By Robert Fears
Proper injection sites are discussed frequently and for a good reason. Injecting animals in the proper locations has value for the producer as well as the consumer. Muscle irritation from an injection of a medication or vaccine develops scar tissue (lesion). Both economic losses to the beef industry and unfavorable consumer perception result from scar tissue in cuts of meat.
“Lesions occur from a cow’s body defense system reacting to the injection. In young stock, lesions can remain through their entire life,” says Kathy Kaufman, coordinator of New York State Cattle Health Assurance Program. “Carcass value is decreased through loss of meat caused by trimming the lesion and resulting increased labor at the packing plant. Injection site lesions and abscesses cost the United States beef industry $4.2 million annually.”
“There is a negative relationship between tenderness and injection sites, including injection sites that have no visible lesion. Intramuscular (IM) injections may create permanent damage regardless of animal age,” says Glenn Selk, professor of animal science emeritus, Oklahoma State University. “Tenderness is reduced in a 3-inch square surrounding the injection site. Moving the injection site to the animal’s neck prevents damage to expensive steak cuts.”
It is important to give injections in the manner stated on product labels. Some product labels allow the choice between subcutaneous (under the skin, SQ) and in the muscle (IM). Always use SQ when permitted by the label and administer the injection by tenting the skin. Grasp a piece of skin between the fingers to make a tent. Slide the needle into the base of the tent under the skin and press the plunger. Check to make sure the vaccine is not coming out the other side of the tent due to the needle being pushed in too far.
Some vaccines may contain irritants which can cause lumps. These lumps blemish the carcass and is another reason that injections should be given in the animal’s neck. Any lump that occurs in the neck is trimmed off during processing and doesn’t reduce value of the carcass.
IM treatments are required when it is necessary to inject a vaccine or medication deep into the muscle for fast absorption. Normally less irritation occurs with this type of injection. Avoid carcass devaluation by injecting deep into the muscle of the neck rather than the muscle mass in the hindquarters.
“Adequately restrain an animal before giving an injection,” advises Jeremy Powell, associate professor and veterinarian, University of Arkansas. “The subject should be kept as still as possible to help prevent broken needles as well as harm to the animal or to the person giving the injection.”
“Needle movement during administration of an intramuscular injection can cause muscle damage and a significant amount of the injection to be deposited SQ. Likewise, any needle movement during a SQ injection may lead to a significant portion of the material deposited IM,” Powell says. “Administration of a product into a site other than where the label recommends may affect absorption of the drug or vaccine, leading to decreased efficacy.”
When administrating more than one injection on the same side of the neck, place the injection sites at least 4 inches apart. Four inches is approximately the width of a hand. The spacing allows better absorption and less interaction between products.
It is the responsibility of the cow-calf producer, stocker operator and feedyards to properly inject cattle. Lesions, in addition to reducing meat tenderness, negatively affects flavor. Consumers are not going to buy beef if it does not give them a pleasant eating experience.
Fears is a freelance writer based in Georgetown, Texas.