A COMPARISON OF WARNER-BRATZLER SHEAR FORCE ASSESSMENT WITHIN AND AMONG INSTITUTIONS

Our objective was to compare measurement of Warner-Bratzler shear forc e of beef longissimus within and among institutions when each institut ion used its own protocol and when all institutions used a standardize d protocol. In Exp. 1, each of five institutions (A, B, C, D, and E) r eceived two adjacent steaks from each of 27 beef strip loins (longissi mus lumborum). Warner-Bratzler shear force was measured for both steak s using the procedures normally used at each institution. In Exp. 2, e ach institution received two adjacent steaks from each of 45 strip loi ns. Shear force was measured for both steaks using a standardized prot ocol. In Exp. 1, Warner-Bratzler shear force was highest (P < .05) for A (4.7 kg) and lowest (P < .05) for B (2.9 kg). Repeatability of shea r force was highest for A and C (.73 and .72), intermediate for D (.63 ), and lowest for B and E (.39 and .44). In Exp. 2, Warner-Bratzler sh ear force was highest (P < .05) for A (5.1 kg) and lowest (P < .05) fo r E (3.7 kg). Repeatability of shear force was highest for A (.87), in termediate for B, D, and E (.81, .75, and .80), and lowest for C (.67) . Shear force values differed within and among institutions due to pro tocol, execution of the protocol, and instrument variation. Thus, comp arisons of Warner-Bratzler shear force data among institutions are cur rently not valid. However, it is possible for institutions to obtain t he same mean shear force value and have high repeatability if a standa rd protocol is properly executed with calibrated equipment.