Friday, March 30, 2018

When to Introduce Calves into Automatic Feeder Pens?

If one wishes to reduce the treatment rate for bovine respirator disease (BRD) among neonatal calves that will be group housed for automatic feeders when should the calves be introduced to the autofeeder/group pens? 5 days, 7, 9, 11, 13 days old?

The evidence seems to be inconsistent and somewhat confusing. One study will show earlier will result in lower BRD rates while another will show later has the same outcome.

A recent study seems to point at another factor tied to BRD rates. That is, when calves receive the same amount of milk (between 6 and 8 liters per day) in  the first two weeks of life the rate of BRD does not seems to differ regardless of when the calves are moved from individual to auto feeder group pens.

This evidence points at reduced milk intake at the key factor in higher BRD rates among neonatal calves. Often calves being held in individual pens before moving into the auto feeder group pens are only fed limited (usually 4 liters per day) milk. The longer calves live on a restricted ration the higher the chances of being diagnosed and treated for BRD. 

Thus, the authors conclude,
"Therefore, we suggest that if introduction to the group (that means to the automatic feeder) is going to be delayed, calves should have access to high milk allowances immediately after colostrum feeding." (p2306)

I might add from my experience trying to bring neonatal calves up on milk that the passive immunity of the calves seemed to make a big difference in my success. Calves that had plenty of clean good quality colostrum soon after birth drank like there was no tomorrow. The calves that missed out on colostrum (I bled calves at 48 hours for blood serum total protein testing - ones that tested 3.5 - 4.5 on a clinical refractometer I called "missed out") took what seemed for ever to come up on milk. And, these calves with poor colostrum management were much more likely to have scours, too.

Reference: Medrano-Galarza, Catalina and Others, " Associations between management practices and within-pen prevalence of calf diarrhea and respiratory disease on dairy farms using automatic milk feeders." Journal of Dairy Science, 101:2293-2308. April, 2018.

Friday, March 23, 2018

Why the Rush to Feed Colostrum?

A recently reported study fed colostrum at 45 minutes, 6 hours and 12 hours after birth. All colostrum was tube fed. The calves received 7.5% of their birth weight in colostrum. 

For example, a 90 pound calf received about 3.25 quarts of colostrum. At 62g/l concentration of antibodies in the colostrum this 3.25 quarts came to 190g of antibodies in this feeding. The average for all calves was right around 195 to 200g at first feeding. 

From blood sampling they determined the efficiency of absorption of the antibodies (IgG).

The average efficiency of absorption of antibodies were (by time of feeding):

45 minutes     52%
6 hours           36%
12 hours         35%

In case you didn't want to figure out the amount of improvement, the 52% efficiency of absorption for 45 minutes represents a 44 percent improvement compared to the 6 and 12 hours feeding procedures.

Fisher, A. J., and Others, "Effect of delaying colostrum feeding on passive transfer and intestinal bacterial colonization in neonatal male Holstein calves." Journal of Dairy Science 101:30299-3109 April 2017.

Monday, March 19, 2018

Abomasal Bloat, Abomasal Emptying, & Feeding Programs

It would be nice to report that there is one simple fix to promote gut health and avoid abomasal bloat. The authors of "Invited Review: Abomasal emptying n calves and its potential influence on gastrointestinal disease", however, after 12 pages of  scientific review offer this summary:
"Ultimately, the exact etiology of abomasal bloat is unknown, but it likely involves both bacteria that produce gas as well as something that slows abomasal emptying." (p29).

So, given that we have only a partial understanding of why abomasal bloat happens, do the authors have any helpful ideas?


They observe that we can follow a few management procedures that avoid slowing down the rate of abomasal emptying.

1. For milk replacer, be cautious when mixing at densities greater than milk. Rates of bloat seem to go up as total solids go well above 15%.  Thus, careful and consistent measurement of water and powder can avoid undesireable fluctuations resulting in very high solids levels.

2. For milk, monitoring solids levels seems to be a very sound practice. Especially when adding additional powder to achieve a fixed solids level (e.g., 15%) careful and consistent measurement of powder can avoid undesireable fluctuations resulting in very high solids levels.

3. The authors observe, "Another strategy to limit the effect on abomasal emptying is to feed smaller volumes of milk more frequently. [They mention that automatic feeders now make this a workable option.] ... Maintaining regular feeding schedules and making sure milk or milk replacer is warm also anecdotally appear to help reduce the incidence of abomasal bloat." (ps30).

Given that consistency of feeding management may be significantly related to regularity of abomasal emptying you may want to review the resource, "Consistency: Calf Care Checklist" found HERE or if you need the URL,

Reference: Burgstaller, J., T Wittek, G. Smith, "Invited Review: Abomasal emptying n calves and its potential influence on gastrointestinal disease" Journal of Dairy Science 100:17-35 March 2018 

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.