While the U.S. pork industry has experienced extremely low levels of antimicrobial residues at slaughter, USDA’s Food Safety and Inspection Service previously reported several penicillin G violative residues in culled sows. 

Using proper sow injection techniques will help increase product efficacy while reducing the likelihood of violative tissue residues at slaughter, according to Steve Larsen, director of pork safety, National Pork Board. By using proper injection techniques you can also reduce injection-site reactions and the chance of broken needles.

First, determine the dosage amount as recommended by the product label or a veterinarian. If the correct dosage of a product is more than 10 milliliters (mls), as indicated by the label or as directed by a veterinarian, multiple injections must be given to deliver the dose. Observing the following steps will help to prevent violative tissue residue at slaughter.

  • Never administer more than 10 mls of an injectable antimicrobial product in one site.
  • Separate injection sites by at least 3 inches when multiple injections must be given to deliver the appropriate dose.
  • If multiple-day therapy is needed, separate injection sites by at least 3 inches from the previous day’s injection site.

When giving a proper injection in the muscle (Intramuscular):

  • Use a spot on the neck just behind and below the ear, but in front of shoulder.
  • Do not use a needle to inject in the ham or loin, unless directed to do so by your veterinarian.
  • Use the proper size and length of needle to ensure the medication is deposited in the muscle, not in other tissues.
  • Change the needle when appropriate to maintain cleanliness and sharpness.
  • Never straighten a bent needle.

Select a clean, sharp needle of appropriate gauge and length to administer the injection. “According to the Pork Quality Assurance Plus (PQA) guidelines, the recommended gauges for breeding stock are 14, 15 or 16 and either 1 inch or 1½ inch lengths,” Larsen says.

There are many variables that can impact how long a needle can be used and when it should be discarded. “Research by the National Pork Board’s pork checkoff has indicated about 20 to 30 injections are about the most a needle can handle,” Larsen says. “However, this is dependent on the quality of needle being used.” 

After a needle is no longer usable, follow proper disposal recommendations. According to PQA Plus guidelines, needles must be disposed according to state medical waste regulations to prevent environmental contamination or injury. Proper disposal involves placing needles (sharps) in a rigid puncture-resistant container immediately after use. Commercially available containers can be purchased from many farm supply stores, safety supply houses, drug stores or from veterinarians.

“For the rules that apply to your farm, contact the agency in charge of overseeing the disposal of biomedical wastes, including needles, in your state,” Larsen advises. “Another option may be to ask your veterinarian, or a local hospital, if they accept farm-generated medical wastes.”

Read more information about agencies in each state that regulate biomedical or infectious waste disposal.