Getting Ahead of Calf Scours

Dr. Steve Dudley

21 Dec 2021

Dr. Steve Dudley, FBN® head of technical services and a practicing veterinarian with Southwest Veterinary Services discusses scours prevention including pre-calving scour vaccines.

Watch now

In his presentation, Dr. Dudley discusses prevention strategies, vaccine modes of action, the different vaccines available on the market and how to use vaccines. 

Calf diarrhea prevention strategies

There are a number of things to consider from a prevention strategy perspective.

Keep facilities clean

Manure management is crucial when thinking about preventing calf scours. Producers should proactively remove manure from calving areas on a regular basis and provide fresh bedding. 

Decrease pathogen load

It’s also important to think about different ways to dilute pathogen load. One of the ways to do this is by separating cows into different calving groups and pastures. Another way is to rotate the herd through pastures every 2-3 weeks to keep the calving area fresh.

This will decrease the amount of pathogens that older calves are passing to newborn calves. It’s common to see scours increase in severity toward the end of the calving period, so implementing management practices to keep pathogen loads low where new calves are being born is helpful.

Stalosan F is a broad spectrum dry disinfectant that can be used in calving facilities. It kills viruses and bacteria to protect animals from infection and disease.  

Vaccinate for protection

Individual vaccines can be distributed to calves but the most important consideration is good colostrum consumption. Using pre-calving vaccines helps build up the cow’s colostrum and improve the quality of the colostrum.

The term, failure of passive transfer, indicates a calf didn’t get antibody protection from the dam. This could be based on not getting enough quantity of colostrum. However, it can also happen when a calf doesn’t receive a high quality of colostrum. Calves get 100% of protection through colostrum consumption. 

What makes up a vaccine?

Manufacturers all use a similar process to make vaccines. They first determine the antigens or “bugs” (viruses or bacteria) that will be within the vaccine. They then determine and add an adjuvant that presents the antigens to the animals in order to improve the response to the vaccine. Each manufacturer has their own proprietary antigens and adjuvants. 

Principles of vaccination

Different herds require different vaccines and vaccination programs. There is not a one size fits all perfect vaccine that works in every situation. The differences can be based on:

  • Herd size

  • Geographic area

  • Climate

  • Soil type - sandy vs. muddy

  • Calving operation type - dry lot calving vs. pasture calving

  • Management capabilities 

How a mama cow’s protection is passed to calves

A cow or heifer is vaccinated and builds up antibodies or protective units to the antigens (bacteria or virus) in the vaccine. Antibodies travel to the udder and become part of the colostrum which the calf then suckles. 

Colostrum has a rich antibody environment as well as energy, fat, and nutritional value for calves. It should be noted that 0% of antibodies are transferred to the calf in utero, which means the calf 100% relies on colostrum for protection against bacteria and viruses

Colostrum delivery to the calf

In an ideal world, calves should receive colostrum within 1-2 hours of birth. The ability to absorb colostrum rapidly declines within 6 hours of a calf’s birth so it is vital that calves receive colostrum as soon as possible. In some cases, it’s important to feed this to the calf via bottle or an esophageal feeder within the first 6 hours of its life. 

Pre-calving scour vaccines

Three of the most common choices for pre-calving scours vaccines are:

Differences among pre-calving scours vaccines

The table below outlines the differences among the pre-calving scour vaccines. All of the vaccines protect against rotavirus and coronavirus. When a vaccine contains more than one virus strain, it is listed. For example, Scourguard contains two stains of rotavirus - G6 and G10. 

The last three columns of the table detail the bacterial pathogens, E. coli K99 and clostridium perfringens, the bacteria known as overeating diseases which cause toxins and sudden death in calves.

Proper vaccination is key

Proper vaccination will help to maximize the quality of colostrum. It’s recommended that heifers get 2 doses. The first dose should be 10-12 weeks from calving. The second dose should be administered 4-6 weeks from calving (this will allow enough time to get into the colostrum). You do need to consider how long your calving interval is because it can potentially change when to vaccinate. 

Cows typically only receive one dose unless the animal is facing additional challenges. 

Always administer vaccines according to label directions. It’s important to use clean syringes and replace your needles every 10 cows. Always use a clean needle when entering the bottle. To clean your needles, use hot water and in some cases dish soap can be used. Just be sure to rinse soapy needles very well. Don’t inject wet animals. Moisture can lead to more abscesses and more problems. 

Stock up and save on vaccines

For more information or to purchase vaccines directly from FBN, please visit our Animal Health store to stock up and save.


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.

Copyright © 2014 - 2021 Farmer's Business Network, Inc. All rights Reserved. The sprout logo, “Farmers Business Network”, “FBN”, “FBN Direct” are registered service marks of Farmer's Business Network, Inc. Feed products are offered by FBN Inputs, LLC and are only available where licensed.

Scour Bos is a registered trademark of Elanco US, Inc. Scourguard is a registered trademark of Zoetis Services LLC. Guardian is a registered trademark of Merck Animal Health.

Dr. Steve Dudley

21 Dec 2021