Guide to feeding newborn calves colostrum

The target of all good dairies should be to minimise mortality, and providing calves with enough good-quality colostrum as quickly as possible after calving is a vital first step to achieve this.

The aim for any dairy is to double a calf’s birth weight by weaning ­– without that all-important first feed of colostrum, calves are less likely to make it through their first days of life.

This is because calves are born with an immature immune system and with very few fat reserves, which makes them very susceptible to the cold and bacteria.

The antibodies found in colostrum will enable the calf to fight off disease until its own immune system is fully developed.

Below, Scott Abbott and Alea Hoffman advise on when colostrum should be collected, how it should be stored and the quantity and speed at which it should be fed to baby calves. 

See also: 7 steps to better calf nutrition

Why is colostrum important?

Immunoglobulins (IgG) are the antibodies in colostrum. When consumed by a calf, these go into the stomach and pass into the small intestine, where they are transferred to the blood. Their absorption declines rapidly right after birth.

Once absorbed into the blood they bind to any bacteria or viruses in the blood system and get resecreted into the small intestine to protect against bacteria that is ingested by the calf.

When should you separate calves from their dams?

Studies have shown separating calves before they are 24 hours old is less stressful on the cow and calf than separating them at two weeks.

It also reduces their exposure to pathogens and improves their chance of getting good colostrum.

Get calves clean, dry and warm to stop them shivering and losing their fat reserves.

When should you milk a cow for colostrum?

Timing of the cow calving and milking her for colostrum has an effect on the quality of that colostrum. This is because the cow will start to reabsorb colostrum into her own blood stream and the start of milk production will dilute it.

Studies have shown the best time to milk a cow is within the first two to six hours of calving. After this, IgG drops off.

When should calves be fed colostrum?

Calves fed within three hours after birth have the highest absorption, so it is best to feed the calf as soon as possible.

Some people recommend feeding 10% of birthweight, but this requires weighing individual calves and this isn’t always possible. Therefore, it’s easier to give a blanket recommendation because birthweight doesn’t vary that much (within breeds). Feed four litres of colostrum within the first two hours of life.

For Jerseys or smaller Holsteins three litres is ample, as they have a smaller stomach to fill.

A second feed of two litres eight to 12 hours later is ideal, as there is still some absorption of antibodies at this time.

How do you know if the colostrum is good enough?

You can measure it using a Brix refractometer. Anything over 22 is good enough quality to achieve a sufficient dose of IgG when you feed four litres. Watch the video on using a refractometer to test colostrum.

Why is it important to keep it clean at all times and how can you ensure this happens?

Antibodies within colostrum are made to bind to bacteria and they don’t care if that’s in the bucket or inside the calf. Once they bind to bacteria they are no longer able to be absorbed by the calf, so dirty colostrum will have a lot less antibodies available in it.

E coli doubles every 20 minutes, so bacteria can spread very rapidly. Most bacteria can grow if the temperature is higher than 4C.

Therefore, it’s good practice to:

• Clean equipment such as milking machines and dump buckets properly.
• Cool it down quickly (less than 4C using ice water). If you put multiple bottles of warm colostrum in a freezer, the freezer can take a long time to cool down the colostrum. It’s best to put it in an ice water bath first and store it in something with a large surface area such as a bag to help cool it down quicker.
• Warm it back up quickly. Don’t rewarm it in really hot water because that can destroy some of the antibodies (maximum of 52C to warm it to 39C for feeding).

Should you pasteurise colostrum?

Providing you don’t heat it to above 60C for 60 minutes, you can maintain good IgG levels. Heating it above this temperature will cause the colostrum to coagulate and turn to gelatine, which makes it more difficult to feed.

Some farms may need to pasteurise colostrum to manage diseases like Johne’s, but providing colostrum is managed well and kept clean, it can be fed without pasteurisation.

How can you check your colostrum management is working properly?

To evaluate the effectiveness of your colostrum programme, you can measure the serum protein levels by taking blood samples from calves between two to seven days of age.

As the calf gets older, serum protein is less accurate as a measure of IgG transfer, because the calf’s own antibody and protein levels increase. An older calf is also more likely to be dehydrated, which makes the reading inaccurate.

If the blood serum tests above 5.5% it shows your colostrum programme is working well. If the score is below this it means the calf has less protection. A high number of calves failing to meet the target of 5.5% suggests you need to review your colostrum management and feeding.  

Should you tube feed or bottle feed a calf colostrum?

Tube feeding colostrum is a quick and efficient way to ensure every calf has the recommended amount quickly after birth.  

When the calf is transitioned to milk after the first one to two feedings, a bottle or bucket should be used.

The problem with tube feeding milk to older calves is that a lot of it will go into the rumen, which isn’t fully developed yet, instead of passing into the abomasum for proper digestion to occur.

Too much milk in the rumen may rot and cause disease. In comparison, the rumen is so small at one day old that nothing much will get in there and it will quickly spill into the abomasum.

If a calf is sick and won’t drink for multiple feedings then you will need to tube feed it, but give it small amounts (one to two litres). Tube feeding electrolytes is also recommended for sick calves that won’t drink.