“That depends,” you say. “Are you talking about comparing the two liquids or whether colostrum feeding affects future production?”
“Both,” I say.
Comparing Colostrum to Milk Components
Colostrum is notorious for containing high levels of immunoglobulins. At 85 to 90 percent, the most prevalent one is immunoglobulin G (IgG), a large Y-shaped protein produced by plasma cells.
These antibodies are used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. Hopefully, your dairy is testing for IgGs with a colostrometer or a refractometer to determine if the quality is sufficient for the first feeding (at least 50 IgG per liter or 22 percent Brix scale).
Besides the IgGs, what makes colostrum so special? Take a look at Figure 1 to see how different colostrum really is from whole milk. Notice that the level of total solids is almost double that of whole milk, 23.9 percent compared to 12.5 percent.
This is attributed to the higher levels of proteins, fats, antibodies and minerals. Our chart shows proteins broken out into antibodies and other proteins to highlight the significant difference between the 6 percent in colostrum and 0.09 percent in regular whole milk.
The amount of fat is also higher in colostrum, 6.7 percent versus 3.9 percent in whole milk. This added fat in colostrum provides energy for heat production to maintain body temperature or thermogenesis.
What we are not able to showcase because much research is underway, are the other molecules that occur in significantly higher amounts in colostrum compared to regular milk – such as relaxin, which affects the development of the reproductive tract, prolactin (18 times higher amounts), insulin (65 times higher), IGF-1 (as much as 155 times higher) and IGF-2 (seven times higher). The exact way these substances influence the calf’s development is the subject of university studies. However, research comparing maternal colostrum and serum-derived colostrum replacement found out that calves fed maternal colostrum had significantly higher feed efficiency, indicating that bioactive factors of maternal colostrum have a long-term effect on the calf.
Because of the differences in composition, colostrum and mature milk need to be handled differently. As you have just seen, colostrum can have twice as many solids as regular whole milk, offering twice the opportunity for bacterial growth. Continue reading about How to take proper care of colostrum.
Caring for Colostrum also Differs from Milk
It is that much more important to store colostrum at cooler temperatures to reduce or even prevent bacterial growth. Heat treating colostrum, often called pasteurizing, can be done – but not the same way you pasteurize whole milk for older calves. Colostrum can only be pasteurized at exactly 140ºF for exactly 60 minutes.
In most situations, this process is sufficient to maintain IgG concentrations and fluid characteristics while eliminating or significantly reducing important pathogens, including Listeria monocytogenes, E. coli, Salmonella enteritidis, Mycoplasma bovid and Mycobacterium paratuberculosis.
Warming colostrum must be done with similar care. On many farms, this is considered the most time-consuming and challenging part of successfully managing colostrum. It is not acceptable to just turn the water on as hot as it goes and throw the frozen colostrum bags or bottles in the sink.
The IgGs limit the temperature that can be used to thaw colostrum. Research has proven that the maximum temperature the IgGs can handle, before they become denatured, is 140ºF. To be safe, aim for thawing your colostrum in 120ºF water.
Before feeding to the calf, check the temperature of the colostrum. The ideal temperature for feeding is the same temperature as the calf’s body, which is around 102ºF. A safe goal for colostrum temperature can range between 100 to 106ºF.
Also, take into consideration the distance the colostrum meal has to travel before it actually gets to the calf. A bottle of warm colostrum can experience temperature drift if there are extreme cold temperatures and a considerable distance to travel.
Why Should Colostrum be Fed as Close to Body Temperature as Possible?
Newborn calves can experience cold stress, especially during the winter months. According to Dr. Michael Van Amburgh, the lower critical temperature for calves less than 21 days old is 42ºF, assuming the calf is dry. Now picture a wet little calf born in the harshest time of the winter.
It will need colostrum at body temperature to help warm the calf from the inside-out. Depending on the severity of the cold stress, it can cause a delay in onset and a significant decrease in the rate of absorption of IgGs. So make sure your newborn calves are not immediately exposed to harsh, cold conditions.
Colostrum Consumption Affects Future Milk Production
Now to the second half of our question; proper feeding of colostrum affects future milk production in two ways: proper immunity transfer and bioactive factors. Feeding 4 quarts of tested, high-quality, clean colostrum within the first 30 minutes at the calf’s body temperature ensures the successful passive transfer of immunity. The result will be a healthier calf that doesn’t need to be treated.
A healthy calf has increased ADG and thus earlier calving age. We also know that age at first calving can be delayed as much as six months for a heifer that required treatment for calfhood infections, such as pneumonia, compared to a heifer that did not.
Not only does earlier calving age start milk production sooner, but it also saves money. The most expensive part of raising cattle is from weaning to parturition. The faster we can get her bred, the faster we can start to see a profit from her.
A heifer that had consumed an adequate amount of good-quality colostrum when she was a calf is likely to produce up to 2,100 pounds more in the first lactation than one that did not consume enough good-quality colostrum as a calf.
In 2005, researchers demonstrated that colostrum intake affects not only pre-pubertal growth but can have an effect on increased milk production through second lactation.
In addition to proper immunity transfer and sufficient energy resources contained in colostrum, research conducted at Cornell University under the supervision of Van Amburgh two years ago indicates that insulin may also influence future milk production.
Colostrum contains 65 times more insulin than calf milk, giving it the potential to influence long-term feed efficiency and with it better milk production.
So our answer is, “Yes, the kind of colostrum and how you feed it today most definitely affects your milk production two years from now.”
What can you do today to ensure that you are getting the most out of your colostrum?
1. Test each cow’s colostrum with a digital or optical refractometer; feed newborns only high-quality colostrum (above 22%Brix).
2. Feed each calf at least 4 quarts or liters of high-quality colostrum.
3. Feed each calf within the first 30 minutes after birth.
4. Store colostrum in a freezer. If stored in a refrigerator, make sure to mark it up with date and time and do not keep it there longer than 24 hours.
5. Warm up colostrum in water no hotter than 120ºF.
6. Test colostrum temperature prior to feeding.
7. Sanitize tube feeder after each use.
8. Have different tube feeders for newborn calves and for sick calves.