Effects of transport time and rest period on the quality of electrically stimulated male cattle carcasses

Forty-five castrated Nelore-breed male cattle, with average age of 37 months, were randomly chosen. The cattle were submitted to the combination of two transport times (up to 2 h and approximately 5 h) and five rest periods (0 h, 6 h, 12 h, 18 h and 24 h). The carcasses were electrically stimulated. After 24 h postmortem, the average of the ultimate pH in the M. Longissimus dorsi (LD) was considered normal (5.57–5.72) for eight out of nine cattle groups. The shear force (SF) was higher for cattle that were not allowed a rest period (0 h) on both transport times, however it was not significant (p > 0.05). This result was compatible with the sarcomere length (SL), which were shorter for those carcasses. The rest period and transport time had no influence on the L∗ (lightness) values, but a∗ (redness) values increased until the 12th hour of rest. The b∗ (yellowness) value was negative for the cattle without a rest period (0 h) and transported for 5 h. The cattle transported for up to 2 h could be allowed a 6-h rest period only, and the cattle transported for 5 h could be allowed a 12-h rest period without the meat quality being affected significantly.