Quick Guide to Feeding Colostrum to Calves


The single, most important meal a calf will consume in its life is the first feeding of colostrum. Knowing when and how to intervene are the first steps for ensuring a productive calf. 

Here, we answer some of the most frequently asked questions regarding colostrum supplements and replacements in your guide to colostrum feeding.

How can good colostrum feeding practices impact long-term productivity?

The impact of good colostrum feeding practices is often overlooked. Good colostrum feeding practices
and feeding more colostrum can lead to improved average daily gain, reduced treatment costs and better feed conversion efficiency. Improvement in these three areas offers financial benefits to any farm or ranch.

Under what circumstances do calves need a colostrum supplement or replacement?

There are many instances where a colostrum product should be fed to calves. For instance, calves born in very cold weather, twin births and calves born to first-calf heifers. However, calves born with difficulty (also known as dystocia) are at the greatest risk for failure of passive transfer of immunity, since they are often slow to get up and suckle. Additionally, these calves’ ability to absorb antibodies may be compromised due to the delay of nursing and altered metabolic parameters.

Whenever calves are born with intervention or assistance, the calf should be given at least a supplement dose of colostrum, if not a full replacement dose. Consider supplementing any calf that has not suckled within 1-2 hours of birth.

When should colostrum be fed?

With each minute that passes after birth, a calf’s ability to absorb antibodies is reduced. By 24 hours the gut is almost completely closed and can no longer absorb antibodies. Therefore, colostrum must be fed as soon as possible after birth, ideally within an hour.

If bottle or tube feeding is necessary (when it is not possible to milk the cow immediately or get the calf up and suckling) a good quality colostrum supplement or replacer is an excellent alternative to ensure the calf receives a timely first meal.

If colostrum has been delayed past 2 hours, feed larger amounts to compensate for reduced absorption.

For better absorption, colostrum should be fed as soon as possible after birth. If colostrum feeding gets delayed past 2 hours after birth, feed larger amounts to compensate for the reduced absorption rate.

How much colostrum do calves need?

When it comes to colostrum, more is better. Most veterinarians now recommend calves receive at least 1 gallon or 4 liters of good quality colostrum, which should provide calves with at least 200-300g of IgG.

Good quality colostrum replacers can be used when the dam does not provide sufficient volume or where colostral quality/IgG/antibody concentration is low. A significant percentage of first-calf heifers produce only small volumes of colostrum, sometimes less than 1 liter. Therefore, their calves would benefit from a colostrum supplement or replacer.

New USDA National Animal Health Monitoring System data shows calves with 8 g/L serum IgG (indicative of failure of passive transfer of immunity) had a 40.3% chance of becoming ill.

Calves with excellent passive immunity, indicated by serum IgG levels of 30 g/L or higher, had just a 29.3% risk of illness.

If feeding 300g of a colostrum replacer, it is recommended to divide the colostrum into multiple feedings. Do not feed the entire amount at once.

How should colostrum be fed?

First, attempt to bottle feed the calf. If the calf does not consume the entire bottle or colostrum feeding is delayed past 6 hours, tube feeding the remainder is suggested in attempt to achieve successful passive transfer of immunity. Since absorption of colostrum slows significantly as each hour passes, calves also benefit from a second and third feeding of colostrum.

Should cold weather calves be treated differently?

Calves have a thermal neutral zone of 59 to 77°F (15 to 25°C), and many are born into even colder conditions. Calves need a timely feeding of colostrum to provide energy to produce body heat and warm them. Colostrum contains unique colostral fat that initiates brown fat metabolism. Brown fat metabolism fuels the calf’s internal furnace for heat and energy to get up, suckle, stay warm and stay alive. (Note, bottle-fed colostrum should be warm but not too hot to immerse your hand in.)

Make feeding colostrum easier! Choose GENEX Foundation™ 150 colostrum in the Perfect Udder® bag. Simply add warm water, shake until mixed, attach a nipple or esophageal tube, and feed.

Can you use colostrum from your own cows, and if so, how?

Herd colostrum can be used to supplement calves of other dams, but it must be done right. A cow’s colostrum should be collected with sanitized equipment within 2 hours of birth of the calf. Then, it should be tested with a refractometer to measure quality. Only colostrum that meets parameters consistent with high IgG/ antibody levels should be used. The colostrum should be cooled in small 1L or less containers, as quickly as possible since bacteria numbers double every 20 minutes. Then, the colostrum should be stored in a refrigerator for no more than 48 hours or frozen for no more than a year. Avoid freezing and thawing repeatedly as this may reduce the quality and lifespan of the colostrum.

What should you look for in a colostrum product?

Examine colostrum supplement and replacer ingredient labels carefully. Colostrum products can be made from various sources. However, the greatest benefits to the calf result from feeding actual colostrum rather than formulas of proteins and fats from other sources. Colostrum-based products contain all the immune, metabolic and growth factors naturally found in maternal colostrum.

One very important ingredient is colostral fat. Colostral fat is essential for activating brown fat metabolism, an important energy source required by the calf immediately after birth.

Colostrum products that contain blood or whey with added vegetable and animal fats not naturally found in colostrum do not provide the same benefits for the calf. In fact, some of these products contain no actual colostrum at all.

Look for products that are regulated by the USDA (United States) or CFIA (Canada) and backed by numerous safety and efficacy studies published in scientific journals.

Can colostrum be fed after 24 hours?

Transition milk is produced by the cow for the first six milkings and represents a gradual decline in the bioactive ingredients found in first milk colostrum. Feeding transition milk can be an extra immune booster in addition to its rich composition of nutrients, energy, growth factors and hormones.

Although the calf can no longer absorb antibodies directly into its bloodstream, the immune factors in transition milk are useful in providing local immunity and protection against infections that cause diarrhea. These benefits can also be provided to calves by feeding a colostrum replacement product in an amount equal to feeding 10g IgG (or 1 cup of first milking maternal colostrum) or more per feeding. This strategy is especially beneficial during times of risk of scours.

Colostrum customized for your generations

Your farm or ranch operation is unique and so are your requirements for a colostrum product. Yet, no matter your circumstances, there’s a colostrum supplement or replacer product to fit your needs. Browse our line of whole bovine colostrum products.

Share this post with your friends!