Mycotoxins in broilers: pathological alterations induced by aflatoxins and ochratoxins, diagnosis and determination, treatment and control of mycotoxicosis

Comprehensive Review of Aflatoxin and Ochratoxin A Dynamics: Emergence, Toxicological Impact, and Advanced Control Strategies

Filamentous fungi exhibit remarkable adaptability to diverse substrates and can synthesize a plethora of secondary metabolites. These metabolites, produced in response to environmental stimuli, not only confer selective advantages but also encompass potentially deleterious mycotoxins. Mycotoxins, exemplified by those originating from Alternaria, Aspergillus, Penicillium, and Fusarium species, represent challenging hazards to both human and animal health, thus warranting stringent regulatory control. Despite regulatory frameworks, mycotoxin contamination remains a pressing global challenge, particularly within cereal-based matrices and their derived by-products, integral components of animal diets. Strategies aimed at mitigating mycotoxin contamination encompass multifaceted approaches, including biological control modalities, detoxification procedures, and innovative interventions like essential oils. However, hurdles persist, underscoring the imperative for innovative interventions. This review elucidated the prevalence, health ramifications, regulatory paradigms, and evolving preventive strategies about two prominent mycotoxins, aflatoxins and ochratoxin A. Furthermore, it explored the emergence of new fungal species, and biocontrol methods using lactic acid bacteria and essential mustard oil, emphasizing their efficacy in mitigating fungal spoilage and mycotoxin production. Through an integrative examination of these facets, this review endeavored to furnish a comprehensive understanding of the multifaceted challenges posed by mycotoxin contamination and the emergent strategies poised to ameliorate its impact on food and feed safety.

Unraveling the combined deleterious effects of ochratoxin A and atrazine upon broiler's health: Toxicopathological, serum biochemical and immunological perspectives

Atrazine, a herbicide, is used for eradication of broad-leaved herbs in corn crop; and ochratoxins, particularly ochratoxin A (OTA), are major pollutants of poultry diet. Existence of both of these hazardous chemicals as residues is obvious as elucidated by various epidemiological findings. The present study was designed to investigate toxicopathological, serum biochemical and immunological alterations incurred by atrazine alone and/or, in combination with OTA in broilers. For this purpose, one-day old broiler chicks (n = 180) were purchased from a local hatching unit and were fed two levels of atrazine (50 and 150 mg/kg) and one level of OTA (100 μg/kg) in different combinations. Results of this experiment showed a significant reduction in feed intake, body weight gain, relative organ weights, serum total protein, albumin and globulin while there was a significant increase in urea and creatinine levels, decreased antibody response to sheep red blood cells, reduced lymphoproliferative response and phagocytic capacity in groups given OTA and atrazine individually in feed and these effects became more pronounced when atrazine was given in combination with OTA suggesting synergistic effects of both toxicants for each other.

Effects of Combinations of Toxin Binders with or without Natural Components on Broiler Breeders Exposed to Ochratoxin A

The objective of this study was to investigate the effects of toxin binders on broiler breeders fed an ochratoxin A (OTA)-contaminated diet. A total of 60 45-week-old female Arbor Acres broiler breeder birds with an initial body weight of 3.65 ± 0.35 kg were randomly divided into 6 treatment groups, with 10 replicates per group and 1 bird per replicate. The trial was conducted for 9 weeks (including 1 week of adaptation). Feed additive 1 (FA1) was composed of clay minerals (85% bentonite and 12% clinoptilolite) with 3% charcoal. FA2 was composed of clay minerals (66.1% aluminosilicates) with natural components (0.8% artichoke and rosemary plant extracts), 7% yeast extract, 0.5% beta-glucans, and 25.6% carriers. The dietary treatment groups were as follows: (1) birds fed an OTA-free basal diet (Negative Control; NC); (2) lipopolysaccharide (LPS)-challenged birds fed a diet including OTA (4 mg/kg) (Positive Control, PC); (3) the PC with 0.05% FA1 (Treatment 1, T1); (4) the PC with 0.10% FA1 (Treatment 2, T2); (5) the PC with 0.10% FA2 (Treatment 3, T3); and (6) the PC with 0.20% FA2 (Treatment 4, T4). The LPS challenge (an intramuscular injection of 1 mg E. coli O55:B5 LPS per kg of body weight) was performed on the first day of the experiment. The results of this experiment show that the PC treatment negatively affected (p < 0.05) egg production, hatchability, Haugh unit, bone mineralization, relative organ weight (abdominal fat, liver), the levels of glutamic oxaloacetic transaminase (GOT), high-density lipoprotein (HDL), and total cholesterol in the blood, and OTA accumulation in the liver compared with the NC. However, supplementation with toxin binders mitigated (p < 0.05) the negative effects of the OTA. Specifically, supplementation with 0.10% FA1 and 0.10% FA2 increased (p < 0.05) eggshell strength by week 4, and the Haugh unit and bone mineralization (phosphorous) by week 8, while decreasing (p < 0.05) the relative weight of the liver and the levels of GOT and HDL in the blood. Supplementation with 0.10% FA2 led to greater improvements in various parameters, including laying performance and bone mineralization, than the other treatments. In conclusion, toxin binders with or without natural components can be effective tools in the mitigation of OTA-induced problems due to their synergistic effects.

Restoring Activity of Milk Thistle (Silybum marianum L.) on Serum Biochemical Parameters, Oxidative Status, Immunity, and Performance in Poultry and Other Animal Species, Poisoned by Mycotoxins: A Review

Grains are major farm animals' diet ingredients, and one of the main concerns is when are mycotoxin (MyT) contaminated, compromising animals' health, performance, and product safety. Among the natural phytocompounds that are being used to prevent MyT damage, silymarin (SIL), an extract from the seed of the milk thistle (MT) is a suitable candidate. This review aims to examine the scientific evidence concerning the anti-MyT toxicity effects of MT/SIL in poultry and livestock. In vitro and in vivo studies (n = 27) showed that MT whole plant, seed, or SIL-standardized extract had positive effects on animal health, performance, and restoring the hepatic activity, with a reduction of organ lesions caused by MyT. Furthermore, showed utility for combating MyT-immunodepression, improving intestinal health, and limiting the excretion of toxins residues in food of animal origin, although in some cases, MT/SIL supplementation does not produce appreciable effects. The use of MT in animal nutrition can be useful since the bioactive compounds, also if present in variable amounts, can help the animals to counteract the effects of MyT. The use of the phytoextract of SIL, due to its cost, can be useful if it reported the specific bioactive compounds, recognize for their pharmacological activities.

Aflatoxins in Feed: Types, Metabolism, Health Consequences in Swine and Mitigation Strategies

Feeding farm animals with aflatoxin-contaminated feed can cause various severe toxic effects, leading to increased susceptibility to infectious diseases and increased mortality, weight loss, poor performance and reduced reproductive capability. Following ingestion of contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in animals. Swine metabolism is not effective in detoxifying and excreting aflatoxins, meaning the risk of aflatoxicosis is increased. Thus, it is of great importance to elucidate the metabolism and all metabolic pathways associated with this mycotoxin. The damage induced by AFB1 in cells and tissues consists of inhibition of cell proliferation, carcinogenicity, immunosuppression, mutagenicity, oxidative stress, lipid peroxidation and DNA damage, leading to pathological lesions in the liver, spleen, lymph node, kidney, uterus, heart, and lungs of swine. At present, it is a challenging task and of serious concern to completely remove aflatoxins and their metabolites from feedstuff; thus, the aim of this study was a literature review on the deleterious effects of aflatoxins on swine metabolism, as well as alternatives that contribute to the detoxification or amelioration of aflatoxin-induced effects in farm animal feed.

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.

Mitigation of Aflatoxin B1 Hepatoxicity by Dietary Hedyotis diffusa Is Associated with Activation of NRF2/ARE Signaling in Chicks

The objective of this study was to explore the mechanism of Hedyotis diffusa (HD) in mediating the detoxification of aflatoxin B1 (AFB1)-induced hepatic injury in chicks. A total of 144 one-day-old male broilers (Cobb 500) were randomly assigned to four treatment groups (n = 6 cages/diet, 6 chicks/cage). After three days of acclimation, the broilers were fed either a control diet (Control), Control plus 0.5 mg/kg of AFB1, or Control plus 0.5 mg/kg AFB1 with 500 or 1000 mg/kg HD for two weeks. Both serum and liver were collected at the end of the feeding trial for biochemistry, histology, and NF-E2-related nuclear factor 2 (NRF2)/antioxidant response element (ARE) signaling analysis. Compared with Control, the AFB1 treatment caused liver injury and decreased (p < 0.05) body weight gain, feed intake, feed conversion ratio, and serum albumin and total protein by 6.2-20.7%. AFB1 also induced swelling, necrosis, and severe vacuolar degeneration in chicks' livers. Notably, HD supplementation at 500 and 1000 mg/kg mitigated (p < 0.05) the alterations induced by AFB1. HD supplementation alleviated (p < 0.05) AFB1-induced impairment in hepatic glutathione peroxidase activity, protein carbonyl, and exo-AFB1-8,9-epoxide (AFBO)-DNA concentrations by 57.7-100% and increased (p < 0.05) the activities of superoxide dismutase and catalase by 23.1-40.9% more than those of AFB1 treatment alone. Furthermore, HD supplementation at the two doses upregulated (p < 0.05) NRF2, NAD(P)H: quinone oxidoreductase-1, heme oxygenase-1, glutathione cysteine ligase catalytic subunit, and glutathione-S transferase A2 and A3 in livers relative to the AFB1 group by 0.99-3.4-fold. Overall, dietary supplementation of HD at a high dose displayed better protection effects against aflatoxicosis. In conclusion, a dietary HD supplementation at 500 and 1000 mg/kg protected broilers from AFB1-induced hepatotoxicity, potentially due to the activation of NRF2/ARE signaling in the chicks.

Assessment of Ochratoxin A Exposure in Ornamental and Self-Consumption Backyard Chickens

Ochratoxin A (OTA) is a mycotoxin that may be present in various food and feed of plant and animal origin, including chicken meat. In Italy, backyard poultry farming is rather widespread. Animals are raised for meat, eggs and for ornamental purpose, and they are often fed with home-made diets not subject to official controls. The purpose of this study was to evaluate exposure of ornamental and backyard chickens to OTA using biliary ochratoxin A as a biomarker. Therefore, bile samples, in addition to kidney, liver and muscle, were collected from 102 chickens reared in 16 farms located in 6 Italian regions. High-performance liquid chromatography method and fluorimetric detection (HPLC-FLD) analysis were carried out firstly on bile from all animals, and OTA was detected in 12 chickens (concentration range 3.83-170.42 µg/L). Subsequently, the kidneys of these chickens were also analysed, and the mycotoxin was not detected. The analytical detection limits (LODs) of OTA in bile and kidney were 2.1 µg/L and 0.1 µg/kg, respectively. In conclusion, these animals were exposed to OTA but their meat can be considered safe, given that this mycotoxin, if present, concentrates highest in kidneys. Biliary ochratoxin A confirms its use as a valid biomarker to assess exposure of poultry to OTA.

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens fed diets naturally contaminated with ochratoxin A

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens fed diets contaminated with ochratoxin A (OTA). One hundred and twenty ROSS 308 broiler chickens were randomly divided into six groups (10 replications, 2 birds per replication). Group I received an uncontaminated and unsupplemented diet, diets of groups II to VI were contaminated with OTA at 172 µg and 200 µg/kg for the starter and grower period, respectively. Furthermore, diets of groups III, IV and V were supplemented with vitamin E at 100, 200 and 100 mg, respectively, and to diets of groups V and VI additionally 100 and 2200 mg PP was added, respectively. Supplementation with PP and vitamin E had no significant effects on the growth performance, dressing percentage or carcass trait parameters of broiler chickens. In chickens exposed to stress, dietary supplementation with vitamin E and/or PP improved the total antioxidant status (p ≤ 0.05), enhanced the blood activity of antioxidant enzymes (p ≤ 0.01) and increased the concentrations of non-enzymatic antioxidants (p ≤ 0.01) in the liver and breast muscles. Regardless of the administered antioxidants, chickens fed diets contaminated with OTA were characterised by lower dressing percentage (p ≤ 0.01), a higher proportion of the liver in the carcass (p ≤ 0.01), lower carcass fat content (p ≤ 0.01), and longer small intestines (p ≤ 0.01) and caeca (p ≤ 0.01). Dietary supplementation with PP improved the water-holding capacity of meat (p ≤ 0.01). The breast muscles of chickens fed diets supplemented with PP and vitamin E were characterised by higher (p ≤ 0.05) concentrations of eicosapentaenoic acid (C_20:5). It was concluded that PP can be an insufficient component of diets for broiler chickens to improve growth performance and mitigate the negative effects of high dose of OTA in diets.

Effects of feeding bentonite clay upon ochratoxin A-induced immunosuppression in broiler chicks

A presence of mycotoxins in feed is one of the most alarming issues in the poultry feed industry. Ochratoxins, produced by several Aspergillus and Penicillium species, are important mycotoxin regarding the health status of poultry birds. Ochratoxins are further classified into to several subtypes (A, B, C, etc) depending on their chemical structures, but ochratoxin A (OTA) is considered the most important and toxic. Bentonite clay, belonging to phyllosilicates and formed from weathering of volcanic ashes, has adsorbent ability for several mycotoxins. The present study was designed to study the effects of bentonite clay upon OTA-induced immunosuppression in broiler chicks. For this, 480 day-old broiler chicks were procured from a local hatchery and then different combinations of OTA (0.15, 0.3, or 1.0 mg/kg) and bentonite clay (5, 10, and 20 g/kg) were incorporated into their feed. At 13, 30, and 42 days of age, parameters such as antibody responses to sheep red blood cells, in situ lymphoproliferative responses to mitogen (PHA-P), and in situ phagocytic activity (i.e., via carbon clearance) were determined respectively. The results indicated there was a significant reduction of total antibody and immunoglobulin titres, lymphoproliferative responses, and phagocytic potential in OTA-treated birds, suggesting clear immunosuppression by OTA in birds in a dose-dependent manner. These results were also significantly lower in all combination groups (OTA with bentonite clay), suggesting few to no effects of feeding bentonite clay upon OTA- induced alterations in different immune parameters.

Mitigation potential of distillery sludge against ochratoxin A induced immunological alterations in broiler chicks

Ochratoxin A (OTA) is a potent mycotoxin injurious to poultry health and an alarming factor for poultry industry while distillery sludge (DS) is a waste product of molasses based industries rich in proteins and certain essential vitamins and other nutrients. The present study was done to estimate the immunological alterations induced by OTA in broiler chicks and amelioration of these alterations by dietary supplementation of DS. For this purpose, 480 one-day old broiler chicks procured from a local hatchery, were divided into sixteen equal groups and were given different combinations of OTA (150, 300 and 1000 µg/kg feed) and DS (5, 10 and 20 g/kg feed). Parameters studied were antibodies response to sheep red blood cells (SRBCs), lymphoproliferative response to PHA-P and phagocytic index as studied by carbon clearance assay. The results of this study showed that feeding DS with 150 and 300 µg/kg OTA ameliorated OTA induced alterations, but this amelioration was partial when 1000 µg/kg OTA was used along with DS. From this study it could be concluded that DS has beneficial effects in birds suffering from ochratoxicosis. However, the proper level of DS to produce such mitigation against specific level of OTA is yet to be determined.

Estimation of ochratoxin A in poultry feed and its ingredients with special reference to temperature conditions

1. The present study was designed to analyse ochratoxin A (OTA) in poultry feed samples (mixed types) along with different poultry feed ingredients collected from different farms and market of Lahore, Pakistan. 2. The whole year (2012-2013) was divided into three sub-periods depending upon environmental conditions, that is, July-October (hot and humid), November-February (winter) and March-June (moderate). During each sub-period 120 samples were collected for each feed and each ingredient constituting a total of 840 samples (120x7 of feed and feed ingredients in each sub-period). 3. The results of this study indicated that the incidence of OTA-positive samples was highest in July-October followed by that during March-June while the incidence was minimum during November-February. Similarly, the largest number of samples was below the maximum tolerable level (MTL) during November-February followed by March-June while the least number of samples was below MTL during hot weather (July-October). 4. This is the first elaborative study regarding the levels of OTA in poultry feed and its ingredients collected from Lahore, Pakistan.

Ameliorative effects of L-carnitine and vitamin E (α-tocopherol) on haematological and serum biochemical parameters in White Leghorn cockerels given ochratoxin A contaminated feed

1. L-carnitine is a quaternary ammonium compound biologically synthesised from the amino acids methionine and lysine while vitamin E (α-tocopherol) is an important antioxidant. The objective of the present study was to evaluate the ameliorative effects of L-carnitine and vitamin E upon haematological and serum biochemical parameters in ochratoxin A intoxicated birds. 2. Day-old White Leghorn cockerels were acclimatised for 2 d, divided in 12 groups with 20 birds in each group. From d 3 of age, they were given different combinations of ochratoxin A (1.0 and 2.0 mg/kg), L-carnitine (1 g/kg) and vitamin E (200 mg/kg) in feed. Haematological (erythrocyte count, leucocyte count, haemoglobin concentration and haematocrit percentage) and serum biochemical parameters (serum urea, creatinine, albumin, total proteins and alanine aminotransferase) were evaluated. 3. Results confirmed that L-carnitine and vitamin E given alone or combined with 1.0 mg/kg ochratoxin A ameliorated toxin induced alterations in haematological and serum biochemical parameters. This amelioration, however, did not occur when ochratoxin of 2.0 mg/kg was given. 4. L-carnitine and vitamin E in combination have the ability to ameliorate ochratoxin altered haematological and serum biochemical parameters. However, the optimum ratio of L-carnitine + vitamin E, to be used to assure such mitigation of ochratoxin A altered changes in haematological and serum biochemical parameters in cockerels, has yet to be determined. The combination used in this study was indeed sufficient to ameliorate the alterations induced by ochratoxin A up to 1.0 mg/kg feed.