Carcass quality evaluation
All steers were slaughtered as they reached around 500 kilograms live weight and butchered following the Thai cutting style by commercial beef production company in Nakhon Ratchasima. Hot carcass (45 min postmortem (p.m)) was weighed. Loin eye area was measured between the 12th and the 13th (Boggs and Merkel, 1981) where sample of Longissimus dorsi were prepared from left carcass side and ageing until 14 days at 4C. Meat pH (pH Meter EUTECH pH Spear ) were determined in LD at 24 hour postmortem. After dissection, the LD samples ware cut into 2.5 cm thick slices, put into Polyvinyl Chloride bags and then stored in the at 4C for 14 days. After that take the sample for analysis meat quality Meat colors were measure by use Minolta, CR-300, Osaka, Japan after take sample outside bag for 45 minutes. The cooking loss were investigated by the method of Devine et al. (1999) and the shear force was measured using a Warner-Bratzler shear (Instron Model 1011). The chemical composition of meat were analyzed by methods of AOAC (1997).