Occurrence of aflatoxins in foods and feedstuffs: Dietary exposure and impaired animal
production in Cameroon
Kana Jean Raphaël
BP: 188 Dschang, Cameroon, Tel: 237 74893394 email: kanajean@yahoo.fr
Context and justification of the project
Mycotoxins are toxic metabolites of fungi produced on cereals during growth, harvest,
transportation, or storage. One family of mycotoxins, the aflatoxins (B1, B2, G1 and G2), are
carcinogenic and immunotoxic that causes reduction in immunoglobulin and several functional
properties of macrophages and heterophilis, and cause growth retardation in animal (Ramos et al.,
1996; D’Mello et al., 1999; Kana et al., 2010a,b). Aflatoxins contaminate foods in the tropic
particularly maize and groundnuts, and manufacture animal feeds, as a result of hot, humid storage
conditions that promote fungal growth (Dalvi and Ademoyero, 1984; D’Mello et al., 1997;
Mabbett, 2004). Several physical factors including grain and feed moisture, humidity, ambient
temperature, storage time and oxygen affect fungal growth. When the right combination of these
conditions occurs, fungal growth begins. This fungal growth is correlated to decreased energy
levels, primarily linked to a decrease in starch and fat values. Considerable research confirms that in
mould corn, the energy content could be reduced as much as 63% (Chen, 2003). Worldwide, it is
estimated that 25-50% of all grains are contaminated with naturally occurring mycotoxins, which
pose a toxic threat to animals and humans.
Although not formally reported, the problem of aflatoxins should be more acute in Cameroon
because the common practice is to feed animal with bad and mould corn, and good grain is for
human consumption. Furthermore, peanut meal which is the most vulnerable ingredient to
mycotoxins is largely used in manufacturing animal feed in this country.
Due to the long half live of aflatoxins accumulate in food; a serious threat to human and animal
health has been implicated in a range of toxicological effects (Robens and Richad, 1992; Chen,
2003; Komkrich, 2004). The greatest economic losses due to aflatoxins are, reduced animal
productivity, increased disease incidence because of immune suppression, subtile but chronic
damage to vital organs and tissues, and interference with reproductive capacities.
Objective
The main objectives of this study are to evaluate the prevalence, and quantify aflatoxins in selected
foods and feeds in Cameroon. The study will also characterize the effect of dietary aflatoxin
exposure on animal immunocompetence, and performances as well as generate information on
aflatoxin occurrence through periodical monitoring, and evolve policies which discourage the
marketing of toxin contaminated foods and feeds.
Methods
Sample collection and analysis
To evaluate the occurrence of aflatoxins, manufactured feeds and ingredients (maize, peanut
meal…) use in animal feeds will be sampled from three, ecological/geographical zones of
Cameroon: Savannah zone, Sudano-guinea zone, and rain forest zone. Blood sample of goat, sheep,
and village chickens will be collected from West and North West Regions of Cameroon. Milk
sample of breast feeding goats, sheeps, and cows will be collected from different
ecological/geographical zones of Cameroon. Both serums collected from blood samples and milk
will be store in labelled tubes in freezer until analysis of aflatoxin DNA adducts or albumin adducts
as surrogates for genotoxicity in animals. Highly sensitive immunoassays (radioimmunoassay
(RIA), enzyme-linked immunosorbent assay (ELISA), or immunoaffinity column assay (ICA)
based on the affinities of the monoclonal or polyclonal antibodies or Near Infrared Spectroscopy
(NIR) coupled with Ultra Performance Liquid Chromatography (UPLC) will be used for aflatoxins
analysis in the host Institution.
Aflatoxin content in feeds will be determine by using the Enzyme Linked Immuno-Sorbent Assay
(ELISA) with appropriate immuno enzymatic kits (Transia Plate Aflatoxin B1, PT 53 2004-Rev 4)
or NIR UPLC.
Potential impacts/potential beneficiaries
The project will generate information on aflatoxins occurrence and their impacts on animal
production in Cameroon. This project will also improve the policy and institutional framework for
the management of aflatoxins, and food security in Cameroon. The overall impact of the project
will be the improvement of health and prosperous people resulting from the availability and
marketing of aflatoxin-safe manufactured animal feeds, feeds ingredients, and animal products. The
primary beneficiaries will be small and medium scale farmers, and poor households in the areas
most vulnerable to aflatoxins exposure. The benefits will accrue to all stakeholders in animal feeds
companies, wholesalers and retailers, and consumers of animal products. A stakeholder workshop
would further ideas for institutional arrangements to further up sale dissemination of information
generated from this study and provide endorsement from key stakeholders such as farmer
organizations, commodity utilization sectors (feed and food industry), and policy makers.
How this project links to our research interests
Our research interest lies on animal nutrition with special reference to poultry nutrition. In our
previous studies (Kana et al., 2010a and b) we have identified some plant charcoal that are effective
in binding aflatoxins in chickens feeds in on station trials. The next steps is to develop partnerships
for monitoring aflatoxins content in feeds ingredients, to assess the impacts of animal exposure to
aflatoxins, to test the efficacy of low cost natural plant charcoals in large-scale field trials, and to
recycle on molecular techniques in laboratory.
Expected results
1-Determine occurrence of aflatoxin in feeds ingredients, and manufacture commercial feeds.
2- Determine the incidence and range of aflatoxin in animal production performances in Cameroon.
3- Initiate a project proposal on aflatoxin management with several modules:
- Donor (University of Dschang, Cameroon)
-Starting and ending date (Duration to define by donor and partners)
-Location (Cameroon)
-Partners (n/a)
Note: Suggestion for appropriate planning and methodology from the host Institution experts will
be welcomed. The proposed methodology is only prospective.
References
1
Chen Y.J., 2003. Mould and mycotoxins: Control from grain to feeding. Feed
International.24 (12): 22 - 24.
2 D’Mello J.P.F., Placinta C.M. and Macdonald A.M.C., 1999. Fusarium mycotoxins : a
review of global implications for animal health, welfare and productivity. Animal Feed
Science and Technology. 80: 183-205.
3
D’Mello J.P.F., Porter J.K., Macdonald A.M.C. and Placinta C.M., 1997. Fusarium
mycotoxins. In: D’Mello J.P.F. (edt.), Hanbook of plant and fungal toxicants. CRC Press,
Boca Raton, FL. Pp 287-301.
4
Dalvi R.R. and Ademoyero A.A., 1984. Toxic effects of aflatoxin B1 in chickens given
feed contaminated with Aspergillus flavus and reduction of the toxicity by activated charcoal
and some chemical agents. Avian Diseases. 28: 61-69.
5
Kana J R, Teguia A and Tchoumboue J., 2010a. The evaluation of activated dietary
charcoal from Canarium schweinfurthii Engl. seed and maize cob as toxin binder in broiler
chickens. Animal Health and Production in Africa. 58 (4) : 358-363.
6 Kana J R, Teguia A and Tchoumboue J., 2010b. Effect of dietary plant charcoal from
Canarium schweinfurthii Engl. and maize cob on aflatoxin B1 toxicosis in broiler chickens.
Livestock
Research
for
Rural
Development.
22
(4)
2010.
http://www.lrrd.org/lrrd22/4/kana22077.htm
7 Komkrich P., 2004 Absorption of aflatoxine. Asian Poultry Magazine, june 2004. Pp 1-2.
8
Mabbett T., 2004 The single most serious constraint on poultry production in humid
climates. Poultry International. November 2004. 43(12). 38 - 41.
9 Ramos A J, Johana F G and Hernandez E, 1996 Prevention of toxic effects of
mycotoxins by means of non-nutritive absorbent compounds. Journal of Food Protection. 59
(6): 631-641.
10 Robens J.F. and Richard J.L., 1992. Aflatoxins in animal and human health. Revue of
Environment Contamination and Toxicology. 127: 69-94.
TIMELINE
Activities
Contents
Duration
In Cameroon
Sample
Duration:
collection
2 months
At host Institution
A rapid recycling on Near Infrared Spectroscopy (NIR) and Ultra
Laboratory
Performance Liquid Chromatography (UPLC) will be very helpful
training at host at the beginning of the stay and well appreciated, to impregnate
Institution
the existing materials and methodologies in the domain. Such
Duration:
1 month.
training would be very useful once returned back to Cameroon.
This constitutes the main motivation of my application. I would
Samples
expect support and indications to undertake all treatments. Host
Duration:
analysis:
Institution assistance during this stage will be of great importance
3 months
for my first real laboratory work using NIR-UPLC.
Data analysis:
I also expect host Institution to provide softwares and assist me
during data processing.
This could be initiated at the host Institution in collaboration with
Scientific
my partners from this Institution, and continued when back in
papers writing
Dschang, where numbers of similar research notes done worldwide
are available for discussion.
Duration:
1 week.