Much has been written about the importance of getting colostrum into baby calves as soon after birth as possible.
Highly vulnerable. Why? Because a calf is born with no – zippo, nada – immunity. She is a veritable pathogen playground if we don’t get the passive immunity transfer job done.
What is passive transfer of immunity? The ability to fight germs, or pathogens, is transferred from a cow to a calf through the colostrum, or first milk, produced by the cow after calving.
First milk vital. Special proteins called immunoglobulins (pronounce this mouthful: immune-oh-glob-u-lynns, hereinafter referred to as Ig or Igs) are present in high quantities in this first milk.
Intestines cooperate (briefly). Meanwhile, the calf’s intestines are able to allow these large Ig molecules to pass through the intestinal lining and into the blood supply (without being digested,) for a short time after birth.
Once the Igs enter the bloodstream in adequate quantities, the calf is provided with some protection from disease until she starts manufacturing enough of her own antibodies to protect her from the disease challenges on the farm.
A fighting chance. Yes, she can still get sick if her immune system is challenged by germs, weather or poor care. If she does get sick, she will have the ability to fight the infections.
What is FPT, or failure of passive transfer? If a calf does not receive enough good quality colostrum soon after birth, she may not have an adequate amount of Igs transferred into her blood to provide her with protection against disease.
Complicated chemistry. Blood levels of Igs can be measured. For dairy calves, 85 percent to 90 percent of the immunoglobulins are IgGs. IgA and IgM immunoglobulins make up the balance. If a calf has greater than 10mg/ml of IgGs, she is considered to have a successful transfer of immunity.
The more, the merrier. If she has less, she has had a failure of passive transfer, or FPT.
Pathogens abound. So what if she fails?
If a calf has no passive transfer she is a sitting duck for everything. Even on the cleanest and best managed farms, the calves are challenged by pathogens.
If she has some transfer, but not high enough blood levels that we would give her the successful transfer award, she is at great risk for infections, both primary and secondary. She simply has no defenses.
Drugs can’t compensate. Drugs cannot make up for a FPT. If the calf becomes ill and a failure of transfer is suspected, her blood level of IgGs should be checked as soon as possible. While you can purchase kits to test this on-farm, I really hope this is an infrequent occurrence and you can let your veterinarian keep an inventory of the test kits.
24-hour window. If the calf does not have adequate levels of immunity, she needs a boost. How? Unless the calf is less than 24 hours old, she is no longer able to absorb enough IgGs through the intestinal walls. The only way in is through the blood supply.
Obviously, we can’t transfuse colostrum, so a blood transfusion from a cow, preferably performed by the veterinarian, is her only option.
The size of the calf and the necessary amount of blood needed to provide adequate immunity must be carefully calculated. I suspect that calves with compromised immunity usually die of whatever disease they may pick up, rather than get a fighting chance with a blood transfusion.
Avoid the worst. While a transfusion may help a compromised calf, this is not an option that any good calf manager wants to have to implement at all. This worst-case scenario can be avoided by careful attention to details at and after calving.
Tips for a successful transfer of passive immunity:
* Clean and sanitize teats before milking the cow.
* Milk into a clean, sanitized dump bucket.
* Pour into clean, clean, clean bottles or other containers and use clean, clean, clean nipples (do you sense an important point here?!)
* Test with a colostrometer to determine if colostrum has enough IgGs to do the job (these can be bought from the local livestock supply store or ordered from catalogs.)
* Feed as much as possible (up to a gallon) as soon as possible after birth. Calves can suck on a bottle when they are still wet … and they usually don’t move quite as fast as when they have dried off!
* Make sure your hands and clothes are clean when feeding colostrum. If you are feeding early enough, you’ll be prying the calf’s mouth open to get that nipple in the first time.
* Freeze good quality colostrum to use when the fresh cow or heifer’s is not good quality.
* Get her out of the calving pen before she tries to get up and goes nose diving (pathogen scooping) in the bedding.
* Don’t forget to dip her navel and get her into a clean, dry, well-ventilated pen.
Of course, you need to do all of the above pretty much at the same time!
Don’t relax. Follow up the first feeding with another feeding of good quality colostrum within 6-12 hours. Any calf feeder knows that there is nothing more satisfying than the feeding where every calf eats and drinks with gusto.
Calves with poor or unsuccessful transfer of passive immunity will make that event seem like an unattainable dream. It doesn’t have to be. Simple steps, care and attention to detail will make it happen.
(The author is the northeast Ohio district dairy specialist with OSU Extension. Send comments or questions in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)