Heat-treated (HT) colostrum offers many benefits when fed to dairy calves. Calves are born agammaglobulinemic because the placenta does not allow antibodies to pass from the dam to the fetus. As a result, neonatal calves rely on passive absorption of antibodies from colostrum in the first few hours after birth to protect them from infectious diseases. The most prevalent of the colostral antibodies is IgG. This antibody is commonly used as an indicator to show that immunity through passive absorption was achieved. In the past, commercial pasteurizers were used to process both waste milk and colostrum, and they achieved temperatures of at least 63°C to reduce risks of microbial contamination from collection and storage. However, heating colostrum to this temperature reduced IgG concentrations and increased viscosity. Recent studies have demonstrated that heating colostrum to a lower temperature (60°C) for up to 120 min drastically decreased bacterial populations while still maintaining IgG levels and viscosity. Research also shows that calves have a reduced risk for illness when fed HT colostrum compared with fresh colostrum because the heat treatment process significantly reduces total coliform counts. Calves that are fed HT colostrum will more efficiently absorb immunoglobulins compared with calves fed unheated colostrum. Plasma samples taken from calves showed that IgG concentrations in calves that were fed HT colostrum increased by 18.4% with a 21% increase in apparent efficiency of absorption compared with calves fed fresh colostrum. Heat treating colostrum is a continually improving technique resulting in an increased rate of IgG absorption in dairy calves.