Effect of dietary supplementation of mannanoligosaccharides on growth performance, ileal microbial counts, and jejunal morphology in broiler chicks exposed to aflatoxins

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain-farm to fork-of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.

Can Red Yeast (Sporidiobolus pararoseus) Be Used as a Novel Feed Additive for Mycotoxin Binders in Broiler Chickens?

Mycotoxin-contaminated feeds may negatively affect broiler chickens’ health; hence, a sustainable approach to achieve mycotoxin elimination is necessary. This study aimed to evaluate the efficacy of red yeast (Sporidiobolus pararoseus; RY) as a novel mycotoxin binder in broilers. A total of 1440 one-week-old male broiler chicks were randomly assigned to 12 treatments in a 3 × 4 factorial design. The dietary treatments included three levels of mycotoxin-contaminated diets (0 µg kg−1 (0% of mycotoxin; MT), 50 µg kg−1 (50% MT), and 100 µg kg−1 (100% MT)) and four levels of mycotoxin binders (0.0 and 0.5 g kg−1 commercial binder, and 0.5 and 1.0 g kg−1 RY). Experimental diets were contaminated with aflatoxin B1, zearalenone, ochratoxin A, T-2 toxin, and deoxynivalenol in the basal diet. Furthermore, the parameters including feed intake, body weight, and mortality rate were recorded on a weekly basis. After feeding for 28 days, blood and organ samples were collected randomly to determine the blood biochemistry, relative organ weights, and gut health. The results indicated that mycotoxin-contaminated diets reduced the average daily weight gain (ADG), villus height (VH), and villus height per the crypt depth ratio (VH:CD) of the intestine, as well as the population of Lactobacillus sp. and Bifidobacterium sp. in the cecal (p < 0.05), whereas they increased the mycotoxins concentration in the blood samples and the apoptosis cells (TUNEL positive) in the liver tissue (p < 0.01) of broiler chicken. In contrast, RY-supplemented diets had better ADG values and lower chicken mortality rates (p < 0.05). Moreover, these combinations positively impacted the relative organ weights, blood parameters, bacteria population, intestinal morphology, and pathological changes in the hepatocytes (p < 0.05). In conclusion, RY supplementation effectively alleviated the toxicity that is induced by AFB1 and OTA, mainly, and could potentially be applied as a novel feed additive in the broiler industry.

Ameliorative effect of nanocurcumin and Saccharomyces cell wall alone and in combination against aflatoxicosis in broilers

Background

The adverse effect of aflatoxin in broilers is well known. However, dietary supplementation of Saccharomyces cell wall and/or Nanocurcumin may decrease the negative effect of aflatoxin B1 because of the bio-adsorbing feature of the functional ingredients in Yeast Cell Wall and the detoxification effect of curcumin nanoparticles. The goal of this study was to see how Saccharomyces cell wall/Nanocurcumin alone or in combination with the aflatoxin-contaminated diet ameliorated the toxic effects of aflatoxin B1 on broiler development, blood and serum parameters, carcass traits, histology, immune histochemistry, liver gene expression, and aflatoxin residue in the liver and muscle tissue of broilers for 35 days. Moreover, the withdrawal time of aflatoxin was measured after feeding the aflatoxicated group an aflatoxin-free diet. Broiler chicks one day old were distributed into five groups according to Saccharomyces cell wall and/or nanocurcumin with aflatoxin supplementation. The G1 group was given a formulated diet without any supplements. The G2 group was supplemented with aflatoxin (0.25 mg/kg diet) in the formulated diet. The G3 group was supplemented with aflatoxin (0.25 mg/kg diet) and Saccharomyces cell wall (1 kg/ton diet) in the formulated diet. The G4 group was supplemented with aflatoxin (0.25 mg/kg diet) and nanocurcumin (400 mg/kg) in the formulated diet. The G5 group was supplemented with aflatoxin (0.25 mg/kg diet) and Saccharomyces cell wall (1 kg/ton diet) in combination with nanocurcumin (200 mg/kg) in the formulated diet.

Results

According to the results of this study, aflatoxin supplementation had a detrimental impact on the growth performance, blood and serum parameters, carcass traits, and aflatoxin residue in the liver and muscle tissue of broilers. In addition, aflatoxin supplementation led to a liver injury that was indicated by serum biochemistry and pathological lesions in the liver tissue. Moreover, the shortening of villi length in aflatoxicated birds resulted in a decrease in both the crypt depth ratio and the villi length ratio. The expression of CYP1A1 and Nrf2 genes in the liver tissue increased and decreased, respectively, in the aflatoxicated group. In addition, the aflatoxin residue was significantly (P ≤ 0.05) decreased in the liver tissue of the aflatoxicated group after 2 weeks from the end of the experiment.

Conclusion

Saccharomyces cell wall alone or with nanocurcumin attenuated these negative effects and anomalies and improved all of the above-mentioned metrics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03256-x.

Use of different adsorbents in broiler diets naturally contaminated by mycotoxins

This study investigated the effects of adding different adsorbent substances to broilers feed naturally contaminated by mycotoxins. Two hundred and eighty male 1-day-old chicks, Cobb Slow® lineage, were distributed in a randomized block design with 4 treatments, 5 repetitions with 14 birds each. The treatments consisted of: T1- basal feed naturally contaminated with mycotoxins. T2- basal feed + Bentonite, Thistle Extract, Yeast Extract, Vitamin E and Choline. T3- basal feed + Bentonite, Thistle Extract, yeast cell wall and Silymarin. T4- basal feed + Bentonite and Algae extract. Performance (weight gain, feed intake, feed conversion) at 7, 14, 21, 28 days were evaluated. At 28 days, a portion of the jejunum was collected in two birds by replicate to study the intestinal morphology. The relative weight of the gizzard, proventricle and total intestine was evaluated. The data obtained were analyzed using the statistical program SAS (9.3). With the use of any adsorbents studied, the performance and liver weight were improved in all evaluated periods. Thus, the inclusion of adsorbents improves the performance of the broiler chickens when the feed is contaminated by mycotoxins.

Effects of aflatoxin B1 and monensin interaction on liver and intestine of poultry – influence of a biological additive (Pichia kudriavzevii RC001)

The aim of this study was to evaluate the effects of aflatoxin B1 (AFB1) and monensin (MONS) interaction on the liver and intestinal histological changes in poultry, and the influence of Pichia kudriavzevii RC001. One-day-old commercial line (Ross 308) broilers (n=120) were individually weighed and randomly assigned to 8 treatments (15 broilers/treatment, 5 broilers per cage and 3 replicates/treatment). The experimental diets were: Group 1: basal diet (BD); Group 2: BD + MONS (50 mg/kg); Group 3: BD + P. kudriavzevii RC001 (1 g/kg); Group 4: BD + AFB1 (100 μg/kg); Group 5: BD + MONS + P. kudriavzevii RC001; Group 6: BD + AFB1 + P. kudriavzevii RC001; Group 7: BD + AFB1 + MONS + P. kudriavzevii RC001; Group 8: BD + AFB1 + MONS. When MONS was added, the typical AFB1 macroscopic and microscopic alterations were intensified. The P. kudriavzevii RC001 cytotoxicity and genotoxicity assays with Vero cells and with broiler chicken’s erythrocytes, demonstrated that P. kudriavzevii RC001 neither were non-cytotoxic nor genotoxic. When MONS was added in the presence of P. kudriavzevii RC001, the toxic effect of AFB1 on liver was not prevented. When P. kudriavzevii was present alone, the same prevention of the pathological damage was observed in the intestine of poultry fed with AFB1. The smallest apparent absorption area was obtained when AFB1 and MONS were added in the feed (P<0.05). AFB1 and MONS interaction demonstrated important toxic effects. Although P. kudriavzevii was effective in ameliorating the adverse effects of AFB1 alone on liver pathology and gut morphology, it was not able to diminish the toxic effects of AFB1 in presence of MONS. It suggests that P. kudriavzevii could be used as feed additive or counteracting the toxic effects of AFB1 in poultry production in the absence of MONS.

Aflatoxins associated oxidative stress and immunological alterations are mitigated by dietary supplementation of Pichia kudriavzevii in broiler chicks

Mycotoxins are the secondary metabolites of certain toxigenic fungi which pose severe health stress in humans, animals and poultry. Certain biological agents and components are used to adsorb mycotoxins in poultry industry which provide promising results in this regard. Pichia kudriazevii (PK), a novel yeast, has the ability to enhance the immune status of poultry chicks. The present study was designed to investigate the ameliorative potential of PK against aflatoxins associated immunosuppression and oxidative stress in broiler chicks. 180-one day old broiler chicks were equally divided into six groups and given different combinations of aflatoxins (300 and 600 μg/kg) and PK (1 g/kg). Parameters studied were antibody response to sheep red blood cells, lymphoproliferative response to PHA-P; phagocytic response by carbon clearance assay system, total antioxidant capacity and total oxidant status of chicks. Results of this experiment confirmed the immunomodulation and antioxidant capacity of PK against 300 μg/kg aflatoxin level. However such amelioration was partial when PK was used with 600 μg/kg aflatoxins. Moreover, the exact ratio of aflatoxin: PK to cause such amelioration still needs to be investigated.

Probiotic gut-borne Saccharomyces cerevisiae reduces liver toxicity caused by aflatoxins in weanling piglets

The present study was conducted to investigate the aflatoxin B1 (AFB1) liver toxicity and gut histomorphometry after gut borne-Saccharomyces cerevisiae supplementation to AFB1-contaminated piglet diets. Thirty-two male mixed-breed piglets (weaned at 21 days old) were housed in individual pens and allowed to acclimate for 7 days. Animals were randomly assigned to four treatments of 22 days: T1 – low AFB1 levels diet (L, 31.6 μg/kg); T2 – L + S. cerevisiae 1 g/kg; T3 – high AFs levels diet (H, 495 μg/kg); T4 – H + S. cerevisiae 1 g/kg. The addition of probiotic yeast was able to reduce 72% of residual AFB1 present in the liver. The liver histopathology of piglets fed AFB1 showed a typical macroscopic and microscopic pattern of subclinical aflatoxicosis that was prevented by the yeast. Also, the addition of the yeast was able to decrease the alanine-aminotransferase (25.5±0.71 U) and aspartate-aminotransferase (26.5±6.10 U) even showing values lower than the control ones. The apparent absorption area showed the greater surface when the probiotic was present alone compared to the control (T1), whereas when present together with the toxin demonstrated a modulatory effect. The addition of probiotic gut-borne S. cerevisiae in the pig diets was effective in counteracting the toxic effects of harmful AFB1 in livers besides a tendency to improve the histomorphometric parameters and modulating the toxic effect of AFB1 on intestine. These results are promising for the production of feed additives that will be used in animal feed, since the probiotic action and the decontamination of mycotoxins in the same product are complemented.

Dietary Mannanoligosaccharide Supplementation Improves Growth Performance, Intestinal Integrity, Serum Immunity, and Antioxidant Capacity of Partridge Shank Chickens

Herein, we assessed the impact of dietary addition of konjac mannanoligosaccharide (MOS) on the growth, intestinal morphology, serum immune status, and oxidative status in Partridge Shank chickens. For the experiment, one-day-old chicks (n=192) were randomized into six replicates (n=8/replicate) and fed four different diets: a basal diet containing 0 (Control group), 0.5, 1, or 1.5 g MOS per kg of diet (g/kg) for 50 d. Relative to the control, the group fed 0.5 g/kg MOS decreased feed consumption from 22^nd to 50^th d and 1^st to 50^th d (P<0.05). By adding MOS, the height of the intestinal villus and the villus height to crypt depth ratio were increased (P<0.05); 1.5 g/kg MOS was the best dosage for these parameters. Jejunal and ileal goblet cell density increased following MOS supplementation at 21 d (P<0.01) and 50 d in the jejunum (P<0.05), respectively. Moreover, adding MOS to the diet increased the contents of IgA and IgM at 21 d (P<0.05) and total antioxidant capacity (P<0.05) at 50 d in the serum but decreased malondialdehyde content (P<0.01) at 21 d in the group fed 0.5 and 1.5 g/kg MOS. The findings suggested that MOS supplementation could affect feed consumption, intestinal health, serous immunity, and antioxidant capacity of Partridge Shank chickens.

Production performance, egg quality, plasma biochemical constituents and lipid metabolites of aged laying hens supplemented with incomplete degradation products of galactomannan

This study was conducted to investigate the efficacy of incomplete degradation products of galactomannan (IDPG) on the production performance, egg quality, plasma parameters, and lipid metabolites of laying hens. A total of 288 laying hens were allocated into 4 treatments and fed diets supplemented with 0%, 0.01%, 0.025%, and 0.05% IDPG. Results showed that IDPG supplementation significantly increases egg production and decreases feed conversion ratio (P < 0.05). Eggs laid by hens receiving IDPG exhibited higher eggshell strength (P < 0.05). Moreover, IDPG supplementation significantly increased the serum albumin content, and decreased the blood ammonia content as well as triglyceride levels in serum and liver (P < 0.05). Overall, IDPG can be considered as an effective feed additive due to its capacity of improving egg production, increasing plasma protein, and changing lipid metabolism of laying hens.

Aflatoxin B1 and Aflatoxin M1 Induce Compromised Intestinal Integrity through Clathrin-Mediated Endocytosis

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.

Mycotoxin and Gut Microbiota Interactions

The interactions between mycotoxins and gut microbiota were discovered early in animals and explained part of the differences in susceptibility to mycotoxins among species. Isolation of microbes present in the gut responsible for biotransformation of mycotoxins into less toxic metabolites and for binding mycotoxins led to the development of probiotics, enzymes, and cell extracts that are used to prevent mycotoxin toxicity in animals. More recently, bioactivation of mycotoxins into toxic compounds, notably through the hydrolysis of masked mycotoxins, revealed that the health benefits of the effect of the gut microbiota on mycotoxins can vary strongly depending on the mycotoxin and the microbe concerned. Interactions between mycotoxins and gut microbiota can also be observed through the effect of mycotoxins on the gut microbiota. Changes of gut microbiota secondary to mycotoxin exposure may be the consequence of the antimicrobial properties of mycotoxins or the toxic effect of mycotoxins on epithelial and immune cells in the gut, and liberation of antimicrobial peptides by these cells. Whatever the mechanism involved, exposure to mycotoxins leads to changes in the gut microbiota composition at the phylum, genus, and species level. These changes can lead to disruption of the gut barrier function and bacterial translocation. Changes in the gut microbiota composition can also modulate the toxicity of toxic compounds, such as bacterial toxins and of mycotoxins themselves. A last consequence for health of the change in the gut microbiota secondary to exposure to mycotoxins is suspected through variations observed in the amount and composition of the volatile fatty acids and sphingolipids that are normally present in the digesta, and that can contribute to the occurrence of chronic diseases in human. The purpose of this work is to review what is known about mycotoxin and gut microbiota interactions, the mechanisms involved in these interactions, and their practical application, and to identify knowledge gaps and future research needs.

The Compromised Intestinal Barrier Induced by Mycotoxins

Mycotoxins are fungal metabolites that occur in human foods and animal feeds, potentially threatening human and animal health. The intestine is considered as the first barrier against these external contaminants, and it consists of interconnected physical, chemical, immunological, and microbial barriers. In this context, based on in vitro, ex vivo, and in vivo models, we summarize the literature for compromised intestinal barrier issues caused by various mycotoxins, and we reviewed events related to disrupted intestinal integrity (physical barrier), thinned mucus layer (chemical barrier), imbalanced inflammatory factors (immunological barrier), and dysfunctional bacterial homeostasis (microbial barrier). We also provide important information on deoxynivalenol, a leading mycotoxin implicated in intestinal dysfunction, and other adverse intestinal effects induced by other mycotoxins, including aflatoxins and ochratoxin A. In addition, intestinal perturbations caused by mycotoxins may also contribute to the development of mycotoxicosis, including human chronic intestinal inflammatory diseases. Therefore, we provide a clear understanding of compromised intestinal barrier induced by mycotoxins, with a view to potentially develop innovative strategies to prevent and treat mycotoxicosis. In addition, because of increased combinatorial interactions between mycotoxins, we explore the interactive effects of multiple mycotoxins in this review.

Compound probiotics alleviating aflatoxin B1 and zearalenone toxic effects on broiler production performance and gut microbiota

In order to alleviate toxic effects of aflatoxins B₁ (AFB₁) and zearalenone (ZEA) on broiler production performance and gut microbiota, three kinds of compound probiotics (CP) were selected. The optimal ratios of Bacillus subtilis, Lactobacillus casei and Candida utilis in broiler diets were 7, 5 and 6 log CFU/g for ZEA biodegradation (CP1); 6, 7 and 7 log CFU/g for AFB₁ biodegradation (CP2); 7, 6 and 7 log CFU/g for ZEA + AFB₁ biodegradation (CP3). A total of 350 1-day-old Ross broilers were randomly divided into 7 groups. Group A was the basal diet, group B-G contained ZEA, AFB₁, ZEA + AFB₁, ZEA + CP1, AFB₁+CP2, ZEA + AFB₁+CP3, respectively. The experiment showed that AFB₁ or AFB₁+ZEA significantly decreased broiler production performance, damaged liver and jejunum, increased mycotoxin residues in broiler body; however, three kinds of compound probiotics additions could alleviate mycotoxin negative effects on the above parameters (p < 0.05). The gut microbiota analysis indicated that AFB₁+ZEA increased jejunal microbial richness, but which were decreased to almost the same level as the control group by CP3 addition. CP3 addition significantly increased jejunal Firmicutes and Lactobacillus aviarius abundances. The correlative analysis showed that gut Lactobacillus aviarius abundance was positively correlated with average daily gain (ADG) of broilers (p < 0.05), while AFB₁+ZEA addition decreased its relative abundance, indicating that CP3 addition increased broiler growth by increasing Lactobacillus aviarius abundance. AFB₁ and ZEA residues in broiler body were negatively correlated with the gut beneficial bacterial abundances (p < 0.01), but positively correlated with the potentially harmful bacterial abundances (p < 0.05), which inferred that CP3 addition could decrease mycotoxin residues through positively regulating gut relative bacterial abundances. In conclusion, compound probiotics could keep gut microbiota stable, degrade mycotoxins, alleviate histological lesions, increase production performance and reduce mycotoxin toxicity for broilers.

Harmful Effects and Control Strategies of Aflatoxin B₁ Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review

The presence of aflatoxin B₁ (AFB₁) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB₁ is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB₁ is carcinogenic and implicated in human liver cancer. This review considers how AFB₁ produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB₁ in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB₁ in poultry.