Table 5.

Effects of age and straw inclusion levels on fatty acid profile (%, of total fatty acids) of LM ¹ from Yiling cull cows ².

Items 3	YCC		OCC			p-Value
	LRS	HRS	LRS	HRS	SEM	Age	Diet	Age × Diet
Saturated
C14:0	3.04	3.28	3.28	3.66	0.29	0.31	0.30	0.81
C15:0	0.29 a	0.21 b	0.21 b	0.23 b	0.016	0.13	0.10	0.006
C16:0	28.95	26.48	26.77	28.64	0.94	0.99	0.75	0.04
C17:0	0.80 a	0.59 b	0.59 b	0.62 b	0.036	0.03	0.03	0.006
C18:0	12.25	10.08	11.22	10.80	0.79	0.85	0.12	0.29
C20:0	0.11	0.10	0.10	0.10	0.006	0.67	0.18	0.48
C21:0	0.05	0.05	0.06	0.04	0.008	0.93	0.10	0.12
C22:0	0.06	0.03	0.04	0.04	0.010	0.70	0.16	0.32
Monounsaturated
C14:1n5c	1.19	1.44	1.36	1.35	0.16	0.80	0.47	0.42
C15:1n5c	0.22	0.15	0.14	0.15	0.045	0.34	0.52	0.40
C16:1n7c	4.01	4.84	4.87	4.98	0.37	0.20	0.22	0.35
C17:1n7c	0.69	0.62	0.57	0.61	0.046	0.16	0.72	0.27
C18:1n9t	0.47	0.48	0.74	0.38	0.095	0.39	0.08	0.07
C18:1n9c	43.66 b	48.19 a	46.33 ab	44.19 ab	1.35	0.63	0.39	0.03
C22:1n9c	0.82	0.38	0.45	0.53	0.14	0.48	0.22	0.09
C24:1n9c	0.09	0.05	0.05	0.07	0.017	0.57	0.65	0.15
Polyunsaturated
C18:2n6c	2.49	2.33	2.51	2.89	0.37	0.44	0.76	0.47
C18:3n6c	0.08	0.06	0.06	0.07	0.014	0.88	0.56	0.36
C18:3n3c	0.19	0.25	0.23	0.23	0.015	0.67	0.04	0.08
C20:2n6c	0.04	0.05	0.07	0.04	0.011	0.48	0.46	0.16
C20:3n6c	0.22	0.17	0.18	0.17	0.046	0.68	0.52	0.69
C20:3n3c	0.02	0.02	0.02	0.02	0.003	0.77	0.45	0.30
C20:4n6c	0.03	0.02	0.02	0.03	0.005	0.48	0.66	0.09
C20:5n3c	0.06a	0.03b	0.03b	0.05ab	0.008	0.36	0.51	0.02
C22:6n3c	0.16	0.10	0.09	0.11	0.027	0.23	0.48	0.11
ΣSFA	45.57 a	40.82 b	42.28 ab	44.14 ab	1.46	0.99	0.34	0.04
ΣMUFA	51.14 b	56.15 a	54.52 ab	52.25 b	1.31	0.85	0.32	0.02
ΣPUFA	3.29	3.03	3.20	3.61	0.45	0.60	0.87	0.47
ΣPUFA/ΣMUFA	0.06	0.05	0.06	0.07	0.009	0.54	0.92	0.24
Σn-6 PUFA	2.85	2.63	2.83	3.20	0.41	0.52	0.87	0.49
Σn-3 PUFA	0.44	0.40	0.36	0.41	0.042	0.44	0.89	0.32
Σn-6/Σn-3 PUFA	6.50	6.50	7.87	7.57	0.63	0.07	0.81	0.81

ab Means followed by different letters in the same row are significant at the p < 0.05. ¹ LM, longissimus dorsi muscle.² YCC, younger cull cows; OCC, older cull cows; LRS, providing 0.7 kg/d rice straw per head; HRS, providing 1.2 kg/d rice straw per head. ³ ΣSFA, sum of saturated fatty acids (C14:0, C15:0, C16:0, C17:0, C18:0, C20:0, C21:0, C22:0); ΣMUFA, sum of monounsaturated fatty acids (C14:1n5c, C15:1n5c, C16:1n7c, C17:1n7c, C18:1n9t, C18:1n9c, C22:1n9c, C24:1n9c); ΣPUFA, sum of polyunsaturated fatty acids (i.e., sum of Σn-6 and Σn-3); Σn-6, sum of C18:2n6c, C18:3n6c, C20:2n6c, C20:3n6c, C20:4n6c; Σn-3, sum of C18:3n3c, C20:3n3c, C20:5n3c, C22:6n3c.