Kudos to the lab researchers who are digging into all the benefits of colostrum instead of just valuing colostrum by the level of colostral immunoglobulins. By studying herd data and a small test group they have concluded that fat, not protein, represents the primary energy source the cow packages into colostrum for the calf.
The term fat broadly encompasses related compounds that have multiple roles in the neonatal calf:
- Fuel
- Thermoregulation
- Hormonal signaling
- Inflammation and immune response
Source: Progressive Dairy, July 15, 2019. Link. There is still a lot of work to do to understand the cow-level and management factors that can alter colostrum fat, as well as what these changes will mean for the newborn calf. Using the preliminary work and the known importance of fats for energy and development, it is time we start paying more attention to this macronutrient.
At present, there is no recommended threshold for colostrum fat levels. We would recommend your colostrum fat should be higher than the fat levels of your bulk milk tank, and to be safe you should feed colostrum that contains more than 5% fat.