Fig. 1.

Effect of Se supplementation of pregnant beef cows with Se-enriched alfalfa hay on serum ovalbumin (OVA) concentrations in their calves after calves received oral OVA at 12, 24, or 36 h of age. Dams consumed 2.5% body weight/day alfalfa hay grown in fields not fertilized with Se (0 g Se/ha; Control), or harvested from fields fertilized with Na-selenite at application rates of 45.0 (Med-Se) or 89.9 (High-Se) g Se/ha for 10 wk ± 16 d prior to calving. Control cows (n = 15) were fed non-Se-fortified alfalfa hay (5.3 mg Se/head daily) plus a mineral supplement containing inorganic Se (3 mg Se/head daily). Med-Se (n = 15) and High-Se cows (n = 15) were fed Se-biofortified alfalfa hay (27.6 and 57.5 mg Se/head daily, respectively); both groups received mineral supplement without added Se. Within each dam treatment group, an equal number of calves were randomly assigned to receive an oral dose of OVA (25 g albumin from chicken egg-white powder dissolved in 100 mL water) at A) 12 h after birth, B) 24 h after birth, or C) 36 h after birth. Serum OVA concentrations were measured at subsequent 12 h intervals. Values that differ at P < 0.05 between treatments have different letters (A–B), and values that differ within a treatment have different letters (a–b).