Relevance of functional properties of dietary fibre in diets for weanling pigs

In Vitro Evaluation of Intestinal Barrier Function after Exposure to Digested Pea Ingredients─Food Matrix Effect

Dietary fibers (DF) are important components of human and animal diets. However, they can decrease protein digestibility and absorption and thus the nutritional value of a food. The aim of this study was to investigate how the form of delivery of pea DF impacted the integrity of the intestinal barrier and, thereby, the potential absorption of molecules. To this end, two pea flours, with either intact or ruptured cell walls, and two controls, pea fibers and pea protein, were digested in vitro and the digesta obtained applied onto a jejunum porcine cell line (IPEC-J2 cells). Cell viability and integrity were evaluated by transepithelial electrical resistance measurement, colorimetric assay (MTS), and immunohistochemistry for tight junction proteins. Additionally, the diffusion of FITC-dextran (FD4) and lucifer yellow (LY) through the epithelial cell monolayers was monitored. The digested pea samples did not alter the IPEC-J2 viability and permeability. For instance, no difference in the diffusion of molecules either FD4 or LY across the monolayers was observed between the different digesta and the control. Similarly, no effect was observed in ZO-1 labeling intensity compared to the control. This study demonstrated that intestinal integrity was maintained whether pea cell walls were intact or ruptured.

Supplemental effects of acidifier and encapsulated butyrate solely and combined in high canola meal diets for nursery pigs

Incorporating canola meal (CM) into nursery pig diets has been limited due to the adverse effects of glucosinolates, sulfur-containing glycosides, presented in Brassica family oilseeds. This study investigated the effects of acidifier supplementation in high CM diets on the performance, organ weights, blood profiles, and hindgut microbial composition of nursery pigs. A total of 315 nursery pigs, average 6.0 ± 1.2 kg body weight (BW), were assigned to 1 of 5 dietary treatments with 9 replicates (7 pigs/pen) in a randomized complete block design. Treatments included; a corn-soybean meal (SBM) based diet with 20% CM (positive control, PC) and corn-SBM-based diet with 40% CM without (negative control, NC) or with acidifier (NCA), or encapsulated butyrate (NCB), or both (NCAB). Diets met nutrient requirements of NRC (2012) in 3 phases; phase 1 (common diet; 0 to 1 wk), phase 2 (experimental diets; 1 to 3 wk), and phase 3 (experimental diets; 3 to 6 wk). Pig BW and pen feed consumption were measured by phase to investigate the growth performance of pigs. At the end of each phase, 1 pig per pen was bled and then euthanized for measurement of organ weight. Cecal digesta was collected only at the end of phase 3 for microbial composition analysis. Pigs fed the NCA diets had greater (P < 0.05) final BW and average daily gain during phase 3 and had a tendency of greater (P = 0.084) overall gain-to-feed ratio than pigs fed the NC diet. Pigs fed the NCA diet had a greater (χ2 < 0.05) percentage of non-diarrhea feces than pigs fed the PC diet for phase 2 and the overall period. Pigs fed PC diet had higher serum thyroxine (T4) concentration at the end of phase 3 (P < 0.05) than pigs fed NC diets. The addition of acidifier in NC diet decreased (P < 0.05) spleen weight and tended to decrease (P = 0.064) liver weight. Pigs fed the NCAB diet had a lower (P < 0.05) large intestine weight compared with those fed NC diet. Pigs fed the PC or NCA diets tended to have less (P = 0.06) the relative abundance of OTU Ssd-00188 (Agathobacter rectalis 99.23%) and NCAB diet increased (P < 0.05) the relative abundance of OTU Ssd-00001 (Lactobacillus amylovorus 99.64%) in the cecal microbiota compared with those fed NC diet. Overall, these findings support the incorporation of high CM levels (up to 40%) with acidifier supplementation in nursery pig diets, mitigating the negative implications of dietary glucosinolates and providing benefits for both canola growers and pig farmers in regions with substantial canola production.

Effect of Dietary Xylanase Inclusion on Growth Performance, Nutrient Digestibility, and Digesta Viscosity of Weaned Pigs Fed Wheat-Soybean Meal-Based Diets

(1) Background: This study aimed to evaluate the effects of dietary xylanase addition on growth performance, nutrient digestibility, volatile fatty acids, and digesta viscosity at different digestive sites in weaned pigs fed wheat-soybean meal-based diets with reduced metabolizable energy. (2) Methods: A total of 312 weaned pigs (5.1 ± 0.9 kg, 20 ± 2 days of age) were assigned to one of six dietary treatments. The experimental diets were formulated in a three-phase nursery feeding program: phase 1 (d0-d7), phase 2 (d8-d21), and phase 3 (d22-d42). The experimental diets consisted of a wheat-soybean meal-based diet formulated to meet pig requirements (positive control, PC); the PC diet with a reduction of 100 kcal of metabolizable energy (ME) (negative control, NC); and the NC diet with either 900, 1800, 3600, or 7200 units of xylanase. Feed disappearance and body weight were measured at d7, 14, 21, and 42 in the nursery phase. The pen fecal score was assessed daily from d0 to d14 and three times a week from d15 to d28. On d21-d24 of the experiment (12 pigs per day), one pig per pen was selected for sample collection: ileal, cecal, and mid-colon digesta for viscosity and ileal digesta, feces for nutrient digestibility, and feces and cecal digesta for the measurement of volatile fatty acid. (3) Results: The addition of xylanase to the NC diets did not improve pig growth performance (body weight, feed conversion ratio, and average daily gain; p > 0.10) during the entire nursery phase. In Week 2 and Week 3, pigs fed xylanase had a lower (χ2 < 0.05) incidence of fecal scores 3 and 4 (diarrhea) than the PC and NC diets. In addition, the apparent total tract digestibility of neutral detergent fiber and acid detergent fiber increased linearly (p < 0.1) in response to xylanase addition. Xylanase addition (900 to 7200 U) decreased digesta viscosity in the colon compared to the PC and NC diets. Furthermore, xylanase addition resulted in a lower (p < 0.05) concentration of acetic, propionic, butyric, valeric, and total volatile fatty acid in cecal samples compared to PC. The addition of xylanase resulted in greater acetic and valeric acid concentrations in cecal samples compared to the NC group (p < 0.10). (4) Conclusions: Xylanase addition can improve nutrient digestibility, particularly at the total tract level, and reduce viscosity in the hindgut, which could be related to decreasing the occurrence of looseness. However, its impact on growth performance was minimal in wheat-soybean meal-based diets with a reduction of 100 kcal of ME.

Gastrointestinal microbiota and metabolites responses to dietary cereal grains in an adult pig model

Corn (C), wheat (W), and paddy rice (PR) are important energy sources and are commonly used in feed production for swine. This study mainly focuses on the variation and regularities of microbiota and metabolites in the gastrointestinal tract (GIT) of pigs in response to C, W, and PR. A total of 18 pigs were allotted into three dietary groups with six replicated pigs and received diets containing C, W, or PR as the sole energy source, respectively. The results showed that digestive parts significantly affected the diversity of microbial communities. Cereal grain sources significantly influenced the β-diversity of microbial communities in the colon and rectum. Campylobacterota and Proteobacteria are mainly distributed in the duodenum, Lactobacillus in the jejunum, and Bacteroidota in the colon and rectum. The W diet increased the Bacteroidota, Spirochaetota, and Prevotellaceae_NK3B31_group abundances and showed the highest concentrations of all short-chain fatty acids (SCFAs) in the hindgut. Fibrobacterota, Bacteroidota, Spirochaetota, Prevotellaceae_NK3B31_group, Prevotella, and Treponema in the colon or rectum were positively correlated with acetate, propionate, butyrate, and total SCFAs. These findings suggested that aerobic bacteria and facultative anaerobes in the foregut will gradually be replaced by anaerobes in the hindgut. The W diet had the best fermentability and was beneficial to the colonization of microbial communities that mainly used carbohydrates. The hindgut flora of the PR diet group may be more balanced with fewer potential pathogenic bacteria. Many microbial communities have been identified to contribute positively to the SCFA production of the hindgut. Collectively, our study revealed the spatial variation regularities of GIT microbial communities in an adult pig model and provided new insights into GIT microbiota and responses of metabolites to cereal grain diets.

Different Physiochemical Properties of Novel Fibre Sources in the Diet of Weaned Pigs Influence Animal Performance, Nutrient Digestibility, and Caecal Fermentation

The effect of including micronised fibre sources (FS) differing in fermentability and hydration capacity (HC) on growth performance, faecal digestibility, and caecal fermentation was investigated in piglets. There were four dietary treatments: a control diet (CON) and three treatments differing in the HC and fermentability of FS added at 1.5% to prestarter (28-42 d) and starter (42-61 d) diets. These were: LHC (low-HC by-product-based insoluble fibre (IF) with a prebiotic fraction (PF) from chicory root); MHC (medium-HC by-product-based IF with a PF); and HHC (high-HC non-fermentable wood-based IF with no PF). There were eight replicates per treatment. Over the entire period, LHC and MHC piglets showed a 10% increase in daily growth and feed intake (p ≤ 0.019) and tended to have a reduced feed conversion ratio (p = 0.087) compared to HHC piglets. At 42 d, faecal protein digestibility increased by 5% in the LHC and MHC groups compared with the HHC group (p = 0.035) and did not differ from the CON group. Both LHC and MHC fibres were more fermented in vitro with caecal inocula from 61 d old piglets than HHC fibre (p ≤ 0.003). These results suggest that balanced soluble and insoluble fibre concentrates can improve piglet performance.

Nutritional guide to feeding wheat and wheat co-products to swine: a review

Inclusion of wheat grain can offer feeding opportunities in swine diets because of its high starch, crude protein (CP), amino acid (AA), and phosphorus (P) content. High concentrations of starch within wheat grain makes it a good energy source for swine. Mean energy content of wheat was 4,900 and 3,785 kcal/kg dry matter (DM) for digestible energy and metabolizable energy, respectively. CP concentration can vary based on the class of wheat which include hard red winter, hard red spring, soft red winter, hard white, soft white, and durum. The average CP of all wheat data collected in this review was 12.6% with a range of 8.5% to 17.6%. The AA concentration of wheat increases with increasing CP with the mean Lys content of 0.38% with a standardized ileal digestibility (SID) of 76.8%. As CP of wheat increases, the SID of AA in wheat also increases. Mean P of wheat was 0.27% and median P was 0.30%. Off-quality wheat is often associated with sprouts, low-test weight, or mycotoxin-contamination. Sprouted and low-test weight wheat are physical abnormalities associated with decreased starch within wheat kernel that leads to reductions in energy. The assumed energy value of wheat grain may need to be reduced by up to 10% when the proportion of sprouted to non-sprouted wheat is up to 40% whereas above 40%, wheat's energy may need to be reduced by 15% to 20%. Low-test weight wheat appears to not influence pig performance unless it falls below 644 kg/m3 and then energy value should be decreased by 5% compared to normal wheat. Deoxynivalenol (DON) contamination is most common with wheat grain. When content is above the guidance level of 1 mg/kg of DON in the complete diet, each 1 mg/kg increase in a DON-contaminated wheat-based diet will result in a 11% and 6% reduction in ADG and ADFI for nursery pigs, and a 2.7% and 2.6% reduction in ADG and ADFI, in finishing pigs, respectively. Wheat co-products are produced from the flour milling industry. Wheat co-products include wheat bran middlings, millrun, shorts, and red dog. Wheat co-products can be used in swine diets, but application may change because of differences in the final diet energy concentration due to changes in the starch and fiber levels of each wheat co-product. However, feeding wheat co-products are being evaluated to improve digestive health. Overall, wheat and wheat co-products can be fed in all stages of production if energy and other nutrient characteristics are considered.

Multi-omics reveal the effects and regulatory mechanism of dietary neutral detergent fiber supplementation on carcass characteristics, amino acid profiles, and meat quality of finishing pigs

This study aimed to reveal the effects and regulatory mechanism of dietary NDF on the performance of pigs by multi-omics analysis. Results showed that 16 % dietary NDF significantly improved meat quality, increased flavor amino acid content, and reduced backfat thickness and the feed-to-gain ratio. 16S rDNA sequencing showed that 16 % NDF significantly increased the abundance of Akkermansia, Lachnoclostridium, and Ruminococcus. Transcript analysis showed that genes related to muscle development and lipid metabolism were significantly modified. Metabonomic analysis showed that 16 % NDF significantly increased amino and fatty acid related metabolites. Correlation analysis suggested that 16 % NDF treatment may alter the gut microbiota and metabolites, regulate the expression of genes related to lipid and amino metabolism, and ultimately affect the flavor and performance of pigs. This study provides a novel understanding about the effect and regulatory mechanism of NDF supplements on the finishing pigs and a relevant reference for the improvement of diet formulation.

Nutrition strategies to control post-weaning diarrhea of piglets: From the perspective of feeds

Post-weaning diarrhea (PWD) is a globally significant threat to the swine industry. Historically, antibiotics as well as high doses of zinc oxide and copper sulfate have been commonly used to control PWD. However, the development of bacterial resistance and environmental pollution have created an interest in alternative strategies. In recent years, the research surrounding these alternative strategies and the mechanisms of piglet diarrhea has been continually updated. Mechanically, diarrhea in piglets is a result of an imbalance in intestinal fluid and electrolyte absorption and secretion. In general, enterotoxigenic Escherichia coli (ETEC) and diarrheal viruses are known to cause an imbalance in the absorption and secretion of intestinal fluids and electrolytes in piglets, resulting in diarrhea when Cl- secretion-driven fluid secretion surpasses absorptive capacity. From a perspective of feedstuffs, factors that contribute to imbalances in fluid absorption and secretion in the intestines of weaned piglets include high levels of crude protein (CP), stimulation by certain antigenic proteins, high acid-binding capacity (ABC), and contamination with deoxynivalenol (DON) in the diet. In response, efforts to reduce CP levels in diets, select feedstuffs with lower ABC values, and process feedstuffs using physical, chemical, and biological approaches are important strategies for alleviating PWD in piglets. Additionally, the diet supplementation with additives such as vitamins and natural products can also play a role in reducing the diarrhea incidence in weaned piglets. Here, we examine the mechanisms of absorption and secretion of intestinal fluids and electrolytes in piglets, summarize nutritional strategies to control PWD in piglets from the perspective of feeds, and provide new insights towards future research directions.

Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets

Weaning is a critical transitional point in the life cycle of piglets. Early weaning can lead to post-weaning syndrome, destroy the intestinal barrier function and microbiota homeostasis, cause diarrhea and threaten the health of piglets. The nutritional components of milk and solid foods consumed by newborn animals can affect the diversity and structure of their intestinal microbiota, and regulate post-weaning diarrhea in piglets. Therefore, this paper reviews the effects and mechanisms of different nutrients, including protein, dietary fiber, dietary fatty acids and dietary electrolyte balance, on diarrhea and health of piglets by regulating intestinal function. Protein is an essential nutrient for the growth of piglets; however, excessive intake will cause many harmful effects, such as allergic reactions, intestinal barrier dysfunction and pathogenic growth, eventually aggravating piglet diarrhea. Dietary fiber is a nutrient that alleviates post-weaning diarrhea in piglets, which is related to its promotion of intestinal epithelial integrity, microbial homeostasis and the production of short-chain fatty acids. In addition, dietary fatty acids and dietary electrolyte balance can also facilitate the growth, function and health of piglets by regulating intestinal epithelial function, immune system and microbiota. Thus, a targeted control of dietary components to promote the establishment of a healthy bacterial community is a significant method for preventing nutritional diarrhea in weaned piglets.

Performance and nutrient digestibility of growing pigs fed highly or low fermentable coarse or finely ground fibre-rich feedstuffs

Dietary fibre is mainly classified according to its chemical characteristics but structure and particle size of fibre-rich feedstuff can also be decisive for digestion and performance. So far, only few studies investigated this in pigs. This experiment aimed to compare coarse and finely ground dried hemp plants and apple pomace regarding performance and ileal and total tract nutrient digestibility of growing pigs. Coarse or finely ground apple pomace or dried hemp plants were added to the diet of 56 nine weeks old growing pigs (DanBred x Duroc), housed in flat decks with each 2 animals. The growing pigs received the experimental diets for three weeks while performance was recorded. Eight pigs per group were sacrificed and digesta and organ tissue sampled. The stomach health was evaluated by visually scoring of the mucosa integrity. Apparent ileal (AID) and total tract digestibility (ATTD) were calculated using titanium dioxide as marker. Statistical analyses were performed using two-way ANOVA (p < 0.05). The highest feed intake (fibre particle size, p = 0.018) and bodyweight gain (fibre particle size, p = 0.018; fibre source x particle size interaction, p = 0.040), was observed in animals fed finely ground apple pomace, while the feed conversion ratio was 8-12% lower in pigs fed finely ground fibre sources (p = 0.012). No differences in stomach mucosa integrity were detected between the groups. The relative pancreas (p = 0.045), stomach (p < 0.001), and jejunum (p = 0.010) weights were higher in animals fed diets containing apple pomace. In contrast, the relative liver, caecum and colon weights were not affected by fibre source or particle size. The AID of protein and amino acids was not affected, while ATTD was increased by fibre source (hemp vs. apple pomace) reducing faecal nitrogen excretion. The AID of calcium was increased when diets contained apple pomace (p < 0.001), while zinc AID and ATTD were enhanced when diets contained dried hemp (p = 0.016; p = 0.016, respectively). Our results suggest that the structure as well as the chemical characteristics should be considered in a future fibre evaluation system in pigs.

Effects of mixed fibres and essential oils blend on growth performance and intestinal barrier function of piglets challenged with enterotoxigenic Escherichia coli K88

This study was to evaluate the effects of supplementing mixed dietary fibres (MDF) and essential oils blend (EOB) either alone or in combination on growth performance and intestinal barrier function in weaned piglets challenged with enterotoxigenic Escherichia coli K88 (ETEC). Forty-two piglets (28 days old) were randomly allocated into six treatments in a 25-day experiment, and fed the basal diet (CON or ETEC) either with antibiotics (AT), MDF, EOB or MDF + EOB. On Day 22 of the experiment, pigs in CON and challenged groups (ETEC, AT, MDF, EOB and MDF + EOB) were orally administered sterile saline and ETEC containing 6 × 1010  CFU/kg body weight respectively. On Day 26, all pigs were euthanized to collect samples. Before ETEC challenge, piglets in MDF and EOB had lower diarrhoea incidence (p < 0.01) than others. After ETEC challenge, piglets in ETEC had lower average daily gain and higher diarrhoea incidence (p < 0.05) than those of CON. Furthermore, compared to CON, ETEC group increased the serum lipopolysaccharide concentration and diamine oxidase activity, and decreased mRNA levels of genes relating to barrier function (aquaporin 3, AQP3; mucin1, MUC1; zonula occludens-1, ZO-1; Occludin), and increased the concentration of cytokines (interleukin-1β/4/6/10, IL-1β/4/6/10) and secretory immunoglobulin A (sIgA) in jejunal mucosa (p < 0.05). However, these deleterious effects induced by ETEC were partly alleviated by MDF, EOB, MDF + EOB and AT. Additionally, compared to ETEC group, MDF increased Bifidobacterium abundance in cecal digesta and butyrate concentration in colonic digesta (p < 0.05). Also, EOB improved propionate concentration in cecal digesta, and MDF + EOB decreased IL-10 concentration in jejunal mucosa (p < 0.05) compared with ETEC. Conclusively, MDF and EOB either alone or in combination can improve growth performance and alleviate diarrhoea via improving intestinal barrier function of piglets after ETEC challenge, and all may serve as potential alternatives to AT for piglets.

Composition of mucus- and digesta-associated bacteria in growing pigs with and without diarrhea differed according to the presence of colonic inflammation

BACKGROUND

In the pig production, diarrhea can occur during different growth stages including the period 4-16 weeks post weaning, during which a diarrheal outbreak also termed as colitis-complex diarrhea (CCD) can occur and it is distinct from post-weaning diarrhea (1-2 weeks post weaning). We hypothesized that CCD in growing pigs is associated with changes in colonic microbiota composition and fermentation patterns, and the aim of the present observational study was to identify changes in digesta-associated bacteria (DAB) and mucus-associated bacteria (MAB) in the colon of growing pigs with and without diarrhea. A total number of 30 pigs (8, 11, and 12 weeks of age) were selected; 20 showed clinical signs of diarrhea and 10 appeared healthy. Based on histopathological examination of colonic tissues, 21 pigs were selected for further studies and classified as follows: without diarrhea, no colon inflammation (NoDiar; n = 5), with diarrhea, without colonic inflammation (DiarNoInfl; n = 4), and with diarrhea, with colonic inflammation (DiarInfl; n = 12). Composition (based on 16S rRNA gene amplicon sequencing) and fermentation pattern (short-chain fatty acids; SCFA profile) of the DAB and MAB communities were characterized.

RESULTS

The DAB showed higher alpha diversity compared to MAB in all pigs, and both DAB and MAB showed lowest alpha diversity in the DiarNoInfl group. Beta diversity was significantly different between DAB and MAB as well as between diarrheal groups in both DAB and MAB. Compared to NoDiar, DiarInfl showed increased abundance of various taxa, incl. certain pathogens, in both digesta and mucus, as well as decreased digesta butyrate concentration. However, DiarNoInfl showed reduced abundance of different genera (mainly Firmicutes) compared to NoDiar, but still lower butyrate concentration.

CONCLUSION

Diversity and composition of MAB and DAB changed in diarrheal groups depending on presence/absence of colonic inflammation. We also suggest that DiarNoInfl group was at the earlier stage of diarrhea compared with DiarInfl, with a link to dysbiosis of colonic bacterial composition as well as reduced butyrate concentration, which plays a pivotal role in gut health. This could have led to diarrhea with inflammation due to a dysbiosis, associated with an increase in e.g., Escherichia-Shigella (Proteobacteria), Helicobacter (Campylobacterota), and Bifidobacterium (Actinobacteriota), which may tolerate or utilize oxygen and cause epithelial hypoxia and inflammation. The increased consumption of oxygen in epithelial mucosal layer by infiltrated neutrophils may also have added up to this hypoxia. Overall, the results confirmed that changes in DAB and MAB were associated with CCD and reduced butyrate concentration in digesta. Moreover, DAB might suffice for future community-based studies of CCD.

Dietary micro-fibrillated cellulose improves growth, reduces diarrhea, modulates gut microbiota, and increases butyrate production in post-weaning piglets

Dietary fiber (DF) supplementation is one of the strategies to prevent on-farm infections; it has the capability to improve gut health and piglet performance. Among the beneficial DFs, micro-fibrillated cellulose (MFC) is a new-generation plant-derived innovative feed ingredient; MFC, originating from sugar-beet pulp, has a hyper-branched structure with the ability to form shear-thinning hydrogel and has a high water-binding capacity. We aimed to determine the effects of MFC supplementation on piglets' performance before and after weaning. We included 45 sows and their piglets in this trial and monitored the results until the piglets were 7 weeks old. Piglets supplemented with MFC had higher body weight and average daily growth (ADG) than did control piglets, both pre- and post-weaning. In addition, MFC supplementation in post-weaning piglets improved butyrate content, and reduced diarrhea incidence. These phenomena, perhaps due to the MFC supplementation at different stages until age 7 weeks. In addition, after weaning, MFC supplementation stimulated the growth of butyrate-producing bacteria such as Ruminococcus.2, Ruminococcaceae.UCG.014, Intestinibacter, Roseburia, and Oribacterium genera, as well as reduced the pathogenic bacteria, such as Campylobacter, and Escherichia. Evidently, supplementation of MFC in feed to young piglets can improve growth performance and butyric acid content and reduce post-weaning diarrhea.

Effects of soybean hulls and corn stalk on the performance, colostrum composition and faecal microflora of pregnant sows

This study was conducted to investigate the effects of different supplementation levels of soybean hulls and corn stalk in high-fibre gestation diet on the performance, colostrum composition and faecal microbiota of sows. Forty first-farrowing Danish Landrace sows were randomly assigned to five dietary treatment groups. The control (CON, 3.15% crude fibre) group was fed a normal diet, and the treatment groups were soybean hulls low-fibre (SHL, 6.00% crude fibre) group, soybean hulls high-fibre (SHH, 8.00% crude fibre) group, corn stalk low-fibre (CSL, 6.00% crude fibre) group and corn stalk high-fibre (CSH, 8.00% crude fibre) group. The weaning weight of the litter and the average daily feed intake of the lactating sows in the SHL, SHH and CSH groups were higher than those in the CON group (p < 0.05). The immunoglobulin A and G levels of the colostrum in the SHL, SHH, CSL and CSH groups were higher than those in the CON group (p < 0.05), and the immunoglobulin M levels in the SHL, SHH and CSH groups were higher than those in the CON group (p < 0.05). The abundance of Proteobacteria at the phylum level in the CON group was higher than that in the CSL, CSH and SHH groups (p < 0.05). The abundance of Lactobacillaceae at the family level in the SHH and CSL groups were higher than that in the CON group (p < 0.05). The abundance of Lactobacillus at the genus level in the SHH and CSL groups were higher than that in the CON group (p < 0.05). In conclusion, SHH group had the best effect, and the optimal crude fibre level in the gestation diet of sows is 8%.

Feeding dietary fermentable fiber improved fecal microbial composition and increased acetic acid production in a nursery pig model

The objective of this study was to determine the fermentable fiber (FF) content of several common fibrous ingredients fed to nursery pigs, and then evaluate the effect of dietary FF level on growth performance and fecal microbial composition. In experiment 1, 54 nursery pigs were randomly allotted to be fed nine diets with six replicate pigs per diet. Dietary treatments included a corn-soybean meal basal diet and eight test diets based on a mixture of the corn-soybean meal diet and corn distillers dried grains with solubles, sunflower meal, oat bran, wheat bran, corn bran, sugar beet pulp (SBP), apple pomace (AP) or soybean hulls (SH). In experiment 2, 180 nursery pigs were housed in 30 pens (six pigs per pen) and randomly allotted to be fed five diets with different FF to total dietary fiber (TDF) ratios, which were 0.52, 0.55, 0.58, 0.61, and 0.64, respectively. Results showed that the FF content in SBP, AP, and SH was greater (P < 0.01) than that in other ingredients. Water binding capacity of fibrous ingredients was positively correlated (P < 0.05) to the digestibility of TDF, acid detergent fiber, and non-starch polysaccharides in test ingredients. Pigs fed the SBP, AP and SH diets had greater (P < 0.05) fecal acetic acid and total short-chain fatty acids (SCFAs) concentrations compared with pigs fed other diets. Fecal acetic acid and total SCFAs concentrations were positively correlated (P < 0.05) with FF content in experimental diets. Average daily weight gain and average daily feed intake of pigs quadratically increased (P < 0.01) as the ratios of FF to TDF increased. Pigs in FF64% group showed higher (P < 0.05) ACE index and fecal acetic acid concentration compared with pigs fed the dietary FF/TDF ratio of 0.52 to 0.61. Compared with the classification system of soluble dietary fiber and insoluble dietary fiber, FF could better describe the mechanism by which dietary fiber has beneficial effects on pig gut health.

Araceae root and citrus fibers tend to decrease Escherichia coli adhesion and myeloperoxidase levels in weaned piglets

Introduction

Weaning is a stressful experience in the piglet's life, and it often coincides with impaired gut health. Post-weaning diarrhea in piglets is frequently caused by enterotoxigenic Escherichia coli (E. coli). The first step of an E. coli infection is the adhesion to host-specific receptors present on enterocytes, leading to pro-inflammatory immune responses. The aim of this study was to examine if specific fiber fractions in the piglet diet can prevent E. coli adhesion and subsequent immune responses.

Methods

The trial included 200 piglets (Danbred × Piétrain): 10 piglets/pen × 10 pens/dietary treatment × 2 dietary treatments. From weaning until 14 days (d14) post-weaning, piglets were fed a control diet or test diet with 2 kg/ton of a mixture of specific fiber fractions derived from Araceae root and citrus. Afterwards, 1 piglet per pen was euthanized, a section was taken at 75% of small intestinal length and E. coli colonization on the mucosal epithelium was quantified by scraping and conventional plating. From the same small intestinal section, histo-morphological indices were assessed, and mucosal scrapings were analyzed for gene expression of pro- and anti-inflammatory cytokines, and NF-kB. Analyses of specific intestinal bacteria and SCFA were performed on samples of intestinal content (small intestine, caecum, colon). Fecal samples were taken to measure myeloperoxidase (MPO), calprotectin and PAP/RAG3A as biomarkers for intestinal inflammation.

Results and discussion

Piglets fed the fiber mixture tended to have decreased E. coli colonization to the mucosal epithelium (5.65 vs. 4.84 log10 CFU/g; P = 0.07), less E. coli in the caecum (8.91 vs. 7.72 log10 CFU/g; P = 0.03) and more Lachnospiraceae in the colon (11.3 vs. 11.6 log10 CFU/g; P = 0.03). Additionally, the fiber mixture tended to increase cecal butyric acid (10.4 vs. 19.1 mmol/kg; P = 0.07). No significant effect on histo-morphological indices and on gene expression of pro- and anti-inflammatory cytokines and NF-kB was observed. The fecal MPO concentration tended to decrease (20.2 vs. 10.4 ng/g; P = 0.07), indicating less intestinal inflammation. In conclusion, this study showed that specific fiber fractions from Araceae root and citrus in piglet weaner diets may decrease the risk of pathogen overgrowth by reducing E. coli adhesion and intestinal inflammation.

Phytogenics and encapsulated sodium butyrate can replace antibiotics as growth promoters for lightly weaned piglets

The objective of this study was to evaluate the effect of essential oils plus dry herbs (PHYTO) and encapsulated sodium butyrate (BUT) supplementation compared with enramycin (ENR), as a growth promoter, on the performance, diarrhoea control and intestinal microbiota in lightly weaned piglets. Two hundred weaned piglets, 20 days old, 4.69 ± 0.56 kg, were submitted during the nursery phase (20 to 69 days of age) to four treatments: control (CTR)-without any additive supplementation; ENR (with 8 ppm of enramycin throughout), BUT (with 2000 ppm between 20 to 34 d, 1500 ppm between 34 to 48 d and 1000 ppm between 48 to 69 d), and PHYTO (150 ppm between 20 to 48 d). At 62 days old, forty piglets (10 replicates per treatment) were slaughtered to perform bacterial identification through 16S rRNA (V3-V4) sequencing of the caecal content. During the second phase of the trial (34 to 48 days), the BUT group showed higher DWG (P = 0.023) and BW (P = 0.039) than the CTR group, and all groups that received additives had better FCR than the CTR group (P = 0.001). In the last phase of the trial (48 to 69 days), the ENR group presented a better FCR (P = 0.054) than the CRT and other groups. In the total period (20 to 69 days), ENR and BUT showed better FCR (P = 0.006) than CRT. Diarrhoea incident data showed differences (P<0.05), favouring the BUT treatment compared to the CTR. Only the Megasphaeraceae and Streptococcaceae families showed differences (p<0.05) in relative abundance between CTR and PHYTO and between CTR and BUT, respectively. Differential abundances of the Megasphaera and Streptococcus genera were observed between CTR and PHYTO and CTR and BUT. Phytogenics and encapsulated sodium butyrate are able and effective for modulating the specific caecal microbiota, improving performance and controlling diarrhoea occurrence.

Large intestinal dynamics differ between fowl and swine: Anatomical modifications, microbial collaboration, and digestive advantages from fibrolytic enzymes

The large intestinal systems of fowl and swine recover nutrients from ileal indigesta by a strategically different manner. Indigesta with fowl enter a short colon where retro-peristalsis using urine from the urodeum carries small particulates and solutes into both ceca while coarse materials collect in the cloaca. Fowl repetitively add fine and soluble materials into both ceca to continue fermentation until complexity of the remainder exceeds microbial action, then contents apart from faeces are entirely evacuated. Indigesta with swine initially enter a short cecum followed by a lengthy progression through to the rectal ampulla. Wall out-pocketings of circular muscle or haustrae occur throughout the length of the pig's cecum and helicoidal colon. Each pocket carries contents acquired earlier in the cecum. Motility collects fines and solutes into haustrae during their progression through the colon whereas coarse particulates assemble in the core. Haustrae contents continually ferment during movement to the distal colon with resulting volatile fatty acids (VFA) and electrolytes being absorbed. Mucin loosely covers the lumen surface in caeca as well as helicoidal colon that may capture microbes from active intestinal contents as well as release others to sustain fermentation. The microbial community continually modifies to accommodate fibre complexity as encountered. Resistant starches (RS) and simple oligosaccharides rapidly ferment to yield VFA while encouraging butyric acid in the cecum and anterior colon, whereas non-starch polysaccharides (NSP) complexity requires extended durations through the remaining colon that enhance acetic acid. Residual fibre eventually results in undue complexity for fermentation and consolidates at termination of the colon. These compact pellets are placed on core contents to form faeces having a nodular surface. Acetic, propionic, and butyric acids represent the bulk of VFA and are derived from non-digestible carbohydrates. Fibrolytic enzymes, when supplemented to feed, may increase the proportion of oligosaccharides and simpler NSP to further the rate as well as extent of fermentation. Active absorption of VFA by mucosal enterocytes employs its ionized form together with Na⁺, whereas direct membrane passage occurs when non-dissociated. Most absorbed VFA favour use by the host with a portion of butyric acid together with by-products from protein digestion being retained to reform mucin and sustain mucosal integrity.

Formulating Diets for Improved Health Status of Pigs: Current Knowledge and Perspectives

Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.

Supplementing oat hulls to the diet of suckling piglets altered their intestinal tract and colonic microbiota development

Current study evaluated the effect of a fine and coarsely ground insoluble dietary fibre source on the gastrointestinal development of suckling pigs. Oat hulls (OH) were selected as a model feedstuff, rich in cellulose, lignin, and insoluble dietary fibre. Three experimental supplemental diets were formulated: a finely ground, low fibre and nutrient dense diet served as control (CON). For the 2 high fibre diets, 15% heat-treated starch in CON was exchanged with OH, either finely (OH-f) or coarsely ground (OH-c). Litters of 10 primi- and multiparous sows (mean litter size 14.6 ± 0.84) were used. Within a litter, experimental diets were allotted to triplets of 4 piglets. From approximately 12 d of age, piglets' individual feed intakes were recorded 2 times per day when separated from their dam for 70 min. Piglets could suckle with their dam for the remainder of the day. On d 24 and 25, from the total pool of 120 piglets, seven healthy well-eating piglets per treatment were selected for post-mortem evaluation, resulting in 14 replicates per treatment. Consumption of OH-c and OH-f did not impede clinical health and production performance of piglets. The full stomach weights tended to be greater for OH-c compared to OH-f whereas CON was intermediate (P = 0.083). Supplementing OH significantly increased ileal villus height and caecal dry matter concentration (P < 0.05). For the colon, OH increased its length, contents weight, short-chain fatty acid concentration and reduced total bacterial count as well as γ-proteobacteria count and proportion (P < 0.05). The OH-c treatment specifically increased full gastrointestinal tract weight and caecum contents weight compared to piglets fed CON and OH-f. Furthermore, OH-c reduced colonic crypt depth when compared to OH-f (P = 0.018). In conclusion, supplementing OH to a diet for suckling piglets exerted subtle developmental effects on gastrointestinal morphology and colonic microbial community. These effects were largely independent from the particle size of the OH.

Review on Preventive Measures to Reduce Post-Weaning Diarrhoea in Piglets

In many countries, medical levels of zinc (typically as zinc oxide) are added to piglet diets in the first two weeks post-weaning to prevent the development of post-weaning diarrhoea (PWD). However, high levels of zinc constitute an environmental polluting agent, and may contribute to the development and/or maintenance of antimicrobial resistance (AMR) among bacteria. Consequently, the EU banned administering medical levels of zinc in pig diets as of June 2022. However, this may result in an increased use of antibiotic therapeutics to combat PWD and thereby an increased risk of further AMR development. The search for alternative measures against PWD with a minimum use of antibiotics and in the absence of medical levels of zinc has therefore been intensified over recent years, and feed-related measures, including feed ingredients, feed additives, and feeding strategies, are being intensively investigated. Furthermore, management strategies have been developed and are undoubtedly relevant; however, these will not be addressed in this review. Here, feed measures (and vaccines) are addressed, these being probiotics, prebiotics, synbiotics, postbiotics, proteobiotics, plants and plant extracts (in particular essential oils and tannins), macroalgae (particularly macroalgae-derived polysaccharides), dietary fibre, antimicrobial peptides, specific amino acids, dietary fatty acids, milk replacers, milk components, creep feed, vaccines, bacteriophages, and single-domain antibodies (nanobodies). The list covers measures with a rather long history and others that require significant development before their eventual use can be extended. To assess the potential of feed-related measures in combating PWD, the literature reviewed here has focused on studies reporting parameters of PWD (i.e., faeces score and/or faeces dry matter content during the first two weeks post-weaning). Although the impact on PWD (or related parameters) of the investigated measures may often be inconsistent, many studies do report positive effects. However, several studies have shown that control pigs do not suffer from diarrhoea, making it difficult to evaluate the biological and practical relevance of these improvements. From the reviewed literature, it is not possible to rank the efficacy of the various measures, and the efficacy most probably depends on a range of factors related to animal genetics and health status, additive doses used, composition of the feed, etc. We conclude that a combination of various measures is probably most recommendable in most situations. However, in this respect, it should be considered that combining strategies may lead to additive (e.g., synbiotics), synergistic (e.g., plant materials), or antagonistic (e.g., algae compounds) effects, requiring detailed knowledge on the modes of action in order to design effective strategies.

Effects of Dietary Fiber Type on Growth Performance, Serum Parameters and Fecal Microbiota Composition in Weaned and Growing-Finishing Pigs

The objective of this study was to evaluate the effects of different SDF to IDF ratios on growth performance, serum indexes and fecal microbial community in pigs. Weaned and growing-finishing pigs were fed a diet containing five different ratios of SDF to IDF from 1:5 to 1:9 and from 1:3 to 1:7, respectively. Results showed a linear tendency that average daily gain (ADG) of weaned pigs decreased but the feed intake to weight gain ratio (F/G) increased as the ratio of SDF to IDF increased from 1:5 to 1:9 (p = 0.06). The ADG of growing-finishing pigs showed quadratic changes (p < 0.05) as ratios of SDF to IDF increased from 1:3 to 1:7. The Shannon index of fecal microbial diversity increased first and then decreased as the SDF to IDF ratio increased from 1:5 to 1:9 (p < 0.05). The Shannon and Chao indexes of fecal microbial diversity in growing-finishing pigs showed significant incremental linearly as the SDF to IDF ratio increased from 1:3 to 1:7 (p < 0.05). In conclusion, the recommended inclusion ratios of SDF to IDF in weaned and growing-finishing pigs diets are 1:7 and 1:5.

Importance of Zinc Nanoparticles for the Intestinal Microbiome of Weaned Piglets

The scientific community is closely monitoring the replacement of antibiotics with doses of ZnO in weaned piglets. Since 2022, the use of zinc in medical doses has been banned in the European Union. Therefore, pig farmers are looking for other solutions. Some studies have suggested that zinc nanoparticles might replace ZnO for the prevention of diarrhea in weaning piglets. Like ZnO, zinc nanoparticles are effective against pathogenic microorganisms, e.g., Enterobacteriaceae family in vitro and in vivo. However, the effect on probiotic Lactobacillaceae appears to differ for ZnO and zinc nanoparticles. While ZnO increases their numbers, zinc nanoparticles act in the opposite way. These phenomena have been also confirmed by in vitro studies that reported a strong antimicrobial effect of zinc nanoparticles against Lactobacillales order. Contradictory evidence makes this topic still controversial, however. In addition, zinc nanoparticles vary in their morphology and properties based on the method of their synthesis. This makes it difficult to understand the effect of zinc nanoparticles on the intestinal microbiome. This review is aimed at clarifying many circumstances that may affect the action of nanoparticles on the weaning piglets' microbiome, including a comprehensive overview of the zinc nanoparticles in vitro effects on bacterial species occurring in the digestive tract of weaned piglets.

Decreased nutrient digestibility due to viscosity is independent of the amount of dietary fibre fed to growing pigs

Fibre content and its effect on chyme viscosity are associated with changes in the digestive system of humans and pigs. It is unclear if fibre content and viscosity affect digestive function independently or interactively. We evaluated apparent ileal digestibility (AID) of nutrients and intestinal function in thirty-six ileal-cannulated barrows fed for 29 d either maize-soyabean meal (MSBM) or high-fibre MSBM + 30 % distillers dried grains with solubles (MSBM + DDGS) modified to three levels of viscosity by adding 5 % non-viscous cellulose (CEL), 6·5 % medium-viscous carboxymethylcellulose (MCMC) or 6·5 % high-viscous CMC (HCMC). Digesta were collected on days 27 and 28 and intestinal samples on day 29. Feeding CMC, regardless of fibre content, increased viscosity of whole digesta (P = 0·003) and digesta supernatant (P < 0·0001) compared with CEL. Feeding MSBM + DDGS or CMC decreased AID of DM (P = 0·003; P < 0·0001) and crude protein (P = 0·02; P < 0·0001) compared with MSBM or CEL. Feeding CMC regardless of fibre content increased jejunal crypt depth (P = 0·02) and ileal goblet cell area (P = 0·004) compared with CEL. Adding DDGS or CMC did not affect villus height and gene expression of jejunal monosaccharide and amino acid transporters. Feeding HCMC, regardless of fibre content, elevated amylase activity by 46 and 50 % in jejunal (P = 0·03) and ileal digesta (P = 0·01) compared with CEL. In summary, diets with increased viscosity decreased nutrient digestibility and induced intestinal changes that were independent of the amount of fibre fed.

Effects of Dietary Cereal and Protein Source on Fiber Digestibility, Composition, and Metabolic Activity of the Intestinal Microbiota in Weaner Piglets

Simple Summary

Rye and rapeseed meal can be alternative feed components for weaner piglets instead of wheat and soybean meal. Both components can help to meet current challenges in pig nutrition, such as increasingly dry weather conditions and the high amount of imported soybean. Since they contain more and differently composed fiber, effects on digestive physiology and intestinal microbiota might help to maintain gut health and prevent post-weaning diarrhea. This study shows that despite a similar composition of the large intestinal microbiota, the higher amount and solubility of complex carbohydrates from rye lead to a higher fermentative activity compared to wheat, which is considered a beneficial effect. The high amount of insoluble dietary fiber in rapeseed-based diets lowered bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria.

Abstract

This study aimed to investigate the effect of fiber-rich rye and rapeseed meal (RSM) compared to wheat and soybean meal (SBM) on fiber digestibility and the composition and metabolic activity of intestinal microbiota. At weaning, 88 piglets were allocated to four feeding groups: wheat/SBM, wheat/RSM, rye/SBM, and rye/RSM. Dietary inclusion level was 48% for rye and wheat, 25% for SBM, and 30% for RSM. Piglets were euthanized after 33 days for collection of digesta and feces. Samples were analyzed for dry matter and non-starch-polysaccharide (NSP) digestibility, bacterial metabolites, and relative abundance of microbiota. Rye-based diets had higher concentrations of soluble NSP than wheat-based diets. RSM-diets were higher in insoluble NSP compared to SBM. Rye-fed piglets showed a higher colonic and fecal digestibility of NSP (p < 0.001, p = 0.001, respectively). RSM-fed piglets showed a lower colonic and fecal digestibility of NSP than SBM-fed piglets (p < 0.001). Rye increased jejunal and colonic concentration of short-chain fatty acids (SCFA) compared to wheat (p < 0.001, p = 0.016, respectively). RSM-fed pigs showed a lower jejunal concentration of SCFA (p = 0.001) than SBM-fed pigs. Relative abundance of Firmicutes was higher (p = 0.039) and of Proteobacteria lower (p = 0.002) in rye-fed pigs compared to wheat. RSM reduced Firmicutes and increased Actinobacteria (jejunum, colon, feces: p < 0.050), jejunal Proteobacteria (p = 0.019) and colonic Bacteroidetes (p = 0.014). Despite a similar composition of the colonic microbiota, the higher amount and solubility of NSP from rye resulted in an increased fermentative activity compared to wheat. The high amount of insoluble dietary fiber in RSM-based diets reduced bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria. Further research should focus on host–microbiota interaction to improve feeding concepts with a targeted use of dietary fiber.

Impact of Citrus Pulp or Inulin on Intestinal Microbiota and Metabolites, Barrier, and Immune Function of Weaned Piglets

We investigated the use of citrus pulp (CP) as a novel prebiotic capable of exerting microbiota and immunomodulating capacities to alleviate weaning stress. Inulin (IN), a well-known prebiotic, was used for comparison. Hundred and 28 male weaned piglets of 21 days old were assigned to 32 pens of 4 piglets each. Piglets were assigned to one of the four treatments, i.e., control, IN supplemented at 0.2% (IN0.2%), and CP supplemented either at 0.2% (CP0.2%) or at 2% (CP2%). On d10–11 and d31–32 post-weaning, one pig per pen was euthanized for intestinal sampling to evaluate the growth performance, chyme characteristics, small intestinal morphology, colonic inflammatory response and barrier integrity, metabolite profiles [gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS)], and microbial populations. The IN treatment and the two CP treatments induced higher small intestinal villus height to crypt depth ratios in comparison with the control diet at both sampling times. All treatments decreased acidic goblet cell absolute counts in the crypts in comparison to the control diet of the duodenum on d10–11 and d31–32. The gene expression of β-defensin 2 was downregulated in colonic tissues following the IN and CP2% inclusion on d31–32. On d31–32, piglets fed with IN and CP0.2% showed lower mRNA levels of occludin and claudin-3, respectively. Not surprisingly, flavonoids were observed in the colon in the CP treatments. Increased colonic acetate proportions on d10–11, at the expense of branched-chain fatty acid (BCFA) levels, were observed following the CP2% supplementation compared to the control diet, inferring a reduction of proteolytic fermentation in the hindgut. The beneficial microbial community Faecalibacterium spp. was promoted in the colon of piglets fed with CP2% on d10–11 (p = 0.04; false discovery rate (FDR) non-significant) and on d31–32 (p = 0.03; FDR non-significant) in comparison with the control diet. Additionally, on d31–32, CP2% increased the relative abundance of Megasphaera spp. compared to control values (p = 0.03; FDR non-significant). In conclusion, CP2% promoted the growth of beneficial bacterial communities in both post-weaning time points, modulating colonic fermentation patterns in the colon. The effects of CP supplementation were similar to those of IN and showed the potential as a beneficial feed supplement to alleviate weaning stress.

Effect of fiber source and crude protein level on nursery pig performance and fecal microbial communities

Reduction in dietary crude protein and addition of fiber could mitigate the incidence and severity of post-weaning diarrhea, a common gastrointestinal condition in newly weaned pigs. Therefore, 360 weanling pigs, initially 5.0 ± 0.10 kg, were used to evaluate the effects of crude protein (CP) level and fiber source on growth performance and fecal microbial communities. At weaning, pigs were randomly assigned to pens and allotted to 1 of 8 dietary treatments in a 2 × 4 factorial with main effects of CP (21 or 18%) and fiber source (none, coarse wheat bran, oat hulls, or cellulose). There were 5 pigs per pen and 9 pens per treatment. Experimental diets were formulated in two dietary phases from d 0 to 10 and 10 to 24, with a common post-treatment diet fed from 24 to 45. The 21% CP diets contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2. By using a maximum SID Lys:digestible CP ratio of 6.35%, the 18% CP diets contained 1.25% SID Lys in both phases. Diets containing a fiber source were formulated to the level of insoluble fiber provided by 4% coarse wheat bran, resulting in the addition of 1.85% oat hulls and 1.55% cellulose. No fiber source × CP level interactions (P > 0.05) were observed. Decreasing CP (and subsequently SID lysine) decreased (P = 0.05) ADG and G:F during the experimental period. From d 0 to 45, ADG decreased (P = 0.05) for pigs fed 18% CP diets compared to pigs fed 21% CP. No effect of fiber source was observed for growth performance. Fecal DM on d 17 increased (P < 0.001) for pigs fed 18% CP diets compared to pigs fed 21% CP diets. Pigs fed diets with added cellulose had increased (P < 0.05) fecal dry matter during the experimental period compared to pigs fed no fiber source or wheat bran. Bacterial community structure was investigated by sequencing the V4 region of the 16S rRNA gene. Analysis indicated a significant difference between CP content at d 24 (P = 0.023) using a Weighted UniFrac distance matrix. Further investigation identified five differential Amplicon Sequence Variants associated with CP content at d 24. In conclusion, reducing crude protein (and subsequently SID Lys) decreased growth performance but increased fecal dry matter content. The source of dietary fiber in nursery diets had no impact on growth performance; but pigs fed added cellulose had increased fecal DM compared with other treatments. Microbial analysis identified differential taxa associated with CP content.

Growth performance, visceral organ weights, and gut health of weaned pigs fed diets with different dietary fiber solubility and lipid sources

The objective of this study was to determine the interactive effects of dietary fiber solubility and lipid source on growth performance, visceral organ weights, gut histology, and gut microbiota composition of weaned pigs. A total of 280 nursery pigs [initial body weight (BW) = 6.84 kg] weaned at 21 d were housed in 40 pens (7 pigs/pen). The pigs were fed four diets (10 pens/diet) in a randomized complete block design in two phases: Phase 1 from 0 to 2 wk and Phase 2 from 2 to 5 wk. The diets were corn-soybean meal-based with either sugar beet pulp (SBP) or soybean hulls (SBH) as a fiber source and either soybean oil (SBO) or choice white grease (CWG) as a lipid source in a 2 × 2 factorial arrangement. The BW and feed intake were determined by phase, whereas visceral organ weights, intestinal histology, and gut microbial composition were determined at the end of the trial. Dietary fiber solubility and lipid source did not interact (P > 0.05) on average daily feed intake and average daily gain across all phases. However, the gain to feed ratio (G:F) for CWG-containing diets was lower (P < 0.05) than that for SBO-containing diets for Phase 1. Also, G:F for SBP-containing diets was lower (P < 0.05) than that for SBH-containing diets for Phase 1 and for the entire study period. Pigs fed SBP-containing diets had greater (P < 0.05) stomach weight, and tended to have greater (P < 0.10) small and large intestine weights relative to BW than those fed SBH-containing diets. Duodenal villous height to crypt depth ratio for CWG-based diets tended to be greater (P = 0.09) than that for SBO-based diets. Fiber solubility and lipid source interacted (P < 0.05) on relative abundance of Bacteroides in the colon such that the relative abundance of the Bacteroides for CWG was greater (P < 0.05) than that for the SBO in SBP-based diet, but not in SBH-based diet. Relative abundance of Butyricicoccus in the colon for SBH-based diet was greater (P < 0.05) than that for SBP-based diet. In conclusion, inclusion of SBH instead of SBP in corn-soybean meal-based diets for weaned pigs can result in increased feed efficiency and relative abundance of Butyricicoccus in the colon, which is associated with improved gut health. Also, inclusion of SBO instead of CWG in the diets for weaned pigs can result in improved feed efficiency during Phase 1 feeding; however, the pigs may recover from the low feed efficiency induced by dietary inclusion of CWG instead of SBO after Phase 1 feeding.

Fiber digestibility in growing pigs fed common fiber-rich ingredients: a systematic review

The application of high-fiber ingredients in the swine feed industry has some limitations considering that high amounts of fiber are resistant to endogenous enzymatic degradation in the pig’s gut. However, there is growing interest in fiber fermentation in the intestine of pigs due to their functional properties and potential health benefits. Many strategies have been applied in feed formulations to improve utilization efficiency of fiber-rich ingredients and stimulate their prebiotic effects in pigs. This manuscript reviews chemical compositions, physical properties, and digestibility of fiber-rich diets formulated with fibrous ingredients for growing pigs. Evidences presented in this review indicate there is a great variation in chemical compositions and physical properties of fibrous ingredients, resulting in the discrepancy of energy and fiber digestibility in pig intestine. In practice, fermentation capacity of fiber components in the pig’s intestine can be improved using strategies, such as biological enzymes supplementation and feed processing technologies. Soluble dietary fiber (SDF) and insoluble dietary fiber (IDF), rather than neutral detergent fiber (NDF) and acid detergent fiber (ADF), are recommended in application of pig production to achieve precise feeding. Limitations of current scientific research on determining fiber digestibility and short chain fatty acids (SCFA) production are discussed. Endogenous losses of fiber components from non-dietary materials that result in underestimation of fiber digestibility and SCFA production are discussed in this review. Overall, the purpose of our review is to provide a reference for feeding the pig by choosing the diets formulated with different high-fiber ingredients.

Physiological response to the weaning in two pig lines divergently selected for residual feed intake

Breeding efficient pigs is a way to reduce dietary costs and environmental waste. However, optimization of feed efficiency must not be linked to a decrease of the ability of animals to cope with stress, such as the weaning. This study characterizes the response after weaning of pigs from two lines divergently selected for residual feed intake (RFI) during growth. Animals of the low (L) RFI line are more efficient than animals from the high (H) RFI line. Thirty-six piglets from each line weaned at 28 days of age were individually housed and fed a conventional dietary sequence. Their performance, behaviour, health and oxidative status, immune and nutritional parameters were followed during three weeks. Daily feed intake and growth rate of pigs from the LRFI line were 35% and 40% lower compared with HRFI (p < 0.001). Pigs from the LRFI-line had lower total tract apparent digestibility (-6% for OM) and suffered more from undernutrition with a 167 and 55% higher plasmatic concentration of NEFA and urea compared with HRFI (p < 0.01). In the first week after the weaning, they had more diarrhoea and had a higher inflammatory status with concentration of haptoglobin 52% higher (p < 0.001). These piglets then seemed to adapt to the weaning conditions and to recover during the second and third weeks. Both lines had similar zootechnical performance and physiological characteristics at the end of the post-weaning period. To conclude, the physiological responses to the weaning differed between lines. Pigs from the LRFI line, selected for greater feed efficiency, were more sensitive to the weaning stress. They were also more resilient as they finally adapted to the new condition and recovered to show similar performance results as pigs of the HRFI line.

Growth performance and gut health of Escherichia coli-challenged weaned pigs fed canola meal-containing diet

An experiment was conducted to evaluate the effects of including canola meal (CM) in diets for weaning pigs challenged with a F18 strain of Escherichia coli on growth performance and gut health. A total of 36 individually housed weaned pigs (initial body weight [BW] = 6.22 kg) were randomly allotted to one of the three diets (12 pigs/diet). The three diets were corn-soybean meal (SBM)-based basal diet (control diet) and the basal diet with 0.3% zinc oxide, 0.2% chlortetracycline, and 0.2% tiamulin (antibiotic diet) or with 20% CM diet. The diets were fed in two phases: Phase 1: days 0 to 7 and Phase 2: days 7 to 20. All pigs were given an oral dose of 2 × 109 CFU of F18 strain of E. coli on day 7. Fecal score was assessed daily throughout the trial. Dietary antibiotics increased (P < 0.05) overall average daily gain (ADG) and average daily feed intake (ADFI) compared by 48% and 47%, respectively. Dietary CM increased (P < 0.05) overall ADG and ADFI by 22% and 23%, respectively; but the ADG and ADFI values for CM-containing diet did not reach those for the antibiotics-containing diet. Dietary antibiotics reduced (P < 0.05) fecal score; however, dietary CM unaffected fecal score. Dietary antibiotics decreased (P < 0.05) liver weight per unit live BW by 16% at day 20, whereas dietary CM did not affect liver weight per unit live BW (29.2 vs. 28.6). Also, dietary antibiotics increased (P < 0.05) serum triiodothyronine and tetraiodothyronine levels for day 14, whereas dietary CM did not affect the serum level of these hormones. Dietary antibiotics reduced (P < 0.05) the number white blood cells and neutrophils by 38% and 43% at day 20, respectively, whereas dietary CM tended to reduce (P = 0.09) the number white blood cells by 19% at day 20. The number white blood cells for CM diet tended to be greater (P < 0.10) than that for antibiotics diet. The dietary antibiotics decreased (P < 0.05) the concentration of individual volatile fatty acids and hence of total volatile fatty acid in cecum by 61% at day 20, whereas dietary CM decreased (P < 0.05) cecal butyric acid concentration by 61% and tended to reduce (P < 0.10) total volatile fatty acid concentration by 30% at day 20. In conclusion, the dietary inclusion of 20% CM improved ADG and tended to reduce white blood cell counts. Thus, inclusion of CM in antibiotics-free corn-SBM-based diets for weaned pigs that are challenged with F18 strain of E. coli can result in their improved performance partly through a reduction of the inflammatory response.

Etiology of Colitis-Complex Diarrhea in Growing Pigs: A Review

Simple Summary

Diarrhea in growing pigs is a challenge for the pig industry since it is associated with reduced animal welfare, retarded growth, increased feed conversion ratio, and is often treated with antibiotics. One of the major causes of diarrhea in the growing period is large intestinal inflammation, often referred to as colitis. The exact causes of colitis-complex diarrhea are still to be understood, but dietary factors and/or pathogens have been recognized as the major factors in developing colitis-complex diarrhea. In this review, a thorough picture of pathogens, dietary factors, and a number of possible biomarkers related to colitis-complex diarrhea is presented.

Abstract

Colitis-complex diarrhea (CCD) in pigs can be defined as a type of diarrhea, which is associated with colonic inflammation and disrupted colonic gut barrier functionality in growing pigs (4–16 weeks post-weaning). It is a challenge for the pig industry as it is associated with the high use of antibiotics, reduced animal welfare, and depressed growth rate. The exact etiology of CCD is still unclear; however, pathogens including Brachyspira (B.) hyodysenteriae, B. pilosicoli, and swine whipworms such as Trichuris (T.) suis have been involved in specific colitis (SC). In the absence of specific pathogens, dietary factors, such as high levels of protein, pelleted feedstuffs, and lack of sufficient antioxidants, can result in non-specific colitis (NSC). On the other hand, supplement of polyunsaturated fatty acids (PUFA) and polyphenols, sufficient supply of essential amino acids (e.g., threonine, cysteine, and proline), short-chain fatty acids (SCFA; especially butyrate), and resistant starch have shown to confer preventing/ameliorating effects on CCD. Different putative biomarkers associated with CCD have been presented. It is anticipated that a comprehensive picture of the possible causes of CCD and potential dietary interventions could cast light on the direction of future studies aimed at developing preventive and curative strategies against CCD in growing pigs.

Source of fiber influences growth, immune responses, gut barrier function and microbiota in weaned piglets fed antibiotic-free diets

This study examined the impacts of different fiber sources on growth, immune status and gut health in weaned piglets fed antibiotic-free diets. Sixty piglets (BW = 8.18 ± 1.35 kg) were assigned to 3 dietary treatments based on BW and gender in a randomized complete block design (5 replicates/treatment and 4 piglets [2 barrows and 2 gilts]/replicate): (1) an antibiotic-free diet (control, CON); (2) CON + 6% wheat bran (WB); (3) CON + 4% sugar beet pulp (SBP). Dietary WB supplementation tended to increase ADG compared with CON from d 1 to 14 (P = 0.051) and from d 1 to 28 (P = 0.099). Supplementation of WB increased (P < 0.05) G:F compared with CON and SBP from d 1 to 14 and from d 1 to 28. Compared with CON, the addition of WB reduced (P < 0.05) diarrhea rate from d 1 to 14 and tended (P = 0.054) to reduce diarrhea rate from d 1 to 28. The addition of WB decreased (P < 0.05) serum diamine oxidase activity on d 14, and up-regulated (P < 0.05) ileal mRNA levels of occludin on d 28 when compared with CON. Piglets fed WB showed decreased (P < 0.05) serum interleukin-6 levels compared to those fed SBP and decreased (P < 0.05) ileal interleukin-8 levels compared to those fed CON and SBP on d 28. Supplementation of WB increased (P < 0.05) serum levels of immunoglobulin A (IgA), IgG and IgM compared with SBP on d 14, and increased (P < 0.05) the levels of serum IgA and ileal sIgA compared with CON and SBP on d 28. Piglets fed WB showed an enhanced (P < 0.05) α-diversity of cecal microbiota than those fed SBP, while piglets fed SBP showed reduced (P < 0.05) α-diversity of cecal microbiota than those fed CON. Compared with CON, the addition of WB elevated (P < 0.05) the abundance of Lachnospira and cecal butyric acid level. Piglets fed WB also showed increased (P < 0.05) abundances of Lachnospira and unclassified_f_Lachnospiraceae compared with those fed SBP. Collectively, the supplementation of WB to antibiotic-free diets improved performance, immune responses, gut barrier function and microbiota compared with the CON and SBP fed piglets. Therefore, supplementing weaned piglets with WB was more effective than SBP.

Measures Matter-Determining the True Nutri-Physiological Value of Feed Ingredients for Swine

Many types of feed ingredients are used to provide energy and nutrients to meet the nutritional requirements of swine. However, the analytical methods and measures used to determine the true nutritional and physiological ("nutri-physiological") value of feed ingredients affect the accuracy of predicting and achieving desired animal responses. Some chemical characteristics of feed ingredients are detrimental to pig health and performance, while functional components in other ingredients provide beneficial health effects beyond their nutritional value when included in complete swine diets. Traditional analytical procedures and measures are useful for determining energy and nutrient digestibility of feed ingredients, but do not adequately assess their true physiological or biological value. Prediction equations, along with ex vivo and in vitro methods, provide some benefits for assessing the nutri-physiological value of feed ingredients compared with in vivo determinations, but they also have some limitations. Determining the digestion kinetics of the different chemical components of feed ingredients, understanding how circadian rhythms affect feeding behavior and the gastrointestinal microbiome of pigs, and accounting for the functional properties of many feed ingredients in diet formulation are the emerging innovations that will facilitate improvements in precision swine nutrition and environmental sustainability in global pork-production systems.

Wheat bran fermented by mixed fungal strains improves the digestibility of crude fiber and may benefit the gut health without impacting the growth performance in weaned pigs

This study was conducted to compare the effect of raw (WB) or mixed fungi-fermented wheat bran (FWB) on the growth, nutrient digestibility and intestinal health in weaned piglets. After the preparation of FWB, twenty-one cross-bred weaned piglets (7.20 ± 0.5 kg) were separated into three groups for a 40-day trial. The pigs in the control group were fed a basal corn-soybean meal diet. For the other two groups, 8% of expanded corn in the basal diet was replaced by equivalent WB or FWB. Results showed that the content of main nutrients and the composition of dietary fiber in FWB improved compared to that for WB. The digestibility of fiber in pigs fed FWB improved (P < 0.05) compared to the control and/or WB without affecting their growth performance. Both WB and FWB decreased the conditional pathogen (Streptococcus) or/and E. coli virulence factor (STb) in the colon compared to control (P < 0.05), and the ratio of villus height to crypt depth (VCR) in jejunum increased (P < 0.05). The number of goblet cells, the expression of MUC-1 and pBD1 in jejunal mucosa, and the proportion of blood CD4⁺ T lymphocyte subset improved (P < 0.05) by FWB rather than WB. Furthermore, although only WB elevated (P < 0.05) the concentration of butyrate in the colon, both WB and FWB increased the number of butyrate-producing bacteria (P < 0.05) compared to the control. Thus, the main advantage of FWB over WB in weaned pigs is its improvement in fiber digestibility.

Fibre supplementation to pre-weaning piglet diets did not improve the resilience towards a post-weaning enterotoxigenic E. coli challenge

Dietary fibre (DF) is implicated in gastrointestinal health of weaned piglets, either through its physiochemical properties, through modulation of gut microbiota and (or) improved gut integrity. We aimed to study the effect of DF enriched supplemental diets fed to suckling piglets ('creep feed') on health and performance after weaning when challenged with an enterotoxigenic E. coli (ETEC). Seventy-two piglets originating from 28 litters had been fed four creep diets, that is a low-fibre control (CON); a diet containing 2% long-chain arabinoxylans from wheat (lc-AXOS) or 5% purified cellulose (CELL) or a diet containing the high fermentable and the low-fermentable fibre source (i.e. 2% lc-AXOS and 5% CELL). Upon weaning, piglets were individually housed and all fed the same diet. On days 7, 8 and 9, animals received an oral dose of ETEC (5 ml containing 107 to 108  CFU/ml). Besides growth performance, faecal and skin scores were recorded daily. Gut permeability was assessed by urinary excretion of Co-EDTA prior and post-ETEC challenge. Repeated measures in time were statistically evaluated with generalized linear mixed models. We used a binominal distribution for evaluating the faecal and skin scores. Feed intake and body weight gain did not differ between treatments (p > .05). Piglets on CELL decreased gain:feed ratio in week 2 + 3 week compared to CON (p = .035). Prior to ETEC challenge, gut permeability tended to increase for lc-AXOS (p = .092). Moreover, lc-AXOS as main effect increased intestinal permeability before ETEC challenge (p = .013), whereas the low-fermentable fibre lead to elevated intestinal permeability after ETEC challenge (p = .014). The incidence of diarrhoea was higher for lc-AXOS + CELL compared with lc-AXOS (p = .036), while skin condition was unaffected. In conclusion, neither the high fermentable nor the low-fermentable fibre source improved post-weaning growth or gastrointestinal health of the piglets.

Effects of high-protein distillers dried grains on growth performance of nursery pigs

A total of 300 pigs (DNA 400 × 200, Columbus, NE), initially 11.1 kg, were used in a study to evaluate the effects of increasing amounts of high-protein distillers dried grains (HP DDG) on growth performance and to estimate its energy value relative to corn. Pigs were weaned, placed in pens with five pigs each, and fed a common diet for 21 d after weaning. Then, pens were assigned to treatments in a randomized complete block design. There were 5 treatments with 12 replicates per treatment. Treatments consisted of 0, 10, 20, 30, or 40% HP DDG, formulated by changing only the amounts of corn and feed-grade amino acids. Pigs were weighed weekly for 21 d to evaluate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). Caloric efficiency was obtained by multiplying ADFI by kcal of net energy (NE) per kg of diet and dividing by ADG. The NE values for corn and soybean meal were obtained from NRC (2012), and initial estimates for HP DDG NE were derived from the Noblet et al. (1994) equation. The energy of HP DDG was estimated based on caloric efficiency relative to the diet without HP DDG. Pigs fed diets with increasing HP DDG had a linear decrease (P < 0.01) in ADG, ADFI, and final body weight. There was a tendency for a quadratic response (P = 0.051) in G:F, with the greatest G:F observed for pigs fed diets with 40% HP DDG. There was a linear reduction (P < 0.05) in caloric efficiency with increasing amounts of HP DDG, indicating the initial NE estimate of HP DDG was underestimated. The use of caloric efficiency to estimate the energy value of HP DDG presents several limitations. This approach assumes that the NE values of corn and soybean meal are accurate and does not take into account possible changes in body composition, which can influence the G:F response as leaner pigs are more efficient. In conclusion, increasing HP DDG in the diet linearly decreased ADG and ADFI. Using caloric efficiency to estimate energy content relative to corn, the HP DDG used in this study was estimated to be 97.3% of the energy value of corn. Direct or indirect calorimetry is needed to confirm this value.

Using Nutritional Strategies to Shape the Gastro-Intestinal Tracts of Suckling and Weaned Piglets

This is a comprehensive review on the use of nutritional strategies to shape the functioning of the gastro-intestinal tract in suckling and weaned piglets. The progressive development of a piglet's gut and the associated microbiota and immune system offers a unique window of opportunity for supporting gut health through dietary modulation. This is particularly relevant for large litters, for which sow colostrum and milk are insufficient. The authors have therefore proposed the use of supplemental milk and creep feed with a dual purpose. In addition to providing nutrients to piglets, supplemental milk can also serve as a gut modulator in early life by incorporating functional ingredients with potential long-term benefits. To prepare piglets for weaning, it is important to stimulate the intake of solid feed before weaning, in addition to stimulating the number of piglets eating. The use of functional ingredients in creep feed and a transition diet around the time of weaning helps to habituate piglets to solid feed in general, while also preparing the gut for the digestion and fermentation of specific ingredients. In the first days after weaning (i.e., the acute phase), it is important to maintain high levels of feed intake and focus on nutritional strategies that support good gastric (barrier) function and that avoid overloading the impaired digestion and fermentation capacity of the piglets. In the subsequent maturation phase, the ratio of lysine to energy can be increased gradually in order to stimulate piglet growth. This is because the digestive and fermentation capacity of the piglets is more mature at this stage, thus allowing the inclusion of more fermentable fibres. Taken together, the nutritional strategies addressed in this review provide a structured approach to preparing piglets for success during weaning and the period that follows. The implementation of this approach and the insights to be developed through future research can help to achieve some of the most important goals in pig production: reducing piglet mortality, morbidity and antimicrobial use.

Canola meal in nursery pig diets: growth performance and gut health

An experiment was conducted to determine the effects of including canola meal (CM) in nursery pig diets on growth performance, immune response, fecal microbial composition, and gut integrity. A total of 200 nursery pigs (initial body weight = 7.00 kg) were obtained in two batches of 100 pigs each. Pigs in each batch were housed in 25 pens (four pigs per pen) and fed five diets in a randomized complete block design. The five diets were corn-soybean meal (SBM)-based basal diets with 0%, 10%, 20%, 30%, or 40% of CM. The diets were fed in three phases: phase 1: day 0 to 7, phase 2: day 7 to 21, and phase 3: day 21 to 42. Diets in each phase were formulated to similar net energy, Ca, and digestible P and amino acid contents. Feed intake and body weight were measured by phase. Immune response and gut integrity parameters were measured at the end of phases 1 and 2. Fecal microbial composition for diets with 0% or 20% CM was determined at the end of phase 2. Overall average daily gain (ADG) responded quadratically (P < 0.05) to increasing dietary level of CM such that ADG was increased by 17% due to an increase in the dietary level of CM from 0% to 20% and was reduced by 16% due to an increase in the dietary level of CM from 20% to 40%. Pigs fed diets with 0% or 40% CM did not differ in overall ADG. Dietary CM tended to quadratically decrease (P = 0.09) serum immunoglobulin A (IgA) level at the end of phase 2 such that serum IgA level tended to reduce with an increase in dietary CM from 0% to 20% and to increase with an increase in dietary CM from 20% to 40%. Dietary CM at 20% decreased (P < 0.05) the relative abundance of Bacteroidetes phylum and tended to increase (P = 0.07) the relative abundance of Firmicutes phylum. Dietary CM linearly increased (P < 0.05) the lactulose to mannitol ratio in the urine by 47% and 49% at the end of phases 1 and 2, respectively, and tended to linearly decrease (P < 0.10) ileal transepithelial electrical resistance at the end of phase 1 by 64%. In conclusion, CM fed in the current study could be included in corn-SBM-based diets for nursery pigs 20% to improve the growth performance and gut microbial composition and reduce immune response. Also, the CM used in the current study could be included in corn-SBM-based diets for nursery pigs at 30% or 40% without compromising growth performance. Dietary CM increased gut permeability, implying that dietary CM at 20% improves the growth performance of weaned pigs through mechanisms other than reducing gut permeability.

Synbiotic Effects of Enzyme and Probiotics on Intestinal Health and Growth of Newly Weaned Pigs Challenged With Enterotoxigenic F18+ Escherichia coli

This study aimed to investigate the effect of dietary supplementation with xylanase and probiotics on growth performance and intestinal health of nursery pigs challenged with enterotoxigenic Escherichia coli (ETEC). Sixty-four newly weaned pigs (32 barrows and 32 gilts with 7.9 ± 0.4 kg BW) were allotted in a randomized complete block design (2 × 2 factorial). Two factors were ETEC challenge (oral inoculation of saline solution or E. coli F18+ at 6 × 109 CFU) and synbiotics (none or a combination of xylanase 10,000 XU/kg and Bacillus sp. 2 × 108 CFU/kg). All pigs were fed experimental diets following NRC (2012) in two phases (P1 for 10 d and P2 for 11 d). The ETEC was orally inoculated on d 7 after weaning. Feed intake and BW were measured on d 7, 10, 15, and 20. On d 20, pigs were euthanized to collect samples to measure gut health parameters and microbiome. Synbiotics increased (P < 0.05) ADG in phase 1 and ETEC reduced (P < 0.05) ADG and G:F in the post-challenge period. ETEC increased (P < 0.05) the fecal score of pigs from d 7 to 13; however, synbiotics reduced (P < 0.05) it at d 9 and 11 in challenged pigs. ETEC increased (P < 0.05) mucosal MDA, IL-6, Ki-67+, and crypt depth, whereas synbiotics tended to reduce TNFα (P = 0.093), protein carbonyl (P = 0.065), and IL-6 (P = 0.064); reduced (P < 0.05) crypt depth and Ki-67+; and increased (P < 0.05) villus height. ETEC reduced (P < 0.05) the relative abundance of Bacteroidetes and Firmicutes and increased (P < 0.05) the relative abundance of Proteobacteria. In conclusion, ETEC challenge reduced growth performance by affecting microbiome, immune response, and oxidative stress in the jejunum. Synbiotics enhanced growth performance by reducing diarrhea, immune response, and oxidative stress in the jejunum.

Effects of fibre-degrading enzymes in combination with different fibre sources on ileal and total tract nutrient digestibility and fermentation products in pigs

The study was conducted to determine effects of a complex of fibre-degrading enzymes (xylanase, cellulase and β-glucanase) on nutrient digestibility, fibre fermentation and concentrations of short chain fatty acids (SCFA) at different parts of digestive tract in pigs fed different fibre-rich ingredients. A total of 36 barrows fitted with T-cannulas in the distal ileum (initial body weight of 41.1 ± 2.7 kg) were randomly allotted to six dietary treatments with three different high-fibre diets including maize bran (MB), sugar beet pulp (SBP) and soybean hulls (SH) with or without supplementation of fibre-degrading enzymes. Enzyme supplementation improved (p < 0.05) apparent ileal digestibility (AID) of dietary gross energy (GE), crude protein, dry matter (DM), organic matter (OM), total dietary fibre (TDF), neutral detergent fibre (NDF) and apparent total tract digestibility (ATTD) of dietary GE, DM, OM, TDF, insoluble dietary fibre (IDF) when pigs were fed MB, SBP or SH diets. When compared to the SBP and SH diets, the AID of GE, DM, ash, OM and NDF in diet MB was higher (p < 0.05), but the hindgut disappearance and ATTD of nutrients, except for ether extract and crude ash, were lower (p < 0.05). Enzyme supplementation increased acetate and total SCFA concentrations in ileal digesta and faeces of pigs. In conclusion, enzyme addition improved IDF fermentation and SCFA concentration in the whole intestine of pigs, and there was a large variation of digestibility of fibre components among MB, SH and SBP owing to their different fibre composition. Therefore, fibre-degrading enzymes should be applied to fibrous diets to improve efficient production of swine, especially considering low fibre digestibility of fibre-rich ingredients.