The objective of this study was to determine the effect of different heating times with 3 levels of colostrum IgG content on passive transfer from a single feeding of colostrum. Colostrum was collected from The Pennsylvania State University dairy and divided by quality (high, medium, or low) based on colostrometer measurement. Colostrum within each quality was pooled to create 3 unique batches. Each batch was further divided in thirds as follows: frozen to be fed without heat treatment, heated at 60°C for 30 min, or heated at 60°C for 60 min. Colostrum samples from each treatment were collected and tested for standard plate count, gram-negative non-coliforms, coliforms, and total IgG concentration. Serum samples were collected from 108 Holstein calves before feeding colostrum and 24 h after birth. These were analyzed for total protein, total IgG, and hematocrit. Colostrum quality (high, medium, or low), heat treatment (unheated, 60°C for 30 min or, 60°C for 60 min), and their interaction were analyzed as fixed effects, with calf sex included as a random block effect. Colostrum IgG was different between quality groups (92.5, 59.4 and 48.1 mg/mL of IgG; P < 0.01). Heating colostrum reduced IgG concentration compared with the control by 9% when heated for 30 min and by 12% when heated for 60 min. Colostrum heated for 60 min had a lower standard plate count than colostrum heated for 30 min or not heated (3.6, 2.0 and 1.8 log cfu/mL). Serum IgG concentration at 24 h increased as colostrum quality increased (18, 22.2 and 24.8 mg/mL; P = 0.02) and tended to increase as heat treatment time increased (19.7, 20.3 and 25 mg/mL of IgG; P = 0.06). Apparent efficiency of absorption was greater in calves that received medium quality colostrum compared with calves fed high quality colostrum (38.1 and 25%; P < 0.01). These results suggest there may be an upper limit to the amount of IgG absorption in a given time period and that medium or high quality colostrum yields similar blood IgG absorption given the same volume of intake.