Tuesday, September 19, 2017

Measuring Colostrum Quality

Measuring colostrum quality is a best management practice. It's not difficult to do and the equipment is inexpensive. Guidelines for using a Brix refractometer are found HERE.

A recent report on a survey of dairy farms in Michigan and Ohio included information from 449 farms (56% <100 cows, 39% between 100-499 cows and 5% 500 cows and greater). 

They were asked if they measured colostrum quality before feeding it to newborn calves. 

Results? The percent measuring were:

>500 cow herds      = 25%
100-499 cow herds = 18%
<100 cow herds      = 3%

These same producers were asked this question:
"Measuring colostrum quality is useful to make decisions on feeding calves colostrum: (responses were Strongly agree, somewhat agree, neither agree or disagreee, somewhat disagree, strongly disagree).

Of the 43 producers that regularly measure quality 41 agreed with this statement - their attitude and behavior matched. 

Of considerable interest to me was that finding that 39% of the farms NOT measuring colostrum quality agreed that measuring quality is useful in making decisions on feeding calves colostrum. 

Of those of the opinion that measuring colostrum quality is not useful, 53% also felt that the process of measuring quality was time consuming. That makes me wonder if they had actually observed the use of a Brix refractometer for colostrum quality measurement.

Reference: Pempek, J.A. and Others, "Dairy calf management - a comparison of practices and producer attitudes among conventional and organic herds." Journal of Dairy Science 100:8310-8321.

Friday, September 15, 2017

Every Time I Try Feeding My Calves More 
They have Scours

This past week I talked with some calf care folks. One of the practices I recommended was feeding calves more than the out-of-date four quarts a day of 20-20 milk replacer. 

The reaction of some folks was captured in the words of one calf care person, "Every time I try what you suggest of feeding more, my calves have scours."

So, I spend about half an hour explaining that we control the conditions that either increase or decrease the chances of calves having diarrhea when fed more that 4 quarts of milk/milk replacer a day. The greater the number of best management practices we follow the lower the opportunity for calves to have diarrhea.

You may want to review this list of 10 factors that I think probably are most likely to make a difference in how calves respond to increased feeding rates. Click HERE for the list (2 pages) or if the link does not work for you try pasting this link in your browser:
http://www.atticacows.com/library/newsletters/FeedingMoreMilkwithoutScoursR1745.pdf 




Thursday, September 14, 2017

How Often Do I Need to Check My 
Colostrum Bacteria Count?

It depends. Well, that is not a very helpful answer.

The national Dairy Calf and Heifer Association Gold Standards thresholds for bacteria counts in colostrum are <5,000cfu/ml coliforms and <50,000cfu/ml total plate count. For an expanded discussion of bacteria in colostrum click HERE

If the farm has not sampled and cultured "as-fed" colostrum for bacteria you can find a sample collection protocol HERE (or in Spanish HERE). I like to see a minimum of 5 samples each time. If the dairy is large enough to have different shifts of workers handling and feeding colostrum then 2 samples from each shift is a good idea.

When the results come back compare them to the standards above. By the way, when ordering the culturing from a lab you often have to specify that you want both speciation (which bacteria are present) and quantification (how many of each species). I usually tell the lab I do not want them to use techniques to get exact counts when the number of colonies on the plate are too numerous to count (often abbreviated as TNTC).

If the farm sample results look good (below standards) I recommend extending the sampling interval to every 3 months. This quarterly interval follows the seasons of the year along with changes in labor availability that go with cropping cycles. 

If the farm sample results contain one or more high count samples I recommend taking corrective action and resampling each month until the results come back in below the farm's goals. If coliform counts are high you may want to review my checklist for reducing these counts (click HERE).

Monday, September 11, 2017

Passive Transfer Failure: It's Hard to Hit Zero!

In research study Holstein heifer calves received their first colostrum feeding at 4 or less hours after birth. They were fed 4.2 quarts of colostrum in one feeding that averaged 58g/l quality - so on the average they received around 240g of Ig's. 

In spite of this exemplary care they still had 2 percent passive transfer failure. The average efficiency of absorption (percent of antibodies fed that end up in the calf's blood) was around 23 percent. However, the range of efficiency was from less than 10 to over 50 percent. 

Another part of the study included calves fed 4 quarts as first feeding (less than 4 hours old) and another 2 quarts before they were 12 hours old. This colostrum averaged nearly 70g/l. With the combination of two feedings of excellent quality  colostrum (added up to 390g of Ig's) a higher level of passive transfer was  achieved.   

Bottom line? If you have a calf now and then that has passive transfer failure don't beat yourself up over it. Genetics always will play a role when you roll the dice and once in a while you will lose. 

Despite the wide range in apparent absorption efficiency demonstrated in this study it was clear that feeding 4 quarts (10% body weight) of good quality colostrum within 4 hours of birth will result in an excellent program for calf immunity. Other research has shown that at this volume similar results will be achieved with either one or two feedings and feeding either by bottle or tube feeder. 
[Click HERE for more on this.]  

Reference: Halleran, J. and Others, " Apparent efficiency of colostral immunoglobulin G absorption in Holstein heifer." Journal of Dairy Science 100;3282-3286. Osaka, J. and Others, "Effect of mass of immunoglobulin intake and age at first colostrum feeding on serum IgG concentration in Holstein calves." Journal of Dairy Science 97:6608-6612.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

Wednesday, September 6, 2017

Guidelines for Storing Colostrum

The September 2017 issue of the calf management newsletter offers guidelines for doing a good job of storing colostrum. Whether refrigerated or frozen, having a backup to fresh colostrum is a best management practice.

The key points are:
·       Start with clean colostrum
·       Reduce growth of bacteria
·       Monitor effectiveness of storage methods

Enjoy.

Friday, September 1, 2017

More on Transition Milk
"Transition Milk is Too Valuable to Sell"

This article [click HERE to go to it online] by Maureen Hanson quotes Dr. Jeremy Schefers from the University of Minnesota Veterinary Diagnostic Laboratory, If the link does not work, try this URL
http://www.dairyherd.com/advice-and-tips/calf-and-heifer/transition-milk-too-valuable-sell 

He is quoted as saying that transition milk is easily worth $30/gallon or $300/cwt because of its value in  promoting good gut health. 

This blog reinforces my transition message in my June 15th Blog on the value of second milkings - about half of the samples tested 50g/L (that is the national threshold for acceptable first feeding colostrum). 

Monday, August 28, 2017

My Ruminations about Rumen pH Among Weaned Calves

By using intensive data collection methods a research team was able to monitor rumen pH in  calves before, during and after weaning. Because of practical limitations (equipment, rumen canulas) the number of calves was limited to six.

"Pre-weaning the average daily pH was low (5.6 ) implying rumen acidosis. The pH reached its lowest levels during the week after weaning (wk 7) with a mean of 5.5 and did not increase before wk 11. Furthermore, ruminal pH was below 5.5 and 5.2 for approximately 745 and 220 minutes daily during wk 7 and 8, respectively. The pH increased significantly in wk 11 and 12 with a mean pH of 6.1."

Even when calves were not eating very much calf starter grain the pH levels were low. I did not expect that finding. In addition to 900g of milk replacer powder daily these calves had free-choice access to chopped straw - supposedly that ration should modify the rumen environment to achieve more favorable pH conditions. Among these few calves clearly the addition of straw did not improve pH conditions pre-weaning.

I noted that rumen pH dropped to 5.2 during weeks 7 and 8 for 220 minutes a day. Those prolonged low pH times suggest a depression of the favorable rumen microbial populations. The article did not mention whether or not  fresh concentrate was provided  before these periods of low pH. If calf "slug fed" on concentrate (usually due to not having a consistent supply 24/7) I would expect depressed pH conditions post feeding.

When feeding my own calves I thought that feeding a big handful of palatable alfalfa hay daily to my older calves would lead to more favorable rumen conditions - the fiber would form a stabilizing mat in the rumen, the calve would be encouraged to spend more time chewing a cud thus delivering more pH neutralizing fluid for the rumen. 

Now ,I wonder about feeding the hay. How well did this dietary rumen adaptation post-weaning work to manage rumen pH? My intent was to start building the appropriate rumen microbial population for fiber digestion (alfalfa hay). I didn't even think about rumen pH.

 I do know that I tried to be sure that after the calves had a milk step-down as part of weaning they always had access to plenty of clean water and palatable calf starter grain - never let either of those run out. At the time I thought that this was a best management practice. I wanted to prevent "slug" feeding (that is, eating an excessively large volume of grain at one time).

I recall that a few of my calves would cycle in their grain intake during weeks six and seven - up and down, up and down over a period of three to five days.  Maybe these were the ones where the rumen pH was very low for prolonged periods of time - perhaps they "went off-feed" because of this - then after recovering they dug into the grain, often eating six or more pounds of grain for the next several days. Then, off-feed again.

Perhaps the take-home message from this research is that we need to pay closer attention to the dietary transitions from weeks 5 through 12 to gradually ease the rumen into the most favorable pH conditions. 

Reference:
J.K. van Niekerk and Others, "Ruminal pH in Holstein dairy bull calves from pre-weaning to post-weaning." Journal of Dairy Science, 100:178 July 2017