Thursday, November 13, 2014

Wood Pens and Calves

If there is one thing to say about using wood for calf pens it is "Don't."

The porous surface of wood favors the penetration of parasite eggs and bacteria. This same surface is supremely difficult to clean. Thus, it becomes an effective way to pass pathogens on from one generation of calves to the next. Maybe you can remember years and years ago when we tried making hutches out of plywood panels - the first 4 or 5 turns of calves did pretty well and then it was steadily downhill from there in terms of calf health.

I was effective in getting this idea across to a client that built a new calf barn. He agreed to use wire pens rather than the wooden boxes that were part of the original plan.

Yesterday I visited the new barn. He proudly showed me how it was about 1/3 full of calves in neat rows of wire pens. One row was against the west wall, two more rows in the middle and one row against the east wall. 

So far so good. BUT, rather than buying enough wire pens to provide a fourth side for the pens along the wall, my client decided to save money and use the wooden sidewalls as the fourth side. How did I manage not to get across that all wood is undesirable?

Well, we had a discussion about this. He agreed to purchase some of the wire panels and for the remainder of the  barn the calves will not be against the outside wooden walls.

As I completed the conversation it occurred to me to mention how far away from the walls the pens should be placed. He had not though that far ahead. "What is your recommendation," he asked. I told he to find out by trial and error.

Using his wire panels (recall they come with various size openings), place one 3 to 4 inches from the wall. Watch calves - can they lick the wall? No, then that distance is okay. Yes, then the pens need to be moved farther away.

Monday, November 10, 2014

If the Bacteria Count Gets High Enough Antibody Absorption from Colostrum is Depressed

Let colostrum sit at 68F for 2.5 to 3 days. Guess what? Bacteria counts can go up into the millions. Or, just let it sit for 12 hours at 90F. Sky high bacteria counts. When culturing for bacteria these are the plates in a lab that smell to high heaven after 24 hours in the incubator; the lab tech staff knows that they will be "TNTC" (too numerous to count). 

What happens when this "bacteria soup" is fed to a newborn calf?  

Let's see what happened in a trial done at Penn State [S.L. Gelsinger and Others, "Effect of heat treatment and bacterial population of colostrum on passive transfer of IgG." Journal of Dairy Science, E-Suppl 1, p578, #1166]. They did let colostrum sit at 68F for about 3 days.

The research team used a measure of antibody absorption called "Apparent Efficiency of Absorption" that is expressed as a percent of antibodies fed that end up in the calf's blood (Quigley, et al., 1998).

Unheated colostrum with low bacteria concentration  - 31%
Unheated colostrum with high bacteria concentration - 16%

Heat-treated colostrum with low bacteria concentration - - - - - - - - - - - 37%
Heated-treated colostrum inoculated with bacteria to get a high count - 14%

Thus, we conclude that high bacteria counts do depress antibody absorption. Resources that might be helpful in reducing bacteria counts can be found at www.calffacts.com. These include a checklist for reducing coliform counts in colostrum (click HERE ) and a colostrum storage checklist (click HERE )





Friday, November 7, 2014

Even Calves Receiving Adequate Colostrum Can Benefit from Feeding Transition Milk

In a recently published article [M. Conneely and Others, "Effect of feeding colostrum at different volumes and subsequent number of transition milk feeds on the serum immunoglobulin G concentration and health status of dairy calves." Journal of Dairy Science, November 2014 97:6991-7000] the authors compared three feeding strategies for transition milk.

They used pooled second milking from the freshly calved cows for transition milk. It was fed at the rate of 2L (2.1 qts.) per feeding. The alternatives were
(1) No transition milk fed,
(2) 2 feedings of this milk at 8:00 and 15:00 hours, and
(3) 4 feedings of this milk at same times.
Recall that book value for 2nd milking fat is 5.4% - or about 36% fat - high energy stuff.

All the calves were fed very high quality colostrum within 2 hours after birth and received at least 300g of IgG. Blood serum IgG values were screaming high - all over 3000mg/dL. So, immunity levels were more than adequate at 24 hours.

Then, they fed transition milk either 2 or 4 more feedings.

Health of calves?

They used the health scoring system designed by McGuirk (click HERE to see this chart, be sure to scroll to second page for picture guide for scoring).

1. "Feeding the transition milk had no effect on the likelihood of being assigned a worse fecal score throughout the study period." p,6999

2. Feeding the transition milk ... "lowered the likelihood of being assigned a worse eye/ear and nasal score during the study period" p6999

During a much less well-designed trial that included about 1,500 calves while I was managing calves at Noblehurst Dairy I fed transition milk (2nd, 3rd, and 4th milking pooled fed within 30 minutes of collection) milk to all the youngest calves for about the first 7 days of life. In all the twelve years at this facility I never had lower scours and pneumonia treatment rates than when I fed transition milk. Completely undocumented, however, for these calves was their immune status - no blood serum total protein values. Compared to the research reported here I am certain not many of our calves had immunity levels nearly as high as theirs.

One nice benefit of feeding transition milk is its high energy value. Compared to feeding a 20% fat milk replacer my transition milk had about 75% more fat - thus, I was feeding not only the components unique to colostrum but also a lot more energy each feeding that first week.

Just a reminder, when feeding transition milk after the first day of life the antibodies are no longer absorbed into the calf's blood. The benefits from these antibodies are at the surface of the gut lining.

Wednesday, November 5, 2014

Does Intensive Milk Feeding Have to
Depress Rumen Development?

Using a slaughter study design a research team in Germany looked at the relationship between different milk feeding levels and rumen development. While not stated in the abstract it seemed clear that the calves were group housed and fed with a computer-controlled automatic feeder.

The low milk replacer feeding rate was 1 2/3 pounds of powder daily. The high milk feeding rate was unlimited milk replacer. These "unlimited-feed" calves increased their consumption of milk powder to well over 2.5 pounds per day with some calves peaking at over 3 pounds by 35 days of age.

The low-fed group continued at 1 2/3 pounds per day until slaughter at 60 days. The high-fed group was stepped down starting at 35 days to 1 2/3 pounds per day. By the end of the study they found that intensive milk feeding did not impair concentrate intake. 

Let me add here that from my experience with intensive feeding my own calves I found these calves came up rapidly on grain intake after I cut back their milk around 35 days. I achieved the most rapid increases in grain consumption by making an abrupt 50 percent drop in milk ration with an extended period between feedings rather than using an extended step down in small increments with a continuation of the regular feeding intervals.

On one hand, by examining the entire rumen tissue from the two groups of calves they found no differences in rumen empty weight and papillae length.

On the other hand, looking at the same rumen tissue they were able to find differences in papillae density in two of the rumen surfaces.

I conclude that when the step-down process from peak milk consumption is done correctly intensive milk feeding does not significantly depress rumen development in preweaned dairy calves. 

Nevertheless, it is easy to screw up the step-down process. You can calculate from the information above that the intensive-fed calves had their last 25 days on the lower milk replacer feeding rate. I regularly see calf operations that are trying to use a three to five day step-down from full feed rates with predictable poor results when intensively fed calves are weaned.

Source: H.M. Hammon and Others, "Intensive milk feeding in calves affects growth performance, metabolic and endocrine traits, but not rumen development" Journal of Dairy Science Vol 97, E-Suppl, #619, page 310. 


Tuesday, November 4, 2014

Colostrum Cubes

Click HERE for a really short but thoughtful summary of cold weather care for calves. Karen Anderson, Extension Educator UMN, has a good bullet-list of to-do activities. 

One of her suggestions is feeding colostrum cubes to young calves. You will appreciate her practical advice from making to feeding these little cubes of liquid gold.

Monday, November 3, 2014

Umbilical Cords: What's "Normal?"

Just in case you ever wondered what is a normal size umbilical cord, as part of a trial on navel dipping a person did this work for you. 

The diameter of umbilical cords on 60 Jersey calves were measured within 30 minutes after birth and again at 24 hours of age.

At birth the average diameter was about 7/8"(22.8mm). Two-thirds of the calf navels fell between 3/4" and just over 1".

At 24 hours the average diameter was about 1/4"(7.64mm). Two-thirds of the calf navels fell between 1/8" and just under 1/2".

So, that gives us an estimate of the "normal shrink" rate. It also suggests that even though an umbilical cord is still 1/2" in diameter at 24 hours this size, while somewhat unusual, does not necessarily mean an infection has begun. I would just tag this calf to be watched over the course of the following week to see that the umbilical cord continues to shrink as it dries up.

A.L. Robinson and Others, "The effect of four antiseptic compounds on umbilical cord healing and infection rates in the first 24 hours in dairy calves from a commercial herd." Journal of Dairy Science Vol. 97, E-Suppl 1, p. 430.