Friday, September 28, 2018

Navel Dipping

In 2014 the National Animal Health Monitoring System completed a calf study involving 104 dairy operations in 13 states. This was an 18-month longitudinal study involving 2,545 heifer calves. Holstein calves made up 89% of the population. By herd size, the study included:

  • Small (30-99cows)            20%
  • Medium (100-499 cows)   32%
  • Large (500+ cows)            48%
What did they out about navel dipping? Seventy-nine percent of the enrolled calves had navels dipped. 

What happened to the other 21% of the calves?

Of the 103 operations reporting 21 of them never dipped navels. Never, nada, not at all. 

Is it profitable not to dip navels? There are good data to say, "No."

For a resource, "Dollars and Cents: Navel Dipping" click HERE.
[URL is http://atticacows.com/library/newsletters/DippingNavelsProfitR1782.pdf]

There is plenty of data to show that overall the rate of omphalitis (infected navels) is lower on dairy operations that routinely dip navels at birth. This probably based on the fact that overall most operations have calving facilities and calf housing that expose calves to high levels of bacteria - high enough to cause navel infections.

At our 1,200 cow operation almost all the calves had navels dipped in the calving pen (tincture of iodine) and then were redipped after being moved into a hutch. We had omphalitis treatment rate of well under one percent - and I did routinely check navels between 10 and 14 days to be sure we were not missing infections. 

Wednesday, September 26, 2018

Salmonella is hard to avoid

A research project was set up to to determine if pasteurization of nonsaleable waste milk influences fecal Salmonella concentrations and prevalence.

All the data came from one large dairy in southwest USA. They collected 1,117 fecal samples and found that 69% of the sample positive for Salmonella.

The percentage positive was the same for calves fed either non-pasteurized nonsaleable milk and pasteurized nonsaleable milk.

Nonsaleable milk samples were collected and cultured (6 of each pasteurized and non-pasteurized). Only one non-pasteurize sample was culture positive for Salmonella.

The authors speculate that Salmonella in the dairy environment was a plausible vector of transmission since the milk regardless of treatment was unlikely to the source of infection. 

I conclude that we must depend on control strategies other than pasteurizing our nonsaleable milk to lower our Salmonella infection rates. 

A case study of a Salmonella outbreak at a calf-raising facility highlighted two prevention:control stratgies.

(1) Monitor passive transfer immunity - in this case study calves with blood serum total protein levels less than 5.0 had twice the mortality rate as those with levels of 5.0 and higher (16% compared to 8%).

(2) "Do not depend on footbaths to kill pathogens, especially Salmonella. It was cultured from multiple footbaths on this raising unit during the outbreak."They found that "providing separate boots, clothing, and rubber gloves to be worn in each calf barn and adhering to traffic flow patterns that do not allow cross-contamination of multiple areas will likely be more effective for managing the risk associated with epidemic salmonellosis."

References: Edrington, T. S. and Others "Effect of waste milk pasteurization on fecal shedding of Salmonella in preweaned calves." Journal of Dairy Science 101:9266-9274 October 2018.
Gardner, C.E. and Others "Case Report - Management of an outbreak of salmonellosis on a commercial calf raising unit." The Bovine Practitioner 38:2 pp 147-154. June 2004.

Monday, September 24, 2018

Blood Serum Total Protein to
Evaluate Passive Transfer of Immunity

Researchers at the University of Guelph (Ontario) used a clinical refractometer with blood serum to assess passive transfer of immunity among calves delivered to a veal operation.

They had 149 Holstein calves in the population. They drew blood on arrival; samples were allowed to clot and by gravity separate the blood serum. Then a digital refractometer was used to read the blood serum total protein (BSTP).

They had a laboratory use the slower and more expensive test (radial immunodiffusion or RID) to arrive at "gold standard" values on the same blood samples - these were compared to the BSTP values.

The match between the values was good. In scientific terms, there were low levels of false negative and false positive values when RID numbers were compared with BSTP numbers. 

Thus, they confirmed once more that blood sampling during the first week of life is an effective way to monitor the overall effectiveness of the colostrum management program on a dairy. 

In an earlier report the same authors compared BSTP values for calves that died with surviving partner calves that arrive the same day from the same source. Again, calves that died had significantly lower BSTP than their partner calves that survived.  

At one of my calf-raising clients several years ago we compared BSTP for a year for calves that died and those that lived. He tested all calves at intake for BSTP. His overall rate of passive transfer failure was low - about 5% below 5.0. His mortality rate was slightly above 5%. However, we found that of the calves that died roughly 75% had passive transfer failure. Of course this was just one operation and one year so it's hard to generalize these findings to other farms. 

References: Renaud, D. L. and Others "Short Communication: Validation of methods for practically evaluating failed passive transfer of immunity in calves arriving at a veal facility." Journal of Dairy Science 101:9516-9520 October 2018.
Renaud, D.L and Others, "Clinical and metabolic indicators associated with early mortality at a milk-fed veal facility: A prospective case-control study." Journal of Dairy Science 101:2669-2678 2018.

Tuesday, September 18, 2018

Moving Calves into an Auto Feeder Pen

Everyone seems to agree that calves should only be moved into an auto feeder pen when they have a strong suckling reflex.

But, individual dairy circumstances seem to lead to a lot of variation. We know that we want calves nursing well from a bottle. After that is accomplished, how much time is available to train calves to drink from the auto nipple?

So, here are some reflections from my recent experiences.

One client moves calves in the morning when they would normally be fed by bottle. A calf care person is available to stay in the pen to be sure each calf goes into the feeding station. The idea is combine a hungry calf with an opportunity to suckle. They guess that at least half of the calves do not require even a second time being guided to the nipple - success!

Another client has their individual calf pens in the same large building as the auto feeder pens. As soon as a calf is aggressively nursing on a bottle the next feeding time she is guided to a "teaching station." This station is an extra auto feeder stall along one outside wall of the utility building. The calf is guided to the nipple, the calf care person manually triggers milk flow and, (we hope) presto, the calf nurses. As soon as the calf seems to have adopted robust nursing behavior she is moved over into the group pen that is being filled at that time. (all-in, all-out pen management) In general, nearly all calves move into the auto pens before 7 days old. However, they experience quite a wide age range in moving to the auto feeder pens with a few calves moving as early as 4 days and others taking as long a 2 weeks. As an aside, if they have a calf with severe scours she is held back in an individual pen and bottle fed along with electrolytes until she shows signs of recovery.

Based on calving rates and numbers planned per pen the length of time to fill a pen may vary very widely from dairy to dairy. One of my largest clients aims for a pen size between 15 and 20 and fills a new pen every 3 to 4 days - very narrow age range. Another much smaller dairy puts all the calves born over 2 weeks in one pen in order to limit the age range - over a year they average about 12 -15 calves per pen. Both dairies hand feed for 4 to 5 days before moving into the group pens.

Another dairy with two "all in all out" auto feeder pens has a 14-day hand feeding protocol for all calves. This protocol avoids all individual decision making - same routine for all calves. regardless of nursing readiness. The reasoning is that by 14 days most of the diarrhea episodes will have occurred in individual pens limiting transmission of disease. My observation is that most of the diarrhea is related to cryptosporidiosis (a parasite) and was going to occur regardless of the housing environment. Given that nearly all calves have scours between 7 and 10 days and on this dairy calf care personnel skills are limited, maybe it is best to use individual housing to make it easy to identify scouring calves eligible for electrolyte feeding. 

Wednesday, September 12, 2018

 Not Enough Colostrum?
Test! Adjust Feeding Volume by Quality.

On Friday, August 10th, I posted "Stretching Your Supply of High Quality Colostrum." This suggested that feeding a somewhat lower volume of high quality colostrum may give adequate levels of circulating antibodies for newborn calves. This post expands on this idea. 

Research completed this past  year at Penn State University suggests a way to make a limited supply of colostrum go farther when feeding newborn calves. Test and adjust volume?

 They divided their colostrum supply into three categories: high, medium or low. 
Measuring actual antibodies (IgG) they found these quality differences:
high         92.5 mg/ml
medium   59.4 mg/ml
low          48.0 mg/ml

They fed the calves and tested blood 24 hours later.
The blood serum total protein levels went up as colostrum quality went up - no big surprise.
high          24.8 mg/ml
medium    22.2 mg/ml
low           18.0 mg/ml

Now, of special interest, was the efficiency of absorption of the antibodies fed.
When they compared the absorption results from calves fed the medium and  high quality colostrum they found the calves had absorbed about the same amount of antibodies regardless of  the volume of antibodies fed.

The calves fed medium quality colostrum had an efficiency of absorption of 38 percent while calves fed the high quality colostrum had a lower level of efficiency - only 25 percent. 

The authors suggest that "there may be an  upper limit to amount of IgG absorption in a given time period." (p277)

Bottom Line? If colostrum supply is low, using a smaller volume (for example, 3 quarts) of high quality colostrum for first feeding may work as well as a larger volume (for example, 4 quarts) of medium quality colostrum.

Reference: Saldana, S. L. and Others, "Effects of difference heating time of high, mediumj and low quality colostrum on IgG absorption in dairy calves." Journal of Dairy Science, 101, Supplement #2, p 277 #T175, 2018.


Tuesday, September 11, 2018

Colostrum Antibody Losses Minimal when 
Heat Treated

We know that heat treating colostrum what contains bacteria will lower the bacteria count.

We know that heat treating colostrum to lower bacteria content will reduce the concentration of antibodies, specifically immunoglobulin G (IgG).

How much reduction?

Well, it depends. In this work done at Penn State University they checked to see how much reduction in both bacteria and antibodies would result from heat treating at 60C (140F) for 30 minutes and 60 minutes.

First, bacteria results. Heat treating resulted in bacteria reductions of approximately 94 % and 95% times of 30 and 60 minutes respectively. So, heat treating works.

Second, antibody losses due to heat treating. At 30 minutes the losses were 9 percent. At 60 minutes the losses were 12 percent. So, while heat treating does reduce antibody concentration the losses are within an acceptable range.

One thing to remember - heat treating will not increase the antibody concentration of colostrum - it is still true that "garbage in - garbage out" applies to colostrum and heat treating. 

Reference: Saldana, S. L. and Others, "Effects of difference heating time of high, mediumj and low quality colostrum on IgG absorption in dairy calves." Journal of Dairy Science, 101, Supplement #2, p 277 #T175, 2018.

Monday, September 10, 2018

Summary Article on Forage Feeding
for Young Calves

This short article summarizes in readable form much of the biology of rumen development among young milk-fed calves.

The link is https://extension.psu.edu/new-thoughts-old-question-should-we-feed-calves-forage 

The bottom line at the end of the article is that forage feeding rates in the range of 5 to 10 percent of total intake is a workable goal.

Depending on  the size of the calf operation on an individual dairy different methods of including forage may be needed. 

With my calves (100 on milk most of the year) I did not have an easy way to get chopped hay. If I had calves consuming around 2 to 3 pounds of textured starter per day it only took 2 ounces of hay per day to equal 5 percent. Ever try to measure 2 ounces of hay?

My solution was to put a handful of good quality second-cutting alfalfa hay in the top of their grain pail three days a week (that made it easy to feed hay on Mon, Wed and Fri). As the calves approached full weaning at 49-52 days of age (eating 5 to 6# of grain daily) I was a little more liberal with the hay. 

I did not depend on relief workers to feed hay - they consistently overfed hay by a factor of 100 to 200 percent.

When my calves moved from individual housing to group housing (5 calves per pen) I limit-fed hay the first week to what they would clean up in around 1/2 an hour per day.

Friday, September 7, 2018

Testing Colostrum for IgG's

The September calf management newsletter with this title highlights:
  • Sick calves? Feeding low quality colostrum could be contributing to the problem!
  • Make colostrum quality testing part of the dairy's SOP for colostrum management.
  • Connect test values to colostrum feeding - keep it simple.
Think about these questions:
  1. What are the chances of having low quality colostrum?
  2. How can we identify low quality colostrum?
  3. Once we  have identified low quality colostrum, how do we avoid using it for first feeding for our heifer calves? 
  4. What can we do if colostrum supplies are low?
URL is http://atticacows.com/library/newsletters/CESeptember2018.pdf or just click HERE.