Turns out that “liquid gold” may not be gold

Colostrum has earned the unofficial moniker “liquid gold,” because of its typically golden color, along with the golden benefits it confers for calf health, growth, and lifetime performance. There’s a common misconception that colostrum’s gold color is indicative of its quality. That’s not necessarily the case, according to Hanne Skovsgaard Pedersen, a veterinarian, researcher, and calf specialist with Denmark-based ColoQuick.

“When I go out on farms, I often hear that we can evaluate colostrum by looking at its color and viscosity.” Pedersen stated on a recent colostrum webinar: “But we’ve learned that there is not a very strong correlation between color, viscosity, and antibody concentration.”

Pedersen shared an example of three first-milking colostrum batches harvested the same morning on a single dairy. They ranged in appearance from thick and bright, golden yellow; to relatively thin and nearly white. Evaluation for quality with a Brix refractometer yielded surprising results. The best sample was the thin, white batch, with a Brix reading of 27. The thick, yellow batch showed a Brix reading of 18, while the intermediate-appearing batch scored 21. In this example, true quality was actually the direct inverse of perceived quality by visual assessment alone.

In addition to measuring colostrum quality, Pedersen emphasized timely administration, explaining that the sieve-like permeations in the intestinal wall close rapidly in the hours after birth, so the time window in which antibodies can be distributed into the bloodstream is small.

Likewise, heavy bacteria loads can clog that distribution process, so hygienic harvest and handling of colostrum are also critical. Pasteurizing colostrum can help to ensure clean colostrum, but it also can be a cumbersome process. ColoQuick has developed a closed-loop system in which colostrum is pasteurized and frozen in the same liner bag that fits inside a sturdy, plastic cartridge.