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ILRI research project to address milk poisoning in Kenya

The International Livestock Research Institute (ILRI) has commissioned a research project that will ascertain the levels of aflatoxins in the milk consumed in Kenya

Kenyans consume more than 145 litres of milk per person annually increasing the risks associated with milk-related aflatoxins.

"Because of the higher milk consumption, especially by young children, pregnant and nursing women, Kenyans are likely to be more at risk from aflatoxin-contaminated milk than other Africans," said Johanna Lindahl, a food safety researcher at ILRI.

The research will determine the risks posed to such different groups of people by exposure to aflatoxin-contaminated milk. The project has been funded by the government of Finland.

Aflatoxin poisoning is produced by fungi Aspergillus, which infests grains such as maize and sorghum that have been badly stored under high moisture content. Consequently, the resultant contaminated feed leads to poisons getting into milk.

The presence of these toxins in food can harm human health and can be lethal in high doses. Kenya is among the world’s hotspots for aflatoxin-related deaths.

According to the Food and Agricultural Organisation (FAO), about 55 per cent of the milk produced in Kenya, mainly from dairy cattle, enters the market. Of this volume, more than 75 per cent is channelled through informal market, with fewer than 30 per cent getting to processors.

Owing to the large amount of milk that is marketed unprocessed and the weak monitoring of markets, there have been concerns about public health risks from diseases and drug residues, according to the FAO. 

Preliminary results of an ILRI study conducted in urban Nairobi showed that 55 per cent of the consumers of raw milk from street stalls and milk hawkers had never heard of aflatoxins.

On the other hand, 80 per cent of consumers from middle-income areas who purchases their milk from shops or supermarkets had heard about it.

Overall, more than 50 per cent of the people who had heard about aflatoxins believed the toxins could be present in milk.

"We have been carrying out a series of participatory rural appraisals in villages to understand the current knowledge, attitudes and practices of farmers," observed Lindahl.

Across rural Kenya, smallholder dairy farmers occasionally feed decomposing grain to livestock, oblivious of the dangers they expose milk consumers.

"We are not aware rotting maize or potatoes could do harm to the milk we consume. We have always fed our cows, chicken and even goats of crop remains and spoilt grains as part of feed supplements to the main feed napier grass," observed Zipporah Njoki, a dairy farmer in Ol Joro Orok division in NyandaruaCounty, one of the main milk producing regions in the country.

At the same time, concerns have been raised on the quality of commercial livestock feed – especially on compositions and safety.

According to the FAO, about 500,000 tonnes of commercial livestock feed was produced in 2007, with most sourced from local grain producers.

The most common commercial feeds include dairy meal, dairy cubes, calf pullets, maize germ, maize bran, molasses, cottonseed cake, wheat pollard and wheat bran.

Research conducted between February 2006 and March 2007 by the Department of Public Health Pharmacology and Toxicology at the University of Nairobi indicated high levels of aflatoxin B1 and M1 in samples of commercial feeds and milk respectively.

Overall, researchers collected 830 animal feed and 613 milk samples from four urban centres in the country. Of these, 86 per cent of the feed samples from farmers had aflatoxinB1 with 67 per cent exceeding the FAO/WHO limit. Meanwhile, 88 per cent of the feed samples from feed millers and 87 per cent of agrochemical shops were also positive for aflatoxins.

Of the milk samples, 72 per cent of the milk from dairy farmers, 84 per cent from large- and medium-scale farmers and 99 per cent of the pasteurised marketed milk had aflatoxins, most of which exceeded the FAO limits. According to the researchers, 67 per cent of the urban smallholder dairy farmers had no knowledge that milk could be contaminated with aflatoxin M1 and neither group knew how they could mitigate against this exposure.

Feed millers knew about aflatoxin B1 in grains and excretion of aflatoxin M1 in milk, but were not alleviating exposure to animals.

In conclusion, the researchers, E. Kangeth’e and K. Langa’t, observed that there was the need to create awareness and establish routine monitoring of animal feeds and milk to reduce animal and consequently human response.

Mwangi Mumero