Some antibodies are absorbed directly into the blood and lymph systems (passing through the intestinal wall) if he nurses soon enough. These help fight systemic infections, attacking pathogens such as pasteurella, streptococcus or salmonella that might cause septicemia or pneumonia. Other antibodies stay in the gut to attack scour-causing pathogens the calf might ingest.
If the cow had strong immunity to various diseases (if you kept her on a good vaccination program before calving), antibodies in her colostrum give her calf immediate protection as soon as he nurses. It does no good to vaccinate the cow against scour-causing E. coli, rotavirus or coronavirus, however, if the calf doesn’t get the colostrum.
For full disease protection, he needs to nurse soon after birth. Studies have shown that the calf’s ability to absorb antibodies into the bloodstream begins to diminish as soon as he’s born, and by four hours old he’s lost 75 percent of that ability. If he takes longer than one hour to nurse, help him nurse his dam or give him substitute colostrum from another cow, or a commercial product.
Frozen colostrum can be kept for emergencies. Commercial substitutes are handy, but not as good as the real thing. Frozen colostrum is better, especially if it’s from a beef cow from your own ranch.
Dairy colostrum may not contain as many antibodies per quart, due to immense volume produced, and may be risky; you may get salmonella or some other pathogen from a dairy. A cow on your place creates the antibodies needed to protect a calf in your environment.
Sometimes, however, it’s quickest to use a commercial colostrum replacer – as when you find a half-frozen newborn calf that needs to be tubed immediately, or you don’t have frozen colostrum and don’t want to milk a wild heifer.
There are several colostrum replacers on the market, but some are more effective than others, according to Dr. Geof Smith of the College of Veterinary Medicine at North Carolina State University. He’s done research on colostrum for many years and tested substitute products.
“Colostrum replacers are mainly used in the dairy industry, most commonly when farms are not doing a good job with colostrum programs – and having disease problems in calves. We often blood-test calves for passive transfer. If the calves are consistently failing these tests, some farms decide to use a colostrum replacer on every newborn calf,” he explains.
“These are also good if the producer is trying to eliminate certain diseases. In the dairy industry, Johne’s disease would be the major one. There’s some use of colostrum replacers in the beef industry, if a producer is trying to get rid of bovine leukosis virus (BLV).
This would be mainly in purebred herds that do a lot of exporting. There are very few other instances in which a beef producer would use it in every calf,” says Smith.
The primary use of replacers in beef herds would be for the occasional calf that for some reason was unable to obtain colostrum from its dam.
“Every beef producer should have a few bags of replacer, for emergencies. This is much easier to keep, and better from a biosecurity standpoint than trying to get colostrum from a neighboring dairy. It’s easier to keep a couple bags of replacer in the cabinet than to suddenly have to go looking for some,” he says.
Using powdered replacer (mixing with warm water for immediate feeding) can be simpler and easier than milking the beef cow, or milking colostrum from a few cows each year to freeze.
“There’s great variation in quality of products and price. You usually get what you pay for. When using it as an emergency source, and only having a couple bags on hand, it makes sense to buy good quality replacer that will do a good job,” says Smith.
“There’s also a difference between colostrum replacers and colostrum supplements. The latter are products (for dairy calves) designed to be mixed with colostrum. Generally they have fairly low immunoglobulin (type G) concentrations, less than 50 grams.
The old Colostrx or Sav-A-Calf products are examples. I don’t recommend their use because their effectiveness has not been supported by research,” says Smith.
Colostrum replacers are intended to be fed instead of cow colostrum and as a rule are higher than supplements in antibody concentration, at least 100 grams per dose. “There are two kinds of replacers.
One is blood-based, made from plasma. The company gets cattle blood from slaughterhouses and harvests (or spins off) the plasma.”
Smith says these types of products have been on and off the market over the years because of BSE. “For a while people thought we should ban all blood-based products, but these are considered to have zero risk for transmission of BSE because the organism that causes BSE lives only in the brain; we don’t find it in blood,” says Smith.
“Disease risk from these colostrum replacers would be very low. They are irradiated, which would kill any bacteria or viruses.” Radiation kills pathogens but does not harm antibodies.
Excessive heating destroys antibodies; this is why you can’t autoclave or pasteurize colostrum at high temperatures. The finished product is tested to make sure no pathogens are coming through, and irradiation seems to work.
The other type of replacer is made from bovine colostrum. Smith says the manufacturing company makes sure the replacer is high quality, and dries it to a powder then irradiates it to kill pathogens. Companies contract with dairies and the cows are properly vaccinated, to have antibodies against the major diseases that calves might be exposed to, Smith explains.
If you are choosing a replacer, select one that’s been tested and performs well. You can’t go by the amount of antibody it contains.
“We found through research that this is not always the determining factor on how effective it is,” he says. “We tried to figure out how much antibody should be in a colostrum replacer, but we tested some replacers that had about 100 grams of IgG and worked fairly well and tested others with much higher levels (150 to 180 grams) that didn’t work as well to protect calves. So it’s not as simple as just looking at the numbers.”
“The reason may be differences in absorption of IgG by the calf. With some products the calves seem to absorb these fairly well, and others not so much. It may be differences in the manufacturing of those products. Choose a product that has been tested, that you know has worked,” he says. 
PHOTOS:
Top: Begin helping the calf to nurse if he doesn’t latch to the mother, then move to bottle-feeding or tube-feeding the colostrum.
Middle: After milking a cow for colostrum, it can be frozen or given to the calf immediately.
Bottom: If a calf doesn’t begin nursing within an hour after birth, begin providing a stomach tube to provide colostrum. Photos by Heather Smith Thomas
