Table 3. Least square means (±SD) of carcass traits according to slaughter age

Trait	Slaughter age (month)
Trait	25 ≥ (n=15)	26–27 (n=87)	28–29 (n=96)	30–31 (n=106)	32–33 (n=71)	34 ≤ (n=28)
Market weight (kg)	687.13±54.27^c	738.11±65.87^b	751.92±70.22^ab	777.99±74.82^a	781.51±74.50^a	779.86±76.06^a
CCW (kg)	405.40±36.95^c	435.46±41.53^b	444.55±46.4^ab	460.62±47.78^a	459.49±49.64^a	460.14±51.54^a
REA (cm²)	84.67±9.01^b	90.43±8.62^a	89.39±9.89^a	89.40±7.86^a	89.75±9.62^a	89.75±7.22^a
BFT (mm)	12.53±4.94^b	13.14±4.83^b	13.28±4.97^b	14.40±5.43^ab	14.66±5.29^ab	16.43±7.26^a
Yield index¹⁾	61.59±1.71^a	61.47±1.53^ab	61.28±1.51^ab	60.85±1.68^abc	60.80±1.54^bc	60.38±2.13^c
DP (%)	58.96±1.31	58.99±1.66	59.08±1.72	59.20±1.85	58.75±1.86	58.94±1.90
Marbling score²⁾	3.47±0.99	3.94±1.40	3.77±1.19	3.95±1.18	4.01±1.18	3.79±1.07
PCY (kg)	262.89±21.32^c	283.47±26.20^b	288.84±28.11^ab	294.66±26.55^ab	294.85±28.90^ab	298.14±31.49^a
Fat yield (kg)	94.22±18.72^c	99.99±17.75^bc	101.99±20.87^abc	111.76±23.45^a	109.90±21.87^ab	106.83±23.84^ab
Bone yield (kg)	38.96±3.35^b	42.13±5.03^a	43.39±5.28^a	43.76±4.76^a	44.13±4.63^a	44.30±6.95^a

Yield index: (11.06398 – [1.25149 × Backfat thickness (mm)] + [0.28293 × Ribeye area (cm²) + [0.54768 × Carcass cold weight (kg)]) ÷ (Carcass cold weight (kg) × 100).
Marbling score: 1-trace, 9-very abundant.
Means within the same row with different superscript are statistically different (p < 0.05).
CCW, carcass cold weight; REA, ribeye area; BFT, backfat thickness; DP, dressing percentage; MS, marbling score; PCY, primal cuts yield