EFFECTS OF POSTEXSANGUINATION DEHAIRING ON THE MICROBIAL LOAD AND VISUAL CLEANLINESS OF BEEF CARCASSES

Ten grain-fed steers or heifers were selected to be dehaired at slaugh ter, while another 10 cattle (of the same kind) were slaughtered and d ressed without dehairing. The carcasses of these animals were evaluate d for bacterial contamination (aerobic plate count [APC], total colifo rm count [TCC], Escherichia coil biotype I, and count and presence of Salmonella spp. and Listeria monocytogenes) after sampling from the br isket, flank, and inside round at each of three sites (after dehiding, after evisceration, and after final carcass washing). Visual defects (hairs and specks) and weight associated with trimmings were also eval uated. Overall, there were no major differences in APC, TCC, or E. col i counts between samples from dehaired cattle and those from conventio nally slaughtered animals. Dehaired carcasses had fewer (P < 0.05) vis ible specks and fewer total carcass defects before trimming (but not a fter trimming) than did carcasses of conventionally slaughtered animal s. There were fewer (P < 0.05) visible hairs both before and after tri mming on dehaired carcasses than on conventionally slaughtered animals , and no hair clusters were observed on dehaired carcasses. The averag e amount of trimmings removed to meet zero tolerance specifications in carcasses of conventionally slaughtered cattle was almost double (2.7 versus 1.4 kg) that required on dehaired animals, but due to large va riation among plant personnel involved with trimming the carcasses, th e difference was not significant (P > 0.05). Overall, dehairing reduce d visual contamination evident on beef carcasses but did not decrease the overall bacterial load.