Consumption of poultry meat and products has increased due to economic crisis, by several factors, people consume chicken meat as it is cheaper than beef meat or meat products. Due to the increasing demand in industry resulting strict measures in disease control and environmental factors, these products may involve some chemical and natural compounds with hazardous properties at a very low concentrations.
By SIDRA YOUNUS
Among these compounds, residues are of concern, including veterinary drugs, environmental pollutants (such as dioxins, pesticides, and phthalates), natural contaminants (mycotoxins), or some substances contaminating poultry product during production or marketing stages. In order to keep the consumers safe from the harmful effects of these compounds, such as genotoxic, immunotoxic, carcinogenic, teratogenic, or endocrine disrupting effects, new strategies for poultry food security have and developed globally. This article includes detailed information on the residues of some potential chemical contaminants in poultry meat and products along with risk analysis regarding their hazardous effects and detection in various matrices.
Food safety is used as a scientific method describing handling, preparation, and storage of food in ways that prevent food-borne illness.
Poultry meat is the cheapest source of protein as compared to meat, mutton.
Residues are substances that can occur in food and feedstuffs naturally or produced by humans as the accidental, intentional, or environmental (persistent organic pollutants like dioxins) contamination of the food with veterinary drugs or phytosanitary products during the production stages. Contaminant is any substance not intentionally added to food, which is present in such food as a result of the production, manufacture, processing, preparation, treatment, packaging, transport, or holding of such food or as a result of environmental contamination. Therefore, all food products are at risk of contamination from several resources, including poultry meat and products.
The development of a primary production and processing standard for poultry meat uses an approach that investigate the sources of potential chemical risks, which may be introduced at different points through the primary production and processing chain. Poultry meat and products supply chain is divided into four distinct steps: primary production, processing, retail, and consumer. At each of these steps, poultry meat and products may be directly or indirectly exposed to chemicals. Direct exposure results when a compound is present in raw food materials, where as in indirect exposure, contaminants cross into food during processing, storage, packaging, or preparation.
In all production stage, there is a risk of iatrogenic contamination of multiple substances such as antimicrobials. These substances are essential for poultry production because of their health benefits, welfare, and performance. Additionally they are substantial to decrease spread of potentially pathogenic organisms from animals to humans and to the environment. Several substances among these drugs used in the treatment have the potential to constitute residues in edible tissues and other food products, which can potentially cause adverse health effects including allergy, toxicological effects, antimicrobial resistance and endocrine disruption in consumers.
Although most consumers are mainly worried about the residues of veterinary drugs in their food, there are many potential contaminants in the environment, which are more likely to contaminate the product from various resources. These include phthalates, persistent organic pollutants, various emerging toxic elements, and pesticides. Some of these compounds in residual amounts in poultry meat and eggs have important harmful effects and known to have genotoxic, immunotoxic, carcinogenic, teratogenic, or endocrine disrupting effects.
It is very important from the health point of view to analysis the relevant chemical substances. Modern testing can identify known chemical substances in complex food substances at very low levels. Additionally, they can also help to determine new emerging chemical substances.
Veterinary drugs are generally prescribed for the treatment and prevention of the diseases mostly coccidia, ectoparasites, fungi, and bacterial infections in poultry. Nowadays, a large part of drug use in poultry farming is precautionary, with the bulk of medications including mainly anticoccidial substances and antibacterial growth promoters.
Poultry feed is typically composed of corn and soybean meal mixtures, including several vitamins and minerals, and generally contains two or three medications. For each development phase, the amounts of the content differ, where starter, grower, finisher, and layer feeds are commercially available. Among all manufacturing costs, drug application and vaccinations cover about 2%. In poultry production, the use of hormones is prohibited and is not considered profitable.
Antimicrobials are widely used for the prevention of the disease and treatment, sustain the health in all poultry treated, induce growth, and enhance the quality of the meat for the purpose of reducing production costs. In some countries, the usage of antimicrobials for the promotion of growth has been prohibited since whereas in some countries, it is still currently been used. Edible tissues of poultry might contain veterinary drug residues, which would cause seroius health issues in human, such as direct toxicological effects, hypersensitivity, allergic reactions, change of gut microflora, and increased bacterial resistance to antibacterials.
Nowadays, the prevention of coccidiosis has become common in modern farming for broilers. Therefore, broiler producers add coccidiostat in grower rations for reduced morbidity and mortality. Ionophores are the most extensive used drugs for the prevention of coccidiosis. Currently, vaccination is popular for the control of coccidiosis, eliminates the risk of residue transfer into poultry products.
Drug residues in poultry eggs are an issue of concern since only a few drugs are approved for laying hens. Residues could be accidental through mixing the feed in the same mill with the previously medicated feed or off-label treatment.
A large part of integrated poultry breeders monitor potential residues in meat or eggs daily. This decreases possibility of drug residues in tissues. Some businesses do further monitoring in tissue before slaughter. Fat and other tissues are analyzed for residues of contaminants such as pesticides, toxic elements, or persistent organic pollutants. Residues of pesticides such as fungicides, herbicides in poultry meat and products are negligible due to the elimination of these compounds to certain extent. Therefore, the risk of adverse health effects on human is assumed to be relatively low.
Fast and successful treatment of poultry infectious diseases is essential since it might lead important economical losses. Therefore, selective, fast-acting, and strong drugs are selected.
Veterinary drugs are generally added to the feed as “feed additive” in the feed factories. Homogeneity of the medicated feed is standardized using specialized mixing equipments, that should be cleaned. In order to prevent cross contamination, medicated feed should be stored in separate area, where the bins in the storage areas should also be cleaned properly.
Entry of undesirable substances into the food chain is mainly due to environmental pollution. Eggs are not a significant source of toxic elements, since only a small amounts of these are able to penetrate the egg. Poultry meat may be contaminated with toxic elements such as arsenic, cadmium, or lead as a result of coming into contact with the materials on the farm or factory or while moving through marketing channels. These three toxic elements can also cause serious health issues.
Organic arsenic compounds have been widely used in the poultry sector for long years as they prevent the diseases, accelerate growth, increase feed efficiency, and increase pigmentation of the meat. More than 90% of these organic arsenic compounds that are given to the chicken as feed additive are excreted with the feces as unchanged. The manures prepared from chicken feces including arsenic are applied to the croplands in order to increase efficiency of the soil, which can cause environmental pollution. Also, residuals of arsenic compounds were seen at body fat, liver, egg, and feather of the chicken fed with organic arsenic compounds.
Pb found in many food products such as giblets and offal at low concentrations . Processing or production of foods in the fields contaminated with Pb was found to increase Pb level at the foods. Recent researches reveal that chronic Pb intoxication with low concentrations were found to cause pain, constipation, anemia, and an increase in hypertension and cardiovascular diseases in adults, while neuropathological disorders and even learning capacities are affected in children.
Cadmium is a metal environmental contaminant, individuals are exposed to Cd through foodstuffs. Absorption of Cd through digestive canal is very low in the humans ,while they are able to accumulate in liver and kidney at significant amounts in human. Cd mainly leads to damage of kidney functions. Also it leads to bone damage both directly and indirectly. Exposure of Cd would lead increased risk for lung, endometrium, urinary bladder, and breast cancer.
In order to avoid the bioaccumulation and for the sake of public health, authorities are obliged to conduct monitoring analysis for metal contamination in poultry.
The control strategies for the environmental pollutants in poultry meat and products includes identification of these compounds and analysis of prevention route. The contaminants at the foodstuffs may be determined with special chromatographic methods, LC/MS and LC/UV , which are the verification methods, and ELISA method , which is a screen method. Along with that, an increase of other screening methods and use of biosensors are available. Since it is cheap and does not require complicated devices. Microbiological methods are qualitative or semi-qualitative methods that are based on the reaction between sensitive bacteria and antibiotic at the sample. The advantages of these methods are their simplicity, reliability and their low price Most preferred screen test is the use of ELISA systems widely available for various kinds of contaminants such as hormones and drugs.
ARTICLE BY SIDRA YOUNUS
GUIDED BY DR NOMAN KHAN
5th NOVEMBER 2021
DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF KARACHI