Monday, April 29, 2013

Successful Passive Transfer of Immunity
I thought you might like to see what a well-organized colostrum management program can accomplish on a commercial Holstein dairy herd. Here are the blood serum total protein numbers.
Note on Blood Serum Total Protein Values:
Current visit                                                  January          October
Number of reported values = 147                   138                  114
Number of values at 4.5 or below = 4             2                      1
Number of values at 5.0 or below = 6             7                      2
Number of values below 5.5 = 19                   9                      6         
Average = 6.1                                                  6.3                   6.4
Median = 6.1                                                   6.3                   6.4

Four quarts of colostrum (greater than 50g/L - green on Colostrometer, 22 on Brix refractometer) within the first hour followed by two more quarts 12-16 hours later.

The four very low values below 4.5 were traced back to one employee who is no longer responsible for feeding newborn calves.  

Friday, April 26, 2013

 Up to 7 Days Okay for Collecting Blood for BSTP
I was just reading an article about heat stress on dams effects their calves. The short story on that is that heat-stressed dams have smaller calves and their calves absorb antibodies from colostrum less efficiently than their counterparts from non-heat-stressed dams. 
But, one of the figures jumped out at me. It reported values of total protein in calves blood by age in days. The protein values were virtually constant for the first 7 days. Thus, this is further evidence that when collecting blood for checking on how well a colostrum management program is working we can obtain reliable values from blood out to 7 days of age. 
Tao, S, APA Monteiro, IM Thompson, MJ Hayen and GE Dahl, "Effect of late-gestation maternal heat stress on growth and immune function of dairy calves." Journal of Dairy Science 95:7128-7136 (December, 2012). Figure 1 Effect of heat stress and cooling during the dry period on hematocrit and plasma total protein of neonatal calves during the first 28 days of age.
Milk Intake for Young Calves
Yesterday I came on some additional data on milk intake among young (weeks 1-3) dairy calves. Calves were fed ad lib milk either by nipple pail or automatic computer feeder. The data below are averages with the first values in US quarts and the second values in litres. Variations among calves were large.

Auto Feeder: Week 1 = 5.4 (5.1); Week 2 = 7.1 (6.7); Week 3 = 8.6 (8/1)
Nipple pail:   Week 1 = 5.3 (5.0); Week 2 = 7.3 (6.9); Week 3 = 8.8 (8.3)
Comparisons of Weeks 1, 2 and 3.
Auto Feeder: Increase from Week 1 to Week 2 = 31%; increase from Week 1 to Week 3 = 59%
Nipple pail:   Increase from Week 1 to Week 2 = 38%; increase from Week 1 to Week 3 = 66%

When given the opportunity healthy young calves will increase their milk intake rapidly in the first three weeks of life. I feel comfortable recommending that early in the first week feeding rates be increased to 5 to 6 quarts per day.

If the farm experiences significant diarrhea problems when these amounts are offered to young calves I recommend reviewing this resource: Feeding more milk without scours .

Wednesday, April 24, 2013

Antibodies not fed never end up in the blood
In a recently reported research project calves were fed maternal colostrum, plasma-derived colostrum replacer and colostrum-derived colostrum replacer. 
One factor influencing the results (maybe depressing the effectiveness of colostrum replacers) was that the colostrum replacers were fed in enough water to make 4 quarts total volume regardless of the package directions to use less water. [plasma-derived colostrum replacer recommends using 1.5 quarts water, colostrum-derived colostrum replacer recommends using 1.3 quarts.]
The amounts of antibodies fed, respectively, were 190g, 150g and 100g.
One measure of antibody passive transfer is blood serum total protein levels. They were, in the order given above, 6.1, 5.3 and 5.3. 

Another way to estimate antibody passive transfer is serum immnoglobulin type g levels (Serum Ig).
These blood (serum Ig) levels were, respectively, 2,098mg/dL, 926mg/dL and 1,139mg/dL. 
Another way to look at these results is the percentage of calves with blood serum total protein levels of 5.2 or greater. These percentages in the order given above were 92%, 29% and 49%.
Moral of the story: antibodies not fed never end up in the blood. If you are going to feed colostrum replacer plan on feeding a minimum of 200g of antibodies. This requires feeding more than one 150g or 100g package of colostrum replacer.
D. Priestley, JH Bittar, L Ibarbia, CA Risco and KN Galvao, "Effect of feeding maternal colostrum or plasma-derived or colostrum-derived replacer on passive transfer of immunity, health, and performance of preweaning heifer calves." Journal of Dairy Science 96:3247-3256. 2013. 

Tuesday, April 23, 2013

Bacteria counts in Colostrum
I received bacteria counts for three colostrum samples:
#1 Collected 4/18, fed to a heifer 4/20  Standard plate count=140cfu/ml, all fecal coliforms.
#2 Collected 4/15, fed to a bull 4/20 Standard plate count=25,680cfu/ml, 80 fecal coliforms, 25,600 other gram negatives.
#3 Collected 4/15, fed to a bull 4/20 Standard plate count=27,190cfu/ml, 1,430 fecal coliforms, 25,760 other gram negatives.
Standard for acceptable bacteria levels in colostrum? I like to see less than 5,000 gram negatives. Dr. McGuirk from Wisconsin is more liberal with a 10,000cfu/ml gram negatives. 
First, it looks like the 4/18 to 4/20 interval works well. Second, it looks like the 4/15 to 4/20 is not working well - excessive bacteria growth.
Maybe samples #2 and #3 had higher inoculation rates?
Maybe samples #2 and #3 had conditions more favorable to post-collection growth?      

Monday, April 22, 2013

Hay: Too much, too soon
Here's the situation. Continuous flow automatic feeder barn. Calves come into pen 1. Stay 4 weeks on auto feeder. Move to pen 2, 4 more weeks on auto feeder with a week-long step-down weaning period. Ration in both pens 1 and 2 is 22:20 milk replacer with Bovatec - fed on a step-up schedule for first week, stays at 10 liters per day until day 49 followed by 7-day step-down. Free choice water and calf starter grain (22% c.p.). Calves move to pen 3 (transition pen) around 60-65 days of age.
Pen 3 ration is free-choice water ,  one-half of feeder space is calf starter grain, one-quarter of feeder is free-choice good quality mixed alfalfa-grass hay, and one-quarter of feeder is free-choice haylage.
Health situation - low scours treatment rates in both pens 1 and 2.  Some pneumonia treatments for calves when moved from pen 1 to pen 2. Many pneumonia treatments when calves are moved from pen 2 to pen 3 - usually 5 to 9 days after being moved. Owners observed that the newest calves in this pen "stand still" for the first week or two. Calves receive intranasal vaccination on day 1.

Pen 3 has a feeder with slanted dividers - 44 spaces. Pen population usually runs between 15 and 25.
I recommended maintaining one-half of the feeder space for the grain ration. I recommended changing the forage ration. First, eliminate the haylage for this pen. Second, for the other half of the feeder, feed only enough of the good quality alfalfa-grass hay to last about one hour once a day. 
Reasoning? Prevent the new entrants to the pen from pigging out on the quite palatable hay by limiting access to only one hour. With the hay spread out with access (22 slants) the newest calves will very likely consume less than one pound of hay each day.  That will be enough to stimulate the growth of the appropriate microorganisms in the rumen to digest the hay. Having eliminated the large amounts of hay there will be plenty of grain consumed to maintain enough energy and protein to meet both maintenance and growth needs. And, with the coccidiostat in the grain they will continue to be protected from cocci growth.
Too much hay too soon. 

Wednesday, April 17, 2013

Scours problems that come and go
 Between three to five times a year this farm has a "scours outbreak." All the calves born for a  period of ten to fourteen days develop scours around seven to twelve days of age that last anywhere from five to ten days. "We don't lose very many calves other than those when we have these outbreaks." How many calves did you lose last year compared to the number that you started in the hutches? "I don't know as we have those numbers. But, it was not very many."

About one-half of the calves are fed their dam's milk when it is collected - anywhere from two to eight hours post calving. The other calves are fed milk from the refrigerator that is warmed to calf body temperature. 

What information would be nice to have here? How about blood serum total protein levels in calves between one and seven days of age? Nope, don't do BSTP testing. How about bacteria counts on "as-fed" colostrum? Nope, have never done that. Do you keep a written record showing when the calf is born and when she gets her first feeding of colostrum? No.

Do you think you could do some of this testing? [You need to know that the herd vet is standing by  my elbow during this conversation] "Yes. I know that Dr. xxxxxx has been suggesting that we do this during this since the first of the year."

And so goes the saga of the vet suggestions.
Looks like spring might be here in Vermont.

Saturday, April 13, 2013

Scours and Up-to-Date Information
So, here we are trying to pin down some possible management changes that could reduce scours treatment rates for preweaned calves on a dairy farm. Treatment rates since mid-March have been very high - not killing calves - taking a LOT of labor, however, to keep calves hydrated.

Colostrum bacteria culture data - yes - unfortunately the samples data are dated late November. At that time bacteria levels were at acceptable levels. A lot could change in four months?

Blood serum total protein data - yes - 37 samples of which 32 were from before March 1st.  Using all 37 samples we find 78% equal to or above 5.2 (Goal=90%) and 73% equal to or above 5.5 (Goal=80%).

Looking only at BSTP since March 25th 67% were below 5.2. Not looking good here. 

Diagnostic lab data are dated 11/19/12, 12/3/12, 12/4/12, and 12/8/12. At least these confirm that salmonella was not present. Basically everything else (viruses, bacteria, parasites) that is common on dairy farms was present. 

Where are we going to start?
1. culture a current "as-fed" sample of colostrum
2. culture a current  "as-fed" sample of milk
3. get as many current BSTP samples as there are calves between 1 and 7 days of age
4. On-farm observe feeding practices looking for consistency (seeConsistency check list) in management practices.

More on this case study after I have a chance to visit the farm.

Thursday, April 11, 2013

 Coccidiosis and Shedding
In a presentation about coccidiosis at the Dairy Calf and Heifer Association meetings Dr. Sheila McGuirk talked about shedding. That's the process where an infected heifer passes eggs (sporulated oocysts) in her feces.

The significance of her remarks about shedding is in the close connection between shedding rates and infection levels. When the infection level is high, so is shedding. And, high rates of shedding in a pen of heifers leads to even higher rates of infection among more animals.

Thus, the action called for in controlling coccidiosis, therefore, is to adopt practices that reduce shedding. Her short list includes:
  • Clean, well-bedded resting space for calves.
  • Optimize ventilation in the barn and calf or heifer pens. 
  • Provide adequate feed space per animal.
  • Minimize weight and age variation between animals in the group.
  • Avoid feeding on the ground unless it is at a bunk.
  • Provide 12" of linear water space per 10 animals.
  • Treat infected animals.
  • Maximize time between successive occupants of the same pen. 
It's all a numbers game. Controlling shedding, even in a pen of heifers that seem "healthy," cuts exposure. Lower exposure levels mean better feed conversion rates.

Wednesday, April 10, 2013

Ventilation, Ventilation, Ventilation
Phone call yesterday, "Calves are sick. We are treating half a dozen new cases every day."
Group housing, ad lib acidified milk feeding, curtains on both sides of barn on east and west sides, positive-tube mechanical ventilation.
First thing to note today is that curtains are all the way up in spite of 40+ temperature [It is raining with a steady 5-10 mph wind from the west]. Yes, both the west and east curtains are all the way up. If you look up you will not see the positive ventilation tubes. Although they arrived last fall they have not been installed.
Good quality air does not just happen. It takes effort. Like lowering the east curtain. Like installing the positive air tubes.
Why is it that sometimes I feel as if I am shouting down a well when delivering recommendations?    

Monday, April 8, 2013


Changes seem to be coming every year in the equipment we have available for on-farm estimates of colostrum quality and blood serum total protein levels. 
I was interested that the newest models (digital) have a menu so you can choose among 2 or more fluids to test.
If you are shopping keep in mind the increased flexibility of these digital refractometers - they look like a good buy to me.  

Sunday, April 7, 2013

When is Colostrum Not Colostrum?
"Anything collected longer than 4 hours post-calving is not colostrum." That is the statement made by Dr. Fernando Soberon during the seminar, "Colostrum and its importance beyond passive immunity."
This breakout session at the Dairy Calf and Heifer Association meeting in Lancaster PA on April 4 and 5 had a number of similarly challenging breakout sessions. 
So, what was Dr. Soberon talking about? He was drawing on research that shows declining antibody concentrations in colostrum the longer we wait for the first milking of a fresh cow. 
These data show that by 14 hours post-calving the antibody concentration is, on the average, down 33 percent from what it was shortly after calving. That value, 33 percent of original antibody concentration, is similar to the typical concentration of second milkings of fresh cows. 
So, maybe he was pushing the limits by saying 4 hours but the general point was well taken. If you want to harvest the antibodies that a cow has spent several weeks concentrating in the udder, you need to milk her as soon as practical after she calves. 
More this week from the DCHA meetings.      

Thursday, April 4, 2013

Newborn calf care tips
 Dr. Sheila McGuirk gave a list of tips for newborn care especially for assisted deliveries:
  •  get calf on her belly - a natural position with her raises head for drainage. Don't hold calves upside down.
  •  rub the calf with a dry towel - rub backwards from tail to head.
  •  stimulate the head with the towel with special attention to the ears, nose and around the eyes - all areas with special sensitivity.
  •  compress andshake the windpipe (trachea) -- this will often get the calf to cough.
  •  for calves not breathing well, try a bit ice water (take a few ice cubes out with you in a small self-sealing plastic bag - this usually gets a calf to gasp or take a deep breath to inflate her lungs.
  •  for calves not breathing well stimulate the nose to get a sneeze response - she suggests poking with a bit of straw in the nostril straight in from the side against the cartilege (sp?) a very sensitive spot OR staight against the end of the nose slightly under the center - again a very sensitive spot.
  •  So, a neat little checklist.
  •  Oh, did I mention I am at the national Dairy Calf and Heifer conference in Lancaster PA?
  •  Maybe something tomorrow our blog.
  •  sam