Review: Chestnut and quebracho tannins in pig nutrition: the effects on performance and intestinal health

Effects of Dietary Inclusion of Avocado Seeds on Performance, Nutrient Digestibility, Plasma Biochemical Profile, and Carcass and Meat Traits of Growing Pigs

Avocado seeds (which are discarded during fruit processing) generate residue that could be utilized in pig feeding. The objective of this study was to test the effects of dietary inclusion of dried-milled avocado seeds (DAS) on pig performance, nutrient and energy digestibility, plasma biochemical parameters, and carcass and meat traits. Twenty-four Landrace × Large White barrows (24 kg body weight, BW) were randomly allocated to three experimental treatments: control diet (CO; 18% CP, 1.12% Lys, and 14 MJ ME/kg), and two diets in which 100 or 200 g DAS/kg partially replaced a CO diet (S10 and S20, respectively). Pigs were individually housed (22 ± 1 °C), and feed and water were provided ad libitum. Animals were weighed weekly and individual intake was monitored daily. The total tract apparent digestibility (TTAD) and nitrogen balance were determined. The experiment ended at 40 kg BW, when the animals were slaughtered for blood and tissue sampling. Voluntary feed intake was not affected by the addition of up to 200 g DAS/kg to the diet. However, growth, nutrient TTAD, and nitrogen retention were depressed at the highest DAS inclusion level. The nutritional characteristics of longissimus lumborum muscle were not affected by DAS ingestion. The inclusion of up to 100 g DAS/kg in the diets of growing pigs could be used to add value to this waste product.

In vitro and in vivo evaluation of the effects of condensed tannins and catechins monomers on antioxidant and intestinal health of Chinese seabass (Lateolabrax maculatus)

Plant-derived condensed tannins (CT) exhibit strong bioactivity of antioxidant, immunostimulation and intestinal protection, but with little clues of the mechanism of action. Since CT are consist of catechins (CAs) monomers, e.g., catechin (CA), epicatechin (EC) and epigallocatechin (EG), we motivated to use the monomers to explore the underlying mechanisms in a seabass model focusing on anti-oxidative stress and intestinal health of Lateolabrax maculatus. An in vitro intestinal primary cell oxidative stress model induced by hydrogen peroxide was set up to assess the antioxidant and immune activities of CT and CAs. Another 56-d feeding trial with 800 fish was conducted to evaluate the effects of CT and CAs on growth performance, intestinal permeability and digestive enzyme activities, intestinal morphology and antioxidant status, and intestinal bacterial flora of fish. Five diets were prepared to contain 0 (G1) and 1 g/kg of CT, CA, EC and EG. Fish were randomly distributed into 20 tanks with 4 tanks per diet and 40 fish per tank, and were fed to apparent satiation twice daily. Results showed that CT and CAs exhibited similar effects in alleviating hydrogen peroxide-induced cell injury by activating nuclear factor erythroid 2-related factor 2 gene expression, and improving antioxidant and immune capacities. Dietary CT and CAs enhanced intestinal antioxidant ability and increased (p < 0.05) the abundance of intestinal Firmicutes, Proteobacteria and Bacteroidetes to oxidative stress tolerant. With a dose of 1 g/kg CT and CA promoted (p < 0.05) intestinal total antioxidant capacity, but slightly induced intestinal injury mainly due to increased (p < 0.05) intestinal permeability (as reflected by increased lipopolysaccharide concentrations) and inhibited (p < 0.05) digestion (as reflected by the decreased trypsin and lipase activities) of fish. In summary, CT and CAs protect intestine from oxidative stress and improve intestinal antioxidant capacity by stimulating antioxidant enzyme system and bacterial flora. CA and EC show similar or superior antioxidant activity than CT.

Control of Neonatal Diarrhea in Piglets with Reduced Antibiotic Use by Application of a Complementary Feed-A Randomized Controlled Farm Trial

The objective of this farm trial was to investigate if the consumption of antibiotics could be reduced when piglets showing early signs of neonatal diarrhea were treated with an oral dose of tannin extract derived from sweet chestnut wood. The farm had a very high incidence of neonatal diarrhea among gilt litters. Gilts were randomized into test or control groups in a 1:1 ratio to compare the consumption of antibiotics used for piglets and piglet mortality during the four-week trial period. Control litters were treated with the oral antibiotic paromomycin, while test litters were treated with the complementary feed O-Nella-Protect. The farm trial included 18 gilt litters comprising 254 piglets. In the control group, 100% of the piglets received antibiotic treatment. In the test group, consumption of antibiotics used against diarrhea was reduced by 84% (p = 0.001) and consumption of antibiotics used for other illnesses was reduced by 45% (p = 0.045). In both test and control groups, six piglets died. Microbiological analysis identified both potential bacterial and viral pathogens. In conclusion, the farm trial indicates that even under the challenge of potentially serious bacterial and viral pathogens, a complimentary feed containing a tannin extract can support piglet health and reduce antibiotic consumption.

Effects of Acorns on Fatty Acid Composition and Lipid Metabolism in Adipose Tissue of Yuxi Black Pigs

The objective of the present research was the examination of how varying proportions of an acorn diet affects the deposition of subcutaneous fat and the composition of fatty acids (FAs) in Yuxi black pigs. Ninety pigs (with a balanced sex ratio and a similar weight 99.60 ± 2.32 kg) were stochastically assigned to the control group (CON) and the dietary acorn experimental groups (AEG). The CON was fed basal diets and the AEG1, AEG2, AEG3, and AEG4 groups were provided with dietary regimens comprising twenty, thirty, forty, and fifty per cent acorns, respectively. Each group consisted of six pigs, with three replicates. The breeding cycle was four months. The results demonstrated that, in comparison with the CON group, the lean meat rate was significantly increased in all test groups (p < 0.05), while in backfat thickness, loin eye area, carcass weight and slaughter rate was no significant difference (p > 0.05). The serum TC/HDL (total cholesterol divided by high-density lipoprotein-cholesterol) and TG/HDL (Triglyceride divided by high-density lipoprotein-cholesterol) levels in the AEG1 and AEG2 groups were significantly lower than the CON group (p < 0.05). There was no significant effect on the composition of FAs (p > 0.05). The number of fat cells in subcutaneous back fat and subcutaneous abdominal fat was significantly increased, and the area of fat cells was decreased (p < 0.05). Furthermore, the levels of ATGL and HSL expression in the subcutaneous back fat, as well as ACC, FAS, ATGL, PPARγ, and HSL expression in the subcutaneous abdominal fat, were significantly increased in the AEG2 group compared to the CON group (p < 0.05). Additionally, the expression of ACC, FAS, FABP4, PPARγ, C/EBPα, and FAS/HSL in the subcutaneous back fat, as well as FABP4, C/EBPα, and FAS/HSL in the subcutaneous abdominal fat, were significantly lower in the AEG2 group compared to the CON group (p < 0.05). In conclusion, it has been found that a 30% acorn diet can inhibit subcutaneous fat deposition and enhance the nutritional value of pork and the health of Yuxi black pigs.

High-concentrate diet supplemented with hydrolysable tannin improves the slaughter performance, intestinal antioxidant ability and barrier function of fattening lambs

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p < 0.05) than those of CON group. Compared with CON group, the carcass weight and intramuscular fat content of lambs in TA1 group were increased (p < 0.05) and the meat shear force was decreased (p < 0.05). The trypsin activity in the jejunum and ileum of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Also, tannin supplementation significantly increased (p < 0.05) the level of jejunal and ileal total antioxidant capacity and reduced (p < 0.05) the jejunal malondialdehyde concentration in lambs. The jejunum and ileum of TA1 lambs showed reduced (p < 0.05) tumor necrosis factor-alpha and increased (p < 0.05) interleukin-10 mRNA levels compared with CON lambs. In the jejunum, the secretory immunoglobulin A content of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Lambs supplemented with tannin at the level of 3 g/d increased (p < 0.05) the gene expressions of claudin-1, claudin-4 and zonula occludens-1 in the jejunum when compared to those of CON and TA2 groups. In summary, tannin supplementation at the level of 3 g/d per animal can improve the production performance and intestinal function of fattening lambs fed a high-concentrate diet.

Enhancing Antibiotic Efficacy with Natural Compounds: Synergistic Activity of Tannic Acid and Nerol with Commercial Antibiotics against Pathogenic Bacteria

The search for synergies between natural products and commercial antibiotics is a promising strategy against bacterial resistance. This study determined the antimicrobial capacity of Nerol (NE) and Tannic Acid (TA) against 14 pathogenic bacteria, including ESKAPE pathogens. TA exhibited the lowest Minimum Inhibitory Concentrations (MICs) at 162.5 µg/mL against Pasteurella aerogenes and 187.5 µg/mL against Acinetobacter baumannii (WHO priority 1). NE showed its lowest MIC of 500 µg/mL against both Pasteurella aerogenes and Salmonella enterica. A total of 35 combinations of NE and 13 of TA with eight commercial antibiotics were analyzed. For NE, combinations with Streptomycin and Gentamicin were effective against Salmonella enterica, Bacillus subtilis, and Streptococcus agalactiae, with antibiotic MIC reductions between 75.0 and 87.5%. TA showed six synergies with Chloramphenicol, Ampicillin, Erythromycin, and Streptomycin against Acinetobacter baumannii, Streptococcus agalactiae, and Pasteurella aerogenes, with MIC reductions between 75.0 and 93.7%. Additionally, 31 additive effects with antibiotics for NE and 8 for TA were found. Kinetic studies on these synergies showed complete inhibition of bacterial growth, suggesting that natural products enhance antibiotics by facilitating their access to targets or preventing resistance. Given their safety profiles recognized by the EPA and FDA, these natural products could be promising candidates as antibiotic enhancers.

The Influence of High-Concentrate Diet Supplemented with Tannin on Growth Performance, Rumen Fermentation, and Antioxidant Ability of Fattening Lambs

This experiment aimed to study the effects of tannin supplementation on growth performance, rumen fermentation characteristics, apparent digestibility and serum biochemistry, and antioxidant and immune indexes in fattening lambs. A total of 36 male Hu sheep lambs (body weight = 15.83 ± 0.48 kg and days of age = 55 ± 2 d) were fed a high-concentrate diet and randomly divided into one of three groups of 12 animals each: control with no tannin (CON) and tannin treatments (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). The feeding experiment lasted for 60 d. The results showed that the average daily gain and ruminal propionate content of lambs in the TA1 group were higher (p < 0.05) than those in the CON group. Lambs fed tannin had significantly increased (p < 0.05) microbial protein and decreased (p < 0.05) ammonia nitrogen concentrations in the rumen. In addition, the crude protein and neutral detergent fiber digestibility of the TA2 group were significantly decreased (p < 0.05) as compared with the TA1 and CON groups, respectively. The serum concentrations of triglyceride, immunoglobulin A, and catalase and the total antioxidant capacity were higher (p < 0.05) in the TA1 group that those in the CON group, whereas an opposite trend of urea nitrogen, interleukin-1β, and malondialdehyde was found between the two groups. Also, tannin supplementation increased (p < 0.05) Lactobacillus and decreased (p < 0.05) Salmonella counts in the feces of lambs. Taken together, tannin supplementation can improve the growth performance, immunity, and antioxidant ability of fattening lambs fed a high-concentrate diet.

Characterisation of Tenebrio molitor Reared on Substrates Supplemented with Chestnut Shell

Tenebrio molitor larvae represent a sustainable protein source for food and feed. The aim of this study was to evaluate the supplementation of chestnut shell, a by-product of the agro-industrial chain, in growth substrates for T. molitor larvae rearing. Seven-week-old larvae were reared on three different growth substrates: the control group (CTRL) was fed wheat bran, treatment group one was fed wheat bran supplemented with 12.5% w/w chestnut shell (TRT1), and treatment group two was fed wheat bran supplemented with 25% w/w chestnut shell (TRT2). Larval weight, substrate consumption, and mortality were recorded weekly. After 14 days, insect meals were produced for bromatological and colorimetric analysis, and bacterial inhibition activity assay using a microdilution method. The amino acid profile of insects was determined using quantitative nuclear magnetic resonance spectroscopy. Our results showed a lower feed conversion ratio and higher larval survival rate % in TRT2 compared to CTRL (p < 0.05). Proteins and lipids of TRT2 were higher than other groups (p < 0.05). Important differences were observed in the amino acid profile of TRT1 and TRT2 compared to CTRL (p < 0.05). TRT1 and TRT2 showed higher E. coli inhibitory activity than CTRL (p < 0.05). In conclusion, chestnut shell supplementation improved the survival and functional characteristics of larvae and likely impacted the insects' metabolism.

Genomic Characterization of Piscicolin CM22 Produced by Carnobacterium maltaromaticum CM22 Strain Isolated from Salmon (Salmo salar)

Carnobacterium maltaromaticum is a species of lactic acid bacteria (LAB) that has been isolated from various natural environments. It is well-known for producing a diverse spectrum of bacteriocins with potential biotechnological applications. In the present study, a new psychrotolerant strain of C. maltaromaticum CM22 is reported, isolated from a salmon gut sample and producing a variant of the bacteriocin piscicolin 126 that has been named piscicolin CM22. After identification by 16S rRNA gene, this strain has been genomically characterized by sequencing and assembling its complete genome. Moreover, its bacteriocin was purified and characterized. In vitro tests demonstrated that both the strain and its bacteriocin possess antimicrobial activity against several Gram-positive bacteria of interest in human and animal health, such as Listeria monocytogenes, Clostridium perfringens, or Enterococcus faecalis. However, this bacteriocin did not produce any antimicrobial effect on Gram-negative species. The study of its genome showed the genetic structure of the gene cluster that encodes the bacteriocin, showing a high degree of homology to the gene cluster of piscicolin 126 described in other C. maltaromaticum. Although more studies are necessary concerning its functional properties, this new psychrotolerant strain C. maltaromaticum CM22 and its bacteriocin could be considered an interesting candidate with potential application in agri-food industry.

Battling Salmonella enteritidis infections: integrating proteomics and in vivo assessment of Galla Chinensis tannic acid

Salmonella infections pose a significant threat to animal and human health. Phytochemicals present a potential alternative treatment. Galla chinensis tannic acid (GCTA), a hydrolyzable polyphenolic compound, inhibits bacterial growth and demonstrates potential as an alternative or supplement to antibiotics to prevent Salmonella infections. However, little is known about the antimicrobial mechanism of GCTA against Salmonella. Here, we revealed 456 differentially expressed proteins upon GCTA treatment, impacting pathways related to DNA replication, repair, genomic stability, cell wall biogenesis, and lipid metabolism using TMT-labeled proteomic analysis. TEM analysis suggested altered bacterial morphology and structure post-treatment. A Salmonella-infected-mouse model indicated that GCTA administration improved inflammatory markers, alleviated intestinal histopathological alterations, and reduced Salmonella enterica serovar Enteritidis (S. Enteritidis) colonization in the liver and spleen of Salmonella-infected mice. The LD50 of GCTA was 4100 mg/kg with an oral single dose, vastly exceeding the therapeutic dose. Thus, GCTA exhibited antibacterial and anti-infective activity against S. Enteritidis. Our results provided insight into the molecular mechanisms of these antibacterial effects, and highlights the potential of GCTA as an alternative to antibiotics.

Isolation of Hydrolyzable Tannins from Castanea sativa Using Centrifugal Partition Chromatography

Castanea sativa wood is a rich source of hydrolyzable tannins, known for their diverse bioactivities. To investigate these bioactive properties further, it is crucial to isolate and characterize hydrophilic compounds effectively. To address this issue, we developed a centrifugal partition chromatography (CPC) method and applied it to an aqueous C. sativa wood extract. We determined the partition coefficients (KD) of the six major compounds using four butanol-/water-based biphasic solvent systems. Initially, we utilized the n-butanol/propanol/water (3:1:4, v/v/v) systems for the first fractionation step. Subsequently, we employed the water/methyl tert-butyl ether/butanol/acetone (8:5:3:4, v/v/v/v) system to fractionate moderately and highly hydrophilic fractions. We calculated the KD values for major compounds of the most hydrophilic fractions using the butanol/ethanol/water (4:1:5, v/v/v) and butanol/isopropanol/water (2:1:3, v/v/v) systems. In total, we isolated 23 compounds through a combination of CPC, size exclusion chromatography, and preparative HPLC. Among these compounds, six have never been previously described. We characterized them by 1D and 2D NMR experiments and high-resolution mass spectroscopy acquisitions.

Beneficial Effects of Castanea sativa Wood Extract on the Human Body and Possible Food and Pharmaceutical Applications

The aim of this review was to investigate the potential use of Castanea sativa wood extract as a food supplement and to evaluate its beneficial properties for human health. The results of the limited amount of studies suggest promising properties, including potential anti-inflammatory effects. The literature indicates that the extract, which is rich in bioactive compounds such as tannins, offers promising therapeutic possibilities for the treatment of conditions associated with chronic inflammation. Consequently, interest in its use in food and pharmaceuticals is growing. Phytochemical studies have reported antioxidant and antimicrobial activities, and anti-inflammatory, anticancer, hypolipidemic, hypoglycemic, and neuroprotective activities. A suitable extraction method and solvent is crucial for the isolation of bioactive compounds, being green extraction technologies outstanding for the industrial recovery of chestnut wood's bioactive compounds. Nevertheless, it is important to emphasize the importance of adhering to regulatory guidelines and obtaining the necessary approvals from regulatory authorities to ensure product safety and compliance. The regulation of herbal medicinal products with proven efficacy and traditional herbal medicinal products is well defined, monitored by authorized bodies, and subject to strict control measures. It is noteworthy that medicinal products are subject to stringent quality testing to ensure safety and efficacy in use, whereas there are no comparable regulatory standards and specific labeling requirements for dietary supplements. When using herbal products, compliance with established standards in health research is essential.

Effect of Dietary Supplementation of Chestnut and Quebracho Tannin Supplementation on Neonatal Diarrhoea in Preweaning Calves

Neonatal calf diarrhoea (NCD) poses a significant health challenge in cattle herds, resulting in considerable economic losses and antimicrobial use. In response to the escalating threat of antimicrobial resistance, viable alternatives are imperative, aligning with European policies. This study evaluated the in-milk supplementation of the chestnut and quebracho tannin extract in preweaning calves on performance, diarrhoea occurrence, Cryptosporidium spp. shedding, protein digestibility, and intestinal health. Twenty newborn calves were divided, after colostrum administration, into two experimental groups for 30 days as follows: the control (CTRL) was fed with whole milk and solid feed, and tannins (TAN) were fed whole milk supplemented with 6/g day of tannin extract and solid feed. Faecal samples were collected on days 0, 3, 7, 14, and 30 for the evaluation of Cryptosporidium oocyst shedding and protein digestibility. Faecal consistency was evaluated during the sampling using the faecal score scale (0-3 scale, considering diarrhoea > 1). The results showed a significant reduction in diarrhoea frequency in the TAN compared to the CTRL group (p < 0.05) over 30 days of the trial. The prevalence of Cryptosporidium spp. was generally low (12%), considering all analysed samples. Protein digestibility revealed comparable values for the TAN and CTRL groups, suggesting that tannins did not negatively affect milk protein availability. In conclusion, the in-milk supplementation of 6/g day of the chestnut and quebracho tannin extract could be considered a valuable functional feed additive to decrease NCD occurrence, thus supporting animal health and decreasing antibiotic use in livestock.

Dietary Supplementation of Tannins: Effect on Growth Performance, Serum Antioxidant Capacity, and Immunoglobins of Weaned Piglets-A Systematic Review with Meta-Analysis

In recent years, the swine industry has witnessed the withdrawal of antibiotics and continuous regulation of zinc and copper oxides in the early-life nutrition of piglets. Due to this development, alternative additives from plant sources have been extensively explored. Therefore, this study's objective was to evaluate the effect of dietary supplementation with tannins on weaned piglets' growth performance, serum antioxidant capacity, and serum immune status using a systematic review and meta-analysis approach. A total of 16 studies with parameters of interest were deemed eligible after a two-step screening process following a comprehensive literature search in the scientific databases of Web of Science, Scopus, ScienceDirect, PubMed, and Google Scholar. The inclusion criteria were mainly (1) studies involving basal diet supplemented with tannins and (2) studies with the quantification of tannin doses, while the exclusion criteria were (1) studies with pre- and post-weaning pigs and (2) challenged studies. Applying the random-effects models, Hedges' g effect size of supplementation with tannins was calculated using R software to determine the standardized mean difference (SMD) at a 95% confidence interval. Sub-group analysis and meta-regression further explored heterogeneity (PSMD < 0.05, I2 > 50%, n ≥ 10). Supplementation with tannins reduced the feed conversion ratio (p < 0.01) but increased the final body weight (p < 0.01) of weaned piglets. Chestnut and grape seed proanthocyanidin tannin sources yielded higher effects on growth performance. In addition, meta-regression models indicated that tannin dosage and supplementation duration were directly associated with tannins' effectiveness on productive performance. In the serum, the concentration of glutathione peroxidase, superoxide dismutase, and total antioxidant capacity were elevated (p < 0.01) in response to tannin supplementation, whereas malondialdehydes was reduced (p < 0.01). Likewise, increased immunoglobin M and G levels (p < 0.01) were detected. In conclusion, dietary supplementation with tannins, particularly with chestnut and grape seed proanthocyanidins, increases the productivity of weaned piglets. At the same time, it is a possible nutritional strategy to mitigate oxidative stress and stimulate gut health. Thus, supplementing chestnut and grape seed proanthocyanidin tannins in the early phase of swine production could be used to alleviate the incidence of diarrhea.

Performance and meat quality in pigs fed hydrolysable tannins from Tara spinosa

This study aimed to assess the effect of dietary tara (Tara spinosa (Feuillée ex Molina) Britton & Rose) hydrolysable tannins on performance and meat quality of finishing pigs. Twenty barrows (crossbred PIC × Piétrain; age: 125 ± 5 d; bodyweight: 60.8 ± 3.89 kg) were randomly assigned to two groups and fed ad libitum for 7 weeks a control diet (CON) or a diet supplemented with 10 g/kg of tara tannins (TAT), respectively. No differences (P > 0.10) on growth performance and carcass traits were observed between the two groups. Meat fatty acid profile was not affected (P > 0.10) by the diet, but the content of C22:5 n-3 tended to be lower (P = 0.079) in TAT pork. Dietary tannins tended to reduce (P = 0.095) meat cholesterol. The diet had no effect (P > 0.10) on fat-soluble antioxidant vitamins, hydrophilic antioxidant capacity, catalase activity, and glutathione peroxidase activity. Superoxide dismutase activity tended to be lower (P = 0.087) in TAT meat than in CON meat. Dietary tannins did not affect (P > 0.10) backfat and meat color development during 6 days of refrigerated storage, but TAT meat tended to be darker (P = 0.082). Meat from pigs fed tara tannins showed lower (P = 0.028) hydroperoxides content and a tendency toward lower conjugated dienes (P = 0.079) and malondialdehyde (P = 0.084) contents. Also, dietary tannins delayed lipid oxidation in meat subjected to oxidative challenges such as catalysis and cooking (P < 0.05). The positive effect of dietary tara hydrolysable tannins on lipid oxidation was likely due to their antioxidant and anti-inflammatory capacity, but it may have been mitigated by the high α-tocopherol content in meat.

Characterization and subchronic oral toxicity of Pentaclethra macroloba (pracaxi) oil in Rattus norvegicus (lin. Wistar)

The trend of replacing antimicrobials as growth promoters in animal nutrition is growing. Functional oils emerge as an alternative because of their richness in bioactive compounds and bioavailability. The present study aims to evaluate the fatty acid profile, antioxidant capacity, composition of phenolic compounds, and toxic capacity in Wistar rats of pracaxi oil (Pentaclethra macroloba). DDPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), and ABTS (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) were performed to assess antioxidant capacity. The composition of phenolic compounds was determined by specific reagents. For the evaluation of subchronic oral toxicity, 40 Wistar albino rats (20 males and 20 females) were randomized into 10 groups with different levels of pracaxi oil administered orally. The doses administered were 0, 300, 600, 1200 and 2400 mg/kg (Group 1 to 5 females and Group 6 to 10 males). The animals were submitted to evaluations described in the OECD manual (Guide 407). The analytical results showed that pracaxi oil has different fatty acids in its chemical composition: oleic, linoleic, arachidic, and behenic acids, which account for more than 90% of its composition. In a smaller percentage, lauric acid (0.17%), myristic (0.09%), palmitic (1.49%), stearic (3.45%), and linolenic acid (1.39%) were also found. According to the results of the antioxidant tests, pracaxi oil has a high antioxidant capacity and is a product with a high presence of phenolic compounds. Regarding the toxicity assessment, there were no alterations in the clinical signs and weight of organs. However, in histology, there were mild alterations of a possible toxic process with the increase in the oil dose. This research is extremely valuable since pracaxi oil is a product with little information about its potential use in animal nutrition.

Supplementation with Antimicrobial Peptides or a Tannic Acid Can Effectively Replace the Pharmacological Effects of Zinc Oxide in the Early Stages of Weaning Piglets

Zinc oxide (ZnO) harms the environment and can potentially increase the number of drug-resistant bacteria. Therefore, there is an urgent need to find safe and effective alternatives to improve gut health and reduce the incidence of diarrhea in weaned piglets. This study conducted an antibacterial test of ZnO, antibacterial peptides (AMPs), and tannic acid (TA) in vitro. Thirty piglets were randomly allotted to one of the following three dietary treatments: ZnO (2000 mg/kg ZnO diet), AMPs (700 mg/kg AMPs diet), and TA (1000 mg/kg TA diet). The results showed that the minimum inhibitory concentrations of ZnO and TA against Escherichia coli and Salmonella were lower than those of AMPs, and the minimum inhibitory concentrations of ZnO, AMPs, and TA against Staphylococcus aureus were the same. Compared to ZnO, AMPs increased the digestibility of dry, organic matter and the crude fat. Additionally, TA significantly (p < 0.05) increased the digestibility of dry and organic matter. On experimental day 14, the plasma interleukin-6 (IL-6) content of piglets supplemented with AMPs and TA was increased significantly (p < 0.05). On experimental day 28, alanine aminotransferase activity in the plasma of weaned piglets in the ZnO and TA groups was significantly (p < 0.05) higher than in piglets in the AMPs group. The levels of plasma IL-6 and immunoglobulin M (IgM) were significantly higher (p < 0.05) in the ZnO and AMPs groups than in the TA group. On experimental days 14 and 28, no significant differences were observed in the antioxidant capacity among the three experimental groups. Intestinal microbial diversity analysis showed that the Chao1 and ACE indices of piglets in the AMPs group were significantly higher (p < 0.05) than those in the ZnO and TA groups. At the genus level, the relative abundance of Treponema_2 was higher in the feces of piglets fed a diet supplemented with TA than in those fed diet supplemented with ZnO (p < 0.05). The relative abundance of Lachnospiraceae was higher in the feces of piglets fed a diet supplemented with AMPs than in those fed diet supplemented with ZnO or TA. Overall, AMPs and TA could be added to feed as substitutes for ZnO to reduce diarrhea, improve nutrient digestibility and immunity, and increase the abundance of beneficial intestinal bacteria in weaned piglets.

Antioxidant and in vitro cosmeceutical activities of chestnut inner shell fermented by Monascus kaoliang

Chestnut inner shell (CIS) was fermented at 30 °C for 12 day using Monascus kaoliang, either in solid or submerged state, and alcohol extracts (70% ethanol) of the fermented CIS were examined for their antioxidant (total phenol content and diphenylpicrylhydrazyl radical scavenging activity) and in vitro cosmeceutical activities (tyrosinase and elastase inhibitory activities). Both activities were significantly increased by the M. kaoliang-fermentation, more apparently by submerged fermentation (SMF) than by solid-state fermentation (SSF). The cosmeceutical activity reached its maximum value on the 3rd day of fermentation. The residual amounts of phenolic acids and catechins in the CIS extracts were increased by the fermentation, up to 395.0 and 344.3 µg/g, respectively. More phenolic acids were produced by SMF than SSF, whereas more catechins were produced by SSF than SMF. Therefore, SMF using M. kaoliang was an efficient process for the utilization of CIS as a source of cosmeceuticals.

Eating Quality of Pork from Entire Male Pigs after Dietary Supplementation with Hydrolysable Tannins

Boar taint is an unpleasant odour and flavour released during heat treatment of pork from uncastrated male pigs. The two main compounds responsible for boar taint are androstenone and skatole. Androstenone is a steroid hormone formed in the testis during sexual maturity. Skatole is a product of microbial degradation of the amino acid tryptophan in the hindgut of pigs. Both of these compounds are lipophilic, which means that they can be deposited in adipose tissue. Several studies have reported heritability estimates for their deposition from medium (skatole) to high magnitudes (androstenone). In addition to efforts to influence boar taint through genetic selection, much attention has also been paid to reducing its incidence using various feeding strategies. From this point of view, research has focused especially on the reduction in skatole content by supplementation of feed additives into the nutrition of entire male pigs. Promising results have been achieved using hydrolysable tannins in the diet. To date, most studies have investigated the effects of tannins on the production and accumulation of skatole in adipose tissue, intestinal microbiota, growth rate, carcasses and pork quality. Thus, the objective of this study was, in addition to determining the effects of tannins on androstenone and skatole accumulation, to assess the effects of tannins on the sensory traits of meat from entire males. The experiment was performed on 80 young boars-progeny of several hybrid sire lines. Animals were randomly assigned to one control and four experimental groups (each numbering 16). The control group (T0) received a standard diet without any tannin supplementation. Experimental groups were supplemented with 1% (T1), 2% (T2), 3% (T3) or 4% (T4) SCWE (sweet chestnut wood extract) rich in hydrolysable tannins (Farmatan). Pigs received this supplement for 40 days prior to slaughter. Subsequently, the pigs were slaughtered, and sensory analysis was applied to evaluate the odour, flavour, tenderness and juiciness of the pork. The results showed a significant effect of tannins on skatole accumulation in adipose tissue (p = 0.052-0.055). The odour and flavour of the pork were not affected by tannins. However, juiciness and tenderness were reduced by higher tannin supplementation (T3-T4) compared to the controls (p < 0.05), but these results were sex-dependent (in favour of men compared to women). Generally, women rated tenderness and juiciness worse than men regardless of the type of diet.

Chestnut-Tannin-Crosslinked, Antibacterial, Antifreezing, Conductive Organohydrogel as a Strain Sensor for Motion Monitoring, Flexible Keyboards, and Velocity Monitoring

Flexible sensing devices (FSDs) fabricated using conductive hydrogels have attracted researchers' extensive enthusiasm in recent years due to their versatility. Considering the complexity of their application environments, the integration of various functional characteristics (e.g., excellent mechanical, antibacterial, and antifreezing properties) is an important guarantee for FSDs to stably perform their applications in different environments. Herein, we developed a multifunctional conductive polyvinyl alcohol (PVA) organohydrogel PVA-CT-Ag-Al-Gly (PCAAG) by using a green, natural, and cheap biomass, chestnut tannin (CT), as a crosslinking agent, nano-silver particles (AgNPs) as an antimicrobial agent, aluminum trichloride (AlCl₃) as a conducting medium, and the mixed water-glycerol as the solvent system. In this organohydrogel system, CT acted not only as the reducing and stabilizing agent for the preparation of antibacterial AgNPs but also as the crosslinking agent owing to its strong multiple hydrogen bonding interactions with PVA, realizing its multifunctional application. The PCAAG organohydrogel possessed outstanding physical and mechanical properties (350.54% of the maximum fracture strain and 1.55 MPa of the maximum tensile strength), considerable bacteriostatic effects against both Escherichia coli and Staphylococcus aureus, and excellent freeze resistance (it could function normally at -20 °C). The motion-monitoring sensor based on the PCAAG organohydrogel exhibited excellent specificity recognition for both large-amplitude (e.g., elbow bending, wrist bending, finger bending, running and walking, etc.) and small-amplitude (frowning and swallowing) human movements. The flexible keyboard constructed by using the PCAAG organohydrogel could easily achieve the transformation between digital signals and electrical signals, and the signal output had both specificity and stability. The velocity-monitoring sensor fabricated by using the PCAAG organohydrogel could accurately measure the speed of the object movement (less than 3% of relative error). In short, the present PCAAG organohydrogel solves the problems of the single application environment and a few application scenarios of traditional conductive hydrogels and possesses remarkable application potential as a multifunctional FSD in many fields such as artificial intelligence, sport management, soft robots, and human-computer interface.

Effects of dietary supplementation with dandelion tannins or soybean isoflavones on growth performance, antioxidant function, intestinal morphology, and microbiota composition in Wenchang chickens

Many benefits have been found in supplementing tannins or soybean isoflavones to poultry, including increased body weight gain, antioxidant activity, and better intestinal morphology. However, few studies tested the influence of dandelion tannins or soybean isoflavones supplementation on Wenchang chickens. This study investigates the effects of dietary supplementation with dandelion tannins or soybean isoflavones on the growth performance, antioxidant function, and intestinal health of female Wenchang chickens. A total of 300 chickens were randomly divided into five groups, with six replicates per group and 10 broilers per replicate. The chickens in the control group (Con) were fed a basal diet; the four experimental groups were fed a basal diet with different supplements: 300 mg/kg of dandelion tannin (DT1), 500 mg/kg of dandelion tannin (DT2), 300 mg/kg of soybean isoflavone (SI1), or 500 mg/kg of soybean isoflavone (SI2). The experiment lasted 40 days. The results showed that the final body weight (BW) and average daily gain (ADG) were higher in the DT2 and SI1 groups than in the Con group (P < 0.05). In addition, dietary supplementation with dandelion tannin or soybean isoflavone increased the level of serum albumin (P <0.05); the concentrations of serum aspartate aminotransferase and glucose were significantly higher in the SI1 group (P < 0.05) than in the Con group and the concentration of triglycerides in the DT1 group (P < 0.05). The serum catalase (CAT) level was higher in the DT1 and SI1 groups than in the Con group (P < 0.05). The ileum pH value was lower in the DT2 or SI1 group than in the Con group (P < 0.05). The jejunum villus height and mucosal muscularis thickness were increased in the DT2 and SI1 groups (P < 0.05), whereas the jejunum crypt depth was decreased in the DT1 or DT2 group compared to the Con group (P < 0.05). In addition, the messenger RNA (mRNA) expression level of zonula occludens 1 (ZO-1) in the duodenum of the SI1 group and those of occludin, ZO-1, and claudin-1 in the ileum of the DT2 and SI1 groups were upregulated (P < 0.05) compared to the Con group. Moreover, the DT2 and SI1 groups exhibited reduced intestinal microbiota diversity relative to the Con group, as evidenced by decreased Simpson and Shannon indexes. Compared to the Con group, the relative abundance of Proteobacteria was lower and that of Barnesiella was higher in the DT2 group (P < 0.05). Overall, dietary supplementation with 500 mg/kg of dandelion tannin or 300 mg/kg of soybean isoflavone improved the growth performance, serum biochemical indexes, antioxidant function, and intestinal morphology and modulated the cecal microbiota composition of Wenchang chickens.

Tannins-Based Extracts: Effects on Gut Chicken Spontaneous Contractility

The impossibility of using drugs for the health of farm animals leads to the search for alternative strategies with two purposes: to maintain animal health and safeguard human health. In this perspective, tannins have shown great promises. These phytocomplexes obtained from natural matrices with multiple health properties may be used as a feed supplement in chicken farms. In this work, we studied two tannin-based extracts (from Castanea sativa Mill. wood and from Schinopsis balansae Engl. Quebracho Colorado hardwood) with different chemical compositions on the spontaneous contractility on the isolated intestinal tissues of healthy chicken. The results showed that the chemical composition of the two phytocomplexes influenced the spontaneous intestinal contractility in different ways by regulating the tone and consequent progression of the food bolus. The chemical analysis of the two extracts revealed that Castanea sativa Mill. wood mainly contains hydrolysable tannins, while Schinopsis balansae Engl. hardwood mainly contains condensed tannins. The two phytocomplexes showed different effects towards gastrointestinal smooth muscle contractility, with Castanea sativa Mill. wood providing a better activity profile than Schinopsis balansae Engl. hardwood.

Effects of zinc oxide and condensed tannins on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment

This experiment was conducted to evaluate effects of zine oxide (ZnO) and condensed tannins (CT), independently or in combination, on the growth performance and intestinal health of weaned piglets in enterotoxigenic Escherichia coli (ETEC-K88)-challenged environment. Randomly divided 72 weaned piglets into 4 groups. Dietary treatments included the following: basic diet group (CON), 1,500 mg/kg zinc oxide group (ZnO), 1,000 mg/kg condensed tannins group (CT), and 1,500 mg/kg zinc oxide +1,000 mg/kg condensed tannins group (ZnO + CT). Dietary ZnO supplementation decreased diarrhea rate from 0 to 14 days, 15 to 28 days, and 0 to 28 days (p < 0.05) and no significant on growth performance. The effect of CT on reducing diarrhea rate and diarrhea index was similar to the results of ZnO. Compared with the CON group, ZnO increased the ileum villus height and improved intestinal barrier function by increasing the content of mucin 2 (MUC-2) in jejunum and ileum mucosa and the mRNA expression of zonula occludens-1 (ZO-1) in jejunum (p < 0.05) and the expression of Occludin in duodenum and ileum (p < 0.05). The effects of CT on intestinal barrier function genes were similar to that of ZnO. Moreover, the mRNA expression of cystic fibrosis transmembrane conductance regulator (CFTR) in jejunum and ileum was reduced in ZnO group (p < 0.05). And CT was also capable of alleviating diarrhea by decreasing CFTR expression and promote water reabsorption by increasing AQP3 expression (p < 0.05). In addition, pigs receiving ZnO diet had higher abundance of phylum Bacteroidetes, and genera Prevotella, and lower phylum Firmicutes and genera Lactobacillus in colonic contents. These results indicated that ZnO and CT can alleviate diarrhea and improve intestinal barrier function of weaned pigs in ETEC-challenged environment. In addition, the application of ZnO combined with CT did not show synergistic effects on piglet intestinal health and overall performance. This study provides a theoretical basis for the application of ZnO in weaning piglet production practices, we also explored effects of CT on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment.

Protective effect of phytogenic plus short and medium-chain fatty acids-based additives in enterotoxigenic Escherichia coli challenged piglets

Post Weaning Diarrhea (PWD) is the most important multifactorial gastroenteric disease of the weaning in pig livestock. Phytogenic (PHY) natural extracts are largely studied as alternatives to antibiotic treatments in combating the global concern of the antimicrobial resistance. The aim of this study was to evaluate the protective effect of innovative phytogenic premix with or without short and medium chain fatty acids (SCFA and MCFA) in O138 Escherichia coli challenged piglets. Twenty-seven weaned piglets were allotted into four groups fed different diets according to the following dietary treatments: CTRL (n = 13) group fed basal diet, PHY1 (n = 7) fed the basal diet supplemented with 0.2% of phytogenic premix, PHY2 (n = 7) fed the basal diet supplemented with 0.2% of phytogenic premix added with 2000 ppm of SCFA and MCFA. After 6 days of experimental diet feeding, animals were challenged (day 0) with 2 × 10⁹ CFU of E. coli and CTRL group was divided at day 0 into positive (challenged CTRL + ; n = 6) and negative control group (unchallenged CTRL-; n = 7). Body weights were recorded at -14, -6, 0, 4 and 7 days and the feed intake was recorded daily. E. coli shedding was monitored for 4 days post-challenge by plate counting. Fecal consistency was registered daily by a four-point scale (0-3; diarrhea > 1) during the post-challenge period. Tissue samples were obtained for gene expression and histological evaluations at day 7 from four animals per group. Lower average feed intake was observed in CTRL + compared to PHY2 and CTRL during the post-challenge period. Infected groups showed higher E. coli shedding compared to CTRL- during the 4 days post-challenge (p < 0.01). PHY2 showed lower frequency of diarrhea compared to PHY1 and CTRL + from 5 to 7 days post-challenge. No significant alterations among groups were observed in histopathological evaluation. Duodenum expression of occludin tended to be lower in challenged groups compared to CTRL- at 7 days post-challenge (p = 0.066). In conclusion, dietary supplementation of PHY plus SCFA and MCFA revealed encouraging results for diarrhea prevention and growth performance in weaned piglets.

Dietary Supplementation with a Blend of Hydrolyzable and Condensed Tannins Ameliorates Diet-Induced Intestinal Inflammation in Zebrafish (Danio rerio)

The current study evaluated the effects of hydrolyzable and condensed tannins from chestnut and quebracho wood, respectively (TSP, Silvafeed^®), on zebrafish with intestinal inflammation induced by a plant-based diet (basal diet). Four experimental diets were prepared as follows: the basal diet + 0 TSP, the basal diet + TSP at 0.9 g/kg of feed, the basal diet + TSP at 1.7 g/kg of feed, and the basal diet + TSP at 3.4 g/kg of feed. Eighty-four zebrafish (Danio rerio) were fed for 12 days with the experimental diets. In zebrafish fed the basal diet, intestine integrity appeared to be altered, with damaged intestinal villi, high immunoexpression of tumor necrosis factor-α (TNFα) and cyclooxygenase 2 (COX2), and high expression of the cox2, interleukin 1 (il-1b), interleukin 8 (cxcl8-l1), and tnfα genes. The tannin treatment partially restored intestinal morphology and downregulated the expression of cytokines. The best activity was detected with 1.7 and 3.4 g/kg of feed. In the guts of all groups, Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes were the most represented phyla. The most represented genera were Plesiomonas and Sphingomonas, belonging to the Proteobacteria phylum; Cetobacterium, belonging to the Fusobacteria phylum; and Lactobacillus, belonging to the Firmicutes phylum. No significant differences were detected among groups, except for a slight decrease in the Fusobacteria phylum and slight increases in the Shewanella and Bacteroides genera with TSP. In conclusion, these results suggest that tannins can improve the zebrafish intestinal inflammation caused by a terrestrial-plant-based diet in a dose-dependent manner.

Hazelnut Skin in Ewes' Diet: Effects on Colostrum Immunoglobulin G and Passive Transfer of Immunity to the Lambs

Passive immunity transfer has a pivotal role in newborn lambs, where the colostrum represents the primary source of immunoglobulins. This study hypothesized that the high content in polyphenolic compounds, mono- and poly-unsaturated fatty acids, and vitamin E of hazelnut skin affects blood and colostrum immunoglobulin G (IgG) concentration and related gamma-glutamyl-transferase (GGT) and lactate dehydrogenase (LDH) levels in sheep and their lambs. In the last 45 days of pregnancy, ewes were divided into a control (CTR) and a hazelnut skin supplemented group (HZN). Blood and colostrum were collected from ewes and lambs before the first suckling, at 24 and 48 h after birth, then IgG concentration, GGT and LDH activity levels were measured. IgG concentration in the colostrum and in lamb's serum were significantly greater in HZN than CTR. No significant difference was detected for ewe's blood. A significant positive correlation was found between IgG and GGT in lambs' serum and colostrum, between IgG and LDH, as well as between GGT and LDH in lambs' serum and colostrum. Our results suggest that hazelnut skin supplementation influences IgG colostrum concentration, with improved immune passive transfer to the suckling lambs. The transfer of maternal derived immune factors is confirmed by the GGT and LDH enzyme activity levels.

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.

Extracts Prepared from Feed Supplements Containing Wood Lignans Improve Intestinal Health by Strengthening Barrier Integrity and Reducing Inflammation

Lignans are known to exhibit a broad spectrum of biological activities, indicating their potential as constituents of feed supplements. This study investigated two extracts derived from the feed supplements ‘ROI’ and ‘Protect’—which contain the wood lignans magnolol and honokiol (‘ROI’), or soluble tannins additional to the aforementioned lignans (‘Protect’)—and their impact on selected parameters of intestinal functionality. The antioxidant and anti-inflammatory properties of the extracts were determined by measuring their effects on reactive oxygen species (ROS) and pro-inflammatory cytokine production in vitro. The impact on intestinal barrier integrity was evaluated in Caco-2 cells and Drosophila melanogaster by examining leaky gut formation. Furthermore, a feeding trial using infected piglets was conducted to study the impact on the levels of superoxide dismutase, glutathione and lipid peroxidation. The Protect extract lowered ROS production in Caco-2 cells and reversed the stress-induced weakening of barrier integrity. The ROI extract inhibited the expression or secretion of interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα). Moreover, the ROI extract decreased leaky gut formation and mortality rates in Drosophila melanogaster. Dietary supplementation with Protect improved the antioxidant status and barrier integrity of the intestines of infected piglets. In conclusion, wood lignan-enriched feed supplements are valuable tools that support intestinal health by exerting antioxidant, anti-inflammatory and barrier-strengthening effects.

Tannic Acid Extracted from Galla chinensis Supplementation in the Diet Improves Intestinal Development through Suppressing Inflammatory Responses via Blockage of NF-κB in Broiler Chickens

The objective of this study was to investigate the effects of adding tannic acid (TA) extracted from Galla chinensis to the diet of broiler chickens on intestinal development. A total of 324 healthy 1-day-old broilers were used in a 42 d study, and divided into two treatment groups at random (six replicates per group). Broilers were either received a basal diet or a basal diet supplemented with 300 mg/kg microencapsulated TA extracted from Galla chinensis. The results showed that dietary supplemented with 300 mg/kg TA from Galla chinensis improved intestinal morphology, promoted intestinal mucosal barrier integrity, and elevated mucosal expressions of nutrients transporters and tight junction protein CLDN3 in broilers. Besides, 300 mg/kg TA from Galla chinensis supplementation decreased the concentrations of inflammatory cytokines in serum and intestinal mucosa and reduced the mRNA expression of NF-κB in intestinal mucosa. Above all, supplementation of 300 mg/kg microencapsulated TA extracted from Galla chinensis showed beneficial effects in improving intestinal development, which might be attributed to the suppression of inflammatory responses via blockage of NF-κB in broiler chickens. These findings will support the use of TA sourced from Galla chinensis in poultry industry.

Salivary Gland Adaptation to Dietary Inclusion of Hydrolysable Tannins in Boars

Simple Summary

Tannins have traditionally been avoided in animal nutrition due to their anti-nutritive effects. However, recent studies reported hydrolysable tannins as beneficial additives that have antimutagenic, anticarcinogenic, antidiarrheal, and antiulcerogenic effects on animals. In a study testing the inclusion of hydrolysable tannins as a potential nutritive factor to reduce boar taint in entire males, significant enlargement of the parotid glands (parotidomegaly) was observed. In this study, we aimed to determine the morphological and immunohistochemical basis for the observed parotidomegaly. We discovered that enlargement of glandular lobules and acinar area, an increased ratio between the nucleus and cytoplasm of serous cells, and increased excretion of proline-rich proteins (PRPs) were characteristic of the experimental group that received the highest dietary tannin intake. The mandibular salivary gland, on the other hand, did not show significant morphological changes among the experimental groups. This suggests increased functional activity of the parotid salivary glands as the first and most important line of defense against high dietary tannin and its potential negative effects.

Abstract

The ingestion of hydrolysable tannins as a potential nutrient to reduce boar odor in entire males results in the significant enlargement of parotid glands (parotidomegaly). The objective of this study was to characterize the effects of different levels of hydrolysable tannins in the diet of fattening boars (n = 24) on salivary gland morphology and proline-rich protein (PRP) expression at the histological level. Four treatment groups of pigs (n = 6 per group) were fed either a control (T0) or experimental diet, where the T0 diet was supplemented with 1% (T1), 2% (T2), or 3% (T3) of the hydrolysable tannin-rich extract Farmatan^®. After slaughter, the parotid and mandibular glands of the experimental pigs were harvested and dissected for staining using Goldner’s Trichrome method, and immunohistochemical studies with antibodies against PRPs. Morphometric analysis was performed on microtome sections of both salivary glands, to measure the acinar area, the lobular area, the area of the secretory ductal cells, and the sizes of glandular cells and their nuclei. Histological assessment revealed that significant parotidomegaly was only present in the T3 group, based on the presence of larger glandular lobules, acinar areas, and their higher nucleus to cytoplasm ratio. The immunohistochemical method, supported by color intensity measurements, indicated significant increases in basic PRPs (PRB2) in the T3 and acidic PRPs (PRH1/2) in the T1 groups. Tannin supplementation did not affect the histo-morphological properties of the mandibular gland. This study confirms that pigs can adapt to a tannin-rich diet by making structural changes in their parotid salivary gland, indicating its higher functional activity.

Medicinal Importance, Pharmacological Activities, and Analytical Aspects of Strictinin: A Mini-Review

BACKGROUND

Plants and their derived products have been used in history as food and medicine. Plant materials are rich sources of fiber, minerals, vitamins, and bioactive phytochemicals, which are useful for human beings. Strictinin is an important phytoconstituent of green tea.

METHODS

Present work mainly focuses on the biological importance, therapeutic potential, and pharmacological activities of strictinin in medicine. Numerous scientific data have been collected from various literature databases such as Google Scholar, Science Direct, PubMed, and Scopus database in order to realize the health beneficial potential of strictinin. Pharmacological data has been collected and analyzed in the present work to find the effectiveness of strictinin against human disorders and complications. Analytical data of strictinin has been also collected and analyzed in the present work.

RESULTS

Scientific data analysis revealed the biological importance of strictinin in medicine. Scientific data analysis signified the therapeutic benefit of strictinin mainly due to its anticancer, antimicrobial, antibacterial, antiviral, and antioxidant activity. However, enzymatic activities, cytotoxicity, effectiveness on skin disorders, and osteogenic potential of strictinin have also been discussed. Analytical data revealed the importance of modern analytical techniques in medicine for the separation, identification, and isolation of strictinin.

CONCLUSION

Present work signified the biological importance and therapeutic benefits of strictinin in medicine and other allied health sectors.

Pharmacological Applications and Action Mechanisms of Phytochemicals as Alternatives to Antibiotics in Pig Production

Antibiotics are widely used for infectious diseases and feed additives for animal health and growth. Antibiotic resistant caused by overuse of antibiotics poses a global health threat. It is urgent to choose safe and environment-friendly alternatives to antibiotics to promote the ecological sustainable development of the pig industry. Phytochemicals are characterized by little residue, no resistance, and minimal side effects and have been reported to improve animal health and growth performance in pigs, which may become a promising additive in pig production. This paper summarizes the biological functions of recent studies of phytochemicals on growth performance, metabolism, antioxidative capacity, gut microbiota, intestinal mucosa barrier, antiviral, antimicrobial, immunomodulatory, detoxification of mycotoxins, as well as their action mechanisms in pig production. The review may provide the theoretical basis for the application of phytochemicals functioning as alternative antibiotic additives in the pig industry.

Effects of Supplementation with a Quebracho Tannin Product as an Alternative to Antibiotics on Growth Performance, Diarrhea, and Overall Health in Early-Weaned Piglets

Simple Summary

The restriction of the use of antibiotics in swine production worldwide has influenced pork production efficiency. New in-feed additives must be sustainable, prevent diarrhea in early weaning piglets, and promote growth performance. Novel in-feed additives, probiotics, prebiotics, organic compounds, mineral salts and vegetable extract have been extensively studied; most have shown some limitations that discourage extensive use. We investigated the plant extract MGM-P (a quebracho tannin product) as an alternative animal feed additive to antibiotics. We considered its unique structure, antibacterial, antioxidant, radical scavenging, and anti-inflammatory activities, and sustainability. We began with a low-level addition trial; 0.3% MGM-P had a more robust effect than 0.2% MGM-P. The findings demonstrated that 0.3% MGM-P supplementation prevented diarrhea in 21-day-old weaned piglets, improving piglet health without adversely influencing growth performance. Practical studies of the mechanisms underlying the effects of MGM-P and the optimal amount for supplementation are needed to confirm our findings.

Abstract

This study assessed the feasibility of using a vegetable extract, MGM-P (quebracho tannin product), as an alternative to antibiotics for weaned piglets; it investigated MGM-P effects on growth performance, diarrhea, and overall health in early-weaned piglets. In total, 24 piglets were allocated to three treatment groups fed basal diets supplemented with 0, 0.2%, or 0.3% MGM-P for 20 days. The addition of 0.3% MGM-P to the diet of early-weaned piglets improved diarrhea incidence, hematological parameters, and intestinal mucosa structure. Furthermore, the addition of 0.2% or 0.3% MGM-P to the diet of early-weaned piglets did not affect their overall health. Importantly, MGM-P had no effects on average daily gain (ADG), average daily feed intake (ADFI), or feed conversion ratio (FCR). Gut morphology analysis showed that treatment with 0.3% MGM-P enhanced the jejunal villus height (p < 0.05) while reducing the ileal crypt depth (p < 0.05) and colon mucosal thickness (p < 0.05). Collectively, the findings suggested that the use of MGM-P as an alternative to dietary antibiotics could improve diarrhea incidence in early-weaned piglets without negative effects on growth performance or overall health.

Condensed Tannins as Antioxidants in Ruminants-Effectiveness and Action Mechanisms to Improve Animal Antioxidant Status and Oxidative Stability of Products

Condensed tannins (CTs) are widely distributed in plants, and due to their recognized antioxidant activity are considered as possible natural antioxidants for application in ruminant diets. A wide range of CT-rich sources has been tested in ruminant diets, and their effects on animal antioxidant status and oxidative stability of their products are reviewed in the present work. Possible mechanisms underlying the CT antioxidant effects in ruminants are also discussed, and the CT chemical structure is briefly presented. Utilization of CT-rich sources in ruminant feeding can improve the animals' antioxidant status and oxidative stability of their products. However, the results are still inconsistent. Although poorly understood, the evidence suggests that CTs can induce an antioxidant effect in living animals and in their products through direct and indirect mechanisms, which can occur by an integrated and synergic way involving: (i) absorption of CTs with low molecular weight or metabolites, despite CTs' poor bioavailability; (ii) antioxidant action on the gastrointestinal tract; and (iii) interaction with other antioxidant agents. Condensed tannins are alternative dietary antioxidants for ruminants, but further studies should be carried out to elucidate the mechanism underlying the antioxidant activity of each CT source to design effective antioxidant strategies based on the use of CTs in ruminant diets.

Growth Performance, Meat Quality and Antioxidant Status of Sheep Supplemented with Tannins: A Meta-Analysis

The objective of this study was to evaluate the effects of dietary supplementation with tannins (TANs) on productive performance, carcass characteristics, meat quality, oxidative stability, and blood serum antioxidant capacity of sheep through a meta-analysis. Using Scopus, Web of Science, ScienceDirect, and PubMed databases, a systematic search was performed for studies published in scientific journals that investigated the effects of TANs supplementation on the variables of interest. Only studies with weaned or older sheep were included. The data analyzed were extracted from 53 peer-reviewed publications. The sheep included in the present study were between 2 and 6 months old, and between 12 and 31 kg of body weight. The effects of TANs were analyzed using random-effects statistical models to examine the standardized mean difference (SMD) between treatments with TANs and control (no TANs). Heterogeneity was explored by meta-regression and a subgroup analysis was performed for covariates that were significant. Supplementation with TANs did not affect dry matter intake, pH, color (L* and b*), Warner-Bratzler shear force, cooking loss and meat chemical composition (p > 0.05). Supplementation with TANs increased daily weight gain (SMD = 0.274, p < 0.05), total antioxidant capacity (SMD = 1.120, p < 0.001), glutathione peroxidase enzyme activity (SMD = 0.801, p < 0.001) and catalase (SMD = 0.848, p < 0.001), and decreased malondialdehyde (MDA) concentration in blood serum (SMD = -0.535, p < 0.05). Supplementation with TANs decreased feed conversion rate (SMD = -0.246, p < 0.05), and the concentration of MDA (SMD = -2.020, p < 0.001) and metmyoglobin (SMD = -0.482, p < 0.05) in meat. However, meat redness (SMD = 0.365), hot carcass yield (SMD = 0.234), cold carcass yield (SMD = 0.510), backfat thickness (SMD = 0.565) and the Longissimus dorsi muscle area (SMD = 0.413) increased in response to TANs supplementation (p < 0.05). In conclusion, the addition of tannins in sheep diets improves productive performance, antioxidant status in blood serum, oxidative stability of meat and some other characteristics related to meat and carcass quality.

Evaluation of Tannin Extracts, Leonardite and Tributyrin Supplementation on Diarrhoea Incidence and Gut Microbiota of Weaned Piglets

The effects of the dietary administration of a combination of Quebracho and Chestnut tannins, leonardite and tributyrin were evaluated in weaned piglets. A total of 168 weaned piglets (Landrace × Large White) were randomly allotted to two experimental groups (6 pens/group, 14 piglets/pen). Animals were fed a basal control diet (CTRL) and a treatment diet (MIX) supplemented with 0.75% tannin extracts, 0.25% leonardite and 0.20% tributyrin for 28 days. Individual body weight and feed intake were recorded weekly. Diarrhoea incidence was recorded by a faecal scoring scale (0-3; considering diarrhoea ≥ 2). At 0 and 28 days, faecal samples were obtained from four piglets/pen for microbiological and chemical analyses of faecal microbiota, which were then assessed by V3-V4 region amplification sequencing. At 28 days, blood from two piglets/pen was sampled to evaluate the serum metabolic profile. After 28 days, a reduction in diarrhoea incidence was observed in the MIX compared to CTRL group (p < 0.05). In addition, compared to CTRL, MIX showed a higher lactobacilli:coliform ratio and increased Prevotella and Fibrobacter genera presence (p < 0.01). The serum metabolic profile showed a decreased level of low-density lipoproteins in the treated group (p < 0.05). In conclusion, a combination of tannin extract, leonardite and tributyrin could decrease diarrhoea incidence and modulate the gut microbiota.

Live Yeast or Live Yeast Combined with Zinc Oxide Enhanced Growth Performance, Antioxidative Capacity, Immunoglobulins and Gut Health in Nursery Pigs

This study aimed to investigate the effects of dietary LY or LY combined with ZnO supplementation on performance and gut health in nursery pigs. 192 Duroc × Landrace × Yorkshire piglets (weaned on d 32 of the age with 9.2 ± 1.7 kg BW) were allocated into four treatments with eight replicate pens, six piglets per pen. The treatments included a basal diet as control (CTR), an antibiotic plus ZnO diet (CTC-ZnO, basal diet + 75 mg/kg of chlortetracycline + ZnO (2000 mg/kg from d 1 to 14, 160 mg/kg from d 15 to 28)), a LY diet (LY, basal diet + 2 g/kg LY), and a LY plus ZnO diet (LY-ZnO, basal diet + 1 g/kg LY + ZnO). The results showed that pigs fed LY or LY-ZnO had increased (p < 0.05) average daily gain, serum IgA, IgG, superoxide dismutase, fecal butyric acid, and total volatile fatty acid concentrations, as well as decreased (p < 0.05) feed conversion ratio and diarrhea rate compared with CTR. In conclusion, pigs fed diets with LY or LY combined with ZnO had similar improvement to the use of antibiotics and ZnO in performance, antioxidant status, immunoglobulins, and gut health in nursery pigs.

Chestnut Shell Tannins: Effects on Intestinal Inflammation and Dysbiosis in Zebrafish

Simple Summary

With the increase in global population the production of animal proteins becomes increasingly crucial. Aquaculture is the first animal protein supply industry for human consumption. Intensive farming techniques are employed to increase productivity, but these may cause stressful conditions for fish, resulting in impaired growth and poor health conditions. Intestinal inflammation is one of the most common diseases of fish in intensive farming. Intestinal inflammation is usually accompanied by an alteration of the microbiota or dysbiosis. Inflammation and dysbiosis are so tightly intertwined that inflammation may contribute to or result from dysregulation of gut microbiota. Natural substances of plant origin rich in bioactive molecules or more simply phytochemicals, have been proved to be able to reduce inflammation and improve the general health status in various commercially relevant species. In this study, we evaluated the effect of tannins, a class of polyphenols, the most abundant phytochemicals, on intestinal inflammation and microbiota in zebrafish (Danio rerio), a small freshwater fish become an attractive biomedicine and aquaculture animal model during the last decades. The zebrafish has been employed in a vast array of studies aiming at investigating the essential processes underlying intestinal inflammation and injury due to its conservative gut morphology and functions. In this study, we administered a diet enriched with chestnut shell extract rich in tannins to a zebrafish model of intestinal inflammation. The treatment ameliorated the damaged intestinal morphophysiology and the microbiota asset. Our results sustain that products of natural origin with low environmental impact and low cost, such as tannins, may help to ease some of the critical issues affecting the aquaculture sector.

Abstract

The aim of the present study was to test the possible ameliorative efficacy of phytochemicals such as tannins on intestinal inflammation and dysbiosis. The effect of a chestnut shell (Castanea sativa) extract (CSE) rich in polyphenols, mainly represented by tannins, on k-carrageenan-induced intestinal inflammation in adult zebrafish (Danio rerio) was tested in a feeding trial. Intestinal inflammation was induced by 0.1% k-carrageenan added to the diet for 10 days. CSE was administered for 10 days after k-carrageenan induced inflammation. The intestinal morphology and histopathology, cytokine expression, and microbiota were analyzed. The k-carrageenan treatment led to gut lumen expansion, reduction of intestinal folds, and increase of the goblet cells number, accompanied by the upregulation of pro-inflammatory factors (TNFα, COX2) and alteration in the number and ratio of taxonomic groups of bacteria. CSE counteracted the inflammatory status enhancing the growth of health helpful bacteria (Enterobacteriaceae and Pseudomonas), decreasing the pro-inflammatory factors, and activating the anti-inflammatory cytokine IL-10. In conclusion, CSE acted as a prebiotic on zebrafish gut microbiota, sustaining the use of tannins as food additives to ameliorate the intestinal inflammation. Our results may be relevant for both aquaculture and medical clinic fields.

The Use of Chinese Skullcap (Scutellaria baicalensis) and Its Extracts for Sustainable Animal Production

Simple Summary

With the increasing pressure to address the problems of bacterial resistance and drug residues, medicinal herbs are gradually taking a more important role in animal production. Scutellaria baicalensis is a common and widely used Chinese medicinal herb. The main bioactive compounds in the plant are baicalein and baicalin. These compounds have many biological functions including anti-oxidation, antipyretic, analgesic, anti-inflammatory, antiallergic, antimicrobial, immunomodulatory, and antitumor effects. S. baicalensis and its extracts can effectively promote animal growth, improve the production performance of dairy cows, reduce the stress and inflammatory response, and have effective therapeutic effects on diseases caused by bacteria, viruses, and other pathogenic microorganisms. This paper summarizes the biological function of S. baicalensis and its application in sustainable animal production to provide a reference for future application of S. baicalensis and other medicinal herbs in animal production and disease treatment.

Abstract

Drugs have been widely adopted in animal production. However, drug residues and bacterial resistance are a worldwide issue, and thus the most important organizations (FAO, USDA, EU, and EFSA) have limited or banned the use of some drugs and the use of antibiotics as growth promoters. Natural products such as medicinal herbs are unlikely to cause bacterial resistance and have no chemical residues. With these advantages, medicinal herbs have long been used to treat animal diseases and improve animal performance. In recent years, there has been an increasing interest in the study of medicinal herbs. S. baicalensis is a herb with a high medicinal value. The main active compounds are baicalin and baicalein. They may act as antipyretic, analgesic, anti-inflammatory, antiallergenic, antimicrobial, and antitumor agents. They also possess characteristics of being safe, purely natural, and not prone to drug resistance. S. baicalensis and its extracts can effectively promote the production performance of livestock and treat many animal diseases, such as mastitis. In this review, we summarize the active compounds, biological functions, and applications of S. baicalensis in the production of livestock and provide a guideline for the application of natural medicines in the production and treatment of diseases.

Can Hydrolysable Tannins in Diet of Entire Male Pigs Affect Carcass, Pork Quality Traits, Amino and Fatty Acid Profiles, and Boar Taint, Skatole and Androstenone Levels?

The slaughtering of entire males increases the probability of incidence of tainted pork due to the presence two main compounds-androstenone and skatole. If a surgical castration of young entire male pigs is stopped in the EU countries, fattening of boars is likely to become one of the most commonly used systems in pig farming. Since skatole production and accumulation in fat tissue can be controlled by dietary approaches, several studies have investigated various feed additives to reduce this compound of boar taint. Ones of the most promising is tannins. The aim of this study was to determine the effect of different dietary tannin level supplementation on carcass, pork quality, chemical, amino and fatty acid composition. as well as perception of boar taint and accumulation of skatole and androstenone in adipose tissue. Eighty entire males were randomly distributed to control (T0) and four experimental groups. Control pigs received standard feed mixture (16.8% CP, 13.9 MJ ME) without any tannin supplementation. Experimental pigs received the same diet with administration of 1% (T1), 2% (T2), 3% (T3) and 4% (T4)-sweet chestnut extract rich in hydrolysable tannins for 40 days (from average live weight of 80 kg until slaughter at average weight 122.28 kg ± 5.63 kg). Dietary tannins supplementation did not show any significant effect on chemical composition, cholesterol content, and amino acid composition of muscle as well as fatty acid composition and androstenone accumulation in adipose tissue. A slight or small effect was observed on carcass and meat quality, respectively. Pigs in groups T4 and/or T3-T4 had higher electrical conductivity in semimembranosus muscle and cooking loss value compared to T1, T2 or T0, T1, and T2 groups (p < 0.05). Tannins in the pig's diet greatly affected fatty acid profile in meat of entire males. The highest tannin levels (4%) increased concentrations of lauric, myristic, vaccenic, linoleic, total PUFA, and n-6 PUFA in muscle compared to the control. Similar results were found in group T3 except for vaccenic, linoleic, and total PUFA. On the contrary, concentrations of heptadecanoic and oleic acids in groups T3 and T4 were lower than those in T1 and T2 groups. Perception of boar taint using "hot iron" method (insertion a hot iron tip of soldering iron into adipose tissue) tended to decrease in T2 group compared with control. Skatole accumulation in fat tissue was reduced in groups T2-T4 at significance level (p = 0.052-0.055) compared to the control pigs. In summary, tannins supplementation had no effect on chemical and amino acid composition as well as fatty acid profile in adipose tissue, and only slight on carcass value. However, 4% concentration of tannins significantly increased content of some fatty acids compared to control group.