Wednesday, May 24, 2017

Hazards of Bacterial Contamination of Colostrum
Dr. Sandra Godden, Univ. MN

I was working on a post to our clinic website in the Metric Calf Resources section when I found this link to this resource by Dr. Godden. She gave this talk at a dairy meeting in Arizona in 2009. But, it does a great job on this topic. Why should we avoid feeding contaminated colostrum.

And, it summarizes the research work done on using potassium sorbate to slow down bacteria growth in colostrum.

So, click HERE for her paper. Or, paste this URL in your Internet browser: http://www.dairyweb.ca/Resources/SWNMC2009/Godden.pdf .

Enjoy.

Thursday, May 18, 2017

Feeding Enough Colostrum to Meet
Energy Needs for First 24 Hours

Mike VanAmburg (Cornell) gave a nice summary of energy needs of dairy calves during their first 24 hours of life. in his presentation at the national Dairy Calf and Heifer Association meetings at Madison WI in April, 2017.

This is his statement:
"Also, colostrum is the first meal and accordingly it very important in establishing the nutrient supply needed to maintain the calf over the first day of life. ... We tend to underestimate the nutrient requirements of the calf, especially for maintenance."

"For example, a newborn Holstein calf at 85 lbs. birth weight has a maintenance requirement of approximately 1.55 Mcal ME (megacalories metabolizable energy) at 72 degrees F. "

He continues, "For comparison, if the ambient temperature  is 32 degrees F the ME requirements for maintenance is 2.4 Mcal."

By my calculations if a calf is only fed 2 quarts of colostrum her first feeding (2.6 Mcal) she will not have much energy left for growth even in summer. Winter weather challenges her to just stay alive on the energy in two quarts of colostrum.

The message to me is to plan in getting at least 4 quarts colostrum into our newborn calves in the first 12 hours with the first feeding preferred in the first 4 hours.

Tuesday, May 16, 2017

Poop Patrol:
Making Sense From Loose Poop

When preweaned dairy calves are housed individually the calf care person has an opportunity to look at poop (aka feces) from each calf.

One of my biggest training challenges while managing a calf enterprise was teaching new workers what to look for in poop and how to assign the correct meaning to various qualities. 

 When I made a major change in my milk feeding program I had to re-learn this business of making sense from loose poop. The new milk feeding rate was increased gradually during the first two weeks with the goal of feeding four quarts twice daily to deliver approximately two pounds of milk replacer powder a day. This was an increase from 1.25 pounds per day.

In my note on Milk Feeding in An Intensive Feeding Program I have a section, "Manure Patrol." [Click HERE for this resource] I had a lot to learn about manure from intensively-fed calves. When you put a lot in the front a lot comes out the back!

A recent presentation at the Dairy Calf and Heifer Association annual conference highlighted this challenge of interpreting the fecal output from intensively-fed preweaned dairy calves.

The author commented,
"A couple of recent studies from my lab are confirming that calves fed greater quantities of milk solids early in life have greater fecal scores [vet-speak for looser poop]; however, when the dry matter percentage of the calves feces were determined there were no differences between calves fed differing quantities of milk solids." (p37).

Bottom Line? Loose poop is normal and okay among these intensively-fed calves.

So, what was my training challenge?

Well, there is loose poop and there is loose poop. I had to show my new helpers the difference between "normal" colored poop (yellowish, straw colored) and white and/or containing blood. They needed to be able to judge consistency differences between "watery" (sick calf) and "loose" (runny, seeps into bedding). 

Just a reminder if you move from limit-fed calves to either free-choice acidified milk or to an automatic feeder, as you increase liquid intake plan on lots more urine. An lots more bedding is always needed to maintain reasonably dry resting space compared to limit-fed calves.

Reference: Ballou, Michael A., "Nutritional strategies to improve the health of pre-weaned calves and growing heifers." Proceedings of the Dairy Calf and Heifer Association, April 11-13, 2017, Madison, WI pp33-40.

Wednesday, May 10, 2017

More on Using Automatic Feeder Data

More data from the joint Minnesota and Virginia researcher team.

Among other findings they found that calves that were diagnosed with treatable diarrhea had significantly slower eating rates up to 3 days before they showed visible signs of scours.

For me the implication is that when we scan the feeding rate screen and spot a calf that has a significant decrease in eating rate she should go on my "watch" list - especially for scours. 

At this point in our understanding of the eating-rate data I don't feel comfortable starting any kind of intervention to prevent scours based on a decrease in eating rate. The difference in rate (healthy calves ate 88ml/minute faster than calves that later had scours) might not be great enough to justify anything more than closer observation.

However, if we diagnose a case of scours right away rather than missing it for a day or two we are more likely to have a positive treatment outcome. 

Reference: Knauer, W.A.,and Others, "The use of day level feeding behaviors to detect illness in group housed automatically fed pre-weaned dairy calves." Proceedings of American Association of Bovine Practitioners, September 15-17, 2016 p.150.

Monday, May 8, 2017

Improving Weaning Results: Keeping
Weaned Calves Growing and Healthy

May 2017 calf management newsletter is now posted on vet clinic website. Click HERE to go to the newsletter. Or, paste to browser http://www.atticacows.com/library/newsletters/CEMay2017.pdf 

Summary:
  • Rate of rumen development is determined by how we care for our calves.
  • Our level of milk feeding is going to influence the consumption of calf starter grain. 
  • What to do with calves that are not ready to wean?
Enjoy.

Wednesday, May 3, 2017

We Still Need to Keep our Colostrum Clean

A study including 18 dairy herds in Quebec Province, Canada, measured bacteria in  "as-fed" colostrum as well as assessing adequate passive transfer of immunity. There were 333 samples.

A total of 219 calves were bled to estimate the level of passive transfer of immunity. The median herd level of successful transfer of immunity was 70 percent (range of herds was from 41% to 1005).

Of the 333 colostrum samples that had standard plate counts completed (total bacteria, aerobic culture). The standard used was 100,000cfu/ml. Above this was considered failure. 

The herd-level success (sample below 100,000cfu/ml) ranged from a low of 3 percent to a high of 75 percent. The median value was 38 percent. This tells us that a lot of highly contaminated colostrum was fed on these 18 farms. 

These data reinforce the facts from a study in Quebec Province nearly ten years ago that had roughly the same results. Colostrum has not gotten cleaner in the past decade.

What can we do to be sure our colostrum meets at least this standard of cleanliness?

1. Sample and culture. We cannot manage what we do not measure. 

2. If bacteria counts are above this threshold (100,000cfu/ml) there are specific steps we should consider to reduce both inoculation and growth. Click HERE to access this 8-point list). 

3. Sample and culture some more. 

Reference: Freycon, P. and Others, "A herd-level study of colostrum management and its association with success of passive transfer in newborn dairy calves." Proceedings of American Association of Bovine Practitioners, September, 15-17, 2016, Volume 49 , p147.

Monday, May 1, 2017

Variation in Growth Rates, Preweaned Calves

The University of Minnesota included 102 heifer calves in a feeding trial. They compared growth and behavior among group-fed calves on an organic dairy. The calves were fed whole milk with Skellerup peach teat feeders either once a day or twice a day for a total of 6 L (6.3 quarts) daily. (13% solids, 4.2% fat, 3.3% protein).

The NRC calf model projects the estimated gain for calves about 81 pounds in a 60F environment with this ration (6.3 quarts daily) at 1.4 pounds per day (protein limited ration, lots of leftover energy with this high fat milk). Calves had a 19% protein calf starter available free-choice.

The variation among calves was evident at 60 days of age:

Holstein calves -                                             low = 0.55kg/day, high = 0.97kg/day [1.2 - 2.1 lbs/day]
HolsteinXMontbeliardeXViking Red -          low = 0.4 kg/day, high = 1.07kg/day [0.9 - 2.4 lbs/day]
HolsteinXJerseyXNormandeXViking Red - low = 0.5kg/day, high = 0.98kg/day [1.1 - 2.2 lbs/day]

The once-a-day calves achieved 85 percent doubling their weight by 60 days. The twice-a-day fed calves achieve 96 percent doubling their weight by 60 days.

When I used a sample of Holstein calves for which I had individual growth rates to compare rate of gain by sire I found that about one-third of the variation could be tied to the sire.

The messages for me are:

1. Expect lots of variation in gain among calves that receive the same care under the same farm conditions. There will be "laggards" (low growth rate) among every group of calves.

2. Given variation the most effective way to get better gains from the "laggards"is to raise the level of nutrition for the entire population.

Reference: Kienitz, M.J., and Others, "Growth, behavior, and economics of group-fed calves fed once or twice daily in an organic production system." Journal of Dairy Science 100:3318-3325. March 2017