Why Is It Important for Calves to Receive Colostrum?

Dr. Erika Nagorske

Dec 19, 2023

While most species like humans and dogs develop an immune system in utero, calves are born without much of an immune system. With this in mind, it’s important to know when you should supplement colostrum. 

Dr. Erika Nagorske, a practicing veterinarian with Southwest Veterinary Services, FBN®’s official veterinary partner, explains why colostrum matters, the differences between replacements and supplements, and how to choose the right one.

Watch Now: Expert Explains Why Colostrum Is Essential

Watch Dr. Nagorske explain why colostrum is essential for calves in the short video Colostrum Replacer 101 or continue reading below to discover the key takeaways. 

Why Does Colostrum Matter?

Colostrum provides calves with a functioning immune system for the first few weeks of life. Over time, they’ll develop their own. 

If they don’t get good quality colostrum, they won’t have a properly functioning immune system. 

Colostrum Requirements

A calf needs 150-200 grams of IgG (antibodies) for a good start to their immune system. These antibodies bind to antigens (bugs) and shut them down from infecting the calf

Usually 4 quarts of cow’s colostrum is enough to achieve this amount of IgGs. Depending on the quality of the cow’s colostrum, it may take more or less for calves to receive the correct amount of IgGs. 

When to Use a Colostrum Replacer or Supplement

There may be times when you need to use a replacer or supplement to ensure calves receive colostrum. This can happen when:

  • A cow is not producing enough colostrum

  • A cow gives birth to twins and doesn’t have enough colostrum

  • The calf is too weak to nurse or has dummy calf syndrome

  • A producer wants to ensure that a high-quality calf has a great immune system

Differences Between Replacements and Supplements

It’s always important to read and follow label instructions to ensure that you are giving your calf the correct amount of replacement.

A replacer refers to a product that has a full replacement of at least 150g of IgG. A supplement refers to a product that only has part of the replacement, generally about 50-60g of IgG.

How to Feed Colostrum Replacer to Calves

A good example of a replacer is a product made by VetOne called Bovine IgG Replacer 115™, which is both cost effective and has 115g of IgG. The active ingredients are colostrum (bovine) and immunoglobulin(s) G. It is given orally. 

[Bovine IgG Replacer 115™ can be purchased from FBN.]

How Much Colostrum Replacement to Give a Calf

One bag of replacer will probably be sufficient if the calf has been nursed by a cow. If you really want to be sure the calf has enough total replacement, it’s recommended to use 1.5 to 2 bags of Bovine IgG Replacer 115™. 

Consider spreading out over time how much colostrum replacement you give the calf. Once you’ve given the calf the first bag, it’s recommended to wait at least 6-8 hours before giving them the other half of the second bag.  

Animal Health Products from FBN

Bovine IgG Replacer 115™ can be purchased directly through the Animal Health section of FBN Direct and shipped straight to your farm.

Proactively managing animal health can help improve farm productivity. FBN offers a broad range of products to select from, including antibiotics, vaccines, reproductive, and more treatments. Plus, with transparent pricing, convenient online shopping, and fast direct-to-farm delivery, FBN makes it easy to care for the health of your herd.


Related Resources


The above is provided for information purposes only and should not be used for the diagnosis or treatment of any condition. This information does not cover all possible variables, conditions, reactions, or risks relating to any topic, medication, or product and should not be considered complete. Certain products or medications may have risks and you should always consult your local veterinarian concerning the treatment of your animals. 

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Dr. Erika Nagorske

Dec 19, 2023

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