Thursday, March 20, 2014

Saving Time Checking Colostrum
for Antibody Concentration

Here is the proposal. When we check colostrum for antibody concentration write down the value (either from Colostrometer or Brix refractometer) and the animal ID. If we assume that this animal will be consistent in her production of colostrum from lactation to lactation, then we can skip checking her colostrum in subsequent lactations - just use the number from the previous one. 

One significant problem with this time-saving procedure is the time involved in both recording and retrieving the information. In my experience both of these cow-side tests require so little time that the processes of handling the data are very likely to overwhelm any time saving running the test.

For this idea to work well then the major factor influencing the concentration of antibodies in colostrum needs to be the genetic profile of the dam. We need to rule out (1) leaking colostrum before calving and before colostrum collection, (2) variations in natural exposure to pathogens over time, (3) variations in vaccine-driven controlled exposure to pathogens, (4) variations in seasonally related dry cow exposure to daylight, (5) variations in length of interval between calving and first milking, and (6) variations in levels of heat stress of cows before calving. 

Given that all of these factors may vary for each cow my best guess is that genetics would only predict somewhere between 20 and 30 percent of the variation of antibody concentration in colostrum. 

Thus, while saving time by not having to check each cow's colostrum might some initial attractiveness the reality of dairy farm operations suggest that this could be an elusive goal.

However, if anyone knows of one or more dairies that consistently record colostrum quality values and animal ID's it would be instructive to use these data to put some numbers to this relationship.

Wednesday, March 19, 2014

Success Feels So Good!

Put yourself in this situation. It is July, 2013. You get the results back from blood testing 9 calves for immunity. The blood serum total protein values are:
4.3
4.8
4.9
5.0
5.2
5.3
5.8
5.9
6.7

As standards for successful colostrum management I recommend 90% at 5.0 or greater and 75% at 5.5 and greater. So, in your case we find that 67% are at 5.0 and greater. And, 33% are at 5.5 and greater.

Not so good. Most of calves are being treated for scours by the time they are 10 days old. 

The dairy already has written protocols for colostrum handling and feeding. So, these were dusted off. Everyone that comes in contact with colostrum in any way was re-trained. We cultured "as-fed"samples of colostrum and bacteria counts were very low.

We did a special re-training on using tube feeders.

Yesterday, March 18th, we drew blood on 6 calves that were less than 7 days old. These are BSTP values:
5.8
6.0
6.2
6.4
6.6
7.0

Success feels so good. It really is possible to do a good job of colostrum management. Pizza for lunch today!

Tuesday, March 18, 2014

Rumen Response to Cold Water

While reading articles describing "normal" body temperature I ran across an article that investigated the effects of feeding various temperature water to calves. "Temperature change within the rumen, crop area, and rectal area when liquid of various temperatures was fed to calves." [Dracy, A. E. and A.J. Kurtenbach, Journal of Dairy Science, Vol 51, No. 11, pp 1787-1790.]

The colder the water the larger the drop in ruminal fluid temperature. That was obvious before doing the measurements. But, how large is the decrease? When about 2 quarts of 46F water was fed the rumen contents plummeted from 104F to 84F. It took about 30 minutes for these rumen contents to get back up to about 100F and a full hour to reach the original 104F.

Why so long to rebound? Well, think about what happens to microbial activity with the temperature drops 20 degrees. Activity slows a lot. When this occurs heat being generated by microbial fermentation goes down. Thus, rather than warming from the inside (microbial fermentation) the contents have to draw heat from the body core.

As the calf recovers from this temperature shock the rumen fermentation will pick up speed and get back to normal. However, we did divert energy from growth with this cold water and we sacrificed roughly 10 to-15 percent of her fermentation time to the recovery phase [time estimate mine, not from research].

The authors also investigated the effects of volume on temperature shock. Using 63F water they fed various volumes ranging from 1.8 quarts to 3.5 quarts (these are about 8 week-old calves not yet weaned).  The smaller volume of water depressed rumen temperature to about 92F compared to the larger amount pushing rumen contents temperature to 87F. These may be compared to normal rumen temperature of these calves of 104F. 

Another research team followed a similar water feeding protocol with lactating cows. When fed 46F water the rumen temperature drop was about 15 degrees, when fed  94F water the same drop was only 4 degrees. The animals drinking the 46F water took about 2 hours to get back to "normal" temperature for rumen contents. [Bewley, J.M et al., "Impact of water intake temperature on reticular temperatures of lactating dairy cows." Journal of Dairy Science vol 91, pp 3880-3887.]

The point of all this discussion is our management decision about what temperature water to feed calves, especially those old enough to have significant rumen microbial fermentation. The closer the water temperature is to calf body temperature the less the negative consequences for rumen fermentation.

And, based on my observations, calves like to drink warm water better than cold water so they drink more. The more water they drink, usually the more calf starter grain they will consume. 

Sunday, March 16, 2014

Persistent Post-Pasteurization 
Contamination

The dairy houses calves in individual pens and feeds pasteurized milk twice daily in pails at the front of the pens. The results just came back from the laboratory. Post-pasteurization bacteria contamination levels are down in milk being fed to calves. Good job. 

We changed the transport tank wash routine using hotter water so that the discharge water is over 120F. The transport tank, pump, hoses and nozzle now wash in a cycle for 10 minutes - after the transport tank is loaded with the hot detergent solution the feeding pump is turned on and the nozzle is propped open and stuck into the hatch opening at the top of the transport tank. Bacteria counts in milk being fed to calves dropped from  200,000cfu/ml to 2,000cfu/ml. That is great.

They are still at 2,000cfu/ml Klebsiella bacteria. And we are feeding 6 quarts of this per day to calves less than a week old. Let's see - 6 quarts is about 5,700ml. If I multiply 2,000cfu/ml times 5,700 ml I get 11,400,000 Klebsiellaa bacteria fed daily. Not so great.

Milk coming from the pasteurizer grows nothing - nada - zip. Why the persistent contamination  being fed to calves?

So, what are the suspected sources of post-pasteurization contamination now?

First, I discovered that the 24 inch hatch at the top of the transport tank was being left open after the tank was washed. That is correct. Left wide open for somewhere between 9 and 13 hours between uses. Well, how clean in the air in a shed connected to a barn full of adult cows?

What would if find it I took a blood agar plate into this barn, lifted off the lid and set it down for 5 minutes? When incubated properly this plate would grow a great crop of bacteria. Cow barn air is loaded with bacteria. Recommendation? Keep the lid closed after the tank is washed.

Second, I checked to see if my recommendation about tearing down the plumbing had been accepted. No. The plumbing for this transport tank, hoses and feeding nozzle are all galvanized steel fittings - no stainless steel anywhere. Everything screws into the next piece. Guess what we will find when we tear this down? A ring of tan residue (biofilm loaded with bacteria) where every fitting screws into the next one.

Short term stop gap action (not including tearing everything apart which will be a big job) is to add a sanitizing step.  This is done just before filling the transport tank with pasteurized milk. Plenty of 170F water, enough chlorine sanitizer to get the chlorine level up to about 500ppm and let it circulate for about 5 minutes. Remember that bacteria kill with a sanitizer is directly related to temperature, concentration of oxidizing agent and duration of exposure.

Well, we are scheduled to collect two sets of milk samples at the end of next week (we collect from the same batch raw, pasteurized, first calf fed and last calf fed samples) from AM and PM feedings. Maybe these coliform counts will be lower.


Friday, March 14, 2014

Just a Reminder!



Registration is now open for the Dairy Calf and Heifer Association annual conference, to be held April 1-3, 2014 at the Hyatt on Main in Green Bay, Wis.


Conference highlights will include: 
  • Unique speakers and a wide variety of industry experts to share research, expertise and advice on calf and heifer management.
  • Both presentations and hands-on demonstrations and tours at some of the industry's best dairy calf and heifer facilities.
  • An educational track specific for farm employees and staff.
  • Networking with other producers and industry leaders.
  • Calf and heifer-specific trade show.
  • Keynote speaker, Donald Driver - NFL superstar, Dancing with the Stars Champion and author.
  • Reception at Lambeau Field and optional behind-the-scenes tour.
Heifer raisers, dairy producers, veterinarians, nutritionists and anyone with a vested interest in raising calves is invited to attend the upcoming conference.

REGISTER TODAY! The pre-registration deadline is March 17.

Register by visiting www.calfandheifer.org or calling 855-400-DCHA (3242). Sponsorship opportunities are also available for this can't miss event.


Additional information can be found online at www.calfandheifer.org. For the complete conference agenda and brochure, click here.  Ju

Monday, March 10, 2014

Diagnosis Bias

"We tend to accept the diagnosis of a problem that fits our set of favorite solutions even when better alternatives are present."

In a short article entitled "Why Good Thoughts Block Better Ones" in the March issue of Scientific American M. Bilalic and P. McLeod talk about "confirmation bias."

They describe "the human brain's dogged tendency to stick with a familiar solution to a problem - the one that first comes to mind - and to ignore alternatives." 

Admitting that this thinking can be very useful, they describe the situation of a person peeling garlic. "Once you have hit on a successful method ... there is no point in trying an array of different techniques every time you need to peel garlic."

They caution us saying, "The trouble with this cognitive shortcut, however, is that it sometimes blinds people to more efficient or appropriate solutions than the ones they already know."

Can we learn to reduce our tendency to slip into confirmation bias? They say that the more expertise on has in their field ... the more immune they are to [confirmation] bias.

Bilalic and McLeod caution us saying, "But no one is completely impervious." Continuing, they say, "Remember that if you already think you know the answer, you will not judge the evidence objectively. Instead you will notice evidence that supports the opinion you already hold, evaluate it as stronger than it really is and find it more memorable than evidence that does not support your view."

I am constantly challenged to be objective. To use measurable outcomes in evaluating the success of a calf enterprise: mortality, morbidity, growth rates. To use quantified measures for assessing the quality of inputs - bacteria plate counts, temperatures, parts per million, hours, weights. Even then, in the back of my mind I need to maintain a little nagging thought, "How else might this [whatever is not good] be explained."

If you want to have fun and can pronounce German, this confirmation bias has the technical name, Einstellung effect.

Merium Bilalic and Peter McLeod, "Why good thoughts block better ones." Scientific American Vol 310:No. 3, pp75-79, March, 2014.

Saturday, March 8, 2014

Materials for Calf Pens

I was looking up information on biofilms today and found an article published in 2002 entitled "Biosecurity for neonatal gastrointestinal diseases."
Barrington, George M., et al. "Biosecurity for neonatal gastrointestinal diseases." The Veterinary Clinics: Food Animal Practice, Vol. 18, No. 1 pp 7-34.
Authors comment on the characteristics of pen surfaces and how they influence the success or failure of various disinfection procedures. Their examples compare unfinished plywood, varnished plywood and plastic.

"Unfinished plywood retains 15-fold more microorganisms than varnished plywood, which supports 15-fold more microorganisms than plastic surfaces." p 11.

Unless I am in error, to compare the microorganism retention rate difference between unfinished plywood (very common pen construction) and plastic I multiply 15 and 15. That comes to 225 times greater microorganism retention on unfinished plywood compared to plastic.

Is it any wonder that when I see pens made of unfinished plywood I am pretty certain that environmental pathogen exposure for newborn calves has the potential to be sky high? 

Then to make "un-good" matters even worse, most unfinished plywood pens are cleaned by simply scraping off lumps of feces. In contrast many plastic or fiberglass pen surfaces are pressure washed with a high-temperature pressure washer (over 160 degrees).

Faced with selecting solid pen surfaces for young dairy calves the less porous surface should always be preferred based on pathogen control.

Thursday, March 6, 2014

March Calving Ease Newsletter
Hot off the press

Buying and Using Household Bleach

Click HERE to connect to the letter. Enjoy!

Previous issues of the newsletter may be accessed at www.atticacows.com by clicking on Calving Ease.
When Vaccines Don't Seem to Make a Difference
A research project recently reported that vaccinations in young calves did not change rates of sickness, death and growth among vaccinated vs. non-vaccinated calves. On the surface one might conclude that vaccinating young calves is a poor risk management practice.
Let's dig a little into the research design to see if that is the appropriate conclusion. For the research report click HERE .
First, 89 percent of the 2,874 calves in the study had successful passive transfer of immunity using 5.2 g/dL threshold. Thus, protection from colostrum against respiratory disease was quite high. 
Second, the research design had four treatments: (1) control - injected with neutral liquid at 2 and 5 weeks, (2) treatment 1 = vaccinated at 2 weeks only, (3) treatment 2 = vaccinated at 5 weeks only, and (4) vaccinated at both 2 and 5 weeks. This design means that 72 percent of the calves on each farm were vaccinated.
Herd immunity (or community immunity) describes a form of immunity that occurs when the vaccination of a significant portion of a population (or herd) provides a measure of protection for individuals who have not developed immunity.[1] Herd immunity theory proposes that, in contagious diseases that are transmitted from individual to individual, chains of infection are likely to be disrupted when large numbers of a population are immune or less susceptible to the disease. The greater the proportion of individuals who are resistant, the smaller the probability that a susceptible individual will come into contact with an infectious individual.[2][Wikipedia definition. 

Ah, so with nearly three-quarters of the population vaccinated, the chances of an un-vaccinated calf coming in contact with a sick calf was, in my opinion, drastically reduced. 

Third, 44 percent of the pneumonia cases in this population occurred before 5 weeks of age - that would be before the vaccinations were completed. Thus, vaccines still in the bottle had no chance of reducing treatment rates (average age at which first treatment occurred was 30 days). 

Fourth, overall 22 percent of the calves were treated at least once for respiratory disease. Unfortunately the report does not describe the feeding program for the calves. One might guess that regardless of vaccination status, some of these cases might have been prevented by a more generous feeding program especially among the younger calves (i.e., less than one month). 

Further, with lots more energy and protein available from a more liberal feeding program the response to vaccination might have been stronger.

Bottomline

In my opinion this study had significant flaws in its design and subsequent data analysis such that its conclusion (vaccination did not change rates of sickness, rates of growth and death) ended up being so specific to the study population its finding have limited use to the rest of us. To their credit the authors did point out that their conclusions did have limited applicability to dairy farms in general. 

Please do not take the conclusions reached by authors uncritically.  
 

Wednesday, March 5, 2014

Just Nothing Like Calves to 
Keep you Humble

I just returned home from a church service in which one finds this sentence which is said at the imposition of ashes on one's forehead:

"Remember that you are dust, and to dust you shall return." BCP p265.

I am sure unlike other worshipers my thoughts turned to all the times in my work with calves. That is both as raising my own calves and as a consultant, I thought of all the times when I have gotten cocky, thinking confidently how much I knew about rearing calves. I knew all the answers.

Then, every time this happens I confront a situation for which I have no answer. I am cut right off at the knees. "If you are so smart why don't you know how to fix this?"

All a matter of perspective. Remember you are dust, and to dust you shall return!

Monday, March 3, 2014


Antibodies in Colostrum Keep Bacteria from Growing?

I am reporting this with a straight face. Believe it or not. The dairyman tells me he doesn't worry about how he handles his colostrum. He said, "My colostrum is so high in antibodies that the bacteria won't grow in it."

I am not pulling your leg. Does he think antibodies are a disinfectant or something?

Somehow here we have a basic disconnect about antibodies. Recall that in plain terms antibodies identify and neutralize objects that are foreign to calves bodies such as bacteria and viruses.That's their job in the immune system. As such they do keep bacteria from multiplying inside the body of a calf.

I suppose that might be where this person got the idea that antibodies keep bacteria from growing. The part he missed entirely is that antibodies are part of the body's immune system - they work inside calves, not in pails of colostrum.

Maybe I will be inspired in the next week or two and come up with some very clear way to explain how antibodies work so even this guy will understand that he really does need to follow best management practices when handling his colostrum to control bacteria contamination levels. 


Saturday, March 1, 2014

Bacteria Win Again

You start with a large, well-run dairy. Pool all the colostrum every day. Separate this into four batches each day.
#1 - batch heat-treatment at 140F for 60 minutes
#2 - heat-treatment in Perfect-Udder bags at 140F for 60 minutes
#3 - freeze fresh in same bags
#4 - refrigerate fresh in same bags

Then, get the colostrum ready to feed the calves (bring to calf body temperature) and take "as-fed" samples.
Culture the samples for bacteria to get (a) total plate count and (b) coliform count.

Average total plate counts (colony forming units/ml)

#1 batch heat-treated             4,000cfu/ml
#2 bag heat-treated               16,000cfu/ml
[Anything under 50,000cfu/ml is considered okay for feeding newborn calves.]

#3 Raw frozen/thawed bag     around 500,000cfu/ml (bacteria soup)
#4 Raw refrigerated bag         over 3,000,000cfu/ml (bacteria soup)

Average coliform counts

#1 batch heat-treated                13
#2 bag heat-treated                     3
[Anything under 5,000cfu/ml is considered okay for feeding newborn calves.]

#3 Raw frozen/thawed bag       6,300cfu/ml (not good)
#4 Raw refrigerated bag          63,000cfu/ml (just plain awful)

I have not corresponded with the research time but I suspect that the colostrum was not chilled promptly post-harvest. Thus, bacteria grew rapidly before the refrigerated and frozen lots got cold enough to slow down the rate of multiplication.

A.A. Kryzer, S.M. Godden and R. Schell, " Effect of feeding colostrum that was heat-treated with Perfect Udder system on passive transfer of immunoglobulin G in neonatal Jersey calves." Proceedings of American Association of Bovine Practitioners, p 171, September 2013.