Chemical residues Flashcards
Chemical residues can be found in the following:
- Animal tissues.
- Milk and eggs after the administration of Veterinary drugs and medicated
premixes. - Application of pesticides to animals
- Consumption of stock feeds previously treated with agricultural
chemicals
this randomly samples tissues from animals at slaughter.
Monitoring
are assayed for veterinary drugs, pesticides and
environmental contaminants and the residue are assessed for
compliance with the applicable MRL or environmental standard.
Tissue samples
by comparison, sample tissues from animals suspected
of violative residues on the basis of clinical signs or herd history. Animals
identified with violative residues of veterinary drugs of pesticides do not
enter the food chain.
Surveillance
KEY PARAMETERS DERIVED IN THE SAFETY AND RESIDUE
EVALUATUIONS
ADI (Acceptable Daily Intake)
Safe Concentration
MRL, or tolerance
Target tissue
Withdrawal time
withdrawal time in cattle is 3 days
Chlortetracycline
cattle 25 days; Swine – 15; turkey-5 days
Ampicillin trihydrate
amount of veterinary drug, expressed
on a body weight basis, that can be ingested daily over a lifetime without
an appreciable risk to human health.
ADI (Acceptable Daily Intake)
maximal allowable concentration of total residues
of toxicologic concern in edible tissue.
Safe Concentration
maximal consideration of residue resulting from the
use of veterinary drug ( expressed in mg/kg or ug/kg on a fresh weight
basis) that is legally permitted as acceptable in or on a food.
MRL, or tolerance –
the edible tissue with residues that deplete to a
concentration below the MRL at a slower rate compared with other edible
tissues.
Target tissue
the period of time between the last administration of
a drug and the collection of edible tissue or products from a treated
animal that ensures the total residues deplete to below the safe
concentration, and the marker residue depletes to below the MRL.
Withdrawal time
affects wool production.
Files, lice, keds and mites
have been
the mainstay for managing infestations for these parasites.
Ectoparasiticides
Pesticides residues in wool are influenced by many factors;
- Chemical and formulation used
- Method of application
- Rate and timing of the chemical application
- Length of wool at the time of application
Products types and chemical groups used;
- spray on products containing insect growth regulators.
- organophosphate pesticides
- short wool plunge or shower dips
- magnesium fluorosilicate
have possible implications for public health,
occupational health and safety, and environmental safety.
Pesticide residues in wool
used in the manufacture of garments is unlikely to pose a human hazard
because any residual pesticide is removed during the scouring process.
Processed wool
poses an occupational hazard to shearers and
other wool handlers through dermal absorption.
Residual pesticide in wool wax
common effects on shearers after shearing sheeps treated with
certain organophosphates and synthetic pyrethroid pesticides.
Nervous disorders and dermal
irritation
The target tissue is frequently the
liver or the kidney.
Residue programs consists of the following;
Monitoring
Surveillance
is calculated from the ADI and considers the weight of an average person
and the amount of the meat, milk and eggs consumed daily by a high
consuming individual.
safe concentration
have been established to ensure
that chemical residues in food do not constitute an unacceptable health risk.
Regulatory and Monitoring systems
