guidelines for antibiotic residue avoidance课件

Guidelines for Antibiotic Residue Avoidance,S. Andrew University of Connecticut,Why Should We be Concerned About Residues in Milk?,The goal is to produce a nutritious, wholesome food for consumers. It is essential to maintain and foster consumer confidence. Profitability,Human Food Safety Issues Sensitivity to antibiotics Immunological response Bacterial resistance to antibiotics No link established between animal use and human pathogen antibiotic resistance (however, there is a potential for this to occur),Antibiotic Residue Defined as:,Detection of antibiotic in milk: 1. at or above the tolerance or safe concentration for approved drugs, or 2. at any concentration for unapproved drugs 3. at any concentration for illegal drugs,Antibiotic Routes of Administration,Intramammary Topical Oral skin Injectable feet Intramuscular teats Intravenous eyes Intrauterine Feed Additives,Major Use of Antibiotics is for the Treatment of Mastitis,Intramammary Dry cow and lactation treatments,Top Five reasons for Residue Violations,1. Milking a treated dry or lactating cow 2. Same milking unit for treated and un- treated cows 3. One quarter treated, milk from other three quarters put in tank 4. Unaware that newly purchased animals were treated 5. Fresh cow milk contained residues from dry cow treatment,Why do Residues Occur? Lack of adequate record-keeping Lack of understanding antibiotic use Poor relationship between producer and veterinarian Sischo, and coworkers, 1997,Regulation of Antibiotic Residues in Milk,Milk is regulated at the bulk tank/tanker truck level. Pasteurized Milk Ordinance (PMO) a. under section 6 milk is sampled 4 times during any consecutive 6 months.,b. Under Appendix N of the PMO - every tanker truck is screened for beta-lactam antibiotics beginning July, 1992 Penicillin Cloxacillin Amoxicillin Cephaprin Ampicillin Ceftiofur - bulk tank also sampled,If the tanker truck sample is: Positive Negative sample re-tested no further 2x action if positive - traced re-tested at back to bulk tank State Lab Regulatory action $,Milk is analyzed for antibiotic Residues using Qualitative Tests The tests used have been evaluated and accepted by FDA for use with bulk tank/tanker truck milk. # of samples tested % positive 1995 3,219,071 0.101% 1996 3,310,772 0.106% Smucker, 1997,Therefore, approximately 99.9% of milk tested is free of antibiotic residues,It appears that we are winning the race! However, 3,507 positive loads in 1996,How to Reduce the Risk of Antibiotic Residue Violations,1. Follow label directions for approved drugs (treatment regimen and withdrawal times) 2. Extra-label use of antibiotic only under veterinarian guidance 3. Identify treated animals and milk into separate bucket.,How to Reduce the Risk of Antibiotic Residue Violations,4. Establish a herd health management program 5. Establish effective record-keeping 6. Education/communication with all personnel involved with milking and treating cows and heifers.,How to Reduce the Risk of Antibiotic Residue Violations,7. Follow the 10-point Milk and Dairy Beef Quality Assurance Program # 2 Establish a valid veterinarian/client/patient relationship #8 Use antibiotic residue screening tests for testing treated cows milk,Bulk Tank/Tanker Individual Truck Cow,At Which Level Should Milk be Tested?,Ideally, screening milk from treated cows before adding the milk to the bulk tank is financially advantageous,However, Many cases of residue violations are due to accidentally milking a dry-treated cow or treated cow Also,The screening tests have not been evaluated by FDA for use with individual cows milk,Major concern is the potential for increased false - positive outcomes. Results in dumping acceptable milk.,The false-positive rate for screening tests used with individual cow milk ranged from: 0 % - 83% Cullor and coworkers, 1994 Andrew and coworkers, 1997 Sischo and Burns, 1993,Screening milk from cows treated with an antibiotic following the appropriate withholding time,Positive result may be due to: 1. Antibiotic present above tolerance 2. Antibiotic present below tolerance 3. False positive outcome,Factors Affecting False-Positive Rates of Antibiotic Residue Screening Tests,Factors associated with: SCREENING TEST MILK _ - Test storage - Somatic cells conditions - Milk fat and protein - Operation of test - Milk sample,Steps to Optimize Screening Test Performance for Individual Cow Milk,1. ESTABLISH AN EFFECTIVE MASTITIS CONTROL PROGRAM! 2. Follow drug withholding times. 3. Match the test to the drug. 4. Test visually normal milk.,Steps to Optimize Screening Test Performance for Individual Cow Milk,5. If result is positive, retest. 6. If positive again, check milk quality and re-test in 24 hours. 7. If positive, send milk sample to milk processor laboratory for testing.,Summary,Residue Avoidance Understanding how antibiot