Milk replacers are formulated to provide dairy calves with the nutrients needed for growth, but not necessarily with the IgG needed to provide enteric immunity. In fact, milk replacers and colostrum replacers vary greatly in the amount of IgG as well as the specificity of IgG, which means not all protein sources are the same.
IgG is integral to a healthier – and thus more valuable – calf. In a 2020 study3, calves that received egg powder supplements to support enteric immunity were heavier than the control group and calves supplemented with EggTek-C had lower mortality. According to the study, body weight increased (P<.05) on days 42 and 56 in calves fed IgY for an average of 10 pounds per calf.