The use of medications in animal food serves important animal health purposes, while at the same time creating unique hazards for a feed mill. The following will provide a summary of FDA requirements and the hazards presented by medication use at a feed mill.
Two FDA Categories -Licensed Facility vs a Non-Licensed One
A license is required for mills that
• Manufacture medicated feed using a Category II, Type A medicated article (to make Type B or Type C feed).
• Manufacture certain liquid or free choice medicated feeds (including some with Category I drugs) where the regulations specify that a license is required. An example would be a proprietary free choice cattle mineral or liquid lick containing a Category I drug (such as chlortetracycline) where the specific formula and performance data belong to one sponsor and are not publicly available.
Drug categories in medicated feed
• Category I drugs: No withdrawal period is required at the lowest approved use level in any species for which the drug is approved.
• Category II drugs:
• Require a withdrawal period at the lowest use level for at least one approved species, or
• Are regulated on a “no residue” or “zero tolerance” basis because of carcinogenic concern. Carbadox is an example of this type of medication.
Types of medicated feed
FDA also defines three types of medicated products used around feed:
• Type A medicated article: Concentrated new animal drug source, used only to manufacture Type B or Type C (or another Type A); not fed directly.
• Type B medicated feed: Intermediate feed containing a drug, used only to manufacture other Type B or Type C feeds; not fed directly. One example would be a chlortetracycline and sulfamethazine Type B medicated cattle feed that is mixed with non medicated ingredients to make a complete Type C finishing ration.
• Type C medicated feed: Final feed that is fed to animals (complete feed, top dress, or free choice), manufactured from Type A or Type B.
Current Good Manufacturing Practices
Mills that are required to be licensed are held to a stricter set of CGMPs than those that are not licensed. One significant difference is that licensed feed mills are required to perform three assays per year per licensed medicated feed at minimum. More may be needed based on risk.
Inspections of Licensed Facilities
FDA regulations state that licensed Category II mills are to be inspected at least every two years, often via state inspectors under contract, and that risk based priorities can affect when and how often they show up.
In practice, some mills may go longer than two years between FDA originated or FDA contracted inspections depending on risk ranking and resource constraints; however, state feed control officials may also inspect for their own state law purposes during that time. This is in part due to the fact that FSMA inspections are often done concurrently with other inspections to be more efficient.
Hazards of Medications
The production of feed with medications creates several types of hazards.
1. Manufacturing and distribution of a medicated feed that goes to the wrong species of animal.
2. Carryover of a medication into a feed intended for a species that would suffer harm from the medication.
3. Use of a medication in an amount that differs from the formulation.
4. Use of the wrong medication.
5. Medication that is not of the correct potency.
6. Incorrect premix or dilution step (e.g., mis making a Type B from Type A, or a Type C from Type B), leading to under or over concentration of the drug in the final feed.
7. Use of expired, deteriorated, or improperly stored medicated articles or premixes that compromise drug stability or potency.
8. Inadequate mixing or segregation in the mixer or conveying system that causes non uniform distribution of the medication within a batch.
9. Mislabeling or incomplete labeling of medicated feeds (missing drug name, concentration, species, directions, or warning statements).
10. Failure to control access or inventory, resulting in unauthorized use or diversion of medicated feed or Type A medicated articles.
11. Inadequate verification of customer identity or species/class at load out, leading to delivery of medicated feed to an unintended operation.
Hazard Control
With that many hazards to consider, is it any wonder that FDA inspectors and third-party auditors focus much attention on how medications are handled? The good news is that there are well-documented methods for controlling each of the hazards and ensuring safe animal feed.
Let’s look at some keys to controlling medication related hazards.
1. Training – Employees who are involved in feed mixing and other activities that involve medications need to be thoroughly trained. Training should start with why controlling this hazard is so important toward preventing animal deaths and illnesses. After that, focus on your SOPs that address that hazards.
Some important SOPs include: 1) medication receiving and storage; 2) inventory control and reconciliation; 3) understanding formulations (recipes) and labeling; 4) hand adding practices and 5) sequencing and flush practices.
Based on the results of FDA inspections, here are a few specific things employees need to know.
Where to find expiration dates and how to cut bags to make sure the dates are maintained.
Why it is important to fold bags closed when not in use.
Why an accurate inventory is important and that discrepancies need to be reported immediately.
Why accurate hand adding is one of the most critical steps in the process.
2. Equipment and Procedure Verifications
• Mixer Uniformity studies
• Scale calibrations
• Carry over studies
3. Equipment cleanout methods including flushing and physical cleanout of mixers and blending equipment. Some automated systems will have a flush built into the process with a defined material and amount to be used. If flushing manually, it is equally important to state the material(s) that can be used for flushing and the amount used. Bulk Feed delivery drivers must be provided with instructions regarding when they are to flush equipment and what is to be done with the material used for flushing. Can it be left at the farm or must they return it to the mill for disposal?
4. Supplier Approval processes to make sure the drug supplier is reputable and complying with FDA rules for drug manufacturing.
5. Assays of medicated feed to confirm that the finished feed includes the correct amount of medication.
Remember that the use of medications in animal feed presents many hazards that must be controlled to manufacture safe feed.
Establish your SOPs and make sure they are followed
Train employees on the SOPs
Verify your procedures through studies and other evaluations.
