In previous work, the use of porcine luteinizing hormone (pLH) in lieu of gonadotropin releasing hormone (GnRH) for synchronizing ovulation improved pregnancy rates in lactating dairy cows. Later, we found that pLH treatment not only altered the LH profile, but also influenced expression of the BMP-15, GDF-9 and TGF-β1 proteins known to promote cumulus expansion and oocyte competence in nonlactating cows. We currently hypothesized that pLH would alter the expression of target genes in the cumulus-oocyte complexes (COC), which regulate oocyte competence. Cyclic nonlactating Holstein cows (n = 8) were subjected to ovarian stimulation with 200 mg FSH. Follicles = 10 mm were aspirated at 21 ± 1 h after giving either 100 µg GnRH or 25 mg pLH im, and COC recovered and frozen until qRT-PCR analysis. Serial blood samples were collected from before giving GnRH/pLH until 20 h after, for plasma LH analysis using an anti-bovine LH monoclonal antibody that cross-reacts equally with both bovine and porcine LH. Plasma LH concentrations and qRT-PCR data were analyzed using MIXED and GENMOD procedures of SAS, respectively. When LH concentrations (ng/mL) were compared in GnRH- and pLH-treated cows, effects of time and time-by-treatment interactions were detected (P < 0.01) with mean LH being higher in GnRH than pLH cows (2.8 ± 0.2 vs. 2.0 ± 0.2) from 30 min until 4 h post-treatment. However, mean plasma LH from 5 to 20 h post-treatment was greater (P < 0.01) in pLH- than in GnRH-treated cows (1.1 ± 0.2 vs. 0.4 ± 0.1). Treatment with pLH altered HAS-2 and GREM-1 mRNA abundance (P < 0.01) by about 26- and 7-fold, in COC of pLH- and GnRH-treated cows, respectively. Whereas the relative expression of AREG abundance tended (P = 0.06) to increase in GnRH-treated cows, EREG, BTC, PGr, COX-2 and PTX-3 mRNA expression were not affected by treatment. This study provides evidence that a prolonged, higher-than-basal LH profile in pLH-treated cows increased the expression of HAS-2 and GREM-1, genes known to improve oocyte competence, which may explain the higher pregnancy rates previously reported when pLH was used to induce ovulation.