Research Supports "Milk & Feed" for Colostrum
Two studies support the practice of "milk & feed" for colostrum management.
The "milk & feed" practice? Collect colostrum from the dam as soon as practical (less than an hour), check for quality and immediately feed to the newborn calf.
The research examined the consequences for feeding freshly collected colostrum compared to colostrum that had been stored and the white blood cells are not longer viable. To be sure no colostrum immune cells were present for their research they froze and thawed the colostrum - thus all the white blood cells were destroyed.
The colostrum immune cells were "adoptively" transferred into the blood by the same process that antibodies are passively transferred. That's why the emphasis on feeding the calf within the first one or two hours after birth.
So, given that the colostrum is collected soon after calving, it is high enough in antibody concentration for first feeding and the calf is fed within an hour or two after birth, what advantages did they find between using the two different kinds of colostrum?
Remember, the whole colostrum and the immune-cell-free colostrum had the same antibody content.
First, they reinforced the previously known fact that colostral immune cells adoptively transfer - they go from the colostrum into the blood.
Second,, these immune cells improve immunity during the first month of life - these comparisons were between feeding freshly collected colostrum and "cell-free" colostrum. On farm this difference would be between two management systems (1) milk & feed and (2) milk, store and feed.
Third, up to 6 to 10 months post colostrum feeding, feeding whole colostrum versus cell-free colostrum resulted in a greater vaccination response.
Management take-home message:
When colostrum is frozen and thawed all the immune cells are destroyed. When colostrum is stored the active immune cell population drops rapidly. Some estimates suggest the level drops to one-half within less than one day. Other estimates set the level of immune cells in refrigerated colostrum at close to zero by two days. Only freshly collected colostrum contains the optimum level of the immune cells.
The bottom line for getting a high level of adoptively transferred immune cells is to milk & feed.
[S.N.Langel and Others, "Effect of feeding whole compared with cell-free colostrum on calf immune status: the neonatal period." Journal of Dairy Science 98:3729-3740 2015 S.N.Langel and Others, "Effect of feeding whole compared with cell-free colostrum on calf immune status: vaccination response." Journal of Dairy Science 99:3979-3994. 2016]