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, points out Steve Larsen, pork safety director with the National Pork Board. By using proper injection techniques you also can reduce injection-site reactions and the chance of broken needles.

First, determine dosage amount as recommended by the product label or a veterinarian. If the correct dosage is more than 10 milliliters, multiple injections must be given to deliver the full dose. Following these steps will help prevent violative tissue residue at slaughter.

  • Never administer more than 10 ml 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), take these steps:
  • Use a spot on the neck just behind and below the ear but in front of the shoulder.
  • Do not inject into the ham or loin, unless directed to do so by your veterinarian.
  • Use the proper needle size and length 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 guidelines, the recommended gauges for breeding stock are 14, 15 or 16 and either 1-inch or 1½-inch lengths.

Many variables can impact how often a needle can be used and when it should be discarded. NPB research indicates that 20 to 30 injections are about the most any needle can handle. 

After a needle is no longer usable, follow proper disposal steps. As outlined in PQA Plus guidelines, needles must be disposed of 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 your local veterinarian.

Contact the agency in charge of overseeing the disposal of biomedical wastes, including needles, in your state. You also can ask your veterinarian, or a local hospital, if they accept farm-generated medical wastes.

You can gain more information about the agencies in each state that regulate biomedical or infectious waste disposal by going to http://1.usa.gov/Jk0lpk.