Chemical contaminants in poultry systems is a huge risk in poultry farmers. Some poultry systems are more prone to chemical contamination than others. Such contamination can come from different sources including food and chemical residues in litter and on land.
Pesticides, persistent organic pollutants and heavy metals are some of chemical contaminants that can affect egg and meat quality. This particularly concerns large scale poultry farming.
Although we see free range as the best poultry farming system, it is only so if birds graze on land that is free of chemical contaminants. As far as large scale poultry farming is concerned, the availability of such land is a rarity.
There is a risk to human health when poultry produce is contaminated. You as a poultry farmer have an obligation to ensure your flocks are free of such contamination. Otherwise, you risk the health of your flocks and their productivity.
4 Types of contaminants in poultry systems
By poultry contamination in poultry systems, we are talking about toxins that birds can become exposed to, according to their housing system. For example the use of contaminated wood shavings as bedding material in deep litter, can result to contamination.
According to Holt et. al., free range and deep litter systems are the poultry systems with highest potential for chemical contamination. Since birds live on artificial surfaces in aviary and cage systems, they’ve less exposure to ground and bedding material contaminants.
Feed and water
Holt and co. in The impact of different housing systems on egg safety and quality, claim that exposure to environmental contaminants through feed and water is uniform. According to them, large scale poultry farming obtain poultry feed more or less from the same sources.
However, Holt et. al. note that free range flocks as being at higher risk of exposure than other poultry systems. Since free range birds are in contact with and ingest soil and organisms in the soil. In case, the soil contains chemical contamination, then respective contaminants are potentially able to find their way into the chicken.
On the other hand, intensive poultry systems can expose respective flocks to unusually higher levels of chemical toxins. In particular, if poultry feed is grown in chemical heavy agriculture, respective toxins are likely to find their way into your flocks.
Persistent organic pollutants
Some chemical pollutants take a long time before they biodegrade or dissipate from an environment. Such pollutants can be considered as persistent. Dioxins or polychlorinated biphenyls are examples of persistent organic pollutants.
The most widely reported chemical contaminations of eggs associated with free-range flocks are increased levels of dioxin-like compounds. These include several classes of chemicals, namely, polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and polychlorinated biphenyls. These compounds are ubiquitous environmental contaminants and are extremely persistent in both the environment and biota.
Holt et. al. noted that “In a California study, eggs from hens raised on soil contaminated from a nearby pentachlorophenol wood treatment plant had elevated levels of dioxins compared with eggs from conventional cage-reared hens.”
Moreover, “In Europe, food survey data show that free-range eggs have higher PCDD/F and polychlorinated biphenyl levels than conventional cage eggs.”
Pesticides and heavy metals
Residues of pesticides and heavy metals in the grazing or coop materials can result to the contamination of poultry produce. Consequently, this can result to toxin levels that are higher that permissible standards. According to Holt et. al.
In Brazil, free-range hens in an area historically treated with dichlorodiphenyltrichloroethane (DDT) for vector control had DDT levels twice the MRL recommended by the Food and Agriculture Organization of the United Nations even though DDT had not reportedly been used in the preceding 9 yr. The residue level was 1,000 times the level of DDT found in commercial eggs purchased at a local market.
In free-range eggs from backyard flocks in Belgium, the heavy metals lead, mercury, cobalt, and thallium had median concentrations 2 to 6 times higher than those of commercial eggs, presumably due to soil contamination. Given the bioaccumulative nature of DDT and heavy metals, these elevated chronic exposures cause a concern that increasing body burdens of these chemicals may result in adverse health effects.
Moreover, the use of contaminated coop building and bedding material can result to similar contamination. Deep litter poultry have a higher contamination risk since they are in constant contact with litter. In case litter material is contaminated, respective chicken will in one way or another be contaminated.
Persistent and residual medications
Poultry medication is yet another avenue through which chemical contamination can occur in poultry systems. As a result, without your intention, chicken produce can have certain chemical toxins.
According to Holt et. al. “to counter the fly problem, the houses must be sprayed or fogged with higher amounts of insecticide, increasing the risk for egg contamination by these agents”
Most poultry medicines are supposed to clear over a certain period. However, when respective periods have not elapsed, chemical toxins will be present. Moreover, the over use of medicines can result to residual chemicals in poultry produces.
Further still, improper administration of medicines can have similar outcomes. Respective residual medications can thereafter be detected in chicken produce or poultry system.
Persistent and residual chemicals from medications is particularly a concern in poultry systems where scientific methods are applied. However, Holt. et. al. suggested that hens in alternative systems are not likely to have lesser exposure.
Raising hens in alternative housing does not inherently lead to higher chemical residues in eggs. In a Canadian study, free-range eggs had lower or similar concentrations of dioxin-like compounds than conventional eggs.
How to minimize chemical contaminants in poultry systems
It is highly important that you minimize if note completely prevent chemical contaminants from your poultry system. Of course, this is easier said than done. Since your flock’s health and productivity depends on their protection from such exposure, putting in the effort can save you a lot.
Importantly still is your obligation to safe guard human health by minimizing the amount of chemical toxicity than can be ingested by humans via the consumption of poultry produce.
First and foremost ensure that your poultry feed and water are as free of chemical toxins as possible. Perhaps 100% contaminant free feed and water is not possible especially in commercial farming. Nonetheless, you can make an effort to make sure your flock has the least possible exposure.
Secondly use, high quality coop building and flock bedding material. Cheap is expensive; saving on quality in the short term can result to contamination and loss in the long term. If you have to, consult with certified builders and obtain your materials from respective suppliers.
Thirdly, administer flock vaccines and medications as instructed. Additionally, follow the prescriptions to the letter and follow treatment conditions to ensure medication effectiveness and take up. You should not sell poultry produce that contains chemical residues. Always ensure medication clear up periods have elapsed before taking produce for sale.
Lastly but not least if you’re free ranging chicken ensure the grounds on which they graze are free of chemical toxins. This should also be the case if you are practising semi intensive or folding unit systems.
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