The effects and mechanisms of acids on the health of piglets and weaners – a review

Effects of organic acid-preserved cereal grains in sow diets during late gestation and lactation on the performance and faecal microbiota of sows and their offspring

BACKGROUND

Organic acids (OA) and maternal nutritional strategies have been demonstrated to promote piglet health and development. The objective of this study was to investigate the effects of incorporating OA-preserved cereal grains into sow diets during late gestation and lactation, aiming to reduce the metabolic demands of lactation while optimising offspring development and growth until slaughter. The experiment compared OA-preserved wheat and barley to conventionally dried grains, focusing on sow and offspring performance, as well as their faecal microbiota during lactation. Forty sows were blocked based on parity, body weight and back fat thickness on d 100 of gestation and assigned to one of two diets: a dried grain lactation diet and a preserved grain lactation diet. Sow faecal samples were collected at farrowing for the coefficient of apparent total tract digestibility (CATTD) of nutrients and microbial analysis. Offspring faecal samples were collected on d 10 postpartum and at weaning (d 26 postpartum) for microbial analysis.

RESULTS

Sow body weight, back fat changes, gestation and lactation length, total piglets born, wean-to-oestrus interval, and lactation efficiency were unaffected by sow diet (P > 0.05). However, sows offered the preserved grain diet exhibited improved CATTD of dry matter, nitrogen, gross energy, and neutral detergent fibre (P < 0.05). While no maternal effect was observed on offspring growth during lactation (P > 0.05), pigs from sows offered the preserved grain diet showed improved growth and feed efficiency from weaning until slaughter (d 168) compared to those from sows offered the dried grain diet (P < 0.05). The preserved grain diet also reduced the abundance of Proteobacteria in sow faeces at farrowing and in their offspring on d 10 postpartum, and improved piglet faecal scores throughout lactation (P = 0.05). At weaning, piglets from sows offered the preserved grain diet exhibited an increased abundance of Lactobacillus and reduced abundance of Alistipes in their faeces (P < 0.05).

CONCLUSION

OA-preserved grains enhanced the CATTD of nutrients in sows, promoted healthier piglet faecal scores during lactation, and improved offspring growth performance post-weaning, potentially linked to beneficial changes observed in the faecal microbiota of sows and their offspring during lactation.

Sustainable Nutritional Strategies for Gut Health in Weaned Pigs: The Role of Reduced Dietary Crude Protein, Organic Acids and Butyrate Production

Weaning in piglets presents significant physiological and immunological challenges, including gut dysbiosis and increased susceptibility to post-weaning diarrhoea (PWD). Abrupt dietary, environmental, and social changes during this period disrupt the intestinal barrier and microbiota, often necessitating antimicrobial use. Sustainable dietary strategies are critical to addressing these issues while reducing reliance on antimicrobials. Reducing dietary crude protein mitigates the availability of undigested proteins for pathogenic bacteria, lowering harmful by-products like ammonia and branched-chain fatty acids, which exacerbate dysbiosis. Organic acid supplementation improves gastric acidification, nutrient absorption, and microbial balance, while also serving as an energy-efficient alternative to traditional grain preservation methods. Increasing intestinal butyrate, a key short-chain fatty acid with anti-inflammatory and gut-protective properties, is particularly promising. Butyrate strengthens intestinal barrier integrity by upregulating tight junction proteins, reduces inflammation by modulating cytokine responses, and promotes anaerobic microbial stability. Exogenous butyrate supplementation via salts provides immediate benefits, while endogenous stimulation through prebiotics (e.g., resistant starch) and probiotics promotes sustained butyrate production. These interventions selectively enhance butyrate-producing bacteria such as Roseburia and Faecalibacterium prausnitzii, further stabilising the gut microbiota. Integrating these strategies can enhance gut integrity, microbial resilience, and immune responses in weaned piglets. Their combination offers a sustainable, antimicrobial-free approach to improving health and productivity in modern pig production systems.

Effects of the Novel LaPLa-Enriched Medium- and Long-Chain Triacylglycerols on Body Weight, Glycolipid Metabolism, and Gut Microbiota Composition in High Fat Diet-Fed C57BL/6J Mice

The roles of medium- and long-chain triacylglycerols (MLCT) on health benefits under high fat diet (HFD) conditions remain in dispute. This study was conducted to investigate the effects of novel LaPLa-rich MLCT on the glycolipid metabolism and gut microbiota in HFD-fed mice when pork fat is half replaced with MLCT and palm stearin (PS). The results showed that although MLCT could increase the body weight in the mouse model, it can improve the energy utilization, regulate the glucose and lipid metabolism, and inhibit the occurrence of inflammation. Furthermore, 16S rRNA gene sequencing of gut microbiota indicated that PS and MLCT affected the overall structure of the gut microbiota to a varying extent and specifically changed the abundance of some operational taxonomic units (OTUs). Moreover, several OTUs belonging to the genera Dorea, Streptococcus, and g_Eryipelotrichaceae had a high correlation with obesity and obesity-related metabolic disorders of the host. Therefore, it can be seen that this new MLCT has different properties and functions from the previous traditional MLCT, and it can better combine the advantages of MLCT, lauric acid, and sn-2 palmitate, as well as the advantages of health function and metabolism. In summary, this study explored the effects of LaPLa-enriched lipids on glycolipid metabolism in mice, providing theoretical support for future studies on the efficacy of different types of conjugated lipids, intending to apply them to industrial production and subsequent development of related products.

Insights in the Development and Uses of Alternatives to Antibiotic Growth Promoters in Poultry and Swine Production

The overuse and misuse of antibiotics has contributed to the rise and spread of multidrug-resistant bacteria. To address this global public health threat, many countries have restricted the use of antibiotics as growth promoters and promoted the development of alternatives to antibiotics in human and veterinary medicine and animal farming. In food-animal production, acidifiers, bacteriophages, enzymes, phytochemicals, probiotics, prebiotics, and antimicrobial peptides have shown hallmarks as alternatives to antibiotics. This review reports the current state of these alternatives as growth-promoting factors for poultry and swine production and describes their mode of action. Recent findings on their usefulness and the factors that presently hinder their broader use in animal food production are identified by SWOT (strength, weakness, opportunity, and threat) analysis. The potential for resistance development as well as co- and cross-resistance with currently used antibiotics is also discussed. Using predetermined keywords, we searched specialized databases including Scopus, Web of Science, and Google Scholar. Antibiotic resistance cannot be stopped, but its spreading can certainly be hindered or delayed with the development of more alternatives with innovative modes of action and a wise and careful use of antimicrobials in a One Health approach.

Drinking Water Supplemented with Acidifiers Improves the Growth Performance of Weaned Pigs and Potentially Regulates Antioxidant Capacity, Immunity, and Gastrointestinal Microbiota Diversity

This study evaluated the potential effects of adding acidifiers to the drinking water on the growth performance, complete blood count, antioxidant indicators, and diversity of gastrointestinal microbiota for weaned pigs. A total of 400 weaned pigs were randomly divided into four treatments. Pigs were fed the same basal diet and given either water (no acidifier was added, control) or water plus blends of different formulas of acidifiers (acidifier A1, A2, or A3) for 35 days. On d 18 and 35 of the experimental period, 64 pigs (four pigs per pen) were randomly selected to collect blood for a CBC test (n = 128) and an antioxidant indicators test (n = 128); 24 pigs (six pigs per group) were randomly selected to collect fresh feces (n = 48) from the rectum for 16S rRNA gene sequencing. Compared to the control, supplementing the drinking water with acidifiers improved the growth performance and survival rate of weaned pigs. Acidifier groups also increased serum catalase (CAT) and total antioxidant capacity (T-AOC) activities, while also displaying a decreased malondialdehyde (MDA) concentration compared to the control. The relative abundance of Firmicutes in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 35; the relative abundance of Lactobacillus in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 18 and 35. The microbial species Subdoligranulum or Ruminococcaceae_UCG-005 had significantly positive correlations with ADG and ADFI or with serum antioxidant indicators, respectively. These findings suggest that supplementing the drinking water with an acidifier has a potential as an antioxidant, which was reflected in the improvement of growth performance, immunity, antioxidant capacity, and intestinal flora.

Acidifiers blend on digestibility, blood metabolites and performance of nursery piglets

ABSTRACT The aim of this study was to evaluate the effect of inclusion of two acidifiers blend (with different protection levels) on the acidification potential in vitro, apparent total tract digestibility of diet nutrients, blood metabolites, and average daily gain of nursery piglets. Two commercial acidifiers blend additives (AC1 and AC2) were evaluated. The acidification potential of the two acidifiers blend added to the diet were tested by buffering capacity and initial pH in vitro. For the evaluation of apparent digestibility of diet nutrients, blood metabolites and average daily gain, two experiments were carried out. The AC2 acidifier had a greater effect on the initial reduction in pH and a lower linear buffering rate of the diet. The use of acidifiers did not improve the nutrient digestibility of the diets and had no effect on the blood metabolite concentrations of urea, total protein, albumin, globulin, and lactate. Although the inclusion of acidifiers in the diets did not affect the apparent total tract digestibility of the diet nutrients the inclusion of the AC2 acidifier at different levels showed a negative quadratic effect on the average daily gain, with the best inclusion level being 0.26%.

Prenatal programming of the small intestine in piglets: the effect of supplementation with 3-hydroxy-3-methylbutyric acid (HMB) in pregnant sows on the structure of jejunum of their offspring

When discussing the scale of the occurrence of diseases of the digestive system in farm animals, particularly pigs in the weaning period, it may be beneficial to study physiological and nutritional factors that could potentially affect the growth, development, and modelling of the structure and function of the digestive tract. Taking into account the reports on the beneficial effects of ß-hydroxy-ß-methylbutyrate (HMB) administration in the prenatal period on the development of various systems it was assumed that the HMB supplementation to pregnant sows can influence intestinal development in the offspring during weaning. Thus, the present experiment was conducted to evaluate the effect of HMB treatment of pregnant sows on jejunum development in offspring at weaning. From 70th day until the 90th day of gestation, sows received either a basal diet (n = 12) or the same diet supplemented with HMB (n = 12) at the dose of 0.2 g/kg of body weight/day. HMB given during prenatal time reduced the thickness of the longitudinal muscle; the apoptotic cell index in epithelium also significantly decreased after the HMB supplementation. Vasoactive intestinal (poly)peptide (VIP) expression in submucosal ganglia significantly increases in prenatally HMB treated piglets. The same strong reaction was observed with the expression of occludin, claudin-3, E-cadherin, and leptin in the jejunal epithelium. The obtained results indicate that the administration of HMB to pregnant sows significantly influenced the expression of VIP, leptin and some proteins of the intestinal barrier of their offspring less influencing the basal morphology.

Growth Performance, Gut Environment and Physiology of the Gastrointestinal Tract in Weaned Piglets Fed a Diet Supplemented with Raw and Fermented Narrow-Leafed Lupine Seeds

Simple Summary

Fermented feed in growing pig nutrition may influence microbiota of the gastrointestinal tract, improve utilization of nutrients from the diet, and reduce the level of excreted ammonia and phosphorus released into the environment. In the research, fermentation of narrow-leafed lupine seeds was provided and fermented seeds were added to the pigs’ diet. In the 28-day experiment, 24 male pigs were divided into three groups. The control group was fed a soybean meal diet, whereas in the experimental diets, 50% of soybean meal (SBM) protein was replaced by raw or fermented lupine seeds. The influence of fermentation on performance results, gut environment and physiology, and selected blood metabolic parameters in young pigs, were analyzed. Fermentation did not affect pigs’ performance, metabolic, microbial and most gastrointestinal tract parameters, but influenced crypt depth, concentrations of short chain fatty acids and p-cresole in the proximal colon segment, and significantly lowered the pH of the middle colon digesta and ammonia contents. Fermentation improved the chemical composition of seeds, but due to the lack of a significant improvement in the performance, the results may prove to be economically unviable.

Abstract

The aim of this study was to: (1) provide controlled fermentation of narrow-leafed lupine seeds; (2) monitor seed composition, and (3) determine the influence of fermentation on the performance, gut environment and physiology, and selected blood metabolic parameters, in young pigs. Firstly, the effect of 24 h lupine seed fermentation by bacteria and yeast on seed chemical composition was determined. It increased contents of crude protein, crude fiber and ash, but reduced nitrogen-free extractive levels. The amino acid profile of fermented lupine (FL) was similar to that of raw lupine (RL) seeds, whereas the contents of oligosaccharides and P-phytate decreased significantly, in contrast to alkaloids. In fermented feed, pH dropped from 5.5 to 3.9. In the 28-day experiment, 24 male pigs were divided into three groups. The control group was fed a soybean meal diet (SBM), whereas in the experimental diets, 50% of SBM protein was replaced by RL or FL. Afterwards, eight pigs from each group were euthanized and their digesta and blood samples were collected. The FL use did not affect pigs’ performance, nor their metabolic, microbial and most gastrointestinal tract parameters, but influenced crypt depth. Fermentation affected concentrations of short chain fatty acids and p-cresole in the proximal colon segment. In the small intestine, the levels of acetate and butyrate decreased, and, in the caecum, the propionate level decreased. Fermentation significantly lowered the pH of the middle colon digesta and ammonia contents compared to RL. A part of SBM may be successfully replaced by RL and FL in young pigs’ diets.