U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
March 9, 2000

INTRODUCTION

The National Milk Drug Residue Data Base is a voluntary industry reporting program. Mandatory reporting is required by State regulatory agencies under the National Conference on Interstate Milk Shipments (NCIMS). Data are reported on the extent of the national testing activities, the analytical methods used, the kind and extent of the animal drug residues identified, and the amount of contaminated milk, including whether it was disposed of properly for non-human use. The system includes all milk, Grade A and non-Grade A, commonly known as manufacturing grade. Grade A milk represents approximately 90% of the milk supply and is regulated through NCIMS by State regulatory agencies. Manufacturing grade milk is under the direction of the regulatory agencies in the States where it is produced and may be subject to the standards recommended by the United States Department of Agriculture (USDA). Data reported to the National Milk Drug Residue Data Base are for educational and analytical purposes and are not intended or suitable for regulatory follow-up.

BACKGROUND

The National Conference on Interstate Milk Shipments (NCIMS) is a voluntary organization directed and controlled by member States to promote the availability of a high quality milk supply. FDA and the NCIMS through their collaborative efforts have developed a cooperative, federal-state program (The Interstate Milk Shipper program) to ensure the sanitary quality of milk and milk products shipped interstate. During the 1991 meeting of the NCIMS, the Conference authorized a national program to compile the results of residue testing by industry and regulatory agencies.

Subsequently, FDA awarded a contract to develop a National Milk Drug Residue Data Base. The data base is operated by an independent third party, under contract to the FDA. The data base design was developed in consultation with a project advisory group with members from the FDA and a NCIMS committee representing dairy producers, dairy processors, USDA, State regulatory agencies, and academia. The data base was designed to promote maximum participation by the dairy industry to report on a voluntary basis all of their testing without compromising any confidential data. Information regarding individual firm's data is not submitted to the data base contractor. The data base includes results of the National Drug Residue Milk Monitoring Program (NDRMMP), a national drug residue in milk sampling program administered by FDA with the full cooperation by the States. Results from this program are reported to the data base by the States.

It is important to recognize that the samples and tests reported do not necessarily represent one hundred percent of the milk supply from every State. However, as State and industry participation in the data base increased, reporting of the number of samples and tests similarly increased. Continuing efforts are being made to ensure that there is uniform reporting among all the States and the industry and to ensure that the drugs and test methods reported are correct.

SUMMARY

This report presents summary data on samples and tests conducted during the Fiscal Year 1999, October 1, 1998 to September 30, 1999. Fifty States and Puerto Rico submitted data for this report.

The Pasteurized Milk Ordinance (PMO) requires that all bulk milk tankers be sampled and analyzed for animal drug residues before the milk is processed. Any tanker found positive is rejected for human consumption.

During this period 4,232,665 samples were analyzed for animal drug residues. Of these samples 4,270 were positive for a residue. A total of 4,371,127 tests were reported on the samples for 15 different groups of families or individual drugs. Forty-nine testing methods were used to analyze the samples for residues. Details are presented in the tables in this report.

SAMPLE RESULTS

A SAMPLE is defined as representing a load or lot of milk sampled and analyzed, e.g. a bulk milk pickup tanker, producer, or over-the-road tanker, a silo, etc.

Table 1 shows the results of the samples tested by source.

Data are reported by four SOURCES OF SAMPLES:

1. Bulk Milk Pickup Tanker - bulk raw milk from a dairy farm.
2. Pasteurized Fluid Milk and Milk Products - after pasteurization; finished product in package form or bulk. Includes milk products such as milk, cream, condensed milk and dry milk products, and condensed and dry whey products.
3. Producer - raw milk obtained from a dairy farm. Samples are reported by the permitting State, rather than by the analyzing State.
4. Other - milk from silos, over-the-road tankers, etc.

A POSITIVE result, as used in this report, means that the sample was found to be positive for a drug residue by a test acceptable for taking regulatory action in a certified laboratory by a certified analyst or the milk was rejected on the basis of an initial test by the milk processors.

The DISPOSITION PER PMO column represents the amount of milk contained in the tank or lot found to be positive and disposed of in accordance with the PMO and/or applicable State regulations. The PMO governs the rules which State agencies use to implement their milk program.

The asterisk (*) notes that a summary of the percent positive cannot be provided because there is not uniformity in terms of sampling in the four categories. For example, the PMO sets forth specific sampling requirements for beta-lactam testing as follows:

1. Bulk Milk Pickup Tanker Samples -- samples are taken daily on every tanker;
2. Pasteurized Fluid Milk and Milk Products -- a minimum of four samples must be tested for each product at each plant every six months;
3. Producer -- each producer must be tested at least four times every six months; and
4. Other -- samples are conducted on a random basis.

Table 2 presents these results in greater detail and shows the number of samples conducted by industry and by regulatory agencies. Industry samples are taken by processing facilities, receiving and transfer stations, and marketing groups or cooperatives. Industry samples may be conducted to meet the industry requirements of Appendix N of the PMO which sets forth testing requirements for animal drug residues or for quality control purposes. Regulatory samples are taken by State and local regulatory agencies.

¹ It is a common practice in some States, including two large milk production States, that bulk milk pick-up tankers pickup milk from Grade A and non-Grade A milk producers on the same truck. Then, these loads are delivered to non-Grade A processing facilities. Because of this commingling of the two grades of milk, all data related to these loads are reported under non-Grade A.

² Note that this represents 0.0665% of the total milk supply of the annual production of 162 billion pounds.

* = See Table 1 for explanation

TESTS CONDUCTED

An objective of the National Milk Drug Residue Data Base is to record every test run on each sample analyzed. Since some samples are analyzed for more than one drug residue, the number of tests run is greater than the number of samples. To avoid duplicate reporting of samples, the number of samples analyzed is reported separately from the number of tests run in the data base.

Table 3 presents summary results of the number of tests which were conducted during October 1, 1998 to September 30, 1999. The term, validated test, as used in this report, is a test used for the screening of raw milk for drug residue which has been evaluated in accordance with Appendix N of the Pasteurized Milk Ordinance and found acceptable by FDA in accordance with the standards established for the evaluation of tests. In addition, FDA validated drug residue detection procedures for screening and quantitation of drug residues in milk may be used. Table 3A presents summary results using validated tests and Table 3B presents summary results using non-validated tests.

* = See Table 1 for explanation.

* = See Table 1 for explanation.

TABLE 3B -- Non-Validated Tests Conducted by Sample Sources October 1, 1998 to September 30, 1999
Source of Sample	Total Tests	Number of Tests Positive	Percent Positive
Bulk Milk Pick-Up Tanker	108,816	50	0.046
Pasteurized Fluid Milk and Milk Products	790	0	0.000
Producer	4,156	5	0.120
Other	6,464	1	0.015
Total	120,226	56	*

* = See Table 1 for explanation.

Table 4 presents additional details in terms of the tests conducted by industry and by regulatory agencies. Tables 4A and 4B present these data by validated and non-validated tests.

¹ It is a common practice in some States, including two large milk production States, that bulk milk pick-up tankers pickup milk from Grade A and non-Grade A milk producers on the same truck. Then, these loads are delivered to non-Grade A processing facilities. Because of this commingling of the two grades of milk, all data related to these loads are reported under non-Grade A.

* = See Table 1 for explanation; Table 2 shows data on the disposition of milk in compliance with the PMO.

* = See Table 1 for explanation.

¹ It is a common practice in some States, including two large milk production States, that bulk milk pick-up tankers pickup milk from Grade A and non-Grade A milk producers on the same truck. Then, these loads are delivered to non-Grade A processing facilities. Because of this commingling of the two grades of milk, all data related to these loads are reported under non-Grade A.

* = See Table 1 for explanation; Table 2 shows data on the disposition of milk in compliance with the PMO.

Table 5 shows the number of tests conducted by family and by individual drug. Tables 5A and 5B present these data by validated and non-validated tests.

Table 6 presents details on the tests used. The data in this table are comparable to Table 5, but the data are arranged by tests within each family/drug. Therefore, the totals are the same in both tables. The tests with the largest use were Snap (Reader) - Beta-Lactams and Charm II Tablet Competitive - Beta-Lactams used to test over 1.217 million and 581 thousand samples respectively. Charm II Tablet Sequential was used to test over 513 thousand samples. Charm BSDA Tablet - Beta-Lactams was used to test over 460 thousand samples. Table 6A shows a comparison of tests conducted using validated and non-validated test methods for sulfonmides and tetracyclines.

* = See Table 1 for explanation.

** Non-Validated Test Method

* = See Table 1 for explanation.

** Non-Validated Test Method

Tables 7-1 to 7-8 present additional details of the testing conducted. These tables show the testing by family and by individual drugs and present results in terms of Grade A and non- Grade A testing. Data on individual drugs listed in these tables, e.g., gentamicin, ceftiofur, etc., are not included in the total for the family, e.g., aminoglycosides, beta-lactams, etc.

Tables 8-1 to 8-8 present details on the number of tests conducted by industry and by regulatory agencies. The data are arranged by test within each family/drug and present results in terms of sample type and Grade A and non-Grade A testing.

To request the complete National Milk Drug Residue Data Base Fiscal Year 1999 Annual Report, please contact Ginger Levin, Project Director, at: GXL@CFSAN.FDA.GOV