pigs with intact tails. To reduce routine tail docking, it is essential to apply specific farm-oriented solutions effectively. To succeed in this aim, it is important to consider farmers' concerns and practices. This study is the first step in that direction.

Asinine milk mitigates stress-mediated immune, cortisol and behavioral responses of piglets to weaning: A study to foster future interventions in humans

Introduction

The present study assessed whether asinine milk supplementation improved the immune and behavioral responses of piglets during an early life weaning stress event as a model for its future use in humans.

Methods

For this, 48 piglets from 4 different litters were used. At 20 days of age, piglets were weighed and allocated with their litter and dam into group pens until 28 days of age. Four piglets from each litter were then randomly assigned to either (1) asinine milk supplementation (n = 16) (2), skimmed cow milk supplementation (n = 16) or (3) no supplementation (n = 16; control group). The supplementations were voluntarily administered for 3 days preweaning and 3 days postweaning using a baby bottle. The effects on the weaning stress response were assessed through salivary cortisol measurements; behavioral tests such as the open field, novel object end elevated plus maze tests; and gene expression of HSD11B1, NR3C1 and IL1B in PBMCs, which was determined by RT-qPCR and normalized to GAPDH and UBB. To test the effect of the supplementations on weight, milk intake, gene expression, and behavior, a randomized block design was used with repeated measurements over time by the PROC MIXED procedure.

Results and discussion

The effects on salivary cortisol were determined using the ratio between the morning and afternoon concentrations, considering the time before and after the weaning event. Principal component analysis (PCA) and Fisher's test were performed to evaluate the behavior test data. When comparing salivary cortisol concentrations between the pre- and postweaning periods, there was a difference (p < 0.05) between the supplementation groups in the afternoon period, suggesting that piglets fed asinine milk had lower afternoon cortisol concentrations postweaning than their counterparts. For the behavioral tests, the supplementations had no measurable effects. No difference was between groups pre- and postweaning for the expression of HSD11B2, which codes for an enzyme that breaks down cortisol. However, the expression of NR3C1, which encodes the glucocorticoid receptor, was significantly upregulated in piglets supplemented with cow milk (mean 1.245; p < 0.05).

Conclusion

Asinine milk downregulated 1L1B gene expression, which codes for an inflammatory cytokine. In conclusion, these results suggest that supplementation with asinine milk may represent a strategy to diminish the damage associated with an early life event by modulating IL1B expression and reducing salivary cortisol levels in piglets undergoing weaning stress. Further transcriptomic and metabolomic studies may improve our understanding of the molecular pathways that mediate this systemic immune-mediated response.

Effects of early postnatal life nutritional interventions on immune-microbiome interactions in the gastrointestinal tract and implications for brain development and function

The gastrointestinal (GI) microbiota has co-evolved with the host in an intricate relationship for mutual benefit, however, inappropriate development of this relationship can have detrimental effects. The developing GI microbiota plays a vital role during the first 1,000 days of postnatal life, during which occurs parallel development and maturation of the GI tract, immune system, and brain. Several factors such as mode of delivery, gestational age at birth, exposure to antibiotics, host genetics, and nutrition affect the establishment and resultant composition of the GI microbiota, and therefore play a role in shaping host development. Nutrition during the first 1,000 days is considered to have the most potential in shaping microbiota structure and function, influencing its interactions with the immune system in the GI tract and consequent impact on brain development. The importance of the microbiota-GI-brain (MGB) axis is also increasingly recognized for its importance in these developmental changes. This narrative review focuses on the importance of the GI microbiota and the impact of nutrition on MGB axis during the immune system and brain developmental period in early postnatal life of infants.

Gut microbiome-produced metabolites in pigs: a review on their biological functions and the influence of probiotics

The gastrointestinal tract is a complex ecosystem that contains a large number of microorganisms with different metabolic capacities. Modulation of the gut microbiome can improve the growth and promote health in pigs. Crosstalk between the host, diet, and the gut microbiome can influence the health of the host, potentially through the production of several metabolites with various functions. Short-chain and branched-chain fatty acids, secondary bile acids, polyamines, indoles, and phenolic compounds are metabolites produced by the gut microbiome. The gut microbiome can also produce neurotransmitters (such as γ-aminobutyric acid, catecholamines, and serotonin), their precursors, and vitamins. Several studies in pigs have demonstrated the importance of the gut microbiome and its metabolites in improving growth performance and feed efficiency, alleviating stress, and providing protection from pathogens. The use of probiotics is one of the strategies employed to target the gut microbiome of pigs. Promising results have been published on the use of probiotics in optimizing pig production. This review focuses on the role of gut microbiome-derived metabolites in the performance of pigs and the effects of probiotics on altering the levels of these metabolites.

Locally Grown Crops and Immunocastration in Fattening Heavy Pigs: Effects on Performance and Welfare

This study aimed to explore dietary replacement soybean meal (SBM) with local pea seeds (PS-L) and the effects of surgically castrated (CM) or immunocastration (IM) in heavy male pigs, on growth performance, feeding behaviour, and tail and ear lesions. Four treatments were arranged factorially (2 × 2), with two sexes and two dietary treatments (96 pigs in eight pens). The inclusion of PS-L was 25%, 30%, and 40% during three phases (40−80 kg, 80−110 kg, and 110−140 kg, respectively). No difference in average daily feed intake (ADFI) and body-weight (BW) between PS-L and SBM could be demonstrated (p > 0.05), but PS-L diet decreased the average daily gain (ADG) at 110−140 kg of BW (p < 0.001) and increased feed conversion rate (FCR) (p < 0.05). The ADG was higher (p < 0.01) in IM than CM in all fattening periods, and the FCR in IM was lower (p < 0.05) than in barrows. IM pigs had lower dressing percentage than CM (p < 0.01). Pigs fed a PS-L diet ate faster but increased their passive behaviour compared with those fed SBM. In conclusion, the PS-L diet did not reduce BW and improved passive behaviour, and IM grew more efficiently, regardless of diet.

Effect of fermented foods on some neurological diseases, microbiota, behaviors: mini review

Fermented foods are among the traditional foods consumed for centuries. In recent years, awareness of fermented foods has been increasing due to their positive health benefits. Fermented foods contain beneficial microorganisms. Fermented foods, such as kefir, kimchi, sauerkraut, and yoghurt, contain Lactic acid bacteria (LAB), such as Lactobacilli, Bifidobacteria, and their primary metabolites (lactic acid). Although studies on the effect of consumption of fermented foods on diabetes, cardiovascular, obesity, gastrointestinal diseases on chronic diseases have been conducted, more studies are needed regarding the relationship between neurological diseases and microbiota. There are still unexplored mechanisms in the relationship between the brain and intestine. In this review, we answer how the consumption of fermented foods affects the brain and behavior of Alzheimer's disease, Parkinson's disease, multiple sclerosis disease, stroke, and gut microbiota.