Friday, May 25, 2018

Bacterial Regrowth and Sanitizing

None of  us create sterile equipment when we clean up from feeding colostrum, milk and milk replacer. Some bacteria remain on these surfaces. Regrowth is inevitable even when we try to suppress it with acid rinses and allowing equipment to air dry. 

In a recent article, "How to properly sanitize calf facilities," Drs. Ollivett and Sockett (Univ. Wisc.) comment on the need to sanitize calf equipment before using it to feed calves. 

"All colostrum and milk or milk replacer feeding equipment should be properly cleaned after use and sanitized not more than two hours prior to use." p73.

We all understand the part about "properly cleaned after use" - the most efficient way to minimize biofilms on buckets and bottles is to clean them ASAP after every single use. Click HERE for a practical on-farm 4-step cleaning protocol. 

What about their recommendation,
"and sanitized not more than two hours prior to use" [emphasis added]

Let's assume that we do a good job of brushing our bottles, nipples and tube feeder in a hot detergent solution, put them through an acid rinse and put them upside down on a rack to air dry until the next use - most likely to be more than two hours later.

How urgent is the need to sanitize them before the next use? 

Colostrum feeding - I felt pretty strongly about minimizing bacteria load for colostrum. I rinsed all my bottles, nipples and tube feeder with a strong bleach solution every single time before colostrum feeding.  No exceptions. All the evidence I have seen in the past decade or so emphasizes the need to feed clean colostrum.

Milk feeding - I was fairly lax about sanitizing bottles for milk-fed calves - the bottles were washed  after every use and put on a rack to drain and dry between feedings. At feeding time my nursing bottle nipples were carried in a 10-quart bucket filled with a strong bleach solution. We only bottle-fed calves until they could be bucket trained so there were not a lot of calves fed with bottles. Looking back it would not have been difficult to sanitize the few bottles - it just did not occur to me to do it. 

Milk feeding all calves with bottles - depending on the potential for bacterial regrowth many calf operations likely could benefit from a pre-use sanitizing rinse. This would depend on (1) how effective is the washing process, (2) is there an acid rinse to lower surface pH, and (3) do the bottles air dry between uses.

Milk feeding calves with buckets - buckets not washed between feedings is common - my calf consulting observations suggest that washing and sanitizing all the buckets is not going to happen when there are 100, 500 or 5,000 calves on milk. Nevertheless, where there are serious issues with scours among 7 to 14 day old calves I have seen cases where using a clean bucket (not sanitized) for every feeding for these youngest calves has led to a significant reduction in treatable scours.

I cannot recall a well-designed study that examined the hypothesis that sanitizing buckets before each milk feeding will improve calf health, feed efficiency and rate of growth among preweaned calves as compared to non-sanitized buckets.  I would really like to see an analysis that shows the extent that sanitation of all feeding equipment for all age calves has a positive cost effective value.

Refererence: T. Ollivett and Donald Sockett, " How to properly sanitize calf facilities." Progressive Dairyman, May 7, 2018, pp 73-74. 

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