Lactating beef cows previously synchronized for estrus (d 0) were assigned to four treatments to assess their effectiveness in increasing blood progesterone (P4) and its effects on tumor necrosis factor-α (TNF-α) and prostaglandin F2α (PGF2α) after the transfer of embryos. At the time of transfer (d 7), cows received no treatment (control;n=16), a controlled internal drug releasing device (CIDR;n=16), human chorionic gonadotropin (hCG;n=15), or gonadotropin releasing hormone (GnRH;n=15). Blood samples were taken on d 7, 14, and 21 for analysis of P4 and tumor necrosis factor-α (TNF-α). Blood was collected (every 15 min for 2 h) in half the animals in each treatment group on d 14 and the remaining half on d 21 for analysis of prostaglandin F2α metabolite (PGFM). Retention rates were 56.2, 62.5, 46.7, and 13.3% for cows in the control, CIDR, hCG, and GnRH groups, respectively. Progesterone was greater (P≤0.05) in cows receiving hCG compared to others on d 14. Progesterone in all treatment groups increased from d 7 to d 14 and declined (P≤0.05) from d 14 to d 21. Contrary to pregnant cows, P4 and TNF-α declined from d 7 to d 21 in nonpregnant cows (P≤0.05). Although PGFM increased by d 21, there was no difference between pregnant and nonpregnant cows.