There's no doubt about it. The beef industry is doing a terrific job at lessening injection site blemishes. In 1991, the National Beef Quality Audit found that 21.6 percent of fed cattle had injection site blemishes in the top butt. In 1999, this defect had dropped to 3.2 percent.

But now there's a new concern: greenish lesions are showing up in beef cases where retailers use modified atmosphere packaging.

"We're finding a 15 percent to 20 percent incidence of greenish lesions in chuck steaks where modified-atmosphere packaging is being used," states Dr. Dee Griffin, University of Nebraska and member of National Cattlemen's Beef Association Beef Quality Assurance (BQA) Task Force. "These greenish lesions are not likely new. We just didn't see them before modified-atmosphere packaging came to the retailer case. Also coming into play is the practice of retailers now using part of the chuck for steaks.

"Put these two factors together and we have a problem. This 15 percent to 20 percent incidence of greenish lesions is a concern and must be reduced."

Dr. Griffin points out that current research indicates that the greenish lesions cannot be traced to a particular product or formulation.

Labeling the greenish lesions "an industry challenge," Dr. Griffin stresses that the percentage of lesions can be reduced by tightening the current injection site zone.

"Our work shows that one chuck muscle plays a major role in the problem," Dr. Griffin states. "By tightening the injection site zone, this particular muscle is avoided, and incidence of lesions can be significantly reduced.

"The greenish lesions are a management problem. Although there are various unknowns, we do know that giving products SubQ when possible, tightening the old injection site zone and administering IM injections at least a hands width ahead of the shoulder will be a big step in addressing the problem."

In addition to requesting that vaccinations be given only in the new injection site zone, Dr. Griffin lists eight areas where quick, easy improvement can be achieved when vaccinating cattle:

1. Use trained individuals who know how to properly vaccinate and follow proper procedure.
2. Follow product labels and adhere to withdrawal times.
3. When products offer a choice of SubQ or IM, administer vaccinations SubQ. Tent all SubQ injections.
4. Use 1 to 1.5" needles for IM and 1/2 to 3/4'" needles for SubQ.
5. Use 16-gauge or 18-gauge needles.
6. Change needles when they become contaminated and don't give injections where mud, manure and other contaminants are present.
7. Change needles at least every 15 animals.
8. Clean syringes properly before using them.

To properly clean syringes, he advises cleaning internal parts of automatic and pistol-grip vaccine syringes in boiling water, then allowing them to cool for at least 10 minutes before using.

To lubricate parts, Dr. Griffin suggests using clean products such as vegetable oil spray. His preference: disposable vaccine syringes or syringes that have disposable parts.

Although Dr. Griffin is a big proponent of giving all injections SubQ, he notes that not all products are labeled for this route of administration.

"Some products must be used IM (intramuscular) because there is no SubQ on the label. But," he adds, "if you have a choice, go SubQ."

Animal health companies applaud the new injection site zone and the other steps Dr. Griffin is encouraging those in the beef industry to follow.

"The practices and the new injection site zone are excellent steps toward lessening injection site blemishes," states Dr. Jim Rhoades of Novartis Animal Vaccines, Inc. "When all of us work together as a team and address BQA issues, significant inroads can be made." ©