- Pat Kirk Angus
Nutrients Newborn Calves Need From Colostrum and What to Look for in a Colostrum Replacement
Updated: Jul 8, 2021
There’s nothing more disheartening than having a calf die just after birth. Many times, there just isn’t an explanation for these types of things. The good Lord knows. But there are a few things cattle farmers can do to promote the health of newborn calves – and that is to make sure calves are getting the nutrients they need just after birth. Most of the time calves get rich, nutrient-packed food from the mother’s colostrum, but sometimes a replacement is needed.

First, let’s talk about the nutrients that a calf needs from its mother cow’s colostrums. A cow’s colostrum is packed with the essentials for your calf’s first few weeks to be healthy. From the day your calf is born till around two weeks of age, nutrition is critical in very specific ratios.
One of the most important components in a cow’s colostrums is fat. The 6.7% fat content of colostrums is the number one reason for newborn calf growth or limiting growth, should fat be deficient. This is especially important as the calf is yet to complete the development of its digestive system and depends on fat for energy, protein balance, and growth.
Because a newborn calf with its forming digestive system still cannot digest unsaturated fats, the saturated fat from its mother’s colostrums is just what the doctor ordered.
Fat is also needed as a carrier for the fat-soluble vitamins A, D, and E found in colostrum.
When you look at fat versus protein needs in newborn calves, something to consider is while protein is mainly used as the building blocks of calves’ bodies for growth and maintenance, fat is the energy protein needs to get the calf growing. Both are needed for healthy newborn cattle growth.
You know, since we’re talking about fat and protein, let’s focus on protein for calf health. Colostrum is around 14% protein. From 4 to 6 weeks, calves live off of only milk protein since they cannot yet digest vegetable proteins.
As we pointed out, protein has two functions for a calf: maintain and grow. They are the building blocks needed for newborn calves to develop healthy and strong tissues, muscles, bones, and organs. Without protein for growth, calves could not grow larger and stronger. On the other hand, protein also assists in maintenance. Each cell in a calf must continually replace itself. Thanks to the protein in your cows’ rich colostrum, baby calves can maintain life. Without protein as a maintenance building block, cells that are not replaced would lead to death.
As calves develop, they will need more protein both for maintenance and growth.
Thankfully, colostrum is packed with this essential nutrient!
Have you heard of IgG? It’s another nutrient, or antibody rather, newborn calves need. IgG, or immunoglobulin, is provided through a mother’s colostrum to support the calf’s immunity to infection and disease. It makes up anywhere from 2 to 23% of the mother cow’s colostrums, then drops to around 0.1% during normal milk production.
The antibodies newborn calves receive from the colostrum’s strong immune protection (passive immunity) help to protect the calves until they can develop their own immune systems (active immunity). It is important for cattle farmers to know that infection and disease are more likely in calves from approximately day 2 when colostrum is gone till around day 18 when the calves’ own immunity peeks.
Immunity for newborn calves?
Check!
The fourth nutrient calve newborns need from colostrum are minerals. Most of the time, cattle farmers are aware that their livestock need minerals, but the difficult part in the whole situation is that there is not much information out there when it comes to newborn calves and minerals.
Thankfully, there are a few things we do know. First, minerals make up 1.1% of colostrum. That’s 2 to 3 times more than in whole milk. In addition, when trace minerals copper, zinc, sulfur, manganese, iron, and selenium in a cow’s milk are in adequate amounts, a calf is more likely to be heavier at weaning time AND stay healthier on its new, non-milk diet after weaning.
The trace mineral selenium, specifically, deserves some attention. According to the veterinarian quoted below, selenium is in greatest deficiency among the trace minerals found in cattle.
“Plus,” veterinarian John Mass (School of Veterinary Medicine, University of California) said, “We've found that when calves are put into a stressful situation, such as co-mingling or entering the feedlot, their immune system doesn't work as well if they are deficient in certain trace minerals," (https://www.beefmagazine.com/americancowman/nutrition/calf_minerals).
Without proper trace mineral amounts, calves can also react poorly to vaccines, become prone to disease, may lose their desire to eat, and will process food with less efficiency leading to underweight calves.
Other mineral requirements for newborn calves are calcium, phosphorus, and magnesium. Thankfully, mama cow usually has the perfect amounts of these in her milk, but when fresh grass and foliage are not an option, you may want to keep an eye on phosphorus. Phosphorus amounts are usually less in dry food like hay and corn stalks than in fresh, green grass. Calcium and phosphorus together in a ratio of 2:1, help to guarantee that calves do not suffer from bone deformities and will protect steers from impaired unitary tracks (also known as water belly).
God engineered cows to produce the nutrients their calves need to survive and thrive, even if that means that the mother cows become deficient in certain nutrients themselves. So, while there is not usually much concern about calves getting enough of the right kinds of nutrients, it is still important to watch that our mother cows are properly cared for to maintain their health.
This brings us to the question of the hour: what happens when a cow does not supply enough colostrum, dies at birth, or rejects its baby? Should the time come, it’s important to be prepared with a good colostrums alternative for newborn calves.
When you go to the farm store looking for a colostrum replacement, there are few things you will want to avoid if you want a healthy calve.
First, avoid bad fat. Unlike saturated fats found naturally in cattle’s colostrum, unsaturated fats like corn oil and soybean oil are not digestible by newborn calves. So look for a colostrum replacement that uses a saturated fat as close to the mother’s as possible.
Second, complex carbohydrates and starch are not well tolerated in newborn calves. This is because baby cattle do not start digesting complex carbs till they are a little over two weeks old, and starches aren’t tolerated until at least two weeks of age.
In addition, some vegetable protein and some sugars in the carbohydrate family, like sucrose (table sugar) should also be avoided until the calf’s digestive enzymes have gained momentum – roughly at three weeks of age. Because lactose sugar in colostrum is low, only 2.7%, colostrum replacements should also be low in sugar. Even a little sugar in a colostrums replacement can cause diarrhea in newborn calves.
Lastly, blood and whey are sometimes used as cheap substitutes in low-quality colostrums replacements. You should avoid these.
Now that you know what to avoid, use all the information you learned above and the nutrient chart below as a guideline to find the right nutrient ratios for calves’ colostrum replacements. You can also contact your local vet for advice on high-quality colostrum replacements for calves.

(Nutrient charts from the University of Kentucky –College of Agriculture’s “Feeding and Managing Baby Calves from Birth to 3 Months of Age," https://afs.ca.uky.edu/files/feeding_and_managing_baby_calves_from_birth_to_3_months_of_age.pdf.)
Look for 150-200g of IgG per gallon of replacement.
Pat Kirk, like most cattle farmers, supplements with a colostrum replacement at times. Where did he go? He went straight to the cattle experts for advice. Veterinarian Megan at Iowa State University has been out to the Pat Kirk Angus farm and suggested a high-quality colostrums replacement for his calf-cow operation.
We hope this newborn calve nutrient guide is a good resource for you during the calving season. Feel free to save and share it with other cattle farmers so we can all be aware of our newborn calves’ nutrient needs.