During the periparturient period, elevated circulating nonesterified fatty acids (NEFA) affect not only the circulating fatty acid (FA) composition, but also that of the peripheral blood mononuclear cells (PBMC) and polymorphonucleocytes (PMN). The changes to specific lipid fractions, however, remain unknown. We hypothesize elevated lipid mobilization will alter FA profiles and therefore gene expression of pro-inflammatory mediators. Starting −28 d before calving, treatment cows (n = 18) received a dry cow ration with an additional 10 kg of corn / head per day, while the control cows (n = 16) received the dry cow ration (no additional corn) with an additional 400 mg of monensin / head per day to minimize lipid mobilization. Postpartum, treatment cows were fasted for 8 h on d +3. Plasma samples were collected on d −28, +3, +12, and +21 relative to parturition to isolate PBMC and PMN for analysis of fatty acid methyl ester (FAME) of cells’ NEFA and phospholipids (PL) fractions. Isolated PMN were analyzed using real-time q-PCR for caspase-1 (CASP), interleukin-8 receptor (IL-8R), and L-selectin (SELL). Data were analyzed as repeated measures ANOVA using mixed model procedures in SAS (9.3) with significance declared at P ≤ 0.05. Several FA concentrations of NEFA and PL fractions in PBMC and PMN changed over time. Eicosanoid precursor C20:4 in the NEFA fraction of PBMC were greater in treatment than control cows (0.51 vs. 1.29 ± 0.27 g/100g FAME; P = 0.02). In contrast, C20:4 of PBMC in PL fraction were greater in control animals (10.06 vs. 8.18 ± 0.56 g/100g FAME; P = 0.02). Anti-inflammatory C20:5 concentrations in the PL fraction of PMN were greater in the treatment group and multiparous animals in a treatment across parity effect (P = 0.05). Although gene expression of CASP, IL8-R and SELL in PMN changed over time (P < 0.0001), no treatment effect was detected. In summary, dietary manipulation altered FA profiles within PBMC and PMN fractions, but did not alter gene expression in PMN.