Table 2.

Comparison of mean polyunsatured fatty acid composition (expressed as mg/g of fatty acid or as a % of total lipid) between grass-fed and grain-fed cattle.

	Fatty Acid
Author, publication year, breed, treatment	C18:1 t11 Vaccenic Acid	C18:2 n-6 Linoleic	Total CLA	C18:3 n-3 Linolenic	C20:5n-3 EPA	C22:5n-3 DPA	C22:6n-3 DHA	Total PUFA	Total MUFA	Total n-6	Total n-3	n-6/n-3 ratio
Alfaia, et al., 2009, Crossbred steers	g/100 g lipid
Grass	1.35	12.55	5.14*	5.53*	2.13*	2.56*	0.20*	28.99*	24.69*	17.97*	10.41*	1.77*
Grain	0.92	11.95	2.65*	0.48*	0.47*	0.91*	0.11*	19.06*	34.99*	17.08	1.97*	8.99*
Leheska, et al., 2008, Mixed cattle	g/100 g lipid
Grass	2.95*	2.01	0.85*	0.71*	0.31	0.24*	na	3.41	42.5*	2.30	1.07*	2.78*
Grain	0.51*	2.38	0.48*	0.13*	0.19	0.06*	na	2.77	46.2*	2.58	0.19*	13.6*
Garcia, et al., 2008, Angus steers	% of total FAs
Grass	3.22*	3.41	0.72*	1.30*	0.52*	0.70*	0.43*	7.95	37.7*	5.00*	2.95*	1.72*
Grain	2.25*	3.93	0.58*	0.74*	0.12*	0.30*	0.14*	9.31	40.8*	8.05*	0.86*	10.38*
Ponnampalam, et al., 2006, Angus steers	mg/100 g muscle tissue
Grass	na	108.8*	14.3	32.4*	24.5*	36.5*	4.2	na	930*	191.6	97.6*	1.96*
Grain	na	167.4*	16.1	14.9*	13.1*	31.6*	3.7	na	1729*	253.8	63.3*	3.57*
Nuernberg, et al., 2005, Simmental bulls	% of total fatty acids
Grass	na	6.56	0.87*	2.22*	0.94*	1.32*	0.17*	14.29*	56.09	9.80	4.70*	2.04*
Grain	na	5.22	0.72*	0.46*	0.08*	0.29*	0.05*	9.07*	55.51	7.73	0.90*	8.34*
Descalzo, et al., 2005, Crossbred steers	% of total FAs
Grass	4.2*	5.4	na	1.4*	tr	0.6	tr	10.31*	34.17*	7.4	2.0	3.72*
Grain	2.8*	4.7	na	0.7*	tr	0.4	tr	7.29*	37.83*	6.3	1.1	5.73*
Realini, et al., 2004, Hereford steers	% fatty acid within intramuscular fat
Grass	na	3.29*	0.53*	1.34*	0.69*	1.04*	0.09	9.96*	40.96*	na	na	1.44*
Grain	na	2.84*	0.25*	0.35*	0.30*	0.56*	0.09	6.02*	46.36*	na	na	3.00*

* Indicates a significant difference (at least P < 0.05) between feeding regimens within each respective study reported. "na" indicates that the value was not reported in the original study. "tr" indicates trace amounts detected.