In general, the three sources of IgG in colostrum products are derived by lacteal secretions (milk, whey, or colostrum), bovine serum extracts, or chicken eggs. Results from one study comparing the efficiency of IgG absorption in a bovine serum product (BSP), cow colostrum (MC; control), and two commercial milk-derived supplements (S-1 and S-2) are shown below in Figure 1. Although AEA was highest in the serum product, blood IgG concentrations were higher for calves consuming MC (containing 200 g IgG) compared to BSP (containing 90 g IgG). These results indicate that the initial concentration of IgG is an important consideration when choosing a powdered supplement. Simply increasing the amount of product supplied to the calf can actually result in decreases in IgG absorption efficiency, so it is best just to feed a higher quality product.
Figure 1. Efficiency of absorption for various colostrum supplements
It is important to know the quality of colostrum to be able to determine which type of product – supplement or replacer – is recommended for a given situation. Be sure to carefully read and follow the manufacturer’s instructions since products may vary in how they are mixed and the number of recommended feedings. Plasma IgG tests may be recommended in situations of high morbidity/mortality to determine prevalence of FTP and the efficacy of colostrum management in the herd.
Source: Janna Kincheloe