Incidence of Injection-Site Blemishes in Beef Top Sirloin Butts'

The occurrence of damaged muscle tissue resulting from intramuscular injections of animal-health products represents a "quality control" problem and an economic loss to the beef industry. Five individual and sequential national audits of injection-site blemishes in beef top sirloin butts have been conducted at the steak-cutter level. During the most recent audit (March 19931, the incidence of injection-site blemishes in top sirloin butts was determined to be 10.87 +_ 2.99%, with an average weight per blemish of 123.39 k 5.48 g. A 5-point classification system used to partition the blemishes into chronological stages of the healing process suggested that the majority of the blemishes origi- nated at the cow-calf or stocker levels, or early in the finishing period. Evaluation of blemish data by geographic location of plant-of-origin suggests that the problem occurs throughout the beef production sector.