Sunday, June 29, 2014

Feeding Temperature for Acidified Milk Replacer

The question I received was about the ideal temperature at which to feed acidified milk replacer to young dairy heifer calves. 

The producer is set up with multiple pens. They have insulated boxes for each pen with a heater in each box for cold weather (it is a naturally-ventilated cold barn in New York State). The barrel in each box is wrapped with a thermostatically-controlled heating unit. Each box contains eight nipple feeding stations.

Fresh milk replacer is prepared twice daily and added to barrels at each pen as needed. The entire feeding system is taken apart between groups, barrel scrubbed and new tubes, check valves and nipples installed.

Now, the question. At what final temperature should the milk replacer be mixed and at what temperature should the heating units be set?

Well, it depends. 

The more conservative position is to keep the acidified milk replace in the 68F to 75F (20C - 24C) range. Calves appear to self-limit meal volume at these temperatures. That is, they seem to decide they have eaten enough at somewhere between 1.5 and 2.5 quarts (1.4 - 2.4L). Supposedly the chances of indigestion are lower with smaller meals compared to larger ones assuming everything else is equal. If the farm was working with whole milk there would be a very low chance that the milk would curdle. 

A more liberal position that favors higher intake levels is to keep the acidified milk replacer closer to calf body temperature (102F, 39C). Calves appear to consume larger meals when the solution is held at this temperature with slightly higher total daily intakes compared to lower-temperature feeding programs. Supposedly the chances of indigestion are higher with larger meals compared with smaller ones assuming everything else is equal. 

When whole milk is used, at these temperatures I have been told that the chances of curdling are higher than when milk is held closer to 70F (21C). Neil Anderson told a story at a meeting about an acidified milk feeding demonstration at a community fair where the barrel, even though  under a tent, sat in the sun and by afternoon the milk temperature went high enough to allow curdling. 

Is there definitive research that compares feeding temperatures in this situation. Not that I know about at this time (June 29, 2014). Anecdotal accounts suggest good results with either temperature - thus, there are probably several variables other than meal size in the mix that predispose calves to suffer from indigestion.

Thus we go back to trying what we think is likely to work and watch the calves. They always tell us how things are going if we are willing to watch them carefully. 

Friday, June 27, 2014

Managing Risk in Stored Colostrum

On June 23rd I was watching a calf care person get ready to put colostrum into a freezer. She put one self-locking one-gallon freezer back inside another. She poured two quarts of colostrum that had been collected about 20 minutes ago into the bags. The bag went into the freezer - she laid it flat.

What are the risks of bacterial contamination of this stored colostrum when it is thawed and warmed to feed a calf?

  • inoculation with environmental bacteria a the time of collection from the cow - I did not watch her collect the colostrum. However, in this case the dam was milked as soon as she was up after calving and steady on her feet - they have a stall in the calving area to restrain fresh cows for milking. I saw a teat dip container and several soiled disposable towels - so let's assume she did a good job of cleaning up teats before milking.
  • inoculation with environmental bacteria at time of collection from equipment - all the stainless steel equipment, even though soiled with just-collected colostrum, appeared to be well maintained. She poured colostrum from the milker can into a gallon-size plastic pitcher in order to transfer it into the plastic freezer bags - it looked clean but it was a potential source of environmental bacteria.
  • placing the colostrum into the freezer at 90-plus degrees - work that I did several years ago on chilling rates showed that in a household refrigerator a two-quart container of 90F colostrum took 10.5 hours to chill to 40F. I would have preferred that she chilled the colostrum in an ice water bath for 30 minutes to take it down to 60F before it went into the freezer. Chilling time to 40F when the colostrum starts at 60F is only 5.5 hours compared to the 10.5 hours when the colostrum is 90F.
What recommendations would I have for this dairy?

1. Once in a while check teat end preparation with an alcohol pad - it should not come away with manure particles.

2. This farm size predicts one to two calvings a day. That means the dedicated milker unit used at the calving pen sits idle most of the time. I would prefer a quick "pre-use" sanitizing rinse with hot water and household bleach just before milking each fresh cow. 

3. Use a similar "pre-use" sanitizing rinse on the tube feeder used to administer the colostrum and on any other equipment involved in colostrum handling and storage.

4. Chill any colostrum that is to be refrigerated or frozen to 60F before placing it into the cooling unit. 

5. Consider using a 50% liquid potassium sorbate food preservative in colostrum that is to be stored for future use. Click HERE to a protocol for using potassium sorbate.

6. Regularly (once a month, once a quarter) collect 5 or more "as-fed" colostrum samples and have them cultured for bacteria. If nothing grows, great! If many, many bacteria grow fix something.

Thursday, June 26, 2014

Ammonia and Calf Health

If  you want to increase your frustration level try searching for research on the impact of atmospheric ammonia on dairy calves. 

Much of the published work refers back to standards set for occupational exposure limits for humans. That is, 25 parts per million  (ppm) for an 8 hour exposure and 35 ppm for a short term exposure over 15 minutes. Several articles mentioned threshold values for livestock of 15ppm but without any supporting references.

Of some promise is a recent article "Impact of atmospheric ammonia on livestock animals - a minireveiw" that, unfortunately for me, was published only in German in March, 2013. I can only hope for a translation in the near future. Maybe this work by J. Seedorf of the Institute of Animal Hygiene and Animal Welfare, School of Veterinary Medicine in Hanover, Germany will propose health-related thresholds.

Documented atmospheric ammonia levels found in calf facilities is available for selected European countries:
Calves on straw bedding: ppm

Country          Mean     Maximum         
England          0.4         3.2
Denmark        1.9         5.7
Germany        1.9         8.3

Calves on Slatted floor, group housing: ppm

Country         Mean     Maximum
Netherlands   7.7         13.7
Germany       5.1          8.5

Using a toxic-gas detector tool (Matheson-Kitagawa Model 8014-400B) I have been trying to measure ammonia gas levels in calf facilities for the past six years. I have been using a baby pig standard of 5 ppm as a desirable threshold.

When I find levels much above 10 ppm at calf-nose level in pens and barns I seem to pretty consistently find persistently high pneumonia treatment levels. At 20 and 25 ppm nearly all the calves are being treated for respiratory symptoms. 

For right now it seems like the advice "ventilate, ventilate, ventilate" is the workable alternative for maintaining a low ammonia exposure level. Of course, there are other factors involved in respiratory health issues.

I have noticed in a few barns that converted from individual pens with calves fed 6 quarts of milk a day to group pens fed either ad libitum acidified milk or automatic feeder 10+ quarts daily that a good deal more bedding has been needed to keep down ammonia levels. I guess it is to be expected that if more liquid goes into the calves more urine is going to come out as well. 

Wednesday, June 25, 2014

High Milk Feeding = No Starter Intake?

Just nothing like hard data. In a study involving 62 Holstein bull calves both milk and calf starter intake were monitored daily. [Miller-Cushon and others, "The Effect of Palatability of Protein Source on Dietary Selection in Dairy Calves. Journal of Dairy Science 97:4444-4454 July 2014]

I reviewed the data presented in the article looking especially at levels of calf starter intake by week of age. Calves were all fed 6.3 quarts of milk replacer (25:19 analysis) daily containing 1.65 pounds (750g) of powder (a fairly intensive milk replacer feeding program). 

Daily starter intake by week averaged:
Week 4   1 pound
Week 5   1.3 pounds
Week 6   1.6 pounds
Week 7   2.3 pounds
Week 8   2.9 pounds

Thus, in spite of the 1 2/3 pounds of milk replacer daily through eight weeks the calf stater consumption increased week-by-week.

The point here is that by 4 weeks the calves were eating one pound of starter (about one quart for the starter that I fed my calves). They had been eating some concentrate regularly for about three weeks by the time they were 35 days old. This is enough to promote good growth of the inner lining of the rumen.

In this study milk replacer feeding continued right through the eight-week study period. In a dairy farm setting we are more likely to see the milk replacer feeding rate drop around 35 to 42 days. I eliminated the PM milk replacer feeding for my calves in preparation for weaning around 45 to 49 days of age (I was feeding 2.2 pounds of powder daily). When the milk replacer volume was cut in half the starter intake jumped up over seven days from about 1 - 1.5 pounds daily to 3.5 - 4.0 pounds a day.

Yes, higher rates of milk or milk replacer feeding do suppress the amount of calf starter consumed compared to minimal milk feeding rates (e.g., 4 quarts a day, 1 pound of m.r. powder daily). But, if careful records are kept we find that calves do eat small amounts beginning around 14 to 21 days of age. This is especially true when clean fresh water is offered daily.

Tuesday, June 24, 2014

Start Right When Feeding Colostrum

I happened to be in the utility room when a worker came in to check the temperature of colostrum. A heifer calf had just been born. He was going to feed her the routine four quarts of colostrum. Thus, two two-quart nursing bottles were heating up in a bucket of warm water. 

On this dairy the colostrum is administered with an esophageal tube feeder. He reached up and took the tube feeder from a hook on the wall. After filling the tube feeder with the contents on one bottle he went off to feed the calf. He took the second bottle with him - I watched as he poured the contents of this bottle into the top of the tube feeder as it emptied - very smooth operation.

A problem that was not at first apparent? Tube feeder cleanliness!

The farm protocol directs each person using the tube feeder to follow a four-step cleaning process each time it is used - (1) prewash rinse (2) wash using chlorinated detergent and brushing (3) acid rinse (4) hang up to dry. By my observation the last person using the tube feeder at best rinsed it out and hung it up to drain.

In a perfect world the last person using the equipment would have followed the cleaning protocol. In this imperfect world the not-so-clean tube feeder was just filled with colostrum and the calf fed. 

Compromise? It seemed clear to me that this worker did not have time to stop and wash the tube feeder before feeding colostrum. But, a quick pre-use sanitizing rinse would have started this process right.

(1) Fill tube feeder with hot water.
(2) Add roughly a tablespoon of household bleach.
(3) Tip and turn the bag to expose all the surfaces to the hot bleach solution.
(4) Drain out through the esophageal tube.

This is a workable compromise. Not good, but better than nothing. 

Just a note on water temperature. Recall that the sanitizing process depends on exposure time, concentration of the sanitizer and solution temperature. If the pre-use sanitizing must be done quickly (for example, 15 seconds) increase the amount of bleach used and increase the water temperature. By increasing water temperature from about 100F to 140F the time needed for bacteria kill drops to approximately one-quarter.

Reference:  accessed 6/20/14.

Sunday, June 22, 2014

Feed Warm Milk

I watched the calf care person feeding milk on a chilly June morning.

He started with the youngest calf. Back and forth he went from row to row - 120 calves total.

Then he came back to check the youngest calves. Of the ten youngest calves only five of them had drunk their milk. He got inside the wire pen and hand-fed each of the five calves - maybe I should say he worked at bucket training them.

I could reach these pails from outside the pens. So I used my rapid-read thermometer to check temperatures. The readings for these five pails of milk were between 70 and 75F. Recall that the body temperature of these young calves is right round 102F. So, why feed milk that is about thirty degrees colder than the calf?  Because that is just the way things work out - the milk he put into their buckets chilled down while he was feeding the rest of the calves. 

I suggested an alternative approach. Remember that he does not know from feeding to feeding how many of these youngest calves are and are not going to drink out of the pail by themselves.

We agreed that the largest number of calves that do not drink out of their pail by themselves is seldom more than eight - more often four or five. 

I proposed that he routinely fill eight bottles with milk. Put on nipples and set them (4 to each five-gallon pail) into pails filled with warm water. Drop them off at the location of the youngest calves as he starts to feed milk. Just leave them there until he completes milk feeding.

Then, when he returns to the youngest calves dump one bottle of warm milk at a time into a milk-feeding pail. If she drinks fine. If she needs assistance help her then before dumping more bottles.

The idea is to leave the bottles in the warm water until each calf is ready to drink either from the bottle or be bucket-trained. At another dairy a second person is available to work individually with the youngest calves. This  4-bottles-in-a-bucket approach works well here, too. They use four five-gallon pails with sixteen bottles.

Of course, in winter weather the water in the five-gallon pails needs to be much warmer than in June. 

Friday, June 20, 2014

Calf Care Done Right

Yet again I was drawn into a discussion yesterday with two persons who had very little knowledge about dairy and especially about caring for calves. I attempted to explain the how and why of calf care in 50 words or less - the elevator-style talk.

That experience made me remember writing a Calving Ease issue about how the attitude of the calf care person makes a difference in rearing calves. Since this was a long time ago I am pretty sure you cannot recall this March 2003 issue - it is printed below. Enjoy.

Calf Care and Husbandry

Imagine being seated next to a city dweller on a plane.  You nod to each other as you struggle to stow belongings in the overhead bins.  Later perhaps you are asked, “What do you do?’  “I raise calves,” you reply.  Since this draws a blank you try to explain.

Provide care to meet basic survival needs

Depending on how one defines jobs there are somewhere between thirty and fifty different jobs involved in meeting the basic survival needs of dairy replacement heifer calves. It won’t work trying to describe all of these to your seatmate from Chicago or LA.

Maybe he/she would understand if you keep things rather general.  “I feed them and take care of their housing.  If they get sick I treat them to help them get better.”  That makes it sound super simple. But we all know that raising calves just doesn’t work that way.

Maybe a compromise between too simple and too detailed is needed.  So, you describe how they live in little condo’s by themselves at first in order to prevent the spread of diseases.  How this housing is kept clean and dry. You describe how your calves are fed twice a day.  And, maybe you explain how calves start out consuming just milk and then grow into eating grain.  How they mature into forage eating ruminants.

You part at the airport with a friendly wave.  Reflecting on how you described your work, however, you have a sense of having missed something.  What you told your seatmate was accurate.  But, did you overlook an aspect of calf care that’s really important? Don’t you do more than just provide care that meets basic survival needs?

Calf care within the context of animal husbandry

As a job calf care can be done very mechanically. Not many interactions have to take place between the caregiver and the calves. Toss bedding into their pens.  Put feed in front of them at regular intervals.  That’s it. But, we know that this mechanistic approach does not work well.  Too many calves get sick, too many calves die. 

Or, quality calf care can be done within the context of good animal husbandry.  This implies frequent and regular interaction between the caregiver and the calves. In a world very sensitive to biosecurity and disease transmission this interaction should not be interpreted as necessarily “touchy–feely” behavior. This person-animal relationship grows out of many small interactions.  A calf responds to the familiar voice.  Feeding time sounds bring the calf to the front of her pen or out of her hutch.  We scold a calf when she gets her nose in the way as we try to feed milk.

All these small connections we make with calves provide us with a picture of what’s normal behavior.  Very large calf enterprises try to retain this connection by scheduling the same persons to take care of certain calves day after day.  This is in contrast to randomly assigning workers to any group of calves. This image of “normal” is an essential ingredient in providing quality calf care in the context of good animal husbandry.

Whether or not we respond to the opportunity daily care gives us to build connections with our calves depends heavily upon our attitudes about calves. Most workers that I have observed that have indifferent or negative feelings about calves do not seem to use these opportunities.  The chances are there to build these “normal” pictures of calf behavior but these calfcare providers aren’t interested. 

Those of us who genuinely like to care for calves take advantage of our work routines to “get to know” our charges.  Not that we are saints.  We all have busy days that stress us out.  On those days we just manage to get calfcare done. Period.

But, in general, we talk to calves, we watch them, we mentally record behaviors that are a little out of line.  We see calves as whole animals.  We know what they should sound like, look like and how they should behave.  Things that are out of line catch our attention.  And we enjoy this human/animal interaction.

How would you have described to your urban seatmate calfcare within the context of good animal husbandry?  Would it have been primarily in terms of behaviors or actions?  Or, would it have been primarily in terms of attitude and feelings?  It’s not as easy to talk about feelings as it is actions.   I am convinced, however, that good animal husbandry practices in calf rearing are associated with positive attitudes about one’s calves. Much of the difference between average and excellent calfcare is consistent and uniform attention to details.  Calfcare persons that have negative feelings about calves seldom have the motivation to attend to all these details.

And, even the calves have this figured out.  They know the difference between positive caregivers and those that just plain don’t like working with calves. 

Our challenge

To recruit, train and retain calfcare persons with positive attitudes toward calves that will provide excellent care within the context of good animal husbandry. That’s our challenge! 

Wednesday, June 18, 2014

Adding Bacteria to Pasteurized Milk

Adding bacteria to pasteurized milk? Yep! Technically, we call this post-pasteurization contamination.

"No," you say. "Why would anyone do that?"

A quick case study. A couple of  years ago I was on a large dairy in China. All the young calves had diarrhea. The dairy had its own lab and could do bacteria counts on colostrum and milk. 

We sampled "as-fed" colostrum, raw milk, milk directly from the pasteurizer and "as-fed" pasteurized milk.

1. Colostrum - fair results, most samples had coliform counts under 5,000cfu/ml and total plate counts in the 25,000 - 35,000cfu/ml range.

2. Raw milk - all under 200,000cfu/ml - that's acceptable for milk going into a pasteurizer.

3. Milk from pasteurizer outlet - all samples under 1,000cfu/ml.

4. "As-fed" pasteurized milk - all samples over 5,000cfu/ml coliforms with total plate counts in the 100,000's.

Ooooops! Clean coming out of the pasteurizer but badly contaminated in the pail for the calf to drink? Not good. 

Culprits?  All the usual suspects.
A. Hose between pasteurizer and transport tank - it was not part of the wash cycle at any time. It turned out to be full of slime. Solution #1 - replace hose. Solution #2 - install a couple of fittings in the pasteurizer plumbing so that when the pasteurizer was washed this hose was also cleaned. 

B. Bottom and sides of the transport tank were spotless - shiny clean. By leaning into the tank I could run my fingers along the underside of the tank top. Ugh! The energetic worker cleaned what she could see - unfortunately neglecting about 1/3 of the tank surface - the upper invisible part.

C. Feeding pails. The dairy had between 900 and 1,000 calves on milk. They had 200 metal feeding pails that were washed between each feeding. So, the first 200 calves got a clean pail, the next 200 calves used a pail that had been use once, and so on. 

A sterile-water rinse sample from a "clean" pail grew a huge crop of bacteria - mostly Staph and Strep species. Problem? Wash protocol needed to be tuned up. They ran one huge sink of lukewarm water, added lots of detergent and all 200 pails were washed in this water (no pre-wash rinsing so lots of milk ended up in this water. The water started out about 100F). 

The end result of this wash routine was a biofilm on the pails that supported extensive bacteria populations. We changed the routine to:
1. pre-wash rinse with lukewarm water
2. wash in hot chlorinated solution with detergent with lots of brushing - they used chemicals from the milking parlor - we made a little float with a piece of styrofoam and stuck a rapid read thermometer in it to monitor wash water temperature - they just added 180F water as needed to keep temperature around 130F.
3. Using parlor wash acid do a post-wash rinse and then set upside down to dry on rolling racks in the utility room. 

I just received an e-mail from this dairy manager. He says they are continuing to monitor raw, pasteurized and "as-fed" milk. Results are well below the thresholds we set when I was at the farm. Along with a good colostrum management program and a coccidiosis control program this milk feeding program is producing healthier calves than before the improvements were adopted.

So, it really is not difficult to add bacteria to pasteurized milk. One must be quite diligent to avoid post-pasteurization contamination.

Best of luck with your calves. 
Pooling Colostrum

Standing behind the rotary milking unit I watched a milker shove the partly full milker bucket from one milking stall to the next. He proceeded to milk a second fresh cow into the milker bucket. This is pooling colostrum. Since the average amount of colostrum for Holstein cows is about twenty-five pounds (three gallons) there is plenty of space in the big plastic 80 pound milker buckets for at least two cows.

Where else does pooling happen? Some farms mix fresh colostrum with a supply held in a refrigerator - dump the warm into the cold. Or, dump colostrum from all the fresh cows milked at one time into a series of five-gallon pails.

Less time when milking: Just slide the 80-pound milker can over to the next cow and keep milking. Or, even when milking into a separate milker bucket it's quicker just to dump the contents into a common five-gallon plastic pail than into separate buckets. 

Not as many buckets and pails to clean. And, no testing and record keeping - colostrum is just colostrum.


One best colostrum management practice is to assess the concentration of antibodies before feeding. This allows the calf care person to feed the highest quality colostrum available as the first feeding for heifer calves. Reliable on-farm technology for quality assessment is available both as a Colostrometer (click HERE for colostrometer resource) and Brix refractometer (click HERE for Brix resource). 

If you do not maintain separate lots of colostrum at least until it is quality tested there is no way to sort out the best to feed first. In a national (USA) study of colostrum quality approximately thirty percent of the samples were below the recognized threshold for acceptable concentration of antibodies for feeding newborn calves. [Morrill, et al. "Nationwide evaluation of quality and composition of colostrum on dairy farms in the United States" Journal of Dairy Science, 95: 3997-4005 July 2012] 

So, poor quality colostrum does exist. Heifers had lower quality colostrum compared to second lactation and greater cows. Dairies that test colostrum have a much higher potential for passive transfer success compared to dairies that do not test and pool colostrum. 

The dairy where I observed the milking with the rotary unit routinely collects fecal samples from all cows at dryoff. Thus, Johnes status of fresh cows is know for all cows and their colostrum is discarded.

But, what if not testing is done? And, colostrum is pooled? Then if a heavy shedding cow's colostrum is pooled with colostrum from other cows many calves can be exposed to the Johnes organism. Each dairy has to assess the level of risk and decide if pooling is acceptable.

Monday, June 16, 2014

Giardia, Yet Again

Yet another herd with Giardia diagnosed in calves. For a quick review on Giardia click HERE.

In this case the origin of the problem was not clear at first. No change had taken place in any routines for the preweaned calves. None of them appeared to have diarrhea associated with a Giardia infection. 

But, calves in the transition barn had persistent scours. Checking out coccidiostat in the feed and rate of consumption did not reveal an mistakes.

A comment by an employee about changing the water supply was a significant clue. Each year in June the drinking water supply for this barn is switched from wells to a pond. This change lowers the chances of the wells not being able to supply enough water for the parlor and other critical needs. 

Previous years have not been an issue for transition calf health. Somehow this year the pond has become contaminated with Giardia. Laboratory results turned up the parasite in both the pond water and feces of infected heifers.

Thus, it is a good idea to keep this troublesome parasite in mind when control measures for coccidiosis fail to halt the persistent diarrhea problems in heifers. 

Wednesday, June 11, 2014

June issue of Calving Ease Newsletter
"Feeding More Without Scours"

We just posted the latest issue of the monthly issues of the newsletter for calf care persons on the website.

To go directly to the June issue click HERE.

The key takehome points (more detail in the newsletter):
·         Before increasing milk feeding rates know your current scours treatment rate.
·         If it is 20 percent or more during the first 4 weeks of life take remedial measures to decrease your treatment rate before increasing feeding rates.
·         There are 10 common differences between dairies that either do or do not have scours problems when feeding rates are increased.
·         Plan for success – put your dairy in the “Low Scours Rate” column before increasing your milk feeding rate.