The National Pork Board has published a fact sheet, Proper Injection-Site Protocols to Prevent Violative Residues in Sows, to educate producers on proper injection technique to increase product efficacy and absorption, while reducing injection-site reactions, broken needles and residues.
The fact sheet describes proper injection site selection and injection techniques to prevent broken needles and violative residues in sows.
Simply observing the proper withdrawal time may not be enough to avoid a violative residue if excessive amounts of product are injected at a single site.
Checkoff-funded research indicates that the deposition of more than 10 mls at a single injection site may result in delayed absorption and possibly result in violative residues at harvest.
Injection sites should be varied by at least 3 in. when giving multiple injections at one time or over a course of multiple day treatment.