Table 4.

Influence of protein and energy level on carcass characteristics and carcass composition of feedlot hair lambs

Item	Energy level (Mcal ME/kg)					Main effects				p-value
	3.05		2.83			Energy level (Mcal ME/kg)		Protein level (%)
	17.55% CP	14.5% CP	17.5% CP	14.5% CP	SEM	3.05	2.83	17.5	14.5	E	P	E×P
Final shrunk wt (kg)	47.49	43.97	47.45	46.78	1.74	45.73	47.12	47.47	45.37	0.26	0.09	0.25
Hot carcass wt (kg)	25.02	23.74	24.91	24.79	1.00	24.39	24.84	24.97	24.27	0.47	0.28	0.37
Chilled carcass wt (kg)	25.23	23.06	24.07	24.39	0.96	23.64	24.22	24.15	23.72	0.32	0.46	0.21
Dressing percentage HCW	51.00	52.45	50.76	52.13	0.76	51.72	51.45	50.88	52.30	0.72	0.08	0.96
Dressing percentage CCW	52.63	53.99	52.51	52.97	0.56	53.31	52.73	52.58	53.48	0.27	0.10	0.40
LM area (cm2)	11.52	11.41	11.60	12.21	0.60	11.47	11.91	11.56	11.81	0.47	0.67	0.55
Kidney-pelvic fat (%)	4.38b	3.41a	3.03a	3.19a	0.29	3.90b	3.11a	3.70	3.30	<0.01	0.10	0.03
Fat thickness (cm)	2.10	1.54	1.86	1.54	0.20	1.82	1.70	1.98b	1.55a	0.46	0.02	0.45
Carcass composition (%)
Muscle	57.95	58.06	57.38	58.92	1.47	58.00	58.13	57.66	58.49	0.72	0.62	0.61
Fat	23.13	23.44	23.40	22.69	0.02	23.28	23.06	23.27	23.07	0.95	0.49	0.36
Bone	18.92	18.50	19.22	18.38	0.54	18.71	18.81	19.07	18.44	0.67	0.04	0.20
Muscle:fat ratio	2.51	2.48	2.45	2.59	0.23	2.49	2.52	2.48	2.54	0.93	0.69	0.57
Muscle:bone ratio	3.06	3.14	2.99	3.21	0.15	3.10	3.09	3.02	3.17	0.42	0.22	0.64

SEM = Standard error mean. E = Energy; P = Protein; E×P = Energy and Protein levels interaction.

^{a, b}Different letters in the same variable indicate statistical differences (p≤0.05).