209 The Effect of Waiting Time at the Lairage of Slaughterhouse of Holstein Bulls After a Short Transport on Animal Behavior, Carcass Quality and Meat Quality

Abstract

Abstract The aim of this study was to evaluate the effect of waiting time at the lairage before slaughter in Holstein bulls after a short transport. Half of the bulls of each transport (n = 8 transports; n = 48 ± 4 bulls/transport) were distributed in two treatments: short waiting time (SWT; < 2h; n = 200) and long waiting time (LWT; from 4 to 8h; n = 184). Behavior of LWT animals was observed with a 15 min scan sampling at the lairage pens. Hot carcass weight (HCW), conformation, fatness and pH in Longissimus dorsi (LD) at the 4th-5th lumbar vertebra between 30 and 36 h postmortem was registered. A caudal section of LD was collected for meat quality evaluation in a subset of 24 animals selected based on HCW and meat pH. Each loin was cut in 5 slices, one to determine instrumental color after 30 min blooming, and the others were disposed to evaluate microbiology (1, 5, 8 and 12 d) and color stability (1 to 12 d). Data were analyzed using mixed models with repeated measures. The percentage of animals standing with LWT treatment decreased (P < 0.001) with waiting time (100% and 64%, 1 h and 6 h, respectively). Meat pH was greater (P < 0.01) for SWT (5.6 ± 0.02) compared with LWT (5.5 ± 0.02); however, the percentage of carcass classified as DFD (pH > 5.7) did not differ between treatments. Lightness (L*) was greater (P < 0.05) for SWT (29.7 ± 0.47) compared with LWT (28.1 ± 0.49). Moreover, on day 12 color stability and enterobacteria count evolved differently (P = 0.09) between treatments. Waiting time below 2 h might impair meat quality as animals might not be able to recover from transport.