By Joshua Kato
An survey done in 2018 by Dr Swidiq Muherwa, Director of Research at the National Livestock Resources Research Institute (NaLIRRI) revealed, ingestion of feed contaminated with aflatoxins not only undermines animal performance and productivity by retarding growth, but also present huge health risks to consumers of animal tissues and products.
While humans can acquire the toxins by consuming foods like maize, sorghum etc affected by the toxins, they can also acquire the same by eating meat or products from affected livestock. The International Agency for Research on Cancer ranks aflatoxin as Group 1 possible cancer causers. In children, they reduce growth, leading to stunting and kwashiorkor.
“Livestock feeds have a higher concentration of toxins than recommended. Most of the time, the livestock are given the poorest feeds after humans make their pick,” Mugerwa says. For example, maize bran, which is the base for mixing livestock feeds comes from the skin of the grain, which at the same time is more vulnerable to mould.
Mugerwa pointed out that despite their importance in sustaining food and nutritional security, economic development and poverty eradication, the productivity and profitability of intensive dairy and poultry industries in Uganda is undermined by the detrimental effects of aflatoxicosis. Aflatoxicosis is the syndrome resulting from ingestion of feeds contaminated with aflatoxins.
“Ingestion of feeds by animals containing such alarming levels of aflatoxins is associated with growth depression owing to aflatoxin-induced decline in feed intake, impaired nutrient utilisation and decline in feed quality. It is estimated that with each mg/kg increase of aflatoxins in the diet, the growth rate for broiler birds would be depressed by at least 5%,” Mugerwa explained
In laying birds, aflatoxicosis reduces egg production and egg size by 10% and 5% respectively, in addition to impairing semen quality.
Additionally, aflatoxins are immune-suppressants and aflatoxicosis has been noted to escalate the susceptibility of birds to infectious diseases such as Newcastle disease.
“Because of these toxins, when you vaccinate chicken from diseases like Newcastle, there is no effect because of the toxins affect the effectiveness of the vaccines in the animal cells,” Mugerwa says.
Allan Iga, a livestock nutritionist advises livestock farmers to use toxic binders in their feeds to reduce the impact of the toxins in maize bran. “Farmers must buy only that bran that is clean, without any blackish substances, but they must also add a toxic binder in the feeds to tame any possible toxins. The product is a blend of sodium bentonite, that is processed and mixed with feeds to stop the effect of the toxins. These can be bought from most agri-input stores.
