Mycotoxin Management: It's a matter of expertise

Poultry are also sensitive to mycotoxins, with different types having different toxic effects. Aflatoxins are the most immunosuppressive toxins; however, broiler chickens are less sensitive than other poultry, for example ducks, geese or turkeys. Type A trichothecenes (T- toxin, HT-2 toxin, diacetoxyscirpenol) are of major concern to poultry industries and cause economic losses in terms of productivity. They are highly toxic for poultry, especially for chickens due to their very low LD50. In particular, T-2 toxin reduces feed intake, body weight, quality of breeding eggs and causes oral lesions. Young chicks and turkey poults are highly sensitive to ochratoxins. These nephrotoxins can suppress feed intake, growth and egg production; as well as causing poor eggshell quality. Signs of exposure to fumonisins are immune suppression, decreased body weight and average daily weight gain as well as increased gizzard weights. In comparison to other species like pigs, poultry appear to be less affected by zearalenone, whilst combinations of mycotoxins can cause significant losses regarding fertility and hatchability.

Aflatoxins, trichothecenes and zearalenone are as important in ruminants as they are in monogastric animals. However, mature ruminants are generally more resistant to the effects of mycotoxins than monogastric animals. This is because some rumen microbes have the ability to detoxify mycotoxins. In general, calves are more sensitive to aflatoxins than adult cattle. The most common mycotoxins: aflatoxins, trichothecenes and zearalenone, are all of importance to cows. Clinical signs of ingestion of aflatoxin contaminated feed includes reduced feed consumption and milk production, diarrhoea, acute mastitis, weight loss, respiratory disorders, hair loss, liver damage and immune suppression. The aflatoxin metabolite aflatoxin M1 is carried over into the milk at a level from 1 to 6% of the aflatoxin B1 consumed. Numerous studies have shown that ruminants are less affected by deoxynivalenol (DON) because it is metabolised into its less toxic de-epoxyde in the rumen. Nevertheless, DON is associated with reduced feed intake and lower milk and milk fat production in dairy cattle. T-2 toxin results in loss of appetite and weight, slower growth, gastroenteritis, lowered milk production, and reduced immune response in calves. In addition, T-2 toxin has been implicated in haemorrhagic bowel syndrome by impairing immune function. Zearalenone causes among other things, abnormal reproductive processes in cattle, sheep and other ruminants – resulting in false heats, anoestrus, premature mammary development and abortions.