The measurement of subcutaneous fat depth on hot beef carcasses with the Hennessy grading probe

Abstract

The left sides of 1118 hot beef carcasses were measured with the Hennessy Grading Probe (HGP) at a site on the rump. Two experienced technicians then measured fat depth at the same site using the cut-and-measure (CM) technique. Only measurements from carcasses where the 2 CM readings were within I mm were used in subsequent analyses (n = 828). Relative to CM, the HGP overestimated and underestimated the fat depth of lean and fat carcasses respectively. A significant (P < 0.001) linear relationship between the HGP and CM readings on the same carcass was demonstrated (r2 = 0.94, r.s.d. = 1.76 mm). The best prediction of CM was obtained when a quadratic HGP term was included (r2=0.94, r.s.d. = 1.72 mm). The HGP, using the regression equation CM = -2.53 + 1.56 (HGP) - 0.008 (HGP)2 is recommended as an alternative to CM for measuring subcutaneous fat depths of beef carcasses.