Dr. Sandra Godden knows colostrum. In fact, the Professor of Dairy Population Medicine at the University of Minnesota has made a career out of studying it – its merits to the calf, how to feed it, how to store it, and how to evaluate and improve its quality.
Godden shared with attendees of the 2018 Dairy Calf and Heifer Association that a frequent question she hears from producers is, “Can I put a preservative in colostrum to make it last longer.”
The answer, she said, was “yes,” with a few caveats. “Potassium sorbate is an approved preservative, and will extend the shelf life about 2 additional days,” she stated. “But I do not advise using non-FDA-approved additives like hydrogen peroxide.”
The researcher shared data that showed a combination of refrigeration and potassium sorbate was the most effective way to store fresh colostrum. Refrigeration-plus-potassium sorbate stretched the storage life approximately 2 additional days (see Figure 1).
She also noted, however, that heat-treated colostrum at 60˚C (140˚F) for 60 minutes was considerably more effective at keeping bacteria counts in fresh colostrum low for an extended period of time. Heat-treated colostrum, with or without potassium sorbate, had sufficiently low levels of bacteria to be fed safely after even 10 days of refrigeration (see Figure 2).
Figure 1. Effect of Storage Temperature and Use of Preservative on Total Bacteria Counts in Stored Fresh Bovine Colostrum (a,b,c,d: Different subscripts differ within given storage period. P < 0.05) (From Stewart et al., 2005).
Figure 2. Comparison of Storage Life of Colostrum Stored Fresh and with Heat Treating, with and without Preservative