Wednesday, February 27, 2013

"Nothing Has Changed"
Here is the conversation I had on Tuesday this week:
Me: How are things going with the calves?
Them: Okay. Well, not so well, really. We are having a big problem with scours in our 10 to 14 day-old calves. We even lost two - the first deaths since the beginning of this year. 
Me: Oh, tell me about what you are doing.
Them: We are taking care of the sick calves with electrolytes, some get antibiotics. You know, keep them alive until they get through it.
Them: But, I can't figure out why we are having a problem. Nothing has changed. [emphasis supplied by me]
Oh, my. If I have heard that phrase once I have heard it hundreds of times. "Nothing has changed."
What the person was telling me  was that of all the things that came readily to mind they could not pick any one of them that represented a change that caught their attention. With a health problem in young calves like scours the causes are multiple - lots and lots of factors can favor diarrhea or "hyperfluidity of feces."
I suggested making a written list of all the places from birth to 10 days of age where:
1. Calves might be exposed to lots of bacteria and parasites including calving, transportation, bacteria in colostrum, bacteria in daily feedings of milk.
2. Calves might be subject to stresses (temperature, wetness, wind, lack of enough food, lack of water, handling, and so on) that could weaken their immune defenses.
  3.   Calves passive immunity from colostrum might be less than ideal including testing for passive immunity levels.
Well, we were interrupted and never had an opportunity to finish the conversation. But the challenge is still there - when confronted with a disease outbreak how can we avoid the mental  trap of thinking, "Nothing has Changed."   

Friday, February 22, 2013

Dehorning Calves
Geni Wren just published a brief summary about dehorning calves.
She summarizes the conflict between economics of anesthetic nerve blocks and animal welfare. Quick read, thought provoking. 

Wednesday, February 20, 2013

If it would just get cold and stay cold

I don't know what the weather has been like where you live but here in western New York State it has been a yo-yo. Many swings in temperature of at least 30 degrees F within 24 hours.

When young calves have issues with passive transfer of immunity combined with marginal nutrition these temperature swings seem to unerringly pick out the weakest calves for pneumonia.

In my personal experience nutrition seems to be a critical factor. I changed my feeding protocol from 16 ounces of powder to 30 ounces daily. Before the change I routinely treated 25 percent of the calves between birth and 2 months for pneumonia in the period from November to April.

After the increase to 30 ounces of powder per day that treatment rate dropped to 5 percent. The first year I thought maybe it was just a mild winter, maybe we didn't have too many stresses (like wild temperature swings). Then the next year and the next year the same low treatment rate. I became convinced that providing plenty of clean, wholesome milk/milk replacer can make a difference in the ability of calves to withstand the stresses of yo-yo weather.

If you have had a similar experience drop me a line; I would enjoy hearing from you.    

Monday, February 18, 2013

Our Friend, Cryptosporidia

In a Swedish study involving 26 herds (13 organic and 13 conventional), 259 cows and 221 calves researchers collected fecal samples to determine the presence of cryptosporidia.

Approximately one-half of the calves regardless of organic/conventional status had infections severe enough so that the calves were shedding oocysts in their feces. 

Variation among herds suggested these factors influencing rate of infection among calves:
  • age of the calf - one to three week-old calves are most likely to be shedding crypto compared to older calves.
  • calves with cleaner bedding are less likely to be shedding compared to calves with soiled bedding. 
  • farmers' attitudes toward biosecurity - this factor should not come as a big surprise to any of us since these attitudes are the basis for reducing exposure to cyrptosporidia oocysts.
Remember these tips for reducing the frequency and intensity of crypto infections among our heifer calves:
  • Calve in clean surroundings.
  • Once the calf stands up, get her away from adult animals including the dam.
  • As soon as practical after birth feed plenty of clean high quality colostrum.
  • House her in as clean environment as practical whether in individual or group pens. 
  • Provide plenty of clean wholesome milk/milk replacer.
This note by Dr. Geof Smith of NC State may be helpful when thinking about managing cryptosporidiosis:
Hoards' Dairyman article

For a quick picture of how common this infection is in the US (from 20 years ago but still probably pretty accurate) click here:
Crypto Overview USA

Friday, February 15, 2013

Don't Assume Too Much!
I was teaching a group about newborn care and colostrum management on Thursday afternoon. A question came  up  about volume of colostrum to feed newborn calves. "Why am I promoting feeding 6 quarts of colostrum to newborn calves?"
That question caught me by surprise. I was quite sure I had not included that in a PowerPoint slide. In response to an earlier question I had quoted research from the Bovine Veterinarian on the proportion of calves that would voluntarily drink varying amounts of colostrum - 2 bottles, 1.5 bottles, 1 bottle, 0.5 bottle.
After several moments of confused dialog  I asked the  person in the audience, "What size nursing bottle do you use to feed colostrum?" 
I assumed 2-quart bottles.
Person asking question assumed 3-quart bottles since they fed all their calves milk using this size bottles. 
I need to write myself a note that should be read just before every one of my public presentations:
Don't  Assume Too Much! 
How often when we are training a new worker do we make the mistake of assuming common knowledge about equipment, animals and feeds? 

Tuesday, February 12, 2013

Short-Day Conditions and Colostrum
So,  here is the question: "I am thinking about housing my dry cows to take advantage of the fact that short-day [8hrs/day vs. long-day 16hrs/day] conditions for them should give me an increase in milk production. Will this change my colostrum?"
Fortunately Morin, D.E. and Others looked at this question  Journal of the American Veterinary Medical Association (237:420-428) August 2010.
They found no relationship between photoperiod length and colostrum volume and antibody concentration. So the answer was simply, "No."
How Big are Your Problems?
We all have difficulties rearing calves. Especially troubling are times when we lose a calf or have a number of sick ones.
To put these issues in perspective let me share a question that appeared in my e-mail last Saturday. The manager works in China. She is responsible for calf operations on 15 dairies spread out over an area roughly the size of 2/3's of the USA. Her two questions were (1) is it possible to pasteurize colostrum without destroying all the antibodies and (2) whether not pasteurization of colostrum would kill Brucella abortus.
The first question I receive many times in a year. It is easy to answer.
The second question I have never been asked before. We are so fortunate to benefit from the efforts of those who have gone before us that took on the job of eradicating Brucella abortus from the dairy industry in the United States. Only eighty years ago father-in-law's Guernsey herd was destroyed by brucellosis. Now we seldom give this disease a thought. We only have a few herds in our practice that still vaccinate against brucellosis as a risk management practice.
In contrast, all of her herds have abortion storms every year. Some of them are confirmed brucellosis cases. And, this in spite of extraordinary measures the dairies take to prevent disease-causing organisms from entering their premises (limited and controlled entry points, chain link perimeter fences, wheel baths for vehicles, 100 percent shower-in:shower-out access for people, extended quarantine restrictions on cattle movement).
Preventing brucellosis is an everyday challenge for her calf rearing staff. In contrast, many of us are concerned because we have a nagging problem with cryptosporidiosis in our 7 to 10 day-old calves.
All a matter of perspective. By the way, the answer to the second question is is almost certainly yes as long as the 60C x 60 minute protocol is followed.
Have a good day. 

Saturday, February 9, 2013

Having Enough
This post has little or nothing to do with managing calves. It's just an observation I made this Saturday morning while driving over to our little country church to shovel snow and get ready for the worship service tomorrow since I am reading Morning Prayer while our priest is away.
I drove past a country home. A non-farm thirty-something couple built it just six years ago - right out in the middle of crop land - they even had to run electricity for an extra mile to this house.  Summer before last they build a nice two-car garage. Last winter both of their cars were snug and nice inside this garage.

In the spirit of our acquisitive society I noticed over this past summer more and more stuff was accumulating in the garage. 

Much like the rest of the Northeast we had snow on Friday afternoon and overnight. Were their cars "snug and nice" inside the garage? No. The garage is now too full of stuff and the cars sit outside. This morning after plowing the driveway the male half of the couple was busy cleaning snow off the two cars. 

Make you wonder about our society of "buy, buy, buy, buy." How much is enough? Chesterton is quoted, "There are two ways to get enough; one is to continue to accumulate more and more. The other is to desire less." Makes you wonder. 

Have a good day.

Thursday, February 7, 2013

Warming Colostrum
I received the bacteria culture information from a client having sporadic severe scours problems among a small number of young calves. Previous cultures of "as-fed" colostrum had bacteria counts varying from  almost no growth to well over 100,000 cfu/ml.
We agreed to sample several batches of colostrum like this:
1. Directly from collection bucket immediately after milking colostrum.
2. Directly from refrigerated nursing bottle.
3. Directly from nursing bottle with warm colostrum just before feeding the calf.
1. All the collection bucket samples were reasonably low - under 5,000 cfu/ml.
2. All the refrigerated nursing bottle samples were still under 20,000 cfu/ml.
3. Wow! Warm colostrum samples were all over the place. The lowest under 10,000cfu/ml with the highest too numerous to count (TNTC) - estimated at 250,000cfu/ml.
What was going on? I discovered that their protocol called for the worker that found a cow in labor to put two refrigerated bottles of colostrum into a water bath to warm. The objective was to have warm colostrum ready to feed about the time the cow delivered the calf.
Part of the time this protocol worked just fine. The cow's labor was reasonably short and the colostrum did not sit warm waiting to be fed very long. Part of the time this protocol did NOT work just fine. The cow's labor was longer than predicted and the colostrum sat and sat and sat and grew more and more and more bacteria until it was bacteria soup.
We agreed that while it was a good idea to feed colostrum promptly after birth the urgency was not so great that there was time to warm the colostrum after the calf was born.
The revised procedures seem to be working better. The number of calves with very severe diarrhea has dropped to nearly zero.

Tuesday, February 5, 2013

Electrolytes for Calves:
A Review
The staff at University of Kentucky have been doing a fine job in publishing a dairy newsletter. In the most recent issue is a well-done review on electrolytes for calves.
Electrolytes for Calves  is the link to this reveiw. Enjoy.

Monday, February 4, 2013

Cryptosporidia and Calf Health
In the December 2012 issue of the Journal of the American Veterinary Medical Association research was reported on the connection between cryptosporidiosis and how much the calves were fed. (Ollivett, T.L. and Others, "Effect of nutritional plane on health and performance in dairy calves after experimental infection with Cryptosporidium parvum" JAVMA 241:1514-1520)
"After a pathogen challenge, calves maintained hydration, had faster resolution of diarrhea, grew faster, and converted feed with greater efficiency when fed a higher plane of nutrition."
In a nutshell the two feeding programs with non-medicated milk replacer were (a) 20-20 m.r. mixed at 15% solids fed 2 quarts twice daily and (b) 28-20 m.r. mixed at 15% solids fed at 3 quarts twice daily first week and 4 quarts  twice daily for the next two weeks. 
Points of interest for me:
  • Shedding - calves were  handled to prevent natural exposure to Cryptosporium parvum. They were experimentally exposed at their 5th feeding on day 3. Shedding started by four days after exposure. Peak shedding occurred on average on eight days after exposure.  Where we have natural exposure at birth these data suggest we should expect shedding to start around 4 days of age and to peak around 8 days of age.
  • Diarrhea - About one-third of the calves did not have diarrhea. However, about one-third of them had severe diarrhea. Not all calves will respond to a crypto infection the same way - we need to watch these 4 to 8 day old calves very carefully in order to provide appropriate and timely care.
  •  Rate of gain - the calves on "normal" feeding program either stood still or lost weight at the end of 3 weeks. The calves on the high or intensive feeding program ate their way through the infection and averaged just under a pound a day gain at the end of 3 weeks. Well-fed calves can gain weight during the first three weeks of age in spite of cyrptosporidiosis.