Colostrum & calf immunity – why is it such a race against the clock?

Colostrum & calf immunity  – why is it such a race against the clock?
By Arnica van der Wiele, Veterinarian, Anexa Ngatea

Are you RAT ready?

RAT means Race Against Time; time to arm your newborn calves with defences against adversity. While human babies are born with their mother’ immunity in their blood (through transfer of antibodies via the placenta), this cannot happen between a cow and her calf, so a calf is born without adequate immunity to fight disease and infection.

In the first weeks to months of a calf’s life, it totally depends on the absorbed antibodies received through drinking colostrum. To enable this absorption, the gut from new-born calves is temporarily ‘open’ for these large immunoglobulin (IgG) antibodies to pass through, as shown in the illustration below.





However, from the moment of birth, the ability of the calf to absorb these antibodies decreases significantly and after 24 hours the gut has ‘closed’ to antibody transfer. After this point, colostrum is still an excellent feed, coating the intestines with antibodies, but these will not enter the bloodstream.
On the cow’s side, a similarly time-related process is happening. Around calving, the antibody levels in the colostrum she is producing are at peak level. From the time of birth, the concentration of antibodies in her colostrum will drop rapidly, regardless of whether you have milked her or not.
This race against the time is illustrated in the chart below.





You can see that the calf’s ability to absorb antibodies, and the cow’s concentration of antibodies are maximum at time of birth and drop rapidly in the first 24 hours.

Good quality colostrum, given in a timely fashion at an appropriate volume will go a long way to ensuring your next batch of calves are healthy and strong. Do you have a plan to give your calves the best start with quality colostrum? Not sure where to start? Give us a call, we’re here to help.

Date Added: Tuesday, 8th May 2018


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