Mycotoxicosis in poultry is undoubtedly the most serious condition which arises due to managemental disturbances at the poultry farm. It refers to all those diseases or disorders caused by the effects of toxins produced by fungal affections. Mycotoxicosis is often subclinical and difficult to diagnose at an early stage. Lower levels cause the occurrence of chronic mycotoxicosis with or without manifested clinical symptoms, but followed by a considerable decrease in production performance, immunosuppressive effects, and the occurrence of residues in poultry meat and eggs. Higher level of mycotoxins results in the appearance of acute mycotoxicosis and increased mortality rate. It is a global problem affecting the poultry farmer’s profits to a greater extent. It is frequently seen at places which have climate with high temperature and humidity and where grains are harvested with high moisture content.
There are numerous mycotoxins in the food chain that cause unwanted biological effects inside human and animal organisms upon ingestion (Bryden , 2007). Different types of mycotoxins are recognised like aflatoxins (Aspergillus flavus); T2 fusariotoxins (Fusarium spp.); ochratoxins (Aspergillus ochraceus); zearelenones etc. All the toxins have diverse activity and causes different types of illness in the bird but all of them lead to reduction in the bird’s growth and performance. The main route of infection is by ingestion of the toxic substance by the birds. Once formed it is difficult to avoid their damaging effects on the bird and not only that they also affect the immunity of the bird and there is increased susceptibility to bacterial infections as well.
The various types of toxins responsible for mycotoxicosis in poultry have different structures, metabolism as well as actions. The level of toxicity is also variable and therefore the different toxins are to be discussed separately.
The places where the climatic conditions are warm and humid, Aflatoxins are a major threat. But prevention must be taken in colder climates when using feedstuffs which have been imported from warm and humid countries.
Among poultry, susceptibility in ducks are the highest, followed by turkeys, broilers, laying hens and quail. Aflatoxins are hepatotoxic with fatty changes, causing hepatocyte degeneration, necrosis, and disturbed liver function. Aflatoxin interferes with vitamin D metabolism, which may cause reduced bone strength in birds. Aflatoxin negatively affects lipid and pigment absorption as they reduce bile salts production. Due to the transfer of aflatoxin into edible products and its carcinogenic effects, most countries have set upper legal limits for aflatoxin in feed.
- Decreased weight gain / anorexia
- Decreased egg production
- Reduce feed conversion efficiency
- Increased mortality
- Immune suppression and increased disease susceptibility
- Reduced fertility and hatchability
- Reduced bone strength
- Fatty and necrosed liver
Depending upon the amount and duration of exposure, ochratoxins A shows its toxic symptoms which mainly involves the kidney and liver. After getting absorbed from the system, its highest concentration can be found in the kidneys, liver and muscles. Inside the liver, ochratoxin A is hydrolysed to OT-alpha and L-phenylalanine and within 48 hours of ingestion, almost 90% of the ingested toxin is secreted. It is considered that the primary effects are perhaps connected with the activity of OTA on enzymes involved in the phenylalanine metabolism (phenylalanine-transferase, phenylalanine-hydroxylase, phenylalanine-lipoperoxide). Another mechanism of the toxicity is based on elevated lipid peroxidation in liver and kidney microsomes (Fuchs, 1988).
Clinical signs :
- Decreased feed intake
- Decreased growth rate and egg production
- Decreased feed conversion efficiency
- Mortality due to acute renal failure
- Poor egg shell quality
- Higher incidence of eggs with blood spots
- Decreased feathering
- Polyurea with wet faeces
- Pale and grossly enlarged kidney
- Fatty liver
Popularly called feed refusal toxins due to its effect on birds feeding tendency which is highly suppressed. In poultry, poisoning can be visualised either as acute or chronic. The acute form, is easily diagnosed because of clear signs and symptoms. However, the chronic form due to unspecific clinical symptoms is difficult to diagnose. After ingestion, T-2 toxin is very rapidly resorbed in the lower parts of the digestive tract (before jejunum), and only one hour after the ingestion it reaches maximum concentration in the blood (Uraguchi and Yamazaki, 1978).
- Oral lesions
- Reduced feed intake
- Reduced weight gain and egg production
- Poor shell quality
- Reduced female fertility and hatchability of fertile eggs
- Immune suppression, reduced vaccination response
- Gizzard erosion
- Necrosis of proventricular mucosa
- Regression of ovaries
- Increased liver weight
These toxins affect the reproductive system of the body due to their oesterogenic activity. In general the toxicity is low and the poultry birds are supposed to be resistant to such toxins. The main symptoms seen are
- Enlarged Vent
- Enhanced secondary sexual characters
Mainly the toxin binders (organic, inorganic) and mycotoxins modifiers (yeast, bacteria, enymes etc.) are employed to check the mycotoxicosis in the birds along with the feed mainly and has broad substrate binding capacity. In this way the binder and the toxin both are excreted by the body through manure.
Mycotoxin binding is achieved through:
It involves weak bonding involving van der Waals interactions and hydrogen bonding
It involves ionic or covalent bonding which is a stronger interaction.
A high level of inclusion of adsorbents can also affect the physical properties of the feed which might disturb feed processing steps such as pelleting as well as altering the actual diet specification. Many toxin binders can impair nutrient utilisation as they bind with the essential nutrients from the feed of the birds.
There is a raised demand of an alternative solution to counter the problems of mycotoxicosis in the poultry farms which at present is a major challenge for the farmers affecting food safety and farm productivity. There is necessity of a solution which is free from side effects and provides a natural cure as well as increases the farm productivity and profitability.
Polyherbal Approach (Vilocym Z):
Herbs have a very crucial role to play in the prevention and treatment aspects, be it humans or animals. They have a number of activities which when utilized wisely can help the poultry farmers wisely overcome the problem of mycotoxicosis as well as improved growth and productions. A number of such preparations are available in the market to combat mycotoxicosis by the help of natural means but as far as farmers view is concerned, he will always prefer a product which has a combination of herbs so as to counter mycotoxicosis and increase production.
Vilocym Z (Ayurvet limited) is one such preparation having a combination formulated with selected herbs like Phyllanthus emblica, Azadirachta indica, Curcuma longa etc. which not only helps to reduce the production of mycotoxins but also detoxifies the mycotoxins by stimulating liver enzymes. Besides herbs, it also has Copper, mannan oligo-sachharides (MOS), Polyvinylpyrrolidone (PVP), buffered organic acids and activated Hydrated Sodium Calcium Aluminium Silicates (HSCAS) which provide mould inhibitory action, mycotoxin biosynthesis inhibitory action, multiple mycotoxin chemosorption action, mycotoxins bio neutralization action, reduction in the colonisation of pathogenic bacteria, digestive tonic and friendly microflora enhancing action, liver tonic and nephrotonic action, antioxidant and immuno-modulatory action.
In a trial, it was found that, the body weight and FCR of the Vilocym Z treated groups was comparable to that of the healthy birds as compared to infected and untreated birds.
Control (C) : no infection given in feed
G1 : aflatoxin 100 ppb + ochratoxins 100ppb
G2 : aflatoxin 100 ppb + ochratoxins 100ppb + Vilocym Z @1 kg/tonne of feed
Duration of trial: 42 days
Some important features of Vilocym Z:
- Broad spectrum mould inhibition
- Inhibition of toxin production
- Binding, inactivation and bio neutralization of multiple mycotoxins
- Better microflora and digestive functions
- Maintenance and improvement in liver and kidney functions
- Growth promotion in chicks
- Better production in broilers, layers and breeders
- Improved immune health and reduced oxidative stress in birds
Bryden, W. L. (2007): Mycotoxin in food chain: human health implication, Asia Pac. J. Clin. Nutr., 16 (suppl 1): 95—101.
Fuchs, R., Hult, K. (1992): Ochratoxin A in blood and its pharmacocinetic properties, Food Chem. Toxic., 30, 201—204.
Uraguchi, K., Yamazaki, M. (1978): Toxicology, Biochemistry and Pathology of Mycotoxins, Hartcourt Press, New York.
*Full report can be accessed on request