Calves were fed 4 quarts of either raw or heat-treated colostrum within two hours of birth. Total bacterial plate count and coliform count were measured in all batches, as was IgG concentration in the colostrum.
The results: the researchers found that on-farm staff could indeed replicate the results achieved in a research setting. Bacterial counts for the heat-treated colostrum were significantly lowered across the board, with no significant effect on colostrum IgG levels.
Healthier calves, too
The study also included a blood draw on every calf at one to seven days of age to compare serum IgG concentrations and TP between the two groups. What’s more, farm staff recorded every disease treatment event of all calves in the study from birth to weaning. “The ultimate measure of this research was to find out if the calves fed the heat-treated colostrum were healthier,” says Godden. “We were pleased to find out that indeed they were.”
Specifically, they found that serum IgG concentrations were significantly higher in the calves fed the heat-treated colostrum. The calves from the heat-treated group also were less likely to suffer from scours, or to be treated for any other disease condition.
“I probably was somewhat biased, but I thought all along that the calves fed the heat-treated colostrum were doing better — eating starter grain earlier and sick less often,” says Kreft. “The numbers proved that they truly were healthier.” As a result of the study, Kreft and the Jon-De crew now feed both pasteurized waste milk (processed in a high-temperature, short-time [HTST] flash pasteurization system), and heat-treated colostrum, which is processed in the same batch pasteurizer they used in the study more than five years ago. A side benefit that Kreft appreciates is that heat treatment preserves the shelf life of colostrum, which they refrigerate after processing but usually do not freeze. The result is a consistent supply of high-quality colostrum that maintains low bacteria numbers for up to five days, compared to the 24 hours that it used to last in refrigeration without heat treatment.
“It takes a lot of work to produce good colostrum, starting months ahead of time with cow nutrition and immunity,” says Kreft. “It’s really important that we take the best possible care of that high-quality product in the final stage —from the time it leaves the cows until it is fed to the calf. Heat-treating helps us to maximize, rather than waste, all of that effort.”