Equipment hygiene and diarrhea risk in young calves

By Dr. Cynthia Miltenburg and Dr. Kristen Edwards on behalf of the Ontario Animal Health Network

Calfhood diarrhea remains one of the most frustrating and costly health issues for dairy producers. A range of infectious agents are implicated, including bacteria (e.g., E. coli, Salmonella), viruses (e.g., rotavirus, coronavirus), and protozoa (e.g., Cryptosporidium). The Bovine Ontario Animal Health Network (OAHN) compiles and reviews veterinary diagnostic submissions each year, with several hundred neonatal diarrhea panels analyzed, illustrating the widespread nature of calfhood diarrhea in Ontario.

Identifying the specific cause of diarrhea is important to guide prevention and management strategies, rather than to determine individual treatments in most cases. Knowing which pathogens are present can help refine vaccination programs, biosecurity measures, and hygiene protocols, and can inform how future cases are managed on the farm.

Some preventative strategies are broadly effective across all farms and pathogens. Ensuring timely and adequate colostrum intake is critical for passive immunity. Hygiene is another universally important factor, as young calves are particularly susceptible to disease, and contamination of colostrum, milk or milk replacer can be a significant source of infection.

A recent study from Quebec highlights an important association between poor hygiene of feeding equipment, especially automatic milk feeders (AMFs), and greater odds of diarrhea in preweaning calves. Using adenosine triphosphate (ATP) luminometry, a rapid hygiene assessment tool, researchers measured contamination levels across seasons, equipment types, and cleaning protocols.

Researchers visited 50 dairy farms over four seasons and tested the cleanliness of feeding equipment including nipples, bottles, buckets, esophageal tube feeders, and AMFs using ATP luminometry. This method detects ATP, an energy molecule found in living cells, which produces measurable light in a bioluminescent reaction, with higher readings indicating higher levels of biological contamination. In addition to equipment testing, the study also assessed calf health and environmental factors, such as ambient temperature, humidity, and ammonia levels.

Key findings:

• Contaminated AMFs were significantly associated with higher rates of diarrhea in calves. The pathogens that cause diarrhea multiply in AMF tubing and can be ingested by calves, increasing disease transmission. These AMF units can be challenging to clean, especially once biofilms (a slimy, invisible layer of bacteria) form, which can persist despite standard washing
• Nipple design influenced contamination levels. Peach teat nipples had higher contamination levels than Merrick’s nipples. Researchers hypothesized that the design makes cleaning more difficult and noted that Peach teat nipples may not always be removed from buckets during cleaning
• Seasonal variation affected contamination. Spring and summer showed higher contamination levels across most equipment types, likely due to warmer temperatures and less frequent cleaning. Cleaning consistency varied across farms, with some showing repeated contamination across seasons, especially for nipples and buckets. Extra vigilance and adjustments to cleaning routines during warmer seasons may be necessary to combat this risk

Calf raisers often manage calves from multiple sources, increasing the risk for pathogen introduction and disease spread. This study reinforces the value of ATP luminometry as a practical, on-farm tool that can be used to monitor hygiene. Regular testing and thorough sanitation, especially of shared equipment like AMFs, can reduce disease risk and improve calf health.

The Bovine Ontario Animal Health Network is a group of veterinarians and specialists working in government, university research and laboratory, and in beef, dairy, and veal practice who meet regularly to monitor and discuss disease trends in Ontario. Our goals are to facilitate coordinated preparedness, early detection, and response to animal health and welfare in Ontario. For our recent reports or more information visit www.oahn.ca.

Tips for managing automatic milk feeders

• Consult with the AMF manufacturer for recommended maintenance and specific requirements
• Clean daily:
  • Flush milk lines and replace nipples daily. Having multiple nipples allows for proper cleaning and drying in between uses
  • Use a detergent for thorough cleaning of components
  • Program the automatic cleaning of the AMF to run three times daily
  • Scrub all surfaces around the nipple that calves touch while feeding daily
• Disassemble and scrub
  • Remove and soak then scrub nipples, hoses, and mixing chambers regularly; use brushes for hard-to-reach areas
  • Inspect for cracks or wear and replace
  • Allow all parts to air dry completely before reassembly
• Use proper water temperature
  • Rinse with lukewarm water to remove milk solids
  • Wash with hot water to sanitize effectively
• Check and calibrate delivery systems regularly