Table 5. Effects of dietary crude protein content on carcass characteristics of Hanwoo cattle

Item	Diet¹⁾		SEM	Gender			SEM	p-value
Item	Control	HCP	SEM	Cow	Heifer	Steer	SEM	Diet	Gender	Interaction
Final SBW (kg)	717.7	707.9	13.75	718.8	698.3	721.3	20.20	0.62	0.64	0.95
Carcass weight (kg)	432.7	421.3	8.70	424.9	421.5	434.5	12.79	0.36	0.70	0.97
Marbling score	61.6	57.4	4.98	58.2	54.3	66.0	7.33	0.55	0.45	0.93
Meat color	5.00	4.93	0.103	5.06	4.83	5.00	0.151	0.61	0.45	0.45
Fat color	3.07	3.16	0.132	3.22	3.00	3.13	0.194	0.66	0.60	0.81
Quality grade	2.26	2.45	0.221	2.44	2.50	2.13	0.325	0.54	0.59	0.88
Back fat (mm)	21.9	17.0	1.49	22.4^a	23.5^a	12.5^b	2.19	0.03	<0.01	0.79
Rib eye area (cm²)	95.8	96.3	2.40	95.3	98.2	94.6	3.53	0.90	0.73	0.16
Yield score²⁾	59.7	63.3	0.97	59.6^b	59.3^b	65.5^a	1.42	0.01	<0.01	0.69
Yield grade²⁾	2.67	2.37	0.156	2.89^a	2.67^ab	2.00^b	0.230	0.19	<0.01	0.55
Yield score_2019³⁾	58.7	60.1	0.38	58.7^b	58.8^b	60.8^a	0.56	0.02	0.01	0.52
Yield grade_2019³⁾	2.71	2.18	0.147	2.67^a	2.67^ab	2.00^b	0.216	0.02	0.02	0.91

Control, contained 156 g/kg DM of CP; HCP, high level of crude protein, contained 173 g/kg DM of CP.
Yield score = 68.184 – 0.625×back fat + 0.130×rib eye area – 0.024×carcass weight + 3.23; A grade, > 67.20; B grade, 63.30 ~ 67.20; C grade, < 63.30.
Based on the revised beef grading system in 2019; Yield score for cow and heifer = (6.90137 – 0.9446 × back fat + 0.31805 × rib eye area + 0.54952 × carcass weight) / (carcass weight × 100); Yield score for steer = (11.06398 – 1.25149 × back fat + 0.28293 × rib eye area + 0.56781 × carcass weight) / (carcass weight × 100); A grade, > 61.83 (cow and heifer) and > 62.52 (steer); B grade, 59.70–61.83 (cow and heifer) and 60.40–62.52 (steer); C grade, < 59.70 (cow and heifer) and < 60.40 (steer).
Means that do not significantly differ with common superscripts within treatments (p < 0.05).
SBW, shrunk body weight; Quality grade, numerical conversion of quality grades (1, 2, 3, 4, and 5 correspond to the 1++, 1+, 1, 2, and 3 grades, respectively); Yield grade, numerical conversion of yield grades (1, 2, and 3 correspond to the A, B, and C grades, respectively).