Thursday, March 15, 2018

Hose Maintenance Pays for Automatic Feeders

Does hose maintenance have an influence on bacteria counts in milk replacer coming out of automatic feeders?

In a study of 17 dairies in southern Ontario samples were collected both from the mixing bowl and at the end of the hose connecting the mixing bowl on the automatic feeder to the mixing bowl.

By season visit the bacteria counts at the end of the hose (% pens over 100,000cfu/ml:

Season         Percent over 100,000cfu
Fall                     85%
Winter                83%
Spring                88%
Summer             74%
Thus we see that high counts at the end of the feeding hose is a common issue.

But, what role did the hose play in these high counts?

They found that, on dairies with lower mixing bowl bacteria counts, in 7 out of 8 measurements the bacteria count actually went down between the bowl and end of hose.

In contrast, they found that, on dairies with higher mixing bowl bacteria counts, in 7 out of 8 measurements the bacteria count went UP between the bowl and end of hose. 

What are my conclusions from these data?

1. If the dairy is doing a good job in sanitizing the mixing bowl they are probably doing an equally good job in keeping bacteria counts down in the hoses as well. Thus, farms with low mixing bowl counts tend to have clean milk replacer coming out of the hoses.

2. Although this study did not report cleaning frequency for the mixing bowl, cleaning frequency for hoses and hose replacement for individual farms, my on-farm experience suggests these good practices tend to cluster - folks that do a good job on one tend to do all of these three jobs well.

3. Because of the long time interval between farm visits (every three months) the "snapshot" observations of calf diarrhea may not have reflected actual occurrence of this intestinal disorder. Further, we have data that show calf care persons generally tend to under-diagnose and under-treat calf diarrhea - missing about 40% of the cases that a trained veterinary observer would find. Thus, we cannot connect cleaning practices in this study to actual calf diarrhea rates.

4. All of us that use automatic feeders need to be sensitive to the need for cleanliness monitoring. At least quarterly (I prefer monthly ) samples need to be collected and sent to a lab to monitor both how many and what kinds of bacteria are present in the milk replacer the calves are drinking.

5. Given we often feed 8 liters or more of milk replacer per day, remember how to translate lab data into daily bacteria intake for each calf:
     CFU/ML (total bacteria)           CFU/Day/calf(8 L/da)
     50                                              400,000
     500                                            4 million
     5000                                          40 million
     50000                                        400 million
     100,000                                     800 million (26 out of 34 pens had this level of contamination!)

Friday, March 9, 2018

What are the "Signals" that a calf is not feeling well?

What do I look for when doing my wellness check on calves?

This note contains very practical "look for" information when walking calves. 

It is HERE or at this URL

Great job by Ann Hoskins.


Thursday, March 1, 2018

Adding Bacteria to Milk with an 
Automatic Feeder?

The recipe seems to be fairly simple.

Start with clean milk replacer powder, put warm water into mixing jar, add powder to jar, mix. Sample the milk from the jar. Presto! Contaminated milk replacer ready to feed calves!

In the study reported by Medrano-Galarza and Others in the March issue of the Journal of Dairy Science from 17 dairies in southern Ontario (Canada) using automatic feeders  roughly 3 out of 4 dairies managed to add more than 100,000cfu/ml bacteria to the milk replacer before it left the mixing jar.

Then, the same milk replacer was sampled coming out of the hose connecting the mixing jar to the nipple. Now 4 out of 5 farms elevated the bacterial contamination to over 100,000 cfu/ml.

I cannot believe these dairies were trying to make their calves sick. The study included calf diarrhea rates for these calves in all four seasons of the year. The rates were:

Fall      = 23%
Winter = 27%
Spring = 25%
Summer = 16%

In my opinion this shows that calves are very tough critters - in spite of this continuous exposure to bacteria in all their milk replacer ration most of them still neither died or were observed with diarrhea. [Mortality was reported at 4% - lower than most values for both USA and Canada.]

Also reported were contamination levels with coliform bacteria in samples coming directly from the mixing jar. These rates of over 10, coliforms were:

Fall         = 12%
Winter    = 17%
Spring    = 12%
Summer = 17%

Calves are tough critters.

How much better could their feed conversion have been without the constant drag of bacterial exposure in their milk?

Reference: Medrano-Galarza, Calalina, S.J. LeBlanc, A. Jones-Bitton, T.J. DeVroies, J. Rushen, A.M. de Passille, M.I. Endres, D.B. Haley. "Associations between management practices and within[pen prevalence of calf diarrhea and respiratory disease on dairy farms using automated milk feeders." Journal of Dairy Science 101:2293-2308 March 2018.