Effect of organic acids on growth performance, intestinal morphology, and immunity of broiler chickens with and without coccidial challenge

Response of different infection models in broiler chickens against supplemental Organic acid - A review

Antimicrobial resistance in microorganisms has emerged as a significant issue in the domain of animal husbandry, leading to the prohibition of sub-therapeutic antibiotics in feed and necessitating the exploration of alternative growth promoters. Organic acids have garnered considerable attention as prospective substitutes, proffering analogous advantages to antibiotics without exacerbating resistance. Nonetheless, their effectiveness against a spectrum of pathogenic infections remains ambiguous. Consequently, this review scrutinizes the efficacy of organic acids in experimental infection models, encompassing necrotic enteritis (Clostridium perfringens), coccidiosis (Eimeria spp.), Pullorum disease (Salmonella spp.), Campylobacteriosis (Campylobacter jejuni), and Colibacillosis (Escherichia coli). The analysis indicates that organic acids exhibit promising outcomes across various infection models. For instance, in trials concerning necrotic enteritis, organic acid supplementation diminished C. perfringens colonization and enhanced intestinal health. Likewise, in investigations of coccidiosis, organic acids alleviated Eimeria-induced damage and improved growth performance. In the context of infections caused by Salmonella and E. coli, these additives displayed considerable antimicrobial efficacy, leading to diminished pathogen loads and an improvement in various indicators of animal health. The review also delineates several proposed mechanisms through which organic acids exert their effects against these pathogens, encompassing direct antimicrobial actions, modulation of gastrointestinal pH, and the augmentation of the host's immune response. These findings imply that organic acids may represent feasible alternatives to antibiotics within animal feed, potentially addressing the concurrent challenges associated with growth promotion and pathogen management. Nonetheless, additional research is imperative to refine dosages, combinations, and delivery methodologies for optimal effectiveness across diverse species and production systems. This thorough evaluation offers significant insights into the formulation of effective, antibiotic-free approaches in animal nutrition and health management.

Responses of Broiler Chickens to Diets of Different Nutritional Planes Supplemented With or Without Organic Acids

BACKGROUND

Scientific information on the diets of various nutritional planes supplemented with organic acids is scarce in tropical environments.

OBJECTIVES

This study was conducted to evaluate the response of broilers to diets of different nutritional planes supplemented with or without organic acids. A total of 240 one-day-old unsexed broiler chicks of the Cobb 500 strain were randomly assigned to 6 treatments, each with 4 replicates having 10 chicks.

METHODS

The treatments were chickens fed an optimal diet (optimal energy and protein) (Diet 1), a medium diet (medium energy and protein) (Diet 2) and a low diet (low energy and protein) (Diet 3), while diets 4, 5 and 6 were diets 1, 2 and 3 supplemented with 4, 6 and 8 g/kg organic acid (Fysal-MP), respectively. The study was laid out in a completely randomized design.

RESULTS

The birds fed diets with organic acid supplementation recorded similar (p > 0.05) final weights compared to those fed an optimal diet (T1); however, the weights were higher (p < 0.05) compared to the chickens on a low diet without organic acid (T3). The feed conversion ratio was better in birds fed diets containing organic acid, irrespective of the nutritional plane. Birds on medium diets with organic acids recorded a higher (p < 0.05) aspartate aminotransferase compared to those on low diets during the starter phase. Birds on a low diet without organic acid recorded a lower (p < 0.05) basal width compared to those on other diets. The microbial counts were reduced (p < 0.05) in broilers fed organic acids, with the lowest reduction in the group fed medium diets with 6 g/kg organic acids.

CONCLUSIONS

It was concluded that organic acid supplementation enhanced blood parameters, carcass traits, growth performance and microbial counts in broiler chickens.

Effects of water acidifiers on the growth performance, intestinal function and gut microflora in broilers

1. This study evaluated the effect of acidified drinking water on the gastrointestinal function and intestinal health of broilers.2. A total of 630 one-day-old male broilers (Arbor Acre) were randomly assigned to one of three treatment groups: drinking water treatment (CON), drinking water + 0.5 ml Selko pH®/L (Selko pH), or + 0.85 ml Forticoat®/L (Forticoat) treated groups. Performance data, gut and digesta samples were collected from the broilers at the age of 21 and 42 d.3. The results showed that acidifying drinking water had no significant effect on body weight or average daily gain (ADG). However, addition of Forticoat significantly increased (p < 0.05) feed conversion ratio (FCR) throughout the experimental period and significantly increased (p < 0.05) pepsin activity on d 21. The Selko pH supplemented drinking water significantly increased (p < 0.05) the relative length of the duodenum and jejunum on d 21. The relative length of the jejunum and caecum on d 42 compared to birds receiving CON. The addition of the Forticoat to drinking water significantly increased (p < 0.05) the relative length of the jejunum and caecum on d 42 than for samples from birds in the CON group. In the caecal chyme, abundance of Blautia, Bifidobasterium, Faecalibacterium, Limosilactobacillus and Akkermania spp. on d 21 were significantly higher (p < 0.05) in the caecum of birds receiving Selko pH than those in CON group and the number of Escherichia Shigella in Selko pH and Forticoat group were significantly lower (p < 0.05).4. Overall, adding Seiko pH and Forticoat to drinking water improved pepsin activity, reduced the number of caecal pathogens, increased the number of beneficial bacteria and improved intestinal health in broilers.

The Characterization of Lactic Acid Bacteria Strains as Components of a Biopreparation for Chickens for Slaughter

Since 2022, the European Union has banned the use of antibiotics in animal production. We conducted studies to characterize Lactiplantibacillus plantarum (47, AN8, and OK-B) and Ligilactobacillus salivarius (AN9) and evaluate their potential to create a biopreparation based on fermented whey for chickens. The following methods were used: lactic acid bacteria (LAB) culture and storage, crystal violet staining, Koch's plate method, Caco-2 cell culture, hydrophobicity test, and spectrophotometric measurements. All bacteria showed weak adhesion to polystyrene and collagen, and the L. plantarum species demonstrated weak adhesion to mucus. All bacteria showed strong adhesion to the intestinal epithelial cell line Caco-2. LAB showed strong autoaggregation and coaggregation with E. coli ATCC10536. The highest affinity for xylene was exhibited by L. salivarius AN9 (above 30%) while, for chloroform, the highest affinity was exhibited by L. plantarum OK-B (approx. 95%); the affinity for n-hexadecane for all strains was below 20%. The highest survival in the presence of bile salts (0.3%) was demonstrated by L. plantarum 47 (above 54%). The effect of low pH resulted in decreased viability for all strains. Significant differences were demonstrated in the concentration of lactic acid between MRS and whey medium after culturing LAB. These results will aid in qualifying these strains for further research to create a functional feed for chickens.

Effects of organic acid blends on the growth performance, intestinal morphology, microbiota, and serum lipid parameters of broiler chickens

Organic acids have emerged as promising alternatives to antibiotic growth promoters in poultry production. The present study was conducted to determine the effects of organic acids blends v.i.z. Acidapure liquid and Acidapure powder supplementation on the growth performance, gut health, gut microbiota, and serum lipid profile of broiler chickens. A total of 120-day-old chicks with similar live body weights were randomly divided into four groups. Each group was further divided into 3 replicates, and each further divided into three replicates of ten bird. The birds in Group 1 (T1) were fed a basal diet supplemented with plain drinking water, those in Group 2 (T2) received basal feed supplemented with Acidapure powder (1 kg/MT feed) and plain drinking water, those in Group 3 (T3) received basal feed supplemented with Acidapure liquid in the drinking water (0.2 ml/l water), and those in Group 4 (T4) received basal feed supplemented with Acidapure powder (1 kg/MT feed) and Acidapure liquid in the drinking water (0.2 ml/l water). Acidapure powder and Acidapure liquid were added to the feed and water of the broilers from 0-42 days of life. The results showed that compared with the control (T1), supplementation with Acidapure powder and liquid in broiler chickens for 42 days increased (P < 0.05) ABW and ADG and reduced FCR in the treatment groups (T2, T3 and T4). At d 21 and 42, all forms of Acidapure supplement increased the VH and CD in the jejunum and ileum and reduced the pH of the ileum. Compared with the control (T1), the combination of Acidapure powder and liquid (T4) increased the gene expression of the tight junction proteins Claudin-1 and Zona Occludense 1 (ZO-1). Compared with the control, Acidapure supplementation reduced the cecal coliform count and total viable count (TVC) and decreased the serum cholesterol and triglyceride levels. In conclusion, Acidapure, as a blend of organic acids, effectively enhances the growth performance and gut health of broilers, making it a viable and safe alternative to traditional antimicrobial growth promoters.

Effect of Dietary Benzoic Acid and Oregano Essential Oil as a Substitute for an Anti-Coccidial Agent on Growth Performance and Physiological and Immunological Responses in Broiler Chickens Challenged with Eimeria Species

To overcome the antimicrobial residues in food, benzoic acid (BA) and oregano essential oil (OEO) are used in the broiler chicken industry. Independently, both exerted anticoccidial and antimicrobial actions and improved growth performance in broiler chickens. Their effect may be multiplied when they are used in combination. This present study was carried out to evaluate the efficacy of dietary BA and OEO alone or in combination as a substitute for a commercial coccidiostatic drug on growth performance and physiological and immunological responses in broiler chickens challenged with Eimeria species. A total of 252 unsexed 1-day-old broiler chicks were equally allotted to 36 pens, each pen containing seven chicks. The pens were randomly assigned to six treatments with six pens (replicates) for each treatment (n = 6)-(i) negative control, (ii) positive control, coccidia-challenged and non-treated, (iii) supplemented with salinomycin (an anti-coccidial drug) at 60 mg/kg of feed and coccidia-challenged, (iv) supplemented with BA at 500 mg/kg of feed and coccidia-challenged, (v) supplemented with OEOat 500 mg/kg of feed and coccidia-challenged (OEO), and (vi) supplemented with BA at 500 mg/kg of feed and OEO at 500 mg/kg of feed and coccidia-challenged (B&O). The liver enzymes and thyroxine and creatinine levels were not affected (p > 0.05) both in coccidia-challenged and supplemented chickens. The BA and OEO applied separately or in combination (B&O) significantly (p < 0.05) reduced gut pathogenic bacteria (Salmonella and Escherichia coli) and Eimeria spp., and concurrently enhanced (p > 0.05) the Lactobacillus population with better body weight gain, improved feed utilization, and superior hematological values. It also up-regulated (p > 0.05) the interferon-γ gene expression and down-regulated (p < 0.05) the interleukin-10 and Toll-like receptor-4 gene expression to protect the chickens from inflammatory reactions, which were not demonstrated in salinomycin-treated birds. The B&O supplementation increased (p < 0.05) the immune system by enhancing Eimeria-specific immunoglobulin Y titer and lymphocyte proliferation response. This study suggests that the combined application of OEO and BA can substitute for a commercial anti-coccidial agent (salinomycin) in controlling coccidiosis as well as improving growth performance, gut health, and immune responses in broiler chickens with a means of antimicrobial-resistant free food products.

Advanced chelate technology-based trace minerals reduce inflammation and oxidative stress in Eimeria-infected broilers by modulating NF-kB and Nrf2 pathways

This study investigated the effects of substituting inorganic trace minerals (ITM) with advanced chelate technology-based TM (ACTM) in broiler chicken feed on productive performance, metabolic profile, humoral immunity, antioxidant status, and modulation of NF-kB and Nrf2 signaling pathways in mixed Eimeria species exposure. The study involved 480 newly hatched male broiler chickens, which were divided into 5 treatment groups, each with 6 replicate cages and 16 chickens per replicate. The experimental treatments included an uninfected negative control group fed a basal diet with recommended inorganic TM levels (NC), an infected positive control group fed the same diet (PC), a PC group supplemented with salinomycin (SAL), and two PC groups in which the basal diet was replaced with 50% and 100% ACTM instead of inorganic TM (ACTM50 and ACTM100, respectively). All groups, except for the NC group, were orally challenged with mixed Eimeria species oocysts on day 14. According to the results, the PC group showed lower feed intake, breast yield, low-density lipoprotein-cholesterol concentration, lactobacillus spp. counts, and serum IgG levels, but higher jejunal TGF-β expression versus the NC group. The broilers in the NC, SAL, and ACTM100 groups showed higher body weight gain, carcass yield, and TGF-β expression, but lower serum alkaline phosphatase activity, ileal E. coli count, and jejunal expression levels of IL-1β, IL-6, IFN-γ, Nrf2, and SOD1 compared to the PC group, with the NC group having the highest body weight gain and lowest IL-1β and Nrf2 expression levels. Furthermore, the administration of ACTM100 treatment improved feed efficiency, increased serum iron, zinc, manganese, and copper levels, enhanced total antioxidant capacity and different antioxidant enzyme activities, and reduced malondialdehyde concentration. In conclusion, complete replacement of ITM with ACTM effectively protects broilers from Eimeria infection, with similar positive effects to SAL treatment in terms of productive performance and anti-inflammatory responses and better antioxidant responses and mineral availability.

Potential benefits of advanced chelate-based trace minerals in improving bone mineralization, antioxidant status, immunity, and gene expression modulation in heat-stressed broilers

Organic sources of trace minerals (TM) in broiler diets are more bioavailable and stable than inorganic sources, making them particularly beneficial during challenging periods such as heat stress (HS) conditions. A 42-d study investigated the effects of using advanced chelate technology-based TM (ACTM) or adding varying amounts of ACTM to broiler diets during HS conditions. The study involved 672 male broiler chickens in 7 treatment groups, including a thermoneutral control (TNC) group and six HS treatments. There were 8 replicate pens per treatment and 12 birds per replicate. The six HS treatments included birds exposed to a cyclic HS environment (34°C) for 8 h and were as follows: HSC, which consisted of the same basal diet with the recommended ITM levels; ACTM50 and ACTM100, which replaced the basal diet with 50% and 100% ACTM instead of ITM; ITM+ACTM12.5 and ITM+ACTM25, which involved adding extra ACTM to the ITM basal diet at 12.5% and 25%, respectively; and ITM125, which used 125% of the recommended levels of ITM in the basal diet. Compared with the HSC treatment, the TNC, ACTM100, and ITM+ACTM25 treatments resulted in increased (P < 0.05) body weight; tibia weight; tibia ash, phosphorus, iron, and manganese contents; secondary antibody titers; and serum TAC and SOD values but decreased (P < 0.05) serum MDA concentrations and the expression levels of the hepatic genes IL-1β, IL-6, and INF-γ. The TNC and ACTM100 groups also showed greater (P < 0.05) feed efficiency, tibia length, tibia zinc content, and hepatic SOD1 expression but exhibited reduced (P < 0.05) hepatic NF-kB expression. Significant increases (P < 0.05) in primary anti-NDV titers, serum GPx1 activity, and Nrf2 and GPx1 gene expression levels were also detected in the ACTM100, ITM+ACTM12.5, and ITM+ACTM25 groups. In conclusion, the findings suggest that replacing ITM with ACTM or adding ACTM to ITM diets, especially at a 25% higher dose, can effectively protect broilers from heat stress by promoting growth, reducing inflammation, and increasing the expression of antioxidant proteins.

Investigation of Potential Gut Health Biomarkers in Broiler Chicks Challenged by Campylobacter jejuni and Submitted to a Continuous Water Disinfection Program

The exploration of novel biomarkers to assess poultry health is of paramount importance, not only to enhance our understanding of the pathogenicity of zoonotic agents but also to evaluate the efficacy of novel treatments as alternatives to antibiotics. The present study aimed to investigate potential gut health biomarkers in broiler chicks challenged by Campylobacter jejuni and subjected to a continuous water disinfection program. A total of 144 one-day-old hatched broiler chicks were randomly allocated to four treatment groups with four replicates each, according to the following experimental design: Group A received untreated drinking water; Group B received drinking water treated with 0.01-0.05% v/v Cid 2000™ (hydrogen peroxide, acetic acid and paracetic acid); Group C was challenged by C. jejuni and received untreated drinking water; and Group D was challenged by C. jejuni and received drinking water treated with 0.01-0.05% v/v Cid 2000™. The use of Cid 2000™ started on day 1 and was applied in intervals until the end of the experiment at 36 days, while the C. jejuni challenge was applied on day 18. Potential biomarkers were investigated in serum, feces, intestinal tissue, intestinal content, and liver samples of broilers. Statistical analysis revealed significant increases (p < 0.001) in serum cortisol levels in C. jejuni-challenged broilers. Serum fluorescein isothiocyanate dextran (FITC-d) increased significantly (p = 0.004) in broilers challenged by C. jejuni and treated with drinking water disinfectant, while fecal ovotransferrin concentration also increased significantly (p < 0.001) in broilers that received the drinking water disinfectant alone. The gene expression levels of occludin (p = 0.003) and mucin-2 (p < 0.001) were significantly upregulated in broilers challenged by C. jejuni, while mucin-2 significantly increased in birds that were challenged and received the drinking water disinfectant (p < 0.001). TLR-4 expression levels were significantly (p = 0.013) decreased in both groups that received the drinking water disinfectant, compared to the negative control group. Finally, the C. jejuni challenge significantly increased (p = 0.032) the crypt depth and decreased (p = 0.021) the villus height-to-crypt-depth ratio in the ileum of birds, while the tested disinfectant product increased (p = 0.033) the villus height in the jejunum of birds. Furthermore, the counts of C. jejuni in the ceca of birds (p = 0.01), as well as its translocation rate to the liver of broilers (p = 0.001), were significantly reduced by the addition of the water disinfectant. This research contributes to novel insights into the intricate interplay of water disinfection and/or C. jejuni challenge with potential intestinal biomarkers. In addition, it emphasizes the need for continued research to unveil the underlying mechanisms, expands our understanding of broiler responses to these challenges and identifies breakpoints for further investigations.

Epidemiological Survey on Post Mortem Coccidiosis in Broiler Chicken in Bejaia Province, Northern Algeria

AIM

The epidemiological survey was carried out to determine the prevalence of eimeriosis in broiler chickens slaughtered depending the season, to determine the different Eimeria species causing the coccidiosis in poultry farms; and to assess the impact of Eimeria parasite on histomorphological structure and oxidative stress parameters of the intestine.

MATERIALS AND METHODS

The study was conducted from December 2018 to December 2019 in the province of Bejaia, Algeria. The intestines chickens (n = 366) were obtained immediately after slaughter, each cut into different segments (duodenum, jejunum, ileum, and caecum). Microscopic and parasitological examinations were performed according to standard procedures. Histomorphometric measurements of intestine were obtained using Image J software. Oxidative stress parameters were carried out from intestine tissue.

RESULTS

Eimeria spp. were detected in 73.77% (95% CI 71.20-76.34) of broiler gut samples. The prevalence varied significantly according to the season, with the lowest rates in winter (42.81%, 95% CI 40.35-45.27) and the highest in autumn (97.92%, 95% CI 97.6-99.4). All seven Eimeria species were identified, most commonly E. necatrix (27.70%), E. brunetti (26.47%), and E. tenella (20.96%). The mean lesion score ranged from 1.51 ± 0.05 to 1.79 ± 0.04. Significant differences in VH/CD ratio of intestinal epithelium (P < 0.001) were observed in different intestinal portions of infested broiler chickens compared to non-infested. The mean MDA concentration of intestinal segments was significantly higher in Eimeria species infested broilers compared to non-infested (P < 0.05). The results show at least one difference in CAT, SOD, and ABTS-+ concentrations (P < 0.05) in both chicken's groups.

CONCLUSION

Our results revealed that coccidiosis is extremely prevalent in slaughtered broilers, with an abundance of pathogenic Eimeria species. Also, it was concluded that infestation induces tissue structure alterations which coincides with the oxidative damage.

Butyric acid and prospects for creation of new medicines based on its derivatives: a literature review

The widespread use of antimicrobials causes antibiotic resistance in bacteria. The use of butyric acid and its derivatives is an alternative tactic. This review summarizes the literature on the role of butyric acid in the body and provides further prospects for the clinical use of its derivatives and delivery methods to the animal body. Thus far, there is evidence confirming the vital role of butyric acid in the body and the effectiveness of its derivatives when used as animal medicines and growth stimulants. Butyric acid salts stimulate immunomodulatory activity by reducing microbial colonization of the intestine and suppressing inflammation. Extraintestinal effects occur against the background of hemoglobinopathy, hypercholesterolemia, insulin resistance, and cerebral ischemia. Butyric acid derivatives inhibit histone deacetylase. Aberrant histone deacetylase activity is associated with the development of certain types of cancer in humans. Feed additives containing butyric acid salts or tributyrin are used widely in animal husbandry. They improve the functional status of the intestine and accelerate animal growth and development. On the other hand, high concentrations of butyric acid stimulate the apoptosis of epithelial cells and disrupt the intestinal barrier function. This review highlights the biological activity and the mechanism of action of butyric acid, its salts, and esters, revealing their role in the treatment of various animal and human diseases. This paper also discussed the possibility of using butyric acid and its derivatives as surface modifiers of enterosorbents to obtain new drugs with bifunctional action.

Modulation of Performance, Plasma Constituents, Small Intestinal Morphology, and Cecum Microbiota in Growing Geese by Dietary Citric Acid Supplementation

To investigate the efficiency and optimum inclusion level of CA in growing geese diets on performance, plasma constituents, and intestinal health, 240 healthy female geese at the age of 28d were randomly allotted six treatment diets incorporated with 0, 0.8, 1.6, 2.4, 3.2, and 4% CA. Each treatment group consisted of five replicates and eight birds per replicate. The findings demonstrated that 3.2% CA supplementation resulted in improved growth performance (ADG, ADFI, and FBW) (p = 0.001), and geese who received CA also showed lower body fat contents (p < 0.05) than the control group. Moreover, geese from the 2.4% and 3.2% CA group had the highest plasma glutathione peroxidase and insulin-like growth factor 1 levels compared to the other groups (p < 0.05). A microbial diversity analysis of the cecum conducted by 16S rDNA sequencing revealed that 3.2% CA supplementation showed a significantly higher abundance of beneficial bacteria (Muribaculaceae, CHKCI001, Erysipelotricha-ceae_UCG_003, and UCG_009) (p < 0.05) and a lower abundance of harmful bacteria (Atopobiaceae, Streptococcus, Acinetobacter, Pseudomonas, and Alistipes) (p < 0.10). Collectively, our results revealed that dietary supplementation with 3.2% CA had several benefits on the performance and physiological health of growing geese by promoting nutrients metabolism, improving antioxidant capacity, and modulating cecum microbiota.

Impacts of Eimeria coinfection on growth performance, intestinal health and immune responses of broiler chickens

Coccidiosis caused by Eimeria is one of the most severe chicken diseases and imposes huge economic losses to the poultry industry globally. Multi-Eimeria species coinfections are common with the most prevalent combination being mixtures of Eimeria acervulina and Eimeria tenella. Although detrimental impacts of either E. acervulina or E. tenella on chicken health are well recognized, no information is available regarding their coinfection effects so far. This study was designed to investigate the influence of coinfection with E. acervulina and E. tenella on broiler chickens. 144 one-day-old broiler chickens within each of trials (trial I or II) were divided into four groups, namely, control group (CG), E. acervulina infection group (EAIG), E. tenella infection group (ETIG) and dual (E. acervulina and E. tenella) infection group (DIG). Then, chickens were measured for weight loss, lesion scores, oocyst outputs, histological changes and expressions of pro-inflammatory (interleukin [IL]-6, IL-8 and IL-18), regulatory (IL-10 and IL-22) cytokines and Toll-like receptors (TLR; TLR2 and TLR4) as well as intestinal barrier (mucin 2 [MUC2] and fattey acid-bingding proteins 2 and 6 [FABP2 and FABP6])- and tight junction (TJ; zonula occluden-1 [ZO-1], occludin [OCLN], and claudins 1 and 5 [CLDN1 and CLDN5])-related proteins at 3, 5, 7, 10, 14 and 21 days post-infection, respectively. Our results consistently showed that although ETIG and DIG exhibited a higher level of weight loss and a more amount of oocyst excretion than EAIG, DIG had lighter lesions than EAIG in the early phase because of coinfection with E. tenella. A higher (P < 0.05) ratio of duodenal villous height to crypt depth was also observed in DIG than EAIG. Moreover, histological changes in the duodenum and cecum varied by single and dual Eimeria infections. Expressions of the intestinal barrier- and TJ-related genes of EAIG, ETIG and DIG were significantly (P < 0.05) upregulated but their levels exhibited differential changes among infected chickens. Similarly, the infected chickens showed significant (P < 0.05) inflammatory responses and higher (P < 0.05) expressions of TLRs in the intestines in comparison to CG. These results presented a comprehensive physiological, pathological and immunological characterization of E. acervulina and E. tenella coinfection in broiler chickens and also shed insights into pathogenesis of multi-coccidia coinfections.

Mass spectrometry-based metabolic profiling for identification of biomarkers related to footpad dermatitis in ducks

1. A new assessment method for duck footpad dermatitis (FPD) evaluation was developed, combining visual and histological characters using the images and sections of 400 ducks' feet at 340 d of age. All ducks were graded as G0 (healthy), G1 (mild), G2 (moderate) and G3 (severe) according to the degree of FPD.2. To reveal the potential biomarkers in serum related to duck FPD, non-targeted metabolomics and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used to explore differential metabolites in each group.3. There were 57, 91 and 210 annotated differential metabolites in groups G1, G2 and G3 compared with G0, which meant that the severity of FPD increased in line with the number of metabolites. Four metabolites, L-phenylalanine, L-arginine, L-leucine and L-lysine, were considered potential biomarkers related to FPD.4. KEGG enrichment analysis showed that the FPD was mainly involved in glycolysis, the tricarboxylic acid (TCA) cycle, the pentose phosphate pathway and amino acid metabolism. These are related to production metabolism and can affect the physiological activities of ducks, which might explain the decrease in production performance.

Applying different morphometric intestinal mucosa methods and the correlation with broilers performance under Eimeria challenge

The intestinal wall has on its surface, protrusions called villi that are responsible for the absorption of nutrients. Commonly, these structures have their dimensions measured to related more area surface with better absorption. However, the measurement of these villi neglects the inflammation and the presence of immature cells that increase the surface area but affect negatively the absorption and compromise the animal performance. The measurements of villi/crypt are traditional tools in animal research; however, they may overlook alterations that impact the mucosal functionality. This study aimed to compare the morphometry of the intestinal villi/crypt with the I See Inside (ISI) scoring methodology, exploring their correlation with zootechnical performance. Therefore, broilers were grouped as nonchallenged (NC) and challenged with Eimeria (CH) and jejunum samples were collected at 22 d for histological analysis. The same villi were submitted to the ISI methodology, which is based on the scoring of 8 parameters related to the inflammatory process, and the measurements of villus height (VH), villus width (VW), crypt depth (CD), crypt width (CW), VH:CD ratio and villi absorptive surface (VAS). The CH group presented higher ISI total score, VW, CD, CW and lower VH, VH:CD, and VAS in comparison to the NC group. While the villi/crypt morphometry did not exhibit correlations with performance, the presence of Eimeria oocysts and the ISI total score was positively correlated (P < 0.05) with the feed conversion ratio (FCR), demonstrating a statistical interaction between high ISI scores and worse performance. In conclusion, a larger villus is not related to better intestinal functionality when this enlargement is unleashed by the immune processes occurring inside. The scoring system that evaluates the type of alteration observed has a direct impact on the animal's zootechnical performance which is not observed with the single metric surface evaluation.

Effects of green tea phytosome on growth performance and intestinal integrity under coccidiosis infection challenge in broilers

This research examined the effects of feeding phytosomal green tea on broilers infected with coccidia. To provide phytosome, green tea extract was loaded into soy lecithin. Groups of chicks included uninfected and untreated control (NC), infected and untreated control (PC), infected and treated with salinomycin control (SC), infected and treated with 300 and 400 mL of green tea extract (GTE300, GTE400), infected and treated with 200, 300, 400 and 500 mL of green tea phytosome (GTP200, GTP300, GTP400, and GTP500). At 14-days posthatch, chickens were orally gavaged, except the NC group with a coccidia vaccine 30 times larger than the approved dose. Body weight (BW), feed intake (FI), and feed conversion ratio (FCR) were determined at 7, 14, 20, 28, 35, and 42 d. The characteristics of the carcass, internal organs and intestinal morphology were assessed on d 42. Applying overdose of coccidiosis vaccine showed experimental Eimeria infection, led to decrease in FI and BW, and increased FCR compared to PC group (P < 0.001). Meanwhile salinomycin, green tea extract, and green tea phytosome compensated the negative effects of Eimeria infection on growth performance. The treatments did not affect carcass, breast, and thigh relative weights. Interestingly, abdominal fat percent was significantly lower in chickens fed GTP300, GTP400, and GTP500 than in those fed GTE300, GTE300, and GTP200 (P < 0.0001). In comparison to the basal diet plus green tea extract forms and NC groups, the PC group increased the relative weights of the liver, spleen, bursa, and pancreas (P < 0.05). The highest values of villus height and villus height to crypt ratio were obtained in duodenum, jejunum and ileum in GTP300 group (P < 0.0001), while, villi diameter in duodenum and ileum decreased the most in GTP300 and GTP500, respectively (P < 0.0001). Consequently, as natural anticoccidial drug delivery systems, 300 mL of green tea phytosome can be introduced as the optimal dose to maximize the benefits of phytosome for intestinal integrity and reduce the consumption of green tea extract.

A meta-analysis of the effect of Eimeria spp. and/or Clostridium perfringens infection on the microbiota of broiler chickens

Coccidiosis in chickens is caused by Eimeria spp. The infection provides a growth advantage to Clostridium perfringens (CP), frequently leading to necrotic enteritis. One approach to alleviate the negative impacts of the diseases is to improve the bacterial composition in chickens, and many experiments investigating chicken enteric health in recent years include the characterization of the bacterial microbiota. This meta-analysis synthesized the data of studies investigating the intestinal microbiota after infection with coccidia and/or CP to provide a basis for future research. Inclusion criteria were that experiments contained a group infected with one or both pathogens and an uninfected control group, the use of 16SrRNA Illumina sequencing and the availability of raw data. A total of 17 studies could be included. Meta-analyses of 3 different data sets were performed: 1 on data of 9 experiments on chickens infected with coccidia only; the second on data of 4 studies on chickens infected with CP only; the third on raw data of 8 experiments with chickens infected with coccidia and CP. The meta-analysis of relative abundance and alpha diversity of the data sets was performed in R using the SIAMCAT and metafor packages. The number of families of interest identified by the analyses of experiments with infection with coccidia only, CP only and the combined infection were 23, 2, and 29, respectively. There was an overlap of 13 families identified by analyses of experiments with infection with coccidia only and of experiments with the combined infections. Machine learning was not able to find a model to predict changes of the microbiota in either 1 of the 3 analyses. Meta-analyses of functional profiles showed a more uniform reaction to the infections with the relative abundance of many pathways significantly altered. Alpha diversity was not affected by infection with either pathogen or the combination. In conclusion, the heterogeneity of these microbiota studies makes recognizing common trends difficult, although it seems that coccidia infection affects the microbiota more than an infection with CP. Future studies should focus on the bacterial functions that are changed due to these infections using metagenome techniques.

Evaluation of Liquid Organic Acids on the Performance, Chyme pH, Nutrient Utilization, and Gut Microbiota in Broilers under High Stocking Density

This study aimed to evaluate the efficacy of organic acids (OAs) in starter broilers and to investigate whether supplemental OAs could alleviate the high stocking density (HSD) stress condition in grower broilers. A total of 408 1-day-old Arbor Acres broilers were assigned into two groups without or with liquid OAs in the starter phase. In the grower phase, each group in the starter phase was divided into a normal stocking density and an HSD. The OA dose was 0.16% at the starter and grower phases. The results showed that at the starter phase, OAs decreased the chyme pH in gizzard and duodenum and increased the activities of chymotrypsin and α-amylase in the duodenal chyme (p < 0.05). In the grower phase, an HSD decreased the growth performance and the ether extract digestibility (p < 0.01). The supplementation of OAs decreased the chyme pH in the gizzard, proventriculus, and duodenum and increased the lipase and α-amylase activities (p < 0.05). The supplemental OAs increased the dry matter and total phosphorous digestibility and the contents of acetic acids, butyric acids, isovaleric acids, and valeric acids (p < 0.05). For cecal microbial compositions at the genus level, an HSD decreased the relative abundance of Blautia, Norank_f__norank_o__RF39, and Alistipes, while supplemental OAs increased the relative abundance of Norank_f__norank_o__RF39 (p < 0.05). In conclusion, although there were no interaction effects between OAs and stocking densities in the present study, it was clear that the supplementation of OAs has beneficial effects on the chyme pH, enzymes activities, and nutrient digestibility in broilers, while an HSD existed adverse effects on the growth performance, nutrient digestibility, and gut microbiota balance in grower broilers.

Effect of benzoic acid, Enterococcus faecium, and essential oil complex on intestinal microbiota of laying hens under coccidia and Clostridium perfringens challenge

The objective of this study was to investigate whether dietary supplementation with benzoic acid, Enterococcus faecium, and essential oil complex (BEC) could help laying hens recover from coccidia and Clostridium perfringens type A challenge. A total of 60 (35-wk-old) Lohmann-laying hens were randomly assigned to 3 experimental groups (10 replicates with 2 hens per replicate): I) control group (CON), II) challenge group (CC), and III) BEC group (2,000 mg/kg BEC). The total experimental period was 8 wk. The results shown that the challenge layers had lower egg-laying rate and average daily feed intake (ADFI) (P < 0.05), and addition of BEC after challenge increased egg-laying rate (P < 0.05). The content of propionic acid (PA) and butyric acid (BA) in short-chain fatty acid (SCFA) was significantly decreased by challenge (P < 0.05). CC and BEC groups had lower villus height to crypt depth ratio (V/C) and higher pathological scores in duodenum (P < 0.05), whereas the BEC group had lower pathological scores in jejunum when compared with the CC group (P < 0.05). The challenge increased the concentration of proinflammatory cytokines (IL-1β and IL-6) (P < 0.05). An increase in the abundance of Bacteroidoes (genus), Bacteroidaceae (family), Bacteroidoes sp. Marseille P3166 (species), Bacteroidoes caecicola (species) was observed in the CC group, whereas the BEC group had higher abundance of Bacteroides caecigallinarum (species). The genera Faecalibacterium and Asterolplasma were positively correlated with egg-laying rate (r = 0.57, 0.60; P < 0.01); and the genera Bacteroides and Romboutsia were negatively correlated with egg-laying rate (r = -0.58, -0.74; P < 0.01). The genera Bacteroides, Lactobacillus, and Rombutzia were positively correlated with jejunal mucosa proinflammatory factor IL-1β level (r = 0.61, 0.60, 0.59; P < 0.01), which were negatively correlated with genera Rikenbacteriaceae RC9, Faecalibacterium, and Olsenlla (r = -0.56, -0.57, -0.61; P < 0.01). There genera UCG.005 was positively correlated with proinflammatory factor IL-6 level in jejunal mucosa (r = 0.58; P < 0.01), which was negatively correlated with Rikenbacteriaceae RC9 (r = -0.62; P < 0.01). The experiment results revealed that the addition of BEC to the diet restored the production performance of the laying hens. In addition, supplementation of 2,000 mg/kg BEC modulated gut health by reducing gut damage scores and modulating microbial composition, thereby promoting recovery of laying hens after coccidia and Clostridium perfringens challenge.

Effects of dietary organic acids and probiotics on laying performance, egg quality, serum antioxidants and expressions of reproductive genes of laying ducks in the late phase of production

Five hundred and forty Cheery Valley ducks were used to investigate the effects of dietary supplementation of acidifier and compound probiotics, individually or in combination, on production performance, egg quality, immune and oxidative status, expression of reproductive, and calcium binding related genes from 42 wk to 48 wk of age. Ducks were randomly allocated to 9 treatment groups with 6 replicates and 10 ducks per replicate for each group. A 3 × 3 factorial arrangement, with 3 dietary inclusion levels of acidifier and probiotics (0, 2, and 3 g/kg acidifier; 0, 1, and 2 g/kg probiotics) were used. The acidifier used was mainly consisted of Benzoic acid, Fumaric acid, phosphoric acid, and formic acid. The main components of the probiotics were Bacillus subtilis and Clostridium butyricum. Dietary supplementation of probiotics improved the daily feed intake, egg production rate, and body weight of ducks (P < 0.05), and diet acidifier also increased the daily feed intake compared to the control (P < 0.01). Egg quality was improved by diet inclusion of probiotics, including Haugh unit, albumen height, egg shape index (P < 0.01), and eggshell hardness (P = 0.05). A significant increase in Haught unit and yolk weight was observed in ducks fed diet added with acidifier (P < 0.05). Acidifier supplementation reduced the total antioxidant capacity (T-AOC), immunoglobulin A (IgA), and IgG content and the catalase (CAT) activity in the serum (P < 0.05), in accompanied with an increased malondialdehyde (MDA) concentration (P < 0.05). Serum total superoxide dismutase (T-SOD) activities were improved by dietary inclusion of probiotics (P < 0.05). There was an interaction effects on serum IgA and IgG contents between acidifier and probiotics (P < 0.05). Diet supplementation of probiotics improved the ovary follicle-stimulating hormone receptor (FSHR) and estrogen receptor (ER) gene expressions (P < 0.01), while dietary acidifier reduced the transcription levels of FSHR and luteinizing hormone receptor (LHR) (P < 0.01) in ovary. In the uterus of the oviduct, expressions of FSHR, and carbonic anhydrase 2 (CA2) were also increased by diet probiotics (P < 0.01), and diet acidifier reduced the gene expressions of calbindin-D28k (CaBP-D28k) and CA2 (P < 0.05). Significant interaction effects between diet acidifier and probiotics were obtained on gene expressions of FSHR, LHR, and ovalbumin (OVAL) in the ovary (P < 0.05), and LHR, CaBP-D28k, and CA2 (P < 0.05) in the uterus. It can be concluded that production performance and egg quality of laying ducks can be improved in the late phase of reproduction by dietary inclusion of probiotics, while the organic acid mixture caused a decline in serum antioxidant and immune capacity of the ducks.

Bioactive compounds, antibiotics and heavy metals: effects on the intestinal structure and microbiome of monogastric animals – a non-systematic review

The intestinal structure and gut microbiota are essential for the animals‘ health. Chemical components taken with food provide the right environment for a specific microbiome which, together with its metabolites and the products of digestion, create an environment, which in turn is affects the population size of specific bacteria. Disturbances in the composition of the gut microbiota can be a reason for the malformation of guts, which has a decisive impact on the animal‘ health. This review aimed to analyse scientific literature, published over the past 20 years, concerning the effect of nutritional factors on gut health, determined by the intestinal structure and microbiota of monogastric animals. Several topics have been investigated: bioactive compounds (probiotics, prebiotics, organic acids, and herbal active substances), antibiotics and heavy metals (essentaial minerals and toxic heavy metals).

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

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

Effects of Chlorogenic Acid on Performance, Anticoccidial Indicators, Immunity, Antioxidant Status, and Intestinal Barrier Function in Coccidia-Infected Broilers

The effects of chlorogenic acid (CGA) on growth performance, anticoccidial indicators (oocysts per gram of excreta, cecal lesion score, and bloody diarrhea score), immunity, antioxidant status, and intestinal barrier function in coccidia-infected broilers were investigated. A total of 240 one-day-old Arbor Acres broilers were randomly divided into four groups with six replicates of ten broilers each for 42 days. Four treatments included control diet (non-infected control, NC), control diet +Eimeria infection (infected control, IC), control diet +0.5 g/kg CGA + Eimeria infection (CGA0.5), and control diet +1 g/kg CGA + Eimeria infection (CGA1). At day 14, each broiler in IC, CGA0.5, and CGA1 groups was orally inoculated with 1 mL saline containing 4 × 105 sporulated oocysts. The results showed that the CGA1 group increased the average daily gain by 12.57% (p < 0.001) and decreased the feed/gain ratio (p = 0.010) and mortality (p = 0.030) by 13.00% and 77.76%, respectively, of broilers from 14 to 42 days compared with the IC group. The CGA1 group decreased the oocysts per gram of excreta (p < 0.001) and bloody diarrhea score (p = 0.001) compared with the IC group. The CGA0.5 and CGA1 groups increased total antioxidant capacity (p < 0.001) at day 21 and villus height (p < 0.001) in the duodenum and jejunum at day 42, and decreased the levels of interleukin 6 (IL-6) (p = 0.002), malondialdehyde (MDA) (p < 0.001), D-lactic acid (p < 0.001), and diamine oxidase (DAO) (p < 0.001) at day 21 and the levels of MDA (p < 0.001) and D-lactic acid (p = 0.003) at day 42 compared with the IC group. In the CGA1 group, villus height in the duodenum (p < 0.001) and jejunum (p = 0.017) increased at day 21 and in the ileum (p < 0.001) at day 42, and the level of DAO (p < 0.001) decreased at day 42 compared with the IC group. Broilers in the IC group had a higher IL-6 level (p = 0.048) at day 42 and lower IL-10 (p = 0.027) and immunoglobulin A (p = 0.042) levels at day 21, and IL-10 level (p = 0.017) at day 42 than those in the NC group, while no significant differences were observed among the NC, CGA0.5, and CGA1 groups. In conclusion, dietary supplementation with 1 g/kg CGA improved growth performance, immunity, antioxidant status, and intestinal barrier function in coccidia-infected broilers.