Aflatoxicosis in poultry: A review. Article (PDF Available) · September with Reads. Cite this publication. Ansuman Mohapatra at. Aflatoxins (AF) are a class of mycotoxins, produced by fungal species of the genus Aspergillus (flavus and parasiticus) and Penicillium puberulum, that are often. Abstract. Poultry has commonly been considered highly susceptible to aflatoxins. However, among domestic fowl there is wide variability in specific species sen.
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Poultry feed production and cost are major issues faced by poultry industries in many countries of the world.
Grains, such as corn, wheat, soybean, rice and their by-products used for the production of poultry feed are shared by humans and animals. Due to the competitive pricing of raw material and their availability on the market, sometimes lower quality feed ingredients are used in poultry feed production. These materials may be stored for longer periods and due to poor storage conditions, they may be contaminated with fungi, especially in humid and hotter countries, such as Indonesia.
Some fungi may produce mycotoxins as secondary metabolites that further contaminate these grains used for feed ingredients. These diseases may vary on the severity, target sites, and mechanism of toxicity. Poultry ingesting mycotoxin in high concentration may likely suffer from acute or sub-acute disease where toxic effects directly affect specific tissues or organs. However, mycotoxicoses in lower levels with continued introduction of mycotoxins may cause chronic disease, which may further worsen by secondary infections due to their immune suppressive effects Naehrer, Mycotoxicoses should be differentiated from mycoses which are systemic diseases caused by invasion of growing fungi into living tissues, initiating mechanical destruction.
They are synthesized and excreted during the maximum growth of certain fungi under favorable conditions Naehrer, Most mycotoxins are known to hazardously contaminate crops and consequently poultry feeds and poultry products, causing significant economic losses associated with their impact on poultry and human health, poultry performance, and domestic as well as international trade.
This paper presents the common clinical signs and pathological lesions caused by the most important mycotoxins in the poultry industry in Indonesia. The process of mycotoxin production by fungi is not well known. Higher mycotoxin contamination can be found in crops subjected to stress, such as drought, poor fertilization or excess of water. A possible explanation is that mycotoxins are produced so that fungi win a competitive advantage on other organisms Rankin and Grau, Despite the fact that proper conditions for growth of fungi can occur at all times during crop growth, harvest, and storage, fungal species can be divided into field fungi, which infect crops as parasites, and storage fungi which grow in feedstuffs stored under suboptimal conditions.
Field fungi are those, which in general require higher moisture to grow and produce mycotoxins, infecting seeds and plants in the field, such as Fusarium sp. Storage fungi are those, which require lower water activity, thus being more prominent after harvest and during storage, such as Aspergillus sp. In general, the production of these mycotoxins is ubiquitous and more prevalent in warm and moderate climates; however, trichothecenes and zearalenone may equally be produced at lower temperatures.
Initial growth of fungi in grains can form sufficient moisture from metabolism to allow for further growth and mycotoxin formation. Finished feed should not be stored for long periods of time as mycotoxin contamination can occur in these products Richard, Each fungus species can produce more than one type of mycotoxin, such as Aspergillus sp.
Therefore, the probability of contamination of certain feed ingredients or finished feed with multi-mycotoxins is very high Speijers and Speijers, Mycotoxins are chemical compounds of low molecular weight and low immunogenic capacity.
They are chemically stable due to their chemical structure and low molecular weight. They resist high temperatures, remain stable during storage and during feed processing conditions Bullerman and Bianchini, Mycotoxins carried over at low levels, such as aflatoxins, ochratoxins, T-2 toxins can be found in the liver, kidney, muscle, and eggs CAST,Volkel et al.
At some extent, they may be a potential risk to consumers of food products of poultry origin Naehrer, Mycotoxin contamination and the severity of the problem caused by these compounds vary from year to year and also from one geographic region to the other. Many fungi contaminate the crop during the growing season and others are seed borne and grow along with the plants, whereas others infect commodities during storage. Contamination and subsequent mycotoxin production may be influenced by the environmental conditions at specific times during the crop development or storage Sanchis, Therefore, the formation of mycotoxins in the field is difficult to control.
The only proven way to determine, if grains contain mycotoxins or not, is to test for them in the laboratory. However, contamination with mycotoxins can be suspected if certain signs or characteristics appear in the raw materials for feed.
Such signs may be visually discolored kernels, musty odor, lighter weight than usually kernels, or with wrinkle kernels in grain Richard, Several hundreds of mycotoxins have been reported and isolated, as many as approximately varieties, with their target sites and toxicity, with varying chemical structures of each one. Masked mycotoxins are mycotoxins that experienced changes in their chemical structures. Protein and glucosides, as an example, can be bound to mycotoxins by growing plants in the field to protect themselves from foreign compounds or by microorganisms which may change the mycotoxin structure during storage.
In rare cases, some mycotoxins conjugates can be excreted directly by fungi, such as 3-acetyldeoxynivalenol and acetyldeoxynivalenol by Fusarium sp. Alteration of mycotoxins structure my also occur during feed processing, as in the case of fumonisin reaction with reducing sugars Lu et al. Unfortunately these conjugate mycotoxins cannot be detected by most routine analysis. However, during digestion the mycotoxin-ligand bond can be released and the mycotoxin act as a toxin, thus causing its hazardous effects on animals Berthiller et al.
When they are simultaneously present, their interactive effects can be classified as additive, synergistic, or antagonistic. The co-exposure of two mycotoxins led to more severe total effect than each individual toxin, even in cases categorized less than additive or antagonistic.
The interaction between mycotoxins often leads to synergistic effects, when the negative effects of one mycotoxin are amplified the presence of another. In case of poultry, synergistic effects were frequently described in instances where aflatoxins were involved, with the same for ochratoxin A, T-2 toxin, and fumonisin B1. Afaltoxin B1, which is known to be a hepatotoxin and ochratoxin A, a nephrotoxin, acted synergistically when fed simultaneously to broiler chicks Huff et al.
Synergistic effects were also seen in broilers fed aflatoxin B1 and T-2 toxin Huff et al. Mycotoxins producing fungi are ubiquitous in nature and under ideal conditions, often contaminate economically important crops in the fields, as well as during their harvest, storage, shipment, and processing.
It is known that mycotoxins exist worldwide where their formation are no longer restricted to hot and humid climates and being widely distributed due to international trade in various agricultural raw materials Naehrer, However, these low levels of mycotoxins may induce subclinical diseases in poultry, which indicated that there is no existing save level for mycotoxins Borutova, Effects of low levels of mycotoxins will be more severe if they are found as multi-mycotoxins that have synergistic or additive effects.
Another common problem with mycotoxins is the contamination of commodities with masked mycotoxins which cannot be detected by routine laboratory analysis Vendl et al. Mycotoxicoses are difficult to diagnose because of a great variation in possible symptoms and target organs as well as pathological lesions.
Toxic effects of mycotoxins can occur at toxin concentration below detection limits.
AFLATOXICOSIS – Diseases of Poultry – The Poultry Site
Their toxic effects in poultry are very diverse, varying from immune suppression to death in severe cases, depending on toxin related type of mycotoxins, level and duration of intakeanimal-related species, sex, age, breed, general health, immune status, nutritional aflatoxicsisand environmental factors farm management, biosecurity, temperature, humidity Naehrer, The mechanisms of mycotoxins toxicity are not fully understood due to the diversity in their chemical structures aflatoxicosiss target organs.
Most mycotoxins can cause lipid peroxidation, damage of membrane structures and their functions, induces apoptosis programmed cell death leading to cellular necrosis Surai,Fink-Gremmels, The mycotoxins may cause immune suppression impairment of immune systemhepatotoxicity damage to the livernephrotoxicity damage to the kidneysneurotoxicity damage to the central and peripheral nervous systemsgenotoxicity damage to DNA leading to cell transformation, abnormal cellular proliferation and finally tumor formation Devegowda and Murthy,Tabbu, Poultry are farm animals with heterogeneous sensitivity to mycotoxins, as different species suffer from different toxic effects.
Ducks, geese, and turkeys seem to be more sensitive to mycotoxicoses than chickens and quails. Young chickens are more sensitive to the effects of mycotoxins. Chickens placed in a hostile environment, such as high temperatures and humidity, poor ventilation, high pohltry, and challenges of other diseases are more susceptible to mycotoxins Naehrer, The effects of mycotoxins in poultry are very complex and varies greatly according to their mechanism of toxicity and primary target organs.
An overview of aflatoxicosis of poultry: its characteristics, prevention and reduction.
When mycotoxins are present simultaneously in feed, they may have synergistic or additive effects. Their aflatxoicosis are diverse, varying from immune suppression to death. A low level of mycotoxins in feed even below its restricted levels when exposed for long periods can impair the immune system leading to the immune pkultry conditions.
Aflatoxins, ochratoxin, trichothecenes, and fumonisins are known to induce immune suppressive effects in chickens, rendering them more susceptible to diseases Singh et al.
In addition, low level of mycotoxins can have an antimicrobial effect and can cause feed passage Devegowda and Murthy, Mycotoxins can inhibit the absorption of vital nutrients for maintaining health condition, growth, productivity, and reproductive, include amino acids, lipid soluble vitamins vitamin A, D, E, and Kand minerals, especially Ca, P Devegowda and Murthy, Even though the effects of mycotoxins are very complex and there is a great variation in possible symptoms, target organs, and pathological lesions from one mycotoxin to the other Naehrer,presumptive diagnosis can be based on clinical signs, pathological lesions on target organs, especially when moldy ingredients or feed are evident.
Samples of feed and ingredients should be collected and promptly submitted for laboratory analysis. Clinical signs and pathological lesion related to mycotoxins are closely related to poultry species, type of mycotoxins, dose ingested, and duration of exposure.
In the field, poultry, such as chickens are exposed to multi-mycotoxins and subjected to a broader variety of stressing factors. Therefore, chickens may exhibit signs and lesions of mycotoxicoses, even at apparent low level of mycotoxins present in the feed Naehrer, Symptoms and lesions can be very general and vary greatly between mycotoxins; usually as a secondary effect of mycotoxicoses.
In the loultry, disease process related to mycotoxicoses tend to be chronic, even though acute or subacute diseases may occurred rarely. They may have systemic or local effects, specific or often non-specific target organ.
The following section presents the common clinical signs and pathological lesions related to the most frequent mycotoxins found in poultry operations, especially chicken farms in Indonesia, include aflatoxins, trichotecenes T-2 toxin, DONpoultrt, fumonisins, and zearalenone.
Field trials, scientific, and laboratory research have been performed leading to different results and conclusions. Nevertheless, it must not be forgotten that effects of mycotoxins are very complex and it is possible that symptoms and pathological lesions aflwtoxicosis to the ones presented here may also occur Naehrer, Aflatoxin is known to have a hepatotoxic effect in chickens Dalvi,Espada et al.
The common clinical signs related to aflatoxicosis in chickens, include decreased feed intake, poor aflatoxicozis and inhomogeneous flocks Figure 1increased mortality, abnormal pigmentation shank, feetfeed passage, and higher feed conversion rate FCR.
The most consistent findings in chickens suffer afpatoxicosis aflatoxicosis was immune suppressive effects, include more susceptible to diseases, decreased responds to vaccination and antibiotic treatment, and decreased resistance to environment stress. In many cases of aflatoxicosis there was an increase in leg problems, leg weakness, reduced bone strength, short shank, and leg deformity.
In some cases, there were anemia and abnormal blood clotting, increased incidence of bruising and down grading, and nervous syndrome abnormal behavior. The most frequent effects of aflatoxicosis in layers and parent aflxtoxicosis were decreased egg production, reduced ni size, poor thin egg shell, pale egg shell and egg yolk. In parent stocks, there was a reduction in fertility and hatchability, increased embryo mortality in the hatchery, and lower semen volume in male parent stocks. The most common pathological lesions associated with aflatoxicosis in chickens were found in liver, lymphoid organs, and testes male parent stocks and the process of this disease was commonly aflaoxicosis.
In acute-subacute aflatoxicosis, the liver appeared enlarged, pale yellow in color, friable, and usually the gall bladder was enlarged and filled with bile. The pancreas was usually small and depigmented and there were hemorrhages on subcutaneous tissues and aflztoxicosis.
In chronic aflatoxicosis, the liver was small, firm, and rounded Figure 2. Sometimes this organ was very aflatodicosis, rounded, and rubbery which very often complicates with ascites and hydropericardium.
The other consistent lesions in aflatoxicosis were found in bursa Fabricius, thymus, and spleen which appeared smaller than normal Figure 3 ; in male parent stocks, the size of testes was significantly reduced Figure 4.
Trichothecenes mycotoxins affect actively dividing cells, such poutlry those lining af,atoxicosis gastrointestinal tracts, skin, lymphoid and erythroid cells.
They have caustic and irritant effects on the skin and mucous membrane Devegowda and Murthy, The common clinical signs related to these mycotoxins were decreased feed intake, included feed refusal or prolonged feed finish, growth depression, inhomogeneous flocks, impaired FCR, immune suppression, poor or abnormal feathering Figure 5dermal and oral lesions crust on the beak, ulcers in oral poulrty Figure 6. Additional symptoms which were commonly found were diarrhea, abnormal pigmentation, anemia, and rickets effects, including severe fragility and bending of long bones and shanks, soft and alatoxicosis of beak.
In layers and parent stocks, there was a sharp decrease in egg afltaoxicosis, poor egg shell, increased number of cracked eggs, reduced egg size; cyanosis of the comb and wattle; decreased fertility and hatchability parent stocks.