Maternal colostrum (MC) infected with M. paratuberculosis contributes to transmission of Johne's disease on dairy farms. Pasteurization is not a viable option, as it reduces colostral IgG and does not eliminate M. paratuberculosis. Therefore, alternatives to MC are required. Sources of exogenous IgG include milk, colostrum, blood and eggs, which are ingredients in colostrum supplements available in the market. However, current products provide insufficient IgG to replace MC. Blood derived IgG are inexpensive, readily available, and can be collected hygienically. Our objective was to develop a highly concentrated fraction from bovine blood for use in a colostrum replacer (CR). Bovine blood was collected from abattoirs under government supervision. Blood was passed fit for human consumption and processed to remove fibrin, lipids, and albumin. The resulting fraction (40 to 60% of DM as IgG) was spray-dried, mixed with ingredients including lactose, whey, whey protein concentrate, fats, vitamins and minerals to produce a CR. Five experiments were conducted, using a total of 238 calves fed MC or CR. Intake of IgG from MC or CR ranged from 100 to 253 g in one or two feedings at 1 and 8 to 12 hours of age. Mean plasma IgG at 24 hours of age ranged from 5.5 to 14.1 and 13.8 to 17.8 g/L in calves fed CR and MC, respectively. In experiments where calves consumed >120 g of IgG from CR, plasma IgG at 24 hours of age was >10 g/L in 75 to 88% of calves. Survival of calves to 56 days of age (determined in one study) did not differ from that of calves fed MC and was >95%. A CR containing Ig concentrate is a viable alternative to MC in Johne's control programs.