NEWSLETTER ARTICLES

Livestock and Natural Resources

INJECTION SITE STUDY IN BEEF CATTLE
by Wayne Jensen

Can intramuscular injections result in tissue damage at the injection site? This was investigated in a study recently reported at Colorado State where 120 weaning-age heifer calves were randomly injected with two of eight compounds - one in the left top sirloin butt, and one in the left outside round. Using new needles for each injection in each animal, the readily available compounds used in the study were a saline solution, two viral vaccines, a bacterin, a vitamin ADE product, and three different antibiotics.

After a period of 178 days, the carcasses of these heifers were evaluated by comparing sites of the injection to the same sites on the right side of the animal receiving an injection. While I did not receive the specific data, it was reported most of the compounds administered caused an unacceptable high incidence of lesions. Sites showing visible lesions also had a greater tenderness variation (toughness) as measured by higher shear force values than the control sites.

This tenderness variation was also found in the injected sites even when no visible lesion was found as compared to the non-injected control sites.

Also interesting was the volume of "toughened" tissue found at the injection site compared to non-toughened tissues at the control site. It varied dependent on the compound and whether it was the round or sirloin butt, but it ranged from 19 to 64 cubic inches.

The message to remember from this work is that all the compounds used in these studies caused unacceptable tissue damage at time of slaughter either from lesions or toughness of the meat at and around the injection site.

Soon, many of you will begin working your calves. You can do your part to reduce this industry problem of tissue damage at injection sites by reading the insert to review the injection procedure for the injectable products you will be using. If it must be administered IM, select the neck as the injection site. If the label indicates it can be used either IM or SQ, select the SQ route. Also, if you aren't the person injecting your cattle, take the time to train those who will. You as the owner are responsible to see the product is administered correctly to do the job the product is intended to do without causing damage to the carcass.