We evaluated the effects of decreasing the frequency of energy supplementation on growth performance and measurements of innate and humoral immune response of preconditioning beef steers. At weaning (d −7), Angus steers (n = 24; BW = 221 ± 31 kg; age = 177 ± 19 d) were allocated to a single drylot pen with free-choice access to fescue hay. On d 0, steers were stratified by BW and age, and randomly assigned to 1 of 8 drylot pens (3 steers/pen). Steers were provided daily ad libitum access to ground fescue hay (17% CP and 58% TDN; DM basis) and similar weekly concentrate offer (12 kg/steer) from d 0 to 42. Treatments were randomly assigned to pens (4 pens/treatment) and consisted of dividing and providing the weekly concentrate offer either 3 (S3; 3.8 kg on Mondays, Wednesdays and Fridays) or 7 times (S7; 1.7 kg daily) per week. Supplements included 50% soyhulls and 50% corn gluten feed (17% CP and 72% TDN; DM basis). Steers were vaccinated using the SelectVAC protocol (Zoetis) on d 7 and 21. Shrunk BW was obtained on d 0 and 42, and blood samples from jugular vein collected on d −7, 0, 7, 8, 9, 10, 14, 21, 22, 23, 24, 28, 35 and 42. Although BW did not differ from d 0 to 42 (P ≥ 0.33), S7 steers had greater mean ADG (1.3 vs. 1.0 ± 0.07 kg/d; P = 0.01), mean hay DMI (2.8 vs. 2.2 ± 0.08 kg/d; P < 0.01) and total DMI from d 0 to 42 (190 vs. 165 ± 4 kg; P = 0.02), but similar G:F compared with S3 steers (P = 0.14; 0.29 vs. 0.26). Plasma concentrations of glucose, insulin, cortisol and ceruloplasmin did not differ (P ≥ 0.33) between treatments. However, S3 steers had greater plasma haptoglobin concentrations on d 8 (1.95 vs. 1.20 ± 0.13 mg/mL; P < 0.01) and 10 (1.39 vs. 0.84 ± 0.13 mg/mL; P < 0.01), and less mean serum bovine viral diarrhea virus-1b (BVDV1b) titers than S7 steers (1.5 vs. 2.5 ± 0.31 log 2 base; P = 0.03). Therefore, decreasing the frequency of energy supplementation from 7 to 3 times weekly during a 42-d preconditioning period decreased hay and total DMI, growth and antibody production against serum BVDV-1b, and increased plasma haptoglobin concentrations of beef steers.