Immune system and inflammatory responses are affected by...-linolenic acid (...LA: 18:3...-3). The objective of this study was to determine the effects of...LA-enriched rations on gene expression of systemic (blood) and local (mammary gland) inflammatory markers in Holstein dairy cattle. Further, the effect of dietary treatments was evaluated on the concentration of...LA in serum phospholipids. Camelina (Camelina sativa) meal (containing 24·2%...LA) was fed at 0, 3, 6, and 9% (dry matter basis) replacing canola meal (rich in 18:1...-9) to provide rations with incremental concentrations of...LA. Lactating primiparous Holstein cows (n = 18) were randomly assigned to a treatment sequence in a 4 × 4 Latin square design. Each period lasted 16 d and milk and blood samples were collected during the final 2 d of each period. Peripheral blood mononuclear cells (PBMC) and milk cells (MC) were harvested, and RNA extracted and converted to complementary DNA for quantitative real time PCR analysis. The effect of dietary treatments (...LA) on the relative abundance of pro- and anti-inflammatory genes in the PBMC and MC was tested by the MIXED procedure of SAS. Expression of pro-inflammatory tumour necrosis factor (TNF)-...in MC was linearly reduced (up to 40%) as dietary...LA increased. Expression of pro-inflammatory markers interleukin (IL)-1..., IL-8, and TNF-...was reduced (29, 20, and 27%, respectively) in PBMC isolated from cows fed 6% camelina meal ration as compared with cows fed 0% (control). Expression of IL-6 was, however, increased with inclusion of camelina meal. Greater dietary...LA linearly increased serum phospholipids...LA contents, and when fed up to 6% DM down-regulated expression of some of the local (milk) and systemic (blood) pro-inflammatory markers in vivo.