I've read ratios of 1-1 to 4-1 is ideal for O6-O3.
Omega-6 fatty acid - Wikipedia, the free encyclopedia
Modern Western diets typically have ratios of n−6 to n−3 in excess of 10 to 1, some as high as 30 to 1; the average ratio of omega-6 to omega-3 in the Western diet is 15/1–16.7/1. Humans are thought to have evolved with a diet of a 1-to-1 ratio of omega-6 to omega-3 and the optimal ratio is thought to be 4 to 1 or lower, and it is even better if there is more omega−3 than omega−6 (especially healthy ratio of omega−6 to omega−3 is from 1:1 to 1:4). A ratio of 2–3/1 omega 6 to omega 3 helped reduce inflammation in patients with rheumatoid arthritis. A ratio of 5/1 had a beneficial effect on patients with asthma but a 10/1 ratio had a negative effect. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 had no effect.
Excess n−6 fats interfere with the health benefits of n−3 fats, in part because they compete for the same rate-limiting enzymes. A high proportion of n−6 to n−3 fat in the diet shifts the physiological state in the tissues toward the pathogenesis of many diseases: prothrombotic, proinflammatory and proconstrictive.
Would I be putting a grain-feed cow on a fad diet if I took it out of the feedlot and put it on pasture eating the grass nature intended?