Effects of xylanase on growth performance, nutrients digestibility and intestinal health in weaned piglets

Productive performance, digestibility, carcass traits and meat quality in rabbits fed triticale-based diets supplemented with xylanase

Cereals such as triticale may contain high levels of xylans and arabinoxylans, limiting its use in diets since they act as anti-nutritional factors. The objective was to evaluate the effects of the enzyme xylanase included in triticale-based diets on productive performance, digestibility, carcass traits and meat quality in growing-finishing rabbits. Eighty rabbits (New Zealand X California breed), 35 days old, with an average initial live weight of 821 ± 26 g, were used. Twenty animals for treatment were used in each one of the fourth experimental treatments: 0, 4000, 8000 and 12,000 XU/kg of xylanase inclusion (XilaBlend 6X). The rabbits were fed ad libitum and fecal excretion was collected on days 7, 14, 21, 28 and 35 of the experimental period. At the end of the experimental period, the rabbits were slaughtered and carcass characteristics and meat quality were measured. A higher (P < 0.05) live weight was observed in rabbits fed diets with the addition of xylanase enzyme on days 4 and 7 of the experimental period. On the other hand, in the average total tract digestibility of organic matter, no significant difference was observed, similar to what occurred in the carcass traits and nutritional quality of the meat. The inclusion of 8000 XU/kg of xylanase enzyme provided the best values of apparent digestibility of total tract protein and dry matter on the finished stage of rabbits.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

Xylanase Impact beyond Performance: Effects on Gut Structure, Faecal Volatile Fatty Acid Content and Ammonia Emissions in Weaned Piglets Fed Diets Containing Fibrous Ingredients

The addition of xylanase to piglet diets is known to improve performance and nutrient digestibility. The present study aimed to assess the impact of new xylanase on the growth performance, nutrient digestibility, and gut function of weaned piglets. A total of 144 pigs, weaned at 28 days (7.48 kg initial body weight, IBW), were assigned to 36 pens and 9 pens per treatment. Dietary treatments were a basal complex control diet, and the basal diet supplemented with 45,000, 90,000 and 135,000 U/kg xylanase. Performance was measured at days 0, 14 and 35. At day 35, samples were collected for assessment of intestinal histology, and volatile fatty acid and ammonia concentrations. After two weeks post-weaning, additional 12 piglets (11.34 kg IBW) were placed in metabolic crates for assessment of apparent total tract nutrient digestibility using a dietary marker. The addition of xylanase at 90,000 and 135,000 U/kg significantly improved average daily gain (333.6 g/day control, 364.86 g/day, 90,000 U/kg, 405.89 g/day, 135,000 U/kg, p < 0.05), G:F (0.557 control, 0.612 90,000 U/kg, 0.692 135,000 U/kg, p < 0.05), and reduced diarrhoea. This was driven improved nutrient digestibility and villus height in the jejunum (372.87 µm control, 432.53 µm 45,000 U/kg, 465.80 µm 90,000 U/kg, 491.28 µm 135,000 U/kg, p < 0.05). Xylanase supplementation also linearly increased faecal butyrate levels and had a quadratic relationship with propionate concentrations. 135,000 U/kg xylanase also reduced ammonia emissions. In conclusion, dietary supplementation with xylanase improved growth performance and feed efficiency in weaning piglets, likely driven by improvements to gut structure and function.

Effects of a Novel Protease on Growth Performance, Nutrient Digestibility and Intestinal Health in Weaned Piglets

This experiment was conducted to evaluate the effects of different protease levels on performance, diarrhea rate, nutrient digestibility, blood metabolites, digestive enzyme activities, and intestinal health of weaned piglets. A total of 96 weaned piglets (Duroc × Landrace × Yorkshire, 28 d of age, initial average BW = 6.55 ± 0.17 kg) were divided into four groups (4 pigs/pen and 6 replicates/group) according to a completely random block design. Piglets were fed different levels of protease (0, 150, 300 or 600 mg/kg of diet) for 28 d. The results showed that the addition of protease had no significant effect on the growth performance of weaned piglets (p > 0.05), and the addition of 300 mg/kg protease significantly increased the apparent total intestinal digestibility (ATTD) of nutrients and the apparent ileal digestibility (AID) of amino acids in weaned piglets (p < 0.05), while the addition of 150 mg/kg and 600 mg/kg protease had no significant effect on the digestibility (p > 0.05). The nutrient digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and total energy (GE) showed a trend of increasing and then decreasing with increasing protease concentration (p < 0.05). Adding 300 and 600 mg/kg protease significantly decreased serum ALB/GLO levels (p < 0.05) and duodenal pH (p < 0.05) and increased duodenal villus height (p < 0.05). The addition of protease significantly increased jejunal trypsin and chymotrypsin activities (p < 0.01) and duodenal and jejunal mucosal tight junction proteins in piglets. The mRNA expression levels of ZO-1 and CLAUDIN-1 in the duodenum together with ZO-1 and OCCLUDIN in the jejunum of piglets in the 300 and 600 mg/kg protease supplementation groups were significantly higher than those in the control group (p < 0.05). The results showed that, compared with the control group, protease could promote nutrient absorption, improve small intestine morphology and enhance digestive enzyme activity in weaned piglets. The suitable addition amount was 150−300 mg/kg in the present study.

Effects of oxidized soybean oil on the performance of sows and jejunum health of suckling piglets

Oils provide a considerable amount of energy to the swine diet, but they are prone to lipid oxidation if not properly preserved. Consumption of oxidized oils can adversely affect the animal organism and even the offspring. This study investigated the impact of oxidized soybean oil in the diets of sows from 107 days gestation to 21 days of lactation on the performance of sows and jejunum health of suckling piglets. Sixteen sows were randomly allocated into two groups: one group (n = 8) was fed with the fresh soybean oil (FSO) diet, and another group (n = 8) was treated with the oxidized soybean oil (OSO) diet. Dietary oxidized soybean oil does not affect sow performance. Antioxidant enzyme activity in the milk was reduced significantly in the OSO group, such as the superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and catalase (CAT) activities (p < 0.05). On Day 21, oxidized soybean oil increased tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) levels in sow milk and the concentrations of TNF-α and IL-8 cytokines in plasma (p < 0.05). Suckling piglets from sows fed on OSO showed a trend towards increased IL-6 and TNF-α in plasma (p < 0.1). The mRNA expression of interleukin 1β (IL-1β) was augmented, whereas interleukin 10 (IL-10) was decreased, and zonula occludens-1 (ZO-1) had a tendency to be down-regulated in OSO treatment. This study revealed that the OSO of feed decreased the antioxidant capacity of milk, further contributing to the inflammatory response in the jejunum of suckling piglets.

Co-production of amino acid-rich xylooligosaccharide and single-cell protein from paper mulberry by autohydrolysis and fermentation technologies

Background

Autohydrolysis is an extensively investigated pretreatment method due to its environmental friendliness. During autohydrolysis, most xylan from hemicellulose can be converted into xylooligosaccharides (XOS), and cellulose in the autohydrolyzed residues can be transformed into glucose after enzymatic hydrolysis. Both of these are value-added biochemicals in the biorefining process. In this work, paper mulberry (PM), which contains abundant protein, was utilized as a raw material to coproduce XOS and single-cell protein (SCP) through autohydrolysis and fermentation technologies.

Results

The results showed that 8.3 g of XOS and 1.8 g of amino acids could be recovered in the autohydrolysate (based on 100 g raw material) after autohydrolysis (170 °C, 1 h). Moreover, 5.7 g of low-DP XOS along with 1.8 g of amino acids could be further obtained from the autohydrolysate after hydrolysis with endo-β-1-4-xylanase. In addition, 20.1 g of fermentable monosaccharides was recovered after hydrolyzing the autohydrolyzed PM with cellulase, which can be used to produce 4.8 g of SCP after fermentation with Candida utilis.

Conclusion

As a valuable application of PM, a novel process is proposed to coproduce amino acid-rich XOS and SCP through autohydrolysis. The carbohydrate of PM is effectively converted to high value-added products.

Comparative Effects of Compound Enzyme and Antibiotics on Growth Performance, Nutrient Digestibility, Blood Biochemical Index, and Intestinal Health in Weaned Pigs

This experiment aims to explore the effects of compound enzyme preparation substituting chlortetracycline on growth performance, serum immune markers, and antioxidant capacity and intestinal health in weaned piglets. A total of twenty-four 28-day-old “Duroc × Landrace × Yorkshire” weaned piglets with an average initial weight of 7.25 ± 0.25 kg were randomly divided into three groups according to their body weight, with eight replicates in each group and one pig in each replicate. The three dietary treatments were basal diet (CON), basal diet + 1,000 mg/kg compound enzyme preparation (cellulase 4,000 IU/g, α-amylase 1,000 IU/g, β-glucanase 150 IU/g, and neutral protease 3,000 IU/g, CE), and basal diet + 75 mg/kg chlortetracycline (CTC). The animal experiment lasted for 28 days and was divided into two stages: the early stage (0–14 days) and the late stage (15–28 days). The results showed that (1) compared with the CON, the CE and CTC significantly increased the ADG of weaned piglets during the early and whole period of experiment (p < 0.05), decreased the F:G in the whole experiment period (p < 0.05), and diarrhea rate in the early stage (p < 0.01). (2) Compared with the CON, the apparent total tract digestibility of ADF and NDF was significantly increased in pigs fed the CE diet in the early and late stages of experiment (p < 0.05) with no significant difference compared with the CTC. (3) Compared with the CON, the concentrations of serum IgA and SOD in weaned piglets were significantly increased in the CE group in the early stage of the experiment (p < 0.05). (4) Compared with the CON group, the acetic acid, propionic acid, and total VFA contents in cecum and colon segments were elevated in the CE group (p < 0.05) with no significant difference compared with the CTC. (5) Compared with the CON group, the villus height of duodenum and jejunum and the ratio of villus height to recess depth of ileum were increased in the CE and CTC group (p < 0.05). (6) Compared with the CON group, the abundance of Lactobacillus significantly increased (p < 0.01) while the abundance of Escherichia coli decreased in the CE group and CTC group (p < 0.01). In conclusion, CE preparation instead of CTC can significantly improve the nutrient digestibility, the immunity, antioxidant capacity, and intestinal health of pigs, which may contribute to the improved growth performance of piglets.

Effects of Replacing Medical Zinc Oxide with Different Ratios of Inorganic: Organic Zinc or Reducing Crude Protein Diet with Mixed Feed Additives in Weaned Piglet Diets

One hundred twenty weaned piglets (9.34 ± 0.74 kg) were used in a four-week experiment to investigate the effects of replacing medical ZnO with a different ratio of inorganic and organic zinc (IZ:OZ) or a low-crude-protein diet (LP) with mixed feed additives (MFAs) in the weaned piglets' diet. The dietary treatments included a control (CON), T1 (T1; ZnO 1000 mg/kg), T2 (IZ:OZ 850:150), T3 (IZ:OZ 700:300), T4 (IZ:OZ, 500:500), and T5 (LP with MFAs (0.1% essential oils + 0.08% protease + 0.02% xylanase)). The growth performance was decreased (p < 0.05) in the CON treatment compared with the T4 treatment. The diarrhea incidence was decreased (p < 0.05) in the T4 and the T5 treatment compared with the CON and the T1 treatments. The apparent total tract digestibility (ATTD) of nutrients were increased (p < 0.05) in the T4 and T5 treatments compared with the CON, T1, and T2 treatments. The T4 treatment had a higher (p < 0.05) ATTD of zinc than the T1, T2, and T3 treatments. The fecal microflora was improved (p < 0.05) in the T5 treatment compared with the CON and T3 treatments. In conclusion, IZ:OZ 500:500 could improve growth performance, nutrient digestibility, and zinc utilization while reducing diarrhea incidence in weaned piglets. Moreover, LP with MFA could replace medical ZnO.

Effects of different inorganic:organic zinc ratios or combination of low crude protein diet and feed additives in weaned piglet diets

Thirty-six weaned piglets with an initial body weight (BW) of 8.43 ± 0.40 kg (28 days of age, ([Landrace × Yorkshire] × Duroc) were randomly assigned to 6 treatments for a 2-week feeding trial to determine the effects of different inorganic zinc (IZ), organic zinc (OZ) or combination of low crude protein diet (LP) and Mixed feed additive (MFA) on diarrhea score, nutrient digestibility, zinc utilization, blood profiles, organ weight, and fecal microflora in weaned piglet diet. The pigs were individually placed in 45 × 55 × 45 cm stainless steel metabolism cages in an environmentally controlled room (30 ± 1°C). The dietary treatments included a negative control (NC), positive control (PC; zinc oxide, 1,000 mg/kg), T1 (IZ : OZ, 850 : 150), T2 (IZ : OZ 700 : 300), T3 (IZ : OZ, 500 : 500), and T4 (LP + MFA [0.1% Essential oils + 0.08% Protease + 0.02% Xylanase]). The daily feed allowance was adjusted to 2.7 times the maintenance requirement for digestible energy (2.7 × 110 kcal of DE/kg BW^0.75). This allowance was divided into two equal parts, and the piglets were fed at 08 : 30 and 17 : 30 each day. Water was provided ad libitum through a drinking nipple. The diarrhea score was significantly increased (p < 0.05) in NC treatment compared with other treatments. The apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and gross energy (GE) was significantly increased (p < 0.05) in the T2 treatment compared with the PC and NC treatments in week 1. In week 2, the ATTD of DM, N, and GE was significantly decreased (p < 0.05) in the NC treatment compared with other treatments. The T3 treatment had significantly higher (p < 0.05) ATTD and apparent ileal digestibility of zinc than the PC and T1 treatments. The Escherichia coli count in feces was significantly decreased in the T4 treatment compared with the NC and T2 treatments. The Lactobacillus count in feces was significantly increased in the T4 and T1 treatment compared with the T2 and T3 treatments. In conclusion, IZ : OZ 500 : 500 levels could improve nutrient digestibility and zinc utilization in weaned piglets, Moreover, MFA in LP diets could be used as a zinc alternative.

Exogenous Enzymes Influenced Eimeria-Induced Changes in Cecal Fermentation Profile and Gene Expression of Nutrient Transporters in Broiler Chickens

Two 21-day experiments were conducted to investigate the effects of exogenous enzymes on growth performance, tight junctions, and nutrient transporters, jejunal oligosaccharides and cecal short-chain fatty acids (SCFA) of broiler chickens challenged with mixed Eimeria. Two different basal diets: high fiber-adequate protein (HFAP; Expt. 1) or low fiber-low protein (LFLP; Expt. 2) were used in the two experiments. In each experiment, birds were allocated to four treatments in a 2 × 2 factorial arrangement (with or without protease and xylanase combination; with or without Eimeria challenge). In Expt. 1, with HFAP diets, Eimeria upregulated (p < 0.05) the expression of claudin-1, but downregulated (p < 0.05) glucose transporters GLUT2/GLUT5. On the contrary, enzymes downregulated (p < 0.05) claudin-1 and alleviated the Eimeria-depressed GLUT2/GLUT5 expression. In both experiments, Eimeria decreased (p < 0.05) cecal saccharolytic SCFA and increased (p < 0.05) cecal branched-chain fatty acids. The challenge × enzyme interaction (p < 0.05) showed that enzymes reversed the Eimeria effects on fermentation pattern shift. In conclusion, Eimeria altered tight junctions and nutrient transporters expression promoted cecal proteolytic fermentation and inhibited saccharolytic fermentation. Exogenous enzymes showed the potential of alleviating the Eimeria-induced intestinal gene expression changes and reversing the unfavorable cecal fermentation pattern.

Modern Hybrid Rye, as an Alternative Energy Source for Broiler Chickens, Improves the Absorption Surface of the Small Intestine Depending on the Intestinal Part and Xylanase Supplementation

The current study investigated the effects of the inclusion of modern hybrid rye (Brasetto variety) to a corn-wheat-based diet, with or without xylanase, on the absorptive surface of the small intestine of broilers. A total of 224 one-day-old male Ross 308 broiler chicks were randomly divided into four experimental groups with seven replicate cages of eight birds/replicate. A 2 × 2 factorial study design was used, with rye inclusion (0% or 20%) and xylanase supplementation (0 or 200 mg/kg of feed) as factors. Inclusion of rye increased duodenal and ileal crypt depth, villi height, the villus-to-crypt ratio and absorption surface area (p < 0.05), and ileal mucosa thickness and crypt width (p < 0.05). Xylanase supplementation attenuated the effects of rye in the duodenum and ileum and decreased the villi height and villus-to-crypt ratio in the jejunum (p < 0.05). Rye and xylanase had no effect on the spatial distribution of claudin 3 and ZO-1 protein, but xylanase supplementation reduced the amount of claudin 3 in the duodenum and jejunum (p < 0.05). The findings of this study indicate that 20% inclusion of modern hybrid rye to the diets of broilers improved the structure of the duodenum and ileum, but these effects were attenuated by xylanase supplementation.

Recombinant production of two xylanase-somatostatin fusion proteins retaining somatostatin immunogenicity and xylanase activity in Pichia pastoris

Somatostatin (SS) is one of the peptide hormones that regulate the endocrine system in animals. When SS is used to immunize animals, the correspondingly generated anti-SS antibody neutralizes the SS and, therefore, alleviates its growth inhibiting effects. This is of great value to the livestock industry; however, previously developed methods fail to obtain enough recombinant SS in an economical way. Herein, we describe the employment of a commonly used feed enzyme, i.e., xylanase, as a carrier protein for recombinant expression of SS in large quantity. The SS gene was fused to one of the two xylanase genes (XynCDBFV and BsXynC) and recombinantly expressed in Pichia pastoris. The purified xylanase-SS fusion proteins displayed excellent antigenicity and immunogenicity. In addition, they retained the enzymatic activities and thermostability of the xylanases, indicating that they can catalyze hydrolysis of xylan in plant cell wall of the animal feeds and stand the high temperature in feed pelleting. Thus, the xylanase-SS fusion proteins serve as an excellent candidate chimeric bifunctional vaccine-feed enzyme protein retaining both SS immunogenicity and xylanase activity. KEY POINTS: • Somatostatin is expressed in P. pastoris as fusion proteins with two xylanases. • The chimeric proteins retain both immunogenicity and xylanase activity. • The xylanase-SS proteins may serve as bifunctional proteins in livestock industry.

Xylanase supplementation in corn-based swine diets: a review with emphasis on potential mechanisms of action

Corn is a common energy source in pig diets globally; when financially warranted, industrial corn coproducts, such as corn distiller's dried grains with solubles (DDGS), are also employed. The energy provided by corn stems largely from starch, with some contribution from protein, fat, and non-starch polysaccharides (NSP). When corn DDGS are used in the diet, it will reduce starch within the diet; increase dietary protein, fat, and NSP levels; and alter the source profile of dietary energy. Arabinoxylans (AXs) comprise the majority of NSP in corn and its coproducts. One strategy to mitigate the antinutritive effects of NSP and improve its contribution to energy is by including carbohydrases within the diet. Xylanase is a carbohydrase that targets the β-1,4-glycosidic bonds of AX, releasing a mixture of smaller polysaccharides, oligosaccharides, and pentoses that could potentially be used by the pig. Xylanase is consistently effective in poultry production and moderately consistent in wheat-based swine diets, but its efficacy in corn-based swine diets is quite variable. Xylanase has been shown to improve the digestibility of various components of swine-based diets, but this seldom translates into an improvement in growth performance. Indeed, a review of xylanase literature conducted herein suggests that xylanase improves the digestibility of dietary fiber at least 50% of the time in pigs fed corn-based diets, but only 33% and 26% of the time was there an increase in average daily gain or feed efficiency, respectively. Intriguingly, there has been an abundance of reports proposing xylanase alters intestinal barrier integrity, inflammatory responses, oxidative status, and other health markers in the pig. Notably, xylanase has shown to reduce mortality in both high and low health commercial herds. These inconsistencies in performance metrics, and unexpected health benefits, warrant a greater understanding of the in vivo mechanism(s) of action (MOA) of xylanase. While the MOA of xylanase has been postulated considerably in the literature and widely studied in in vitro settings, in wheat-based diets, and in poultry, there is a dearth of understanding of the in vivo MOA in pigs fed corn-based diets. The purpose of this review is to explore the role of xylanase in corn-based swine diets, discuss responses observed when supplemented in diets containing corn-based fiber, suggest potential MOA of xylanase, and identify critical research gaps.

Effects of dietary supplementation of compound enzymes on performance, nutrient digestibility, serum antioxidant status, immunoglobulins, intestinal morphology and microbiota community in weaned pigs

The objective of this study was to evaluate the effects of compound enzymes (CE) (containing per g 375 U amylase, 2500 U protease, 4000 U xylanase and 150 U β-glucanase) on performance, nutrient digestibility, serum antioxidant status, immunoglobulins, intestinal morphology, volatile fatty acids contents and microbiota community in weaned pigs. Seventy-two pigs (Duroc × Landrace × Yorkshire, weaned at d 28) with an average body weight of 8.49 ± 0.87 kg were allotted into two treatments with six replicate pens per treatment (three barrows and three gilts per pen) according to sex and body weight in a randomised complete block design. The treatments contained a corn-soybean meal-barley basal diet (CON) or a basal diet supplemented with 1000 mg CE/kg (CE). The study was divided into phase 1 (d 1 to 14) and 2 (d 15 to 35). The average daily gain was increased (p < 0.05) in pigs fed CE in phase 2 and overall (d 1 to 35) compared with CON. These pigs had greater (p ≤ 0.05) serum IgA, IgG, superoxide dismutase and catalase contents, as well as tended to increase serum IgM content and apparent total tract digestibility (ATTD) of organic matter in phase 1 compared with CON. In phase 2, pigs supplemented with CE showed greater (p < 0.01) ATTD of dry matter, organic matter, crude protein and gross energy compared with CON. These pigs also had increased (p < 0.05) IgA, IgG, IgM, superoxide dismutase contents, and decreased (p < 0.05) malondialdehyde content in serum compared with CON. Moreover, pigs fed CE had higher (p < 0.05) villus height and villus height to crypt depth ratio in ileum, and tended to increased acetic acid content in colon compared with CON. Furthermore, pigs fed CE had increased (p < 0.05) relative abundance of Firmicutes at phylum level, Lactobacillales at order level, Lactobacillaceae at family level, Bacilli at class level, Lactobacillus at genus level in caecum and colon, as well as lower (p < 0.05) relative abundance of Bacteroidetes at phylum level, Bacteroidales at the order level, Bacteroidia at class level, Clostridium_sensu_stricto_6 at genus level in colon compared with CON. In conclusion, dietary inclusion of compound enzymes could effectively improve nutrient digestibility, serum antioxidant status, immunoglobulin, gut morphology, microbiota community, and therefore improve performance in weaned pigs.

Tannic acid prevents post-weaning diarrhea by improving intestinal barrier integrity and function in weaned piglets

Background

Tannic acid (TA) is potential to reduce diarrhea in weaning pigs, but knowledge about the influence of TA on intestinal barrier integrity and function is still scarce. This experiment was conducted to investigate the effects of dietary TA supplementation on growth performance, diarrhea rate, intestinal barrier integrity and function of weaned pigs.

Methods

A total of 108 crossbred (Duroc × Landrace × Yorkshire) piglets, with an initial average body weight of 6.60 ± 0.27 kg, were allotted to 3 groups (6 pigs/pen and 6 replicates/group) in a randomized complete block design according to their gender and body weight. Piglets were fed the basal diet with 0 (control, CON), 0.2% and 1.0% TA, respectively. The trial lasted for 28 d.

Results

Compared with the CON group, dietary 0.2% and 1.0% TA supplementation didn’t affect ADFI, ADG and F:G (P > 0.05), but reduced diarrhea rate, diarrhea index and diarrhea score of piglets (P < 0.05), reduced diamine oxidase (DAO) activity and D-lactic acid concentration in serum (P < 0.01). The higher occludin expression and localization were observed in the duodenum, jejunum and ileum after supplementation with 0.2% or 1.0% TA (P < 0.05). Adding 0.2% TA to diet significantly decreased crypt depth, increased villus height/crypt depth ratio in the duodenum (P < 0.05), and dietary 1.0% TA tended to decrease crypt depth (P < 0.10) and significantly decreased villus height (P < 0.05) of the ileum. Moreover, lower malondialdehyde content in the ileum was detected in the pigs fed 1.0% TA (P < 0.05). In the duodenum, both 0.2% and 1.0% TA groups had higher occludin (OCLN) mRNA and 0.2% TA group had higher zonula occludens-2 (ZO-2) level (P < 0.05). Meanwhile, dietary 1.0% TA supplementation tended to up-regulate OCLN mRNA levels in the jejunum (P < 0.10) and 0.2% TA supplementation tended to up-regulate zonula occludens-1 (ZO-1) mRNA levels in the ileum (P < 0.10).

Conclusion

In conclusion, dietary supplementation of 0.2% or 1.0% TA could effectively alleviate post-weaning diarrhea without altering growth performance in weaned piglets, which might be achieved by improving intestinal barrier integrity and function.