Wednesday, October 16, 2013

Practical Ways to Chill Colostrum
One way to reduce the frequency of scours among young calves is to feed clean colostrum. As a best management practice we want to feed colostrum before bacteria in it can multiply - a practical goal is within one-half hour after it is collected.
However,  many times we do not feed colostrum this quickly. Therefore, we are interested in chilling colostrum because the closer we get to 40F (compared to 100F out of the cow) any bacteria in the colostrum grow more slowly.
I took a picture of this dedicated colostrum chiller at a large dairy. Yes, it was custom made just for chilling colostrum. Works great but a bit on the expensive side.

More practical methods? Here are three on-farm ideas.

This farm chose to pour freshly-harvested colostrum into 2-quart pitchers purchased at Wal-Mart. The white ones shown in the picture were used for colostrum that tested the highest with a Colostrometer. Not shown are the blue pitchers used for the lower quality colostrum. As long as ice is floating in the water this method will chill colostrum from about 100F to 60F in 30 minutes.

This farm chose to wash 1-gallon plastic jugs. They were filled with about 3.5 gallons of water and frozen. As colostrum was collected it was poured into clean 5-gallon pails (about 3 gallons) and a jug of ice added. When ice is added at the ratio of 1 part ice:4 parts colostrum the colostrum will chill from about 100F to 60F in 30 minutes. This dairy has several used refrigerators so this pail went directly into one of them after a lid was added.

Many dairies that use this method of "bottles-in-colostrum" choose to freeze 1 or 2-liter soft-drink bottles rather than 1-gallon jugs. As long as the 1:4 ratio of ice-to-colostrum is followed chilling to 60F within 30 minutes will happen.

This dairy purchased a used ice machine at a restaurant auction. Using plastic tubs that were purchased in a size to fit into their second-hand refrigerator, they bottled off colostrum as it was collected. Bottles go into the tub, ice and some water are added and the whole tub goes into the refrigerator. There is a lid at the left in the picture so that tubs can be stacked if necessary.

Note the blue nitrile gloves over the nipples - after they test the colostrum for antibody concentration the bottles containing the lower quality colostrum get blue gloves and the higher quality ones get white gloves.

Do you have another idea that you would like to share? Just contact me a or write a comment at this Blog.

Tuesday, October 15, 2013

How long does it take to chill colostrum in a refrigerator?
Why are we interested in chilling colostrum? We know that the time required for bacteria in colostrum to double (generation time) increases as temperature decreases. Thus, one simple way to reduce bacteria counts in stored colostrum is to chill it from cow body temperature (slightly over 100F) to typical refrigerator temperature (around 40F).

 Estimated generation times for coliform bacteria in colostrum are:
 20 minutes @ 100F, 
150 minutes @ 60F, 
12 hours @ 50F and 
greater than 24 hours @ 40F.

Using two used refrigerators in good working condition in the garage of our vet clinic during August I set them up with temperature sensors and data loggers. I chose to load them with selected volumes of colostrum in different kinds of containers at either 90F or 60F. 

So, how long does it take to chill colostrum to 40F in a refrigerator?

1. How warm is the colostrum when it goes into the refrigerator?

If we load 10 2Qt. nursing bottles at 90F they will arrive at 40F in about 24 hours!
If we load 10 2Qt. nursing bottles at 60F they will arrive at 40F in about 13 hours.

2. How much colostrum goes into the refrigerator at one time?

Assuming the colostrum starts at 90F in 2Qt. nursing bottles the time to 40F looks like this:
     Bottles  Gallons  Hours           Hours to Chill
                                 to 40F          to 40F if start at 60F
          2          1          10.7                    7.4
          4          2          16.0                    9.9
          6          3          18.9                   11.7
          8          4          21.2                   13.1
          10        5          23.7                   13.2  (80% reduction in chilling time)

My chilling times for bottles were measured with the bottles all pushed together as they are typically in an on-farm refrigerator.

3. What size container is used for the colostrum?

I used 5-gallon pails, 1-gallon bottles and 2-quart nursing bottles. Chilling times for all containers were very similar with a trend to slightly more rapid chilling (in 5-gallon lots) in smaller containers. Container size has only a marginal effect on chilling rate in this situation.

Bottom Line for low-bacteria count stored colostrum
  • Start with a low inoculation level - clean
  • Chill rapidly (no more than 30 minutes) to 60F before refrigerating or freezing.

Monday, October 14, 2013

Shock Loading Refrigerators
You are in a dairy utility room. A worker comes in with five gallons of colostrum fresh from the milking parlor. Open door of refrigerator, in goes the colostrum, close door of refrigerator. 

Question: What will happen inside the refrigerator during the next hour? Using two used refrigerators in good working condition I collected interior temperatures under selected loading conditions. I chose nursing bottles and a 5-gallon pail as containers. We chose loading volumes of three, four and five gallons of 90F colostrum. The data look like this:

                          Peak Interior Temperature of Refrigerator (F)
                                 Type of Container
                            5 Gallon        2Qt Nursing
                            Pail                Bottles
Volume     3         44.7               50.4
(Gallons)  4         47.5               54.6
                 5         48.3               59.4   
The interior temperature before opening the door to load the colostrum was approximately 34F. It is easy to see as the load volume increased the peak interior temperature inside the refrigerator went up.
Not so easy to anticipate is the significantly higher peak temperatures for colostrum stored in nursing bottles compared to the single  5-gallon pail. I placed all the bottles in the middle of the space pressed tightly against each other - in a cluster of 6, 8 or 10 bottles depending on the load volume.

On one hand, even if you follow similar "shock-loading" practices this probably will not ruin someone's lunch. On the other hand, if you have  temperature-sensitive products stored in this same refrigerator "yo-yo"ing up to around 60F once or twice a day may not be a best management practice.

By the way, when colostrum is chilled to 60F before loading, refrigerator interior temperatures do not follow this pattern.


Thursday, October 10, 2013

What happens when you feed milk more frequently in an accelerated feeding program for dairy calves?
The basic study design was to feed milk at the same rate to calves with three different feeding frequencies - twice, three time and four times a day. The feeding rates started at 4 qts/day for 14days, 7 qts/day for days 15-21 and 8 qts/day for days 22 up to 1 week before weaning at which time calves received 4 qts/day once a day for a week.
So, remember that all the calves received the same amount of milk in this accelerated or intensive feeding program. Only thing that varied was the frequency of feeding. 
No differences in calf health were reported. Starter intake was reported to be the same regardless of milk feeding frequency.

Rates of gain were by frequency of milk feeding:

2X = 730g or 1.6pounds/day   (56day total = 90.0 pounds gain)
3X = 760g or 1.67pounds/day  (56day total = 93.7 pounds gain)
4X = 790g or 1.74pounds/day  (56day total = 97.4 pounds gain)

All of these are very respectable rates of gain. A tough question is the cost effectiveness of 4X vs 2X feeding. What was the extra labor cost of 4X vs. 2X? What value do we assign to the extra 7 pounds of body weight at the end of the milk feeding program?

Any ideas from BLOG readers? 

McCullough, S. A. and Others, "Effect of milk feeding frequency and weaning age on growth and intake of dairy calves" JDS 91:E-Suppl, p221, #256 2013

Wednesday, October 9, 2013

Cold Weather and Concrete
We all know how calves in a group pen like to lie next to something - a wall, a straw bale, a gate.
What if the wall is concrete? What if the wall if much colder than the calf?
  This picture was taken during warm weather. Note the calves lying along the wall in the background.
Now, fast forward to winter weather. This wall temperature will drop below freezing. Three changes will keep calves from being chilled along this wall.
1. Calf blankets will be put on calves as they go into the pen and remain on until around five weeks of age. 
2. A series of small square bales of straw will be added to line the concrete wall. Thus, calves will continue to lie along the rear of the pen but will be forced away from the cold concrete.
3. Long straw will be added on top of the wood shavings to promote "nesting."
Do give some thought to where calves lie down and the potential for losing body heat into adjacent building structures. 

Tuesday, October 8, 2013

Pasture Conversations
I have been reading articles in what is for me a new website, On Click HERE to go to their "About" page.
You will find a variety of resources - the publication is trying to translate research and experience "into grazing practices they can use right now."

In their words, "So that’s what you’ll get from us: the best ideas and research, from the people who’ve been successful doing them, documented so you know they work, and translated into steps that you can start using right away."
If you have an interest in grazing dairy cattle I suggest you take a look at this resource.

Friday, October 4, 2013

We Soak our Bottles and Tube Feeder
"We don't have to wash our bottles and tube feeder because we soak them every week."
This comment was meant to excuse the calf care person from washing bottles and tube feeder after every use. She "rinses" her equipment after each use in hot water during the week. At the end of the week all this stuff goes into this sink to "soak clean."


She uses enough household bleach to create a 500 parts per million(ppm) concentration of the sodium hypochlorite ingredient. See Bleach Dilution Table.
Two problems here:
1. Not washing after each use allows the build up of biofilms on the inside surfaces of both bottles and tube feeder. Once these begin to coat these surfaces the effectiveness of bleach for killing bacteria drops dramatically. If you can either see or remove with a fingernail the biofilm from a surface the chances of killing bacteria with soaking is not much over zero. For more than you want to know about biofilms click on this: Biofilm
2. The standard ppm for soaking (see bleach dilution table) is  2,000, not 500. This assumes that the equipment does not have a significant biofilm.
My best bet for solving her "persistent scours problem" in this sanitation situation? Just bite the bullet and wash all the equipment after every use. Click HERE for an effective washing protocol.

Thursday, October 3, 2013

Whole Milk vs. Milk Replacer for Calves
Today I was asked about feeding whole milk to calves rather than milk replacer.
Here is the situation. The owner buys cheap bull calves at a sale barn. He has been feeding milk replacer. Last week a nearby dairy offered him waste milk free - just come get it. His question was essentially, "Would feeding whole milk be better for the calves than milk replacer [he was feeding 20-20]?"
I explained that as an energy source waste milk at roughly 4.0 percent fat is substantially higher in energy than his 20-20 milk replacer. In fact the waste milk is likely 50 percent higher in energy!
However, on the downside, waste milk can be quite variable in both composition and dry matter. That is, dry matter on just the one farm could easily vary from 11 to 15 percent solids. This fluctuation can encourage scours in calves compared to a fixed dry matter percentage. How much of a risk? Probably low but present. 
Protein and fat levels can go up and down, too. This may be less of an issue given these levels are higher than the milk replacer he is presently feeding. 
I recommended that on several different days he get samples of the milk that is being offered. Freeze them and get them to a lab to be cultured for bacteria. Coming out of the cows the bacteria levels are likely to be acceptable for feeding calves. But, depending on post-collection handling, waste milk bacteria counts often approach 1,000,000 cfu/ml - very, very high and unacceptable for feeding calves. 
I have to admit that I did not get information from him about the bacteria counts of the "as-fed" milk replacer on his operation. I hope this was not too great an omission. 

Wednesday, October 2, 2013

EZ Nursing Bottle with a Peach Teat
A client called yesterday. They use the 3-quart nursing bottles sold by Milk Specialties with the name "Advance E-Z Nurse." These bottles work well with their bottle holders. However, they wanted to take advantage of Peach Teat technology. If you are unfamiliar with Peach Teat technology click Peach Teat .

Our in-house problem solver came up with this solution. This is a picture of the original equipment - 3-quart E-Z Nurse bottle, white screw ring and nipple.

He removed the screw ring and sat the nipple on a wooden cutting board. Using a very sharp utility knife he separated the nipple from its base. The cut was as vertical as he could make it.
The opening in the ring is close to the diameter of the retaining collar on a Peach Teat. Thus he could snap the ring and Peach Teat together. 
All that remained was to attach the modified nipple assembly to the bottle with the white screw ring.
  We have another satisfied client.
I advised the client to monitor this assembly for milk residue buildup where the two parts come together. That appears to be the only weak point in this innovative adaptation.

Tuesday, October 1, 2013

Automatic Feeder Cannot Solving Building Problems
Calves on this farm were being fed with gang feeders - six nipples on each one with no internal dividers. Two feeders per pen of ten calves were filled twice daily with 3 liters of milk replacer per calf.
The calves were not gaining well, scours treatment rate was acceptable but the treatment rate for pneumonia was over fifty percent during the eight weeks the calves were in this pen. 
In order to improve the situation the automatic feeder was installed. The high pneumonia treatment rate continued as well as the low growth rates.
Look at the picture again. Don't look at the feeder. Look in the background. Barn has concrete/stone walls about 10-12 inches thick. There are eight windows on the far side that only open 1/2 way. No openings on the side behind us other than the door that can be left open. Ends of the building are solid. No mechanical ventilation. 
What are the chances that changing the feeding practice in a poorly ventilated building is going to solve respiratory illness problems? Would you agree the answer is, "Low?"
A chart showing desired air exchange rates for selected size heifers by season may be viewed by clicking HERE .