. 2018 Jun 21;96(7):2698–2709. doi: 10.1093/jas/sky161

Table 4.

Percentage of fatty acids (mg/100 mg total fatty acids) in the chuck, loin, and round muscles at increasing ages

Fatty acid	Muscle	Age, mo					Pooled SEM	Significant differences¹
Fatty acid	Muscle	12	16	20	24	28	Pooled SEM	A	M	A × M
Palmitic, 16:0	Chuck	25.5^fg	24.8^g	28.1^ab	27.4^bcd	24.3^g	0.31
	Loin	27.8^abcd	28.2^ab	26.9^cde	26.6^de	25.8^g	0.27	0.001	0.001	0.001
	Round	28.6^a	27.9^abc	28.8^a	28.0^abc	26.8^de	0.19
Palmitoleic, 16:1n-7	Chuck	7.09	6.51	6.36	6.28	5.69	0.11
	Loin	5.96	6.54	6.31	5.51	5.77	0.12	0.002	0.08	0.22
	Round	6.71	6.17	6.44	5.99	5.73	0.14
Stearic, 18:0	Chuck	19.7^a	17.3^b	11.9^e	11.6^ef	10.2^f	0.55
	Loin	18.9^a	18.0^b	15.0^c	10.8^f	10.2^f	0.54	0.001	0.009	0.001
	Round	19.3^a	17.3^b	14.2^c	12.9^d	10.1^f	0.49
Oleic, 18:1n-9	Chuck	43.4^d	46.6^bc	48.9^a	49.3^a	48.7^ab	0.43
	Loin	41.9^e	42.02^e	45.9^c	47.3^b	47.6^b	0.42	0.001	0.001	0.013
	Round	40.1^f	43.5^d	44.6^d	47.1^bc	46.9^bc	0.42
cis-Vaccenic, 18:1n-7	Chuck	1.33^abc	1.24^bc	1.16^c	1.43^a	1.41^a	0.03
	Loin	1.27^abc	1.32^ab	1.18^c	1.24^bc	1.36^ab	0.02	0.05	0.48	0.04
	Round	1.28^ab	1.20^bc	1.36^ab	1.20^bc	1.34^ab	0.03
Linoleic, 18:2n-6	Chuck	0.78^f	1.32^de	1.25^e	1.63^d	7.26^a	0.35
	Loin	1.91^d	1.52^de	2.51^c	6.46^ab	6.90^a	0.34	0.001	0.001	0.001
	Round	1.73^d	1.64^d	1.70^d	3.01^b	6.85^a	0.29
α-Linolenic, 18:3n-3	Chuck	0.35^cd	0.29^de	0.33^cd	0.29^de	0.64^b	0.02
	Loin	0.23^fg	0.27^ef	0.23^fg	0.23^fg	0.64^b	0.03	0.001	0.001	0.001
	Round	0.25^efg	0.20^g	0.23^fg	0.24^efg	0.86^a	0.04
MUFA:SFA²	Chuck^A	1.17	1.31	1.42	1.48	1.66	0.03
	Loin^B	1.06	1.09	1.28	1.46	1.55	0.03	0.001	0.001	0.14
	Round^B	1.02	1.13	1.23	1.34	1.49	0.03

^a–gMeans within a fatty acid with common superscripts do not differ (P > 0.05). ^A,BMuscles with different superscripts differ (muscle main effect P < 0.05). Data are means for n = 10 steers sampled sequentially in each muscle.

¹A, age; M, muscle; A × M, age × muscle interaction.

²MUFA:SFA = (14:1n-7 + 16:1n-7 + 18:1n-9 + 18:1n-7)/(14:0 + 16:0 + 18:0). Less abundant fatty acids are not listed in the table.