Acton: Colostrum essential for calf immunity, health at beginning of life

Andy Acton of Deep South Animal Clinic in Ogema, Saskatchewan reminds cow/calf producers that baby calves have to absorb antibodies from their mother’s colostrum because they don’t get any from her via the bloodstream while they are in the uterus.  

This passive immunity from colostrum is very important, he emphasizes.

“There is more to passive immunity from colostrum than the temporary immunity,” Acton says. “There are other factors gained from colostrum than just the antibodies absorbed when calves suckle the first time.”

Understanding disease

Illness occurs when the body is overwhelmed by infection, Acton explains. A healthy animal with strong immunity is less likely to become sick.  

“Immunity refers to the body’s ability to fight off pathogens, and this ability is developed in a complex process in which the body creates specific weapons for fighting specific invaders,” he says.

One method of fighting off infection involves production of antibodies.  When pathogens like viruses or bacteria enter the body, they start invading tissues and causing damage by multiplying and creating toxic products.  

Acton notes the damage stimulates the body to create an antibody to react with the invading agent and neutralize it.  

Antibodies are carried throughout the body in the bloodstream.

Acton comments, “A cow in a clean environment may not become exposed to very many disease-causing organisms, but cattle are often confined in corrals, small pens or pastures that have been contaminated by heavy cattle use and come in contact with other cattle, with more chance of disease spread.”  

Through vaccination and natural exposure to various pathogens, he notes the cow develops many antibodies and strong immunity.  

“During the last part of pregnancy, she puts these antibodies into the colostrum she produces, so her calf can have instant immunity right after he suckles,” Acton comments.

Inside colostrum

Along with antibodies in colostrum, Acton says, “There is also some absorption of white blood cells of different kinds in that colostrum from their mother.  These are not present in a colostrum replacer we’d buy.”

Calves get more actual protection from the dam’s colostrum than from a commercial product. 

“Some of the immune modulators that are not actual antibodies are also important to the calf,” Acton says.

Absorption window

Newborns have a limited window of time to absorb antibodies from their mother’s colostrum.  

“The optimal time for colostrum consumption is the within the first six hours of life,” Acton explains. “But, this window may be smaller in certain conditions. We may only have two hours of optimal absorption in cold weather.”  

“Some factors shorten this window, and some things lengthen it,” he says.

Biological factors

As soon as the calf suckles, the “open gut” starts to close to prevent absorption of pathogens. 

Acton explains suckling stimulates the gut to close up, because it’s always a race between the antibodies from colostrum and the pathogens the calf might ingest.  If the calf manages to suck a little bit or if producers feed it a little, the gut closes up quicker than if the calf had nothing.  

“The time window for the gut to absorb something in this situation is a lot longer than if the calf gets a small amount of colostrum,” he explains.

Heather Smith Thomas is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.