Effects of tannic acid on cecal volatile fatty acids and susceptibility to Salmonella typhimurium colonization in broiler chicks

Comparison of the Effects between Tannins Extracted from Different Natural Plants on Growth Performance, Antioxidant Capacity, Immunity, and Intestinal Flora of Broiler Chickens

In this study, four plant tannins, including AT (Acacia mearnsii tannin, 68%), CT (Castanea sativa tannin, 60%), QT (Schinopsis lorenzii tannin, 73%) and TT (Caesalpinia spinosa tannin, 50%) were added to broiler diets for 42 days to evaluate and compare their effects on growth performance, antioxidant capacity, immune performance and gut microbiota in broilers. The results showed that the supplementation of five tannins could increase the production of T-AOC, GSH-Px, SOD and CAT and reduce the production of MDA in the serum of broilers (p < 0.01), but the antioxidant effect of the AT group was lower than that of the other three groups (p < 0.01). All four tannins decreased the level of the pro-inflammatory factor IL-1β and increased the level of the anti-inflammatory factor IL-10 (p < 0.01). CT, QT and TT decreased the levels of pro-inflammatory factors IL-6 and TNF-α (p < 0.01), while AT and CT increased the level of IL-2 in serum (p < 0.01). Supplementation with four tannins also increased the levels of IgG, IgM, IgA and sIgA in serum (p < 0.01) and the levels of ZO-1, claudin-1 and occludin in the jejunum (p < 0.01). The detection results of ALT and AST showed that CT, QT and TT decreased the concentrations of ALT and AST in serum (p < 0.01). The results of the gut microbiota showed that the abundance of Clostridia and Subdoligranulum increased, and the abundance of Oscillospiraceae decreased, compared to the control group after adding the four tannins to the diets (p > 0.05). In addition, CT, QT and TT decreased the abundance of Lactobacillus and increased the abundance of Bacteroides compared to the control group, while AT showed the opposite result (p > 0.05). Overall, our study shows that tannins derived from different plants have their own unique effects on broilers. AT and CT can promote broilers' growth better than other tannins, CT has the best ability to improve immune and antioxidant properties, and QT and TT have the best effect on broilers' liver protection.

The effects of a Bacillus licheniformis and phytase mixture added to broiler diets on growth performance, nutrient digestibility, and cecal microecosystem

This study aims to evaluate the effects of Bacillus licheniformis and 6-phytase added alone or in combination to broiler chicken diets on the growth performance, apparent ileal digestibility coefficient (AID) of nutrients, microbial activity, and cecal bacterial communities. In total, 400 one-day-old female Ross 308 chicks were randomly allocated to 4 dietary treatments (10 replicate pens, 10 birds each). The following groups were defined: NC (negative control), basal diet without any feed additive supplementation; NC+Pro, basal diet with addition of the B. licheniformis preparation (500 g/t of diet); NC+Phy, basal diet with addition of phytase (200 g/t of diet); and NC+Pro+Phy, basal diet combined with both studied additives. B. licheniformis positively affected (P<0.05) the feed intake (FI) and feed conversion ratio (FCR) in the first 10 d of bird rearing. Moreover, phytase supplementation elevated the FCR from 21 to 35 d. In the entire experiment, an interaction between phytase and probiotic was observed only in terms of decreasing the bird FI (P=0.005) without a negative effect on the FCR (P>0.05). Furthermore, the AID of ether extract was improved by phytase supplementation. In terms of the cecal microecology, both separately administered factors promoted Lactobacillaceae in the ceca. Interactions between probiotic preparation and phytase were noted that indicated a decreased Clostridiales population and favored Ruminococcaceae proliferation. It can be concluded that for the first time in the available literature, the favorable interactions between B. licheniformis and phytase resulted in improved performance and cecal microbiota changes in broilers.

The Potential Utilization of High-Fiber Agricultural By-Products as Monogastric Animal Feed and Feed Additives: A Review

With the increase in world food demand, the output of agricultural by-products has also increased. Agricultural by-products not only contain more than 50% dietary fiber but are also rich in functional metabolites such as polyphenol (including flavonoids), that can promote animal health. The utilization of dietary fibers is closely related to their types and characteristics. Contrary to the traditional cognition that dietary fiber reduces animal growth, it can promote animal growth and maintain intestinal health, and even improve meat quality when added in moderate amounts. In addition, pre-fermenting fiber with probiotics or enzymes in a controlled environment can increase dietary fiber availability. Although the use of fiber has a positive effect on animal health, it is still necessary to pay attention to mycotoxin contamination. In summary, this report collates the fiber characteristics of agricultural by-products and their effects on animal health and evaluates the utilization value of agricultural by-products.

Dietary Application of Tannins as a Potential Mitigation Strategy for Current Challenges in Poultry Production: A Review

Simple Summary

There are diverse challenges in the poultry production industry that decrease the productivity and efficiency of poultry production, impair animal welfare, and pose issues to public health. Furthermore, the use of antibiotic growth promoters (AGP) in feed, which have been used to improve the growth performance and gut health of chickens, has been restricted in many countries. Tannins, polyphenolic compounds that precipitate proteins, are considered as alternatives for AGP in feed and provide solutions to mitigate challenges in poultry production due to their antimicrobial, antioxidant, anti-inflammatory and gut health promoting effects. However, because high dosages of tannins have antinutritional effects when fed to poultry, determining appropriate dosages of supplemental tannins is critical for their potential implementation as a solution for the challenges faced in poultry production.

Abstract

The poultry industry has an important role in producing sources of protein for the world, and the size of global poultry production continues to increase annually. However, the poultry industry is confronting diverse challenges including bacterial infection (salmonellosis), coccidiosis, oxidative stress, including that caused by heat stress, welfare issues such as food pad dermatitis (FPD) and nitrogen and greenhouse gasses emissions that cumulatively cause food safety issues, reduce the efficacy of poultry production, impair animal welfare, and induce environmental issues. Furthermore, restrictions on the use of AGP have exacerbated several of these negative effects. Tannins, polyphenolic compounds that possess a protein precipitation capacity, have been considered as antinutritional factors in the past because high dosages of tannins can decrease feed intake and negatively affect nutrient digestibility and absorption. However, tannins have been shown to have antimicrobial, antioxidant and anti-inflammatory properties, and as such, have gained interest as promising bioactive compounds to help alleviate the challenges of AGP removal in the poultry industry. In addition, the beneficial effects of tannins can be enhanced by several strategies including heat processing, combining tannins with other bioactive compounds, and encapsulation. As a result, supplementation of tannins alone or in conjunction with the above strategies could be an effective approach to decrease the need of AGP and otherwise improve poultry production efficiency.

Effect of direct-fed microbial addition in guinea fowl (Numida meleagris) diets on performance and health responses

The present study was conducted to investigate the effect of intermittent use of direct-fed microbial addition (DFM-"RE3®") on growth performance and health status of indigenous guinea fowls in northern Ghana. One-hundred and eighty day-old guinea keets were randomly assigned to 4 direct-fed microbial (DFM) treatments that included: control, daily, 3 consecutive days per wk (3CDW), and 7 days repeated every other wk (7DREOW) at 1.5 ml/L through water from day 1 to 56 days. Feed intake, body weight gain, and blood hematological and serum biochemical properties were recorded. The treatments had no effects (P > 0.05) on the hematological or serum biochemical properties recorded. Birds on DFM treatments appeared to consume less feed (range: 1,584 to 1,824 g/d) compared to the control (1,870 g/d/head). Birds on DFM treatments daily and 3CDW gained more (P < 0.05) weight (334 to 394 g/d) compared to the control (306.1 g/head) with keets on daily DFM supplementation recording the lowest (P < 0.05) feed conversion ratio. The total blood protein, globulin, lipids, albumin concentrations, and cholesterol concentrations were not affected (P > 0.05) by DFM supplementation. Supplementing birds with 1.5 mL of RE3®/liter of water daily can improve body weight. Further research on immune competence from the spleen, thymus, and bursa fibrosis for evidence of increased immune competence in probiotic administered birds is recommended.

Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production

Naturally occurring plant compounds including tannins, saponins and essential oils are extensively assessed as natural alternatives to in-feed antibiotics. Tannins are a group of polyphenolic compounds that are widely present in plant region and possess various biological activities including antimicrobial, anti-parasitic, anti-viral, antioxidant, anti-inflammatory, immunomodulation, etc. Therefore, tannins are the major research subject in developing natural alternative to in-feed antibiotics. Strong protein affinity is the well-recognized property of plant tannins, which has successfully been applied to ruminant nutrition to decrease protein degradation in the rumen, and thereby improve protein utilization and animal production efficiency. Incorporations of tannin-containing forage in ruminant diets to control animal pasture bloat, intestinal parasite and pathogenic bacteria load are another 3 important applications of tannins in ruminant animals. Tannins have traditionally been regarded as "anti-nutritional factor" for monogastric animals and poultry, but recent researches have revealed some of them, when applied in appropriate manner, improved intestinal microbial ecosystem, enhanced gut health and hence increased productive performance. The applicability of plant tannins as an alternative to in-feed antibiotics depends on many factors that contribute to the great variability in their observed efficacies.

Use of Plant Extracts as an Effective Manner to Control Clostridium perfringens Induced Necrotic Enteritis in Poultry

Necrotic enteritis (NE) is an important concern in poultry industry since it causes economic losses, increased mortality, reduction of bird welfare, and contamination of chicken products for human consumption. For decades, the use of in-feed antimicrobial growth promoters (AGPs) has been the main strategy to control intestinal pathogens including Clostridium perfringens (CP), the causative agent of NE. However, the use of AGPs in animal diet has been linked to the emergence and transmission of antimicrobial resistance through food-borne microorganisms, which has led to the ban of AGPs in many countries. This scenario has challenged the poultry industry to search for safer alternative products in order to prevent NE. In this context, the utilization of natural plant extracts with antimicrobial properties appears as a promising and feasible tool to control NE in chicken. In this paper, we review the scientific studies analyzing the potential of plant extracts as alternative feed additives to reduce NE in poultry, with focus on two types of plant products that arise as promising candidates: tannins and essential oils. Some of these products showed antimicrobial activity against CP and coccidia in vitro and in vivo and are able to increase productive performance, emulating the bioactive properties of AGPs.

Arginine and vitamin E improve the immune response after a Salmonella challenge in broiler chicks

Two experiments were conducted to evaluate the effects of Arg, vitamin E (VE), and mannanoligosaccharide (MOS) on the immune response and clearance of Salmonella in broiler chickens. In each experiment, 1-d-old chicks (n = 160) were randomly distributed into 4 groups: antibiotic-free diet (negative control, CTL-), antibiotic-supplemented diet (positive control, CTL+), antibiotic free-diet plus Arg and VE (AVE), or antibiotic-free diet plus Arg, VE, and MOS (AVM). Birds were orally challenged with 10(6) cfu of a novobiocyn and nalidixic acid-resistant Salmonella enterica serovar Typhimurium strain at d 7 (experiment 1) or at d 3 (experiment 2). Heterophil- (HOB) and monocyte- (MOB) oxidative burst and lymphocyte proliferation (LPR), antibody titers, and Salmonella content in the ceca were measured at several intervals postinfection (PI). In experiment 1, both AVM and AVE decreased HOB compared with the controls 5 and 9 d PI, but increased LPR 9 d PI. In the same experiment, birds fed the AVE diet had higher MOB than birds fed CTL+ or the AVM diet at 7 d PI, whereas 9 d PI birds fed the AVM diet had the highest MOB. In experiment 2, birds fed the AVE diet had higher MOB, HOB, and LPR than birds in the other treatments 7 and 14 d PI, except at 7 d PI, when MOB was not different among treatments. Birds fed the AVM diet had the highest IgA antibody titer, and a higher IgM antibody titer than the CTL+ birds. In experiment 1, Salmonella Typhimurium content in the ceca was lower in birds fed the AVM diet compared with birds fed the CTL- diet 3 d PI, but later on (10 and 17 d PI), and in experiment 2 (7, 14, and 21 d PI), Salmonella Typhimurium concentrations were not different among treatments. Thus, Arg and VE improved immune response after a Salmonella Typhimurium challenge in young chicks, and although they did not reduce Salmonella Typhimurium concentrations in the ceca, they may improve bacterial resistance against other pathogens in commercial growing conditions.

Use of plant-derived antimicrobials for improving the safety of poultry products

Salmonella Enteritidis and Campylobacter jejuni are the 2 major foodborne pathogens transmitted through poultry products. Chickens are the reservoir hosts of these pathogens, with their intestinal colonization being the most significant factor causing contamination of meat and eggs. Effective preslaughter strategies for reducing the colonization of birds with these pathogens are critical to improve the microbiological safety of poultry products. An antimicrobial treatment that can be applied through feed represents the most practical and economically viable method for adoption on farms. Additionally, a natural and safe antimicrobial will be better accepted by producers without concerns for toxicity. This symposium talk discussed the potential use of plant-derived, GRAS (generally recognized as safe)-status molecules, caprylic acid, trans-cinnamaldehyde, eugenol, carvacrol, and thymol as feed supplements for reducing cecal populations of Salmonella Enteritidis and C. jejuni in chickens. Additionally, the effect of plant molecules on Salmonella virulence genes critical for cecal colonization in chickens was also discussed.

Quantification of Enterobacteriaceae in faeces of captive black rhinoceros (Diceros bicornis) in relation to dietary tannin supplementation

Free-ranging browsing herbivores ingest a range of secondary plant compounds, such as tannins, with their natural diet. As many of these substances have been shown to have antibacterial properties, it could be speculated that a lack of such compounds in captive zoo diets could favour the growth of potentially pathogenic intestinal bacteria. The effect of a supplementation of a conventional diet (N, consisting mainly of grass hay and/or lucerne hay and pelleted compound feeds) fed to eight captive black rhinoceroses (Diceros bicornis) from three zoological institutions with either tannic acid (T), a source of hydrolysable tannins, or quebracho (Q), a source of condensed tannins, was investigated. The number of faecal colony forming units (CFU) of Enterobactericeae was determined by colony count of dilution series from fresh faeces applied to MacConkey agar plates. Tannins were added to the diets at approximately 5-15 g/kg dry matter, depending on the varying intake of roughage and compound feeds by the animals. There was no difference in the number of CFU between diets N (95.0 x 10(5) +/- 225.3 x 10(5)/g fresh faeces) and T (164.3 x 10(5) +/- 225.1 x 10(5)/g fresh faeces); in contrast, diet Q led to a significant reduction in CFU (4.3 x 10(5) +/- 6.5 x 10(5)/g fresh faeces) compared with the other diets. These findings suggest that condensed tannins could have the potential to reduce the number of potentially pathogenic intestinal bacteria, and that the deliberate inclusion of tannin sources in the diets of captive wild animals should be further investigated. The fact that tannic acid, shown to have antibacterial effects in various in vitro studies, did not have an effect in this study, emphasizes that the relevance of tannin supplementation for intestinal health must be verified in vivo.

Probiotic alternatives to reduce gastrointestinal infections: the poultry experience

The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.