Residue Testing - Andy Grist PDF

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Andy Grist...

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Residue Testing Understand processes involved in testing of food animals for residues of antimicrobials and pesticides. Why Test? - Antibiotic use in animals → less efficacious in humans - Effects of Sex hormones and growth promoters National Surveillance Plan: - Statutory Program → Managed by VMD - Veterinary Residues Committee - which samples + when + where - FSA = Red Meat + Poultry carcasses at slaughterhouse - Animal Health = live animals + feed + milk - CEFAS = Salmon + trout from farms - Fisheries Research Services - Scottish fish farms - DEFRA (Egg marketing inspectors) = Eggs from packing stations - First Screening detects +ves (high Se) - Animal Health investigation on farm → corrective action - Serious cases → legal investigation by DEFRA - Second Screening confirms levels - Non-Statutory Program - Sampling from popular mean/animal product presentations - Collection from shops + border inspection posts - Central Science Lab in York - VMD informs retailers of Positive samples purchased from their stores - Contact of consumer organisations, local authorities, trade associations, producers where appropriate Maximum Residue Limit (MRL) - Maximum concentration of residue accepted by the EU in a food obtained from an animal that has received a veterinary medicine. - Committee for Medicinal Products for Veterinary Use (CVMP) - Assesses safety of residues - Annex I = Final MRLs - Data in dossier adequate - Annex II = MRLs not necessary - No risk to consumer - Annex III = Provisional MRLs - Further studies required - Annex IV = Residues pose unacceptable risk to consumer - Products prohibited in food producing animals - E.g. Chloramphenicol, Chloroform, Metronidazole No-Effect Level - Maximum dose of a substance that can be consumed over a stated period without producing detectable ill effects.

- Used to create withdrawal period. Withdrawal Period - Until elapsed - animal/products NOT FOR HUMAN CONSUMPTION - Time which passes between the last dose given to the animal and the time when the level of residues in the tissues or products is lower than/equal to the MRL. - Quoted on Food Chain Information - Exist to ensure MRL not exceeded - ensure consumer safety - Large safety margin when MRL set so no risk even if residue present Residue Sampling - VMD decides how many from each abattoir and what tests - FSA notified - monthly Sampling Schedule (what tissues required) - AO or FSA takes samples Suspicion of Residues - Prohibited substance, e.g. Hormone Growth Promoter - Secondary sexual characteristics, crest/teat development, restlessness, behaviour - mounting, aggression, even level of finish in groups of different breeds. - Samples = blood + urine/faeces (Urine if B-agonist suspected) - Unauthorised substance (annex IV) - Residues > MRL - Signs of recent illness (mastitis, lameness, pneumonia, metritis, poor condition) - Emergency slaughter animals - Injection site bruising, smell, swelling - Evidence of Implants - Ear → detain carcass amd submit whole ear for analysis - Any other part of carcass → surrounding tissue excised and submitted for analysis (DO NOT dissect out implant) - Slaughter - Not held in lairage > 48 hrs - Disease Control Order 2003 - So detain carcass and offal instead of live animal - Results - VMD informs OV by telephone results ASAP followed by written confirmation - Positive → further action depends on type of substance - VMD issues specific instructions - Unauthorised substances → immediate investigation → DEFRA prosecution? Understand the organisational aspects of residue testing in meat production. NOAH (National Office of Animal Health) - Lists products and withdrawal periods - Farmers required by law to record all uses of medicines to help ensure withdrawal periods observed.

Authorised Officer (AO) - The Animals and Animal Products (Examinations for Residues and Maximum Limits) Regulations 1997 - Detention - Animals for pre-slaughter inspection - Animals for further examination or sampling - Animals/carcasses until results known FBO Responsibility - Assist AO - Have (+ keep) full info on animals - owner, holding, records (traceability)...