Effect of humic acids on intestinal viscosity, leaky gut and ammonia excretion in a 24 hr feed restriction model to induce intestinal permeability in broiler chickens

Xylanase and stimbiotic supplementation improve broilers performance and nutrient digestibility across both wheat-barley and corn-based diets

The present study investigated the effects of supplemental xylanase or stimbiotic in male broiler chickens fed either corn- or wheat-barley-based diets. A total of 1,296 Ross 308 day-old chicks were assigned to a 2 × 3 factorial design, evaluating the effects of diet grain source (wheat-barley or corn) and additives (none, xylanase, or stimbiotic). The stimbiotic used in the present study contained xylanase and fermentable xylo-oligosaccharides. Each treatment was replicated 8 times, with 27 birds per replicate pen. At day 21, 3 birds per pen were selected for blood sample collection and another 3 birds at day 27 for digesta collection. The final body weight at day 42 was not statistically affected by grain source, additive supplementation, or their interaction (P > 0.05). Over the entire production period (0-42 d), an interaction between grain source and additive supplementation was found for feed conversion ratio (FCR), where xylanase or stimbiotic improved the FCR across the diet type, with a more pronounced improvement achieved when supplemented to the wheat-barley based diets (P < 0.01). A feed grain × additive interaction resulted in lower total feed intake in birds fed the wheat-barley based diets only in response to stimbiotic (P < 0.05). Ileal viscosity was also affected by an interaction between grain source and additive supplementation, in which viscosity reduction by xylanase or stimbiotic was only achieved in birds fed the wheat-barley based diets (P < 0.01). Similarly, an interaction was found in the ileal digestibility coefficient of protein (P = 0.016) and starch (P = 0.006), where either xylanase or stimbiotic improved the digestibility only in birds offered the wheat-barley based diets. Serum fluorescein isothiocyanate dextran level was higher in birds fed the corn-based diets compared to those fed the wheat-barley based diets (P < 0.01). These results suggest that dietary supplementation with either xylanase or stimbiotic improved feed efficiency, regardless of the dietary grain source, likely through enhanced nutrient digestibility and/or reduced digesta viscosity.

Effect of feed supplementation with humic substances on phenotypic resistance profiles of Escherichia coli isolates from the ceca of broiler chickens

Humic substances (HS), natural complex-forming feed additives, are believed to reduce the bioavailability of antimicrobials to the gut microbiome, thereby limiting the emergence and spread of antimicrobial resistance in the food chain. However, this hypothesis has not yet been adequately verified experimentally. Our study was focused on the isolation of Escherichia coli (E. coli) from the ceca of 80 broiler chickens bred for 37 d under controlled conditions. Chickens in the control and experimental groups (40 broilers each) were fed standard commercial feeds, but the diet for experimental chicken was permanently supplemented with HS (99.3% feed + 0.7% HS). After slaughter and evisceration at the end of fattening period, the cecal contents of all chickens were subjected to microbiological analysis aimed at the enumeration, isolation and genotypic identification of E. coli strains by the species-specific PCR method. In total, 58 E. coli strains from control chickens and 60 strains from HS-fed chickens were tested for resistance against 19 antimicrobials using the broth microdilution method based on minimum inhibitory concentration breakpoints. Resistance to at least one antimicrobial was detected in almost 90% of E. coli isolates from control chickens, but in only 68.33% of isolates from HS-fed broilers (P < 0.01). In the experimental group, a noticeable decrease in resistance rates for ampicillin (31.78%), trimethoprim (22.88%), sulfamethoxazol (20.86%), and tetracycline (19.71%) was observed. The effect for fluorochinolones was less pronounced (0.09 ≤ P < 0.90). Feed supplementation with HS also reduced the prevalence of multidrug resistance (20.0% vs. 43.1%; P < 0.01) and led to a complete elimination of co-resistance to six and more antimicrobial classes. Additionally, no extended-spectrum beta-lactamase production could be predicted for E. coli isolates from HS-fed broilers. This is probably the first experimental study demonstrating a direct beneficial effect of HS-supplemented diet on the phenotypic resistance profiles of E. coli isolates from the ceca of commercially raised broiler chickens, showing that HS as feed additives can effectively reduce the phenotypic expression of antimicrobial resistance in E. coli.

Design of a sustainable biorefinery for the valorization of waste from the baker's yeast industry through process simulation: A case study for the production of animal feed, fertilizers, and biofuels from vinasse

The present work deals with the biotechnological valorization of the vinasse through a sustainable biorefinery. The aim was to design and analyze, through process simulation, a biorefinery for the valorization of vinasse in products such as organo-mineral fertilizers, supplements for animal feed, and biogas. For this purpose, the SuperPro Designer software was used, and a modified hierarchical decomposition method was applied. One base case and three scenarios were techno-economically assessed, and the net present value was used as a selection criterion. The technological configuration with the best techno-economic criterion was analyzed socially and environmentally. The results suggest that the best configuration of the biorefinery corresponded to scenario 3, with a net present value of USD$73,364,000, a number of direct employees of 38, and a blue water footprint of 16.16 m3/h. These findings highlight the potential of the design of biorefineries to address the valorization of vinasses in Colombia and worldwide.

G, Hargis BM, Téllez-Isaías G. Assessment of the Impact of Humic Acids on Intestinal Microbiota, Gut Integrity, Ileum Morphometry, and Cellular Immunity of Turkey Poults Fed an Aflatoxin B1-Contaminated Diet

A recent study published data on the growth performance, relative weights of the organs of the gastrointestinal tract, liver histology, serum biochemistry, and hematological parameters for turkey poults fed an experimental diet contaminated with aflatoxin B1 (AFB1) and humic acids (HA) extracted from vermicompost. The negative effects of AFB1 (250 ng AFB1/g of feed) were significantly reduced by HA supplementation (0.25% w/w), suggesting that HA might be utilized to ameliorate the negative impact of AFB1 from contaminated diets. The present study shows the results of the remaining variables, as an extension of a previously published work which aimed to evaluate the impact of HA on the intestinal microbiota, gut integrity, ileum morphometry, and cellular immunity of turkey poults fed an AFB1-contaminated diet. For this objective, five equal groups of 1-day-old female Nicholas-700 turkey poults were randomly assigned to the following treatments: negative control (basal diet), positive control (basal diet + 250 ng AFB1/g), HA (basal diet + 0.25% HA), HA + AFB1 (basal diet + 0.25% HA + 250 ng AFB1/g), and Zeolite (basal diet + 0.25% zeolite + 250 ng AFB1/g). In the experiment, seven replicates of ten poults each were used per treatment (n = 70). In general, HA supplementation with or without the presence of AFB1 showed a significant increase (p < 0.05) in the number of beneficial butyric acid producers, ileum villi height, and ileum total area, and a significant reduction in serum levels of fluorescein isothiocyanate-dextran (FITC-d), a marker of intestinal integrity. In contrast, poults fed with AFB1 showed a significant increase in Proteobacteria and lower numbers of beneficial bacteria, clearly suggesting gut dysbacteriosis. Moreover, poults supplemented with AFB1 displayed the lowest morphometric parameters and the highest intestinal permeability. Furthermore, poults in the negative and positive control treatments had the lowest cutaneous basophil hypersensitivity response. These findings suggest that HA supplementation enhanced intestinal integrity (shape and permeability), cellular immune response, and healthier gut microbiota composition, even in the presence of dietary exposure to AFB1. These results complement those of the previously published study, suggesting that HA may be a viable dietary intervention to improve gut health and immunity in turkey poults during aflatoxicosis.

Protective effects of sodium humate on the intestinal barrier damage of Salmonella Typhimurium-challenged broilers

Salmonella Typhimurium (S. Typhimurium) infections can lead to severe intestinal damage and reduce growth performance in broilers. Thus, this study examined the potential mitigating impact of sodium humate (HNa) on intestinal barrier damage resulting from S. Typhimurium infection in broilers. A total of 320 1-day-old Arbor Acres broilers were randomly assigned into 5 treatments with 8 replicates. On d 22-24, broilers in the CON group were challenged with 1 ml of PBS, while broilers in the other groups were challenged with 1 ml of 3 × 109 CFU/ml S. Typhimurium, daily. Dietary administration with 4 g/kg of HNa increased (P < 0.05) the final body weight, jejunal secretory immunoglobulin A (sIgA), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and catalase (CAT) levels as compared with the MOD group broilers. Furthermore, HNa alleviated intestinal barrier damage by increasing villus height (VH), upregulating protein expression of Occludin, Claudin-1, and zonula occludens-1 (ZO-1), inhibiting toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway activation, and decreasing the secretion of inflammatory cytokines (P < 0.05). Collectively, the present study showed that HNa mitigated intestinal barrier damage induced by S. Typhimurium infection in broilers.

Evaluation of the efficacy of humic acids to counteract the toxic effects of aflatoxin B1 in turkey poults

This study aims to evaluate the efficacy of humic acid (HA) from worm compost as an adsorbent for aflatoxin B1 (AFB1) in turkey poults. The experiment involved the inclusion of 0.25% (w/w) HA in the diet of turkey poults consuming aflatoxin-contaminated feed (250 ng AFB1/g). A total of 350 1-day-old female Nicholas-700 turkey poults were randomly allocated to five equal groups: negative control (basal diet); positive control (basal diet + 250 ng AFB1/g; HA (basal diet + 0.25% HA); HA + AFB1 (basal diet + HA + 250 ng AFB1/g); and zeolite + AFB1 (basal diet + 0.25% zeolite + 250 ng AFB1/g). Each group had seven replicates of 10 poults (n = 70). The impact of HA addition was evaluated in terms of performance parameters, relative organ weights, liver histological lesions, and serum biochemical and hematological constituents. In general, the addition of HA improved body weight (BW), body weight gain (BWG), and feed conversion rate (FCR). Furthermore, HA effectively mitigated the toxic effects caused by AFB1 in the majority of the analyzed variables. The results indicated that HA effectively counteracted the AFB1-induced toxic effects in turkey poults. Based on these findings, it can be concluded that HA is capable of removing AFB1 from the contaminated diet.

Therapeutic Efficiency of Humic Acids in Intoxications

Humins, humic and fulvic acids represent molecules with complex structures. These compounds comprising humic substances (HS) exist naturally in soil, brown coal, peat, and water. They are formed during the decomposition and transformation of organic matter (animal and plant remains) and their formation explains several theories. Within their chemical structures, there are numerous phenolic and carboxyl groups and their derivatives that affect their different properties, such as their solubility in water or their absorption of cations or mycotoxins. The manifold chemical structure of HS alters their polyelectrolyte character and thus their chelating efficiency. For many years, HS have been studied due to their detoxification, anti-, and pro-inflammatory or anticancer and antiviral ability. This article summarizes the antioxidant and adsorption properties of humic acids, highlighting their usefulness in intoxications.

Can the broiler industry rely on results of existing life cycle assessment and environmental assessments studies to inform broilers' nutritional strategies?

The goal of this systematic review is to investigate the applicability of the results from existing life cycle analysis (LCA) and environmental assessments studies in informing nutritional strategies for environmentally sustainable poultry meat production. This paper reports on a Rapid Evidence Assessment (REA) of articles published between 2000 and 2020. The studies reviewed were conducted in developed countries including UK, France, Germany, Sweden, Norway, The Netherlands, Denmark, Belgium, Canada, and USA. All articles were written in English. The REA includes studies on LCA of differing strains of meat poultry and production systems, studies on poultry manure emission and studies on environmental assessments of plant-based feed ingredients. The review covered studies on soil carbon dynamics associated with plant-based ingredients. Web of Science, Scopus, and PubMed were used to obtain the 6,142 population articles. The multistage screening process resulted in 29 studies from which 15 studies included LCA while the rest 14 studies analyzed NH₃ emission of broilers. All studies based on LCA were descriptive and did not include replications. Only 12 studies assessed the effect of interventions to reduce NH₃ emission of broiler litter using replicated layout designs. It is concluded that the broiler industry in UK, EU, and North America cannot rely on results of existing LCA and environmental assessments studies to inform their nutritional strategy and poultry meat production due to a shortage of reliable in vivo data assessing interventions in controlled studies.

Humic Acids Preparation, Characterization, and Their Potential Adsorption Capacity for Aflatoxin B1 in an In Vitro Poultry Digestive Model

Vermicompost was used for humic acid (HA) preparation, and the adsorption of aflatoxin B₁ (AFB₁) was investigated. Two forms of HA were evaluated, natural HA and sodium-free HA (SFHA). As a reference, a non-commercial zeolitic material was employed. The adsorbents were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy (EDS), zeta potential (ζ-potential), scanning electron microscopy (SEM), and point of zero charge (pHpzc). The adsorbent capacity of the materials when added to an AFB₁-contaminated diet (100 µg AFB₁/kg) was evaluated using an in vitro model that simulates the digestive tract of chickens. Characterization results revealed the primary functional groups in HA and SFHA were carboxyl and phenol. Furthermore, adsorbents have a highly negative ζ-potential at the three simulated pH values. Therefore, it appears the main influencing factors for AFB₁ adsorption are electrostatic interactions and hydrogen bonding. Moreover, the bioavailability of AFB₁ in the intestinal section was dramatically decreased when sorbents were added to the diet (0.2%, w/w). The highest AFB₁ adsorption percentages using HA and SFHA were 97.6% and 99.7%, respectively. The zeolitic material had a considerable adsorption (81.5%). From these results, it can be concluded that HA and SFHA from vermicompost could be used as potential adsorbents to remove AFB₁ from contaminated feeds.

Effect of the Addition of Humic Substances on Morphometric Analysis and Number of Goblet Cells in the Intestinal Mucosa of Broiler Chickens

The mechanisms of action of humic substances (HS) as growth promoters in poultry are unknown. In this study, the productive performance, histology, and number of goblet cells (GC) in the intestinal villi of broilers under steady-state digestive conditions and under abrupt changes in diet with the addition of HS was evaluated. Broilers housed individually were offered three treatments from 14−28 days: 1 = diet with white corn/soybean meal, without growth promoter antibiotics (nonGPA); 2 = with GPA (GPA); and 3 = with 0.3% HS. At day 28, two diets were suddenly introduced: (A) white corn/soybean meal plus dried distillers’ grains with solubles (DDGS); and (B) white/blue corn/soybean meal/DDGS, keeping the three original treatments. Diets A and B were also exchanged on day 37. FCR was lower with GPA and HS compared to nonGPA from 14−38 days (p < 0.05); at day 28, under steady-state digestive conditions, HS had a similar effect to GPA on the histology and GC number in the jejunum villi. The number of GC in the jejunum of HS-fed broilers on days 29 and 38, after diet changes, behaves similarly to that of AGP-fed broilers (p > 0.05). HS appears to strengthen the mucosal protection of the epithelium of the intestine.

Effects of Feed-Through Sulfur on Growth Performance, Atmospheric Ammonia Levels, and Footpad Lesions in Broilers Raised Beginning with Built-Up Litter

To the poultry industry, ammonia accumulation within poultry houses can be a costly issue, as this can lead to problems with bird performance, damage to economically important parts such as paws, and customer disapproval due to animal welfare concerns. Common management practices for ammonia control can be quite effective; however, these methods are used variably from farm to farm, which necessitates ammonia control measures that poultry companies can more uniformly implement across all contract growers. One possible measure is ammonia control through feed additives, which would allow poultry companies more direct control over the treatment. This project explored the efficacy of elemental sulfur added directly to the feed (feed-through sulfur) in controlling litter ammonia levels, live performance, and paw quality of broilers raised on built-up litter over three successive flocks. Feed-through sulfur on its own showed inconsistent effects on performance or footpad lesions after 38 days of production compared to sodium bisulfate or control treatments. However, combination of feed-through sulfur and sodium bisulfate showed a potential synergistic effect on ammonia levels and litter pH, although there were few differences between treatments and controls; therefore, additional research must be explored to confirm these observations.

Addition of Different Levels of Humic Substances Extracted from Worm Compost in Broiler Feeds

Different sources and inclusion levels of humic substances (HS) have been tested in broiler rations as an alternative to the addition of growth promoter antibiotics (GPA) with promising results. The current study was carried out to assess the influence of HS extracted from worm compost on broiler production parameters, carcass yield, tibia characteristics, lactic acid bacteria (LAB) counts, excretion of Eimeria oocysts, and antioxidant status of breast meat. A total of 1200 broilers were used, housed in groups of 30 per pen, and assigned to five treatments: 1 = basal diet with GPA (positive control), 2 = basal diet without GPA (negative control), 3-5 = basal diet with 0.15, 0.30, and 0.45% HS, respectively. The data was subjected to a variance analysis and orthogonal contrasts. The FI decreased linearly (p < 0.05) from 1-14, 29-42, and 1-42 days as the inclusion of HS in the feed increased. The FCR had quadratic responses (p < 0.01) from 29-42 and 1-42 days concerning the HS inclusion levels. Lactic acid bacteria was higher (p ˂ 0.05) in ten-day-old chicks with 0.45% HS in the diet. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity antioxidant potential decreased linearly (p < 0.05) concerning increasing HS in the feed. The results indicate that HS can be used as growth promoters in broiler feeds.

Current experimental models, assessment and dietary modulations of intestinal permeability in broiler chickens

Maintaining and optimising the intestinal barrier (IB) function in poultry has important implications for the health and performance of the birds. As a key aspect of the IB, intestinal permeability (IP) is mainly controlled by complex junctional proteins called tight junction proteins (TJ) that link enterocytes together. The disruption of TJ is associated with increased gut leakage with possible subsequent implications for bacterial translocation, intestinal inflammation, compromised health and performance of the birds. Despite considerable data being available for other species, research on IP in broiler chickens and in general avian species is still an understudied topic. This paper reviews the available literature with a specific focus on IP in broiler chickens with consideration given to practical factors affecting the IP, current assessment methods, markers and nutritional modulation of IP. Several experimental models to induce gut leakage are discussed including pathogens, rye-based diets, feed deprivation and stress-inducing agents such as exogenous glucocorticoids and heat stress. Although various markers including fluorescein isothiocyanate dextran, expression of TJ and bacterial translocation have been widely utilized to study IP, recent studies have identified a number of excreta biomarkers to evaluate intestinal integrity, in particular non-invasive IP. Although the research on various nutrients and feed additives to potentially modulate IP is still at an early stage, the most promising outcomes are anticipated for probiotics, prebiotics, amino acids and those feed ingredients, nutrients and additives with anti-inflammatory properties. Considerable research gaps are identified for the mechanistic mode of action of various nutrients to influence IP under different experimental models. The modulation of IP through various strategies (i.e. nutritional manipulation of diet) may be regarded as a new frontier for disease prevention and improving the health and performance of poultry particularly in an antibiotic-free production system.

Effects of sodium humate and glutamine combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned calves

This experiment was conducted to investigate the effects of sodium humate (HNa) and glutamine (Gln) alone or combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned Holstein calves. In a 14-day experiment, 40 calves at 51 ± 3 days of age were randomly allocated to four treatment groups: (1) NC (basal diet), (2) NC + 5% HNa, (3) NC + 1% Gln, and (4) NC + 5% HNa + 1% Gln. Calves combined supplementation with HNa and Gln had a higher (P < .05) ADG, serum concentration of glucose (GLU), IgA, and IgG but lower fecal scores, diarrhea incidence, serum concentration of TNF-α, and IL-10 compared with NC group (P < .05). Compared with NC group, HNa + Gln group showed higher (P < .05) serum GSH and T-AOC activities but lower (P < .05) concentration of MDA and D-lac. Furthermore, the abundances of Prevotella ruminicola, Bifidobacterium, and Lactobacillus in rectal digesta were increased (P < .05), but the Escherichia coli was significantly decreased. In conclusion, combined supplementation with HNa and Gln can effectively improve the immune status, antioxidant capacity, and intestinal microflora of the weaned calves while reducing diarrhea incidence.

Algae-based feed ingredient protects intestinal health during Eimeria challenge and alters systemic immune responses with differential outcomes observed during acute feed restriction

Compounds in microalgae-derived feed ingredients in poultry diets may improve intestinal physiology and immunity to protect against damage induced by physiological and pathogen challenges, but mechanisms are examined sparingly. The study objective was to evaluate changes to intestinal morphology, permeability, and systemic immunity in broilers fed a proprietary microalgae ingredient during 2 separate challenge studies. In study 1, two replicate 28 d battery cage trials used 200 Ross 308 broilers each (n = 400) fed a control diet ± 0.175% algae ingredient. Half of the birds were subjected to a 12 h feed restriction challenge and fluorescein isothiocyanate dextran (FITC-D) intestinal permeability assay on d 28. Study 2 used 800 broilers randomly assigned to the same dietary treatments and housed in floor pens for 42 d. At d 14, intestine and spleen samples were collected from 10 birds/ diet. Half of the remainder was orally inoculated with 10X Coccivac-B52 vaccine in a 2 × 2 factorial treatment design (diet and Eimeria inoculation). The FITC-D assay was conducted at 1, 3, 7, and 14 d post-inoculation (pi) while intestinal and spleen samples were collected at 3, 7, 14, and 28 dpi for histomorphology and flow cytometric immune cell assessment. Study 1 validated intestinal leakage via FITC-D absorbance induced by feed restriction but showed no algae-associated protective effects. In study 2, algae preserved intestinal integrity during coccidiosis (P = 0.04) and simultaneously protected jejunal villus height as early as 7dpi (P < 0.0001), whereas intestinal damage resolution in control birds did not occur until 14 dpi. Algae inclusion increased splenic T cells in unchallenged broilers at d 14 by 29.6% vs. control (P < 0.0001), specifically γδ T cell populations, without impacting performance (P < 0.03). During Eimeria challenge, splenic T cells in algae-fed birds did not show evidence of recruitment to peripheral tissues, while control birds showed a 16.7% reduction compared to their uninoculated counterparts from 3 to 7 dpi (P < 0.0001). This evidence suggests the algae ingredient altered the immune response in a manner that reduced recruitment from secondary lymphoid organs in addition to protecting intestinal physiology.

Effect of humate supplementation to feed and/or litter on performance, intestinal viscosity, litter quality, and occurrence of footpad dermatitis in broilers fed barley-based diets

We investigated the effect of in-feed and/or in-litter supplemental humate against footpad dermatitis (FPD) in broilers fed diets based on barley. Three hundred and sixty 1-day-old Ross 308 broiler chickens were randomly distributed to 24 floor pens (4 treatments, each consisting of 6 replicate pens; 15 chickens per pen) as a completely randomized design with 2 × 2 factorial arrangement of two levels of supplemental humate in feed (0 and 1 g/kg feed) and litter (0 and 5 g/kg litter). Growth performance, intestinal viscosity, litter quality, and incidence and severity of FPD in broilers were measured. In addition, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined in blood and footpad tissues of broilers with different FPD scores. The results revealed that there was no interaction between humate supplementation to feed and litter. Neither dietary nor litter supplementation of humate had a significant effect on growth performance, intestinal viscosity, litter quality, and occurrence of FPD. And also, MDA and SOD levels in serum and footpad tissue did not affect by either dietary or litter supplementation of humate. The presence of FPD (score 1) had no effect on MDA and SOD levels in serum, however, increased the MDA and SOD levels (P < 0.001, P = 0.001, respectively) in footpad tissue of broilers. The intestinal viscosity did not differ between FPD scores 0 and 1. In conclusion, findings of this experiment suggest that humate supplementation to feed and litter did not alleviate FPD development in broilers fed diets based on barley. In addition, the presence of FPD lesions increases the MDA and SOD levels in the footpad tissues.

Composition and inclusion of probiotics in broiler diets alter intestinal permeability and spleen immune cell profiles without negatively affecting performance1

Probiotic feed additives with potential to enhance performance, health, and immunity have gained considerable popularity in commercial broiler production. The study objectives were to measure broiler performance, gut integrity, and splenic immune cell profiles in birds fed one of two probiotics at two inclusion levels. Nine hundred sixty Ross 708 broilers (12 per pen) were randomly assigned to no additive control, 0.05% or 0.10% LactoCare (Lactobacillus reuteri), or 0.05% or 0.10% LactoPlan (Lactobacillus plantarum) dietary treatments for 6 wk. On day 27, a 20-pen subset was utilized for a fluorescein isothiocyanate dextran (FITC-d) assay, where half of the pens were subject to a 12-h feed restriction (FR) pregavage. Serum collected from blood drawn 1-h postgavage was analyzed for relative fluorescence of FITC-d absorbed across the intestinal barrier as a gut leakiness indicator. On day 42, spleens from eight birds per treatment were collected for immune cell profile analysis by multicolor flow cytometry. Although performance outcomes were not affected by dietary treatment, FITC-d absorption post-FR was increased 57% in the 0.05% LactoPlan treatment, and was decreased by 12.6% in the 0.05% LactoCare diet, 12% in the 0.10% LactoCare diet, and 22% in the 0.10% LactoPlan diet compared with the control. This indicates a positive impact in barrier integrity maintenance due to 0.05% and 0.10% LactoCare and 0.10% LactoPlan diet following a challenge. Immune cell profiles varied between the two probiotic compositions, with an approximately 50% reduction in splenic innate immune cells (monocyte/macrophage+) in birds fed LactoPlan (P < 0.0001) and greater overall percentages of CD45+ leukocytes and CD3+ T cells in birds fed 0.10% LactoCare (P < 0.0001). LactoPlan diets shifted splenic T-cell populations in favor of CD8α + cytotoxic T cells (TC; P = 0.007), while higher inclusions (0.10%) of either probiotic increased the percentage of activated CD4+ helper T cells (TH; P < 0.0001). These results indicate that compositionally different probiotics had varying effects on the gut permeability and splenic immune cell profiles in broiler chickens, particularly at higher inclusion rates, but observed changes to underlying physiology did not negatively impact performance outcomes. The ability of a probiotic to alter gut permeability and immune cell profile, therefore, may depend on the compositional complexity of the product as well as inclusion rate.

Effect of the Addition of Humic Substances as Growth Promoter in Broiler Chickens Under Two Feeding Regimens

Simple Summary

The rapid spread of antimicrobial-resistant genes in bacterial communities is a threat to human, animal, and environmental health that continues to progress inflexibly. Humic substances (HS) are promising complex molecules as an alternative to reduce the use of growth promoter antibiotics (GPA) in animal feeds. Improvements in productivity, intestinal health, immune response, and antioxidant status have been reported in broilers supplemented with HS. In the present study, broilers fed with an extract of HS (EHS) from a worm compost had similar carcass yield and excretion of coccidian oocysts but increased Clostridium perfringens and lactic acid bacteria (LAB) compared to broilers fed diets added with GPA. Broilers subjected to feed restriction had reduced growth performance and meat quality. These results confirm the growth-promoting effect of ESH, which could be explained by higher abundance of the beneficial LAB and by reducing the multiplication of harmful parasites in the gut of broilers.

Abstract

Humic substances (HS) from different sources have been evaluated to replace or reduce the use of growth promoter antibiotics (GPA) in the feeds of broiler chickens. The objective was to evaluate the growth performance, tibia measurements, nutrient balance, meat quality, and microbiological status of broiler fed with an HS extract (EHS) under ad libitum (ADLIB) or feed restriction (REST). Individually caged broilers (n = 180, 14–35 day of age) were assigned to a factorial arrangement of three dietary treatments: (1) positive control with bacitracin methylene disalicylate (BMD) and salinomycin; (2) negative control without BMD nor salinomycin, and (3) same as negative control with 0.25% EHS, and two feeding regimens 1) ADLIB or REST for 24 h on d 1, 7, and 14. Results were subjected to ANOVA. Positive control and EHS-fed broilers showed higher carcass yield (p < 0.05) and lower oocyst excretion (p < 0.01) compared to negative control birds. Lactic acid bacteria (LAB) and Clostridium perfringens (C. perfringens) were higher in negative control and EHS-broilers compared to positive control (p < 0.01). In conclusion, higher carcass yield, lower C. perfringens and oocyst excretion were found in positive control and higher carcass yield, higher LAB and lower oocyst excretion were found in EHS-fed broilers. Broilers subjected to REST had reduced growth performance and meat quality. In conclusion, EHS could be used to increase the carcass yield and beneficial LAB in broilers.