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Calves, milk and bacteria: How clean is your kitchen?

Kelli Boylen for Progressive Dairy Published on 31 October 2019
Bottle feed a calf

Colostrum, milk and milk replacers are all excellent sources of nutrients for calves, but also for bacteria.

Jenn Bentley of Iowa State University Extension says when that abundance of nutrients is combined with moisture, you have the key elements for bacterial proliferation, which can be detrimental to your calves’ health.



“Cleanliness in the calf kitchen is something we don’t often think about, but it really can help reduce pathogen levels,” she says. “In order to start and maintain a healthy life, calves must be cared for in a way that prevents outbreaks and spread of diseases, and promotes growth and development of their digestive system.”

Bentley strongly recommends reading the labels of your cleaning products for several reasons. “There is a lot of important information on there,” she says. “And most importantly, make sure the disinfectants you are using on your farm are effective for the pathogens that are an issue on your farm.”

For example, quaternary ammonium disinfectants (commonly referred to as “quats”) are effective on staph and strep microorganisms, but not coccidia. Ammonium hydroxide or a phenol would be best to use against coccidia, according to Dr. Danelle Bickett-Weddle, associate director of the Center for Food Security and Public Health at Iowa State University.

Many products have a minimum contact time to kill pathogens. Bentley adds that knowing the recommended safety precautions can prevent injury to the user, your animals and the environment. 

The Antimicrobal Spectrum of Disinfectants


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Also, make sure you are using the correct amount of product for the amount of water you are using in your sink. Using too little is likely not effective, she says, and “using more than the recommended amount of product is a waste of money.”

As a basic rule, she says thorough cleaning is accomplished by initially rinsing all equipment with lukewarm water to remove as much milk residue as possible, followed by vigorous scrubbing with detergent and 49ºC water. She says hot water can “bake” residue onto the surface.

Dr. Don Sockett, whose foundational research on cleaning calf equipment as a veterinary microbiologist with the Wisconsin Veterinary Diagnostics Lab at the University of Wisconsin – Madison equipment, says the right temperature and detergent are critical to properly cleaning feeding equipment. Feeding equipment should then be scrubbed with a clean brush for two to three minutes in water that is at least 54ºC with a caustic detergent that has a pH of 11 to 12. Rinse once, and then rinse a second time with cold water mixed with an acid (pH of 2 to 3) and 50 parts per million (ppm) of chlorine dioxide. Allow to air dry. Sockett says it is important to understand that the caustic detergent emulsifies the fats and breaks down the protein and carbohydrates. The acid wash solubilizes and removes the mineral deposits often found on the calf feeding equipment. 

Charateristics of selected disinfectants

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Bentley says it is very important to use the correct alkaline and/or caustic soap to ensure emulsification of fats and breakdown of carbohydrates and proteins.


Different chemical agents have different and specific purposes. She explains that detergents are used to break up organic deposits such as fat and protein. Rinsing with water alone is not effective, and bacteria can lie beneath the surface created by residual fat and protein.

A disinfectant, used after the surface is cleaned with detergent, is used to kill microorganisms. “Using detergents and disinfectants is an effective combination to reduce the bacterial load and prevent the formation of biofilm,” she says.

A sanitizer can be used within two hours prior to using the equipment, and this helps reduce the number of microorganisms on a surface. “But,” Bentley says, “it is not as effective as a disinfectant. It may be used as a way to improve hygiene in the calf kitchen, but not as a substitute of good practices.”

Containers used to store or transport milk should also be rinsed in lukewarm water. Then, scrub with water hotter than 49ºC with liquid detergent and bleach, or dry, chlorinated detergent. Add acid, and rinse with warm water. Do not rinse off acid solution. (Since they do not come into contact with saliva from calves, there are fewer steps necessary.)

It’s not just cleaning the equipment that is important; removing moisture is the other key factor in shutting down bacterial reproduction. Bentley says this is easy to achieve by simply allowing feeding equipment to dry thoroughly, such as by placing them upside down in a drying rack individually to allow complete air circulation for surfaces to dry completely between use. Allow to air dry, and do not stack pails or place upside down on concrete floor.

1119ca boylen disinfectant label preview

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Look at the surfaces of feeding equipment when it is wet – from buckets to whisks and nipples to bottles. Bentley says if there is any beading of the water, that is a sign a biofilm has built up on the surfaces. She says this is common when feeding equipment is only rinsed with water or a strong enough detergent has not been used. This biofilm, consisting of a matrix of protein, sugars and fat, strongly adheres to surfaces and will take physical and chemical cleaning practices to remove.

“Even though surfaces may appear clean to the naked eye, there may be bacteria actively growing and thriving on minuscule amounts of residue caused by improper cleaning,” Bentley says. She says there are two common ways to evaluate cleanliness of surfaces – one of which is using a protein swab and the other is through bioluminescence.

Both of these methods are widely used in human food processing facilities to monitor the effectiveness of their surfaces and equipment sanitation procedures and prevent the spread of pathogenic bacteria.

“A calf kitchen is also a food processing facility, therefore, both techniques can be easily applied at the farm level,” she says.  end mark

Kelli Boylen is a freelance writer based in northeast Iowa.

PHOTO: A clean calf kitchen and clean feeding equipment is an important part of raising healthy calves. Getty Images.