Monday, 29 October 2012

Monday Movie - Grass Tetany and Minerals

I wrote not long ago about the importance of having forages tested and knowing what you are feeding your animals.  Here is a great video out of Oklahoma State (Go Pokes!) about the importance of making sure that you have the right minerals in a diet, especially with forages that are known to cause problems, like wheat pasture.

While you're there, check out some of the other cow-calf corner videos.   Great little snippets of information on cattle production.

Thursday, 25 October 2012

Counting Down

It's about to be crunch time.  I finish my animal research in 5 days.  Then I'll be in the lab and running statistics for about 2 weeks.  Then it's on to finishing the writing, setting a date, and putting the last five years work into the hands of my committee.

I haven't been great about posting regularly lately, more because unless it's fescue or energy balance it doesn't cross my path most days.  So, since I know my brain is going to need a break now and again in the next few weeks I thought I'd ask you what you'd like me to write about.

Any burning questions concerning animal nutrition, research, metabolism, or something else entirely?  Post a comment here or send me a message.  I'd love to know that what I'm writing interests you!

One of my six boys.  There might not be many of them, but they keep me busy!

Monday, 22 October 2012

Cuting Boards

English: Plastic cutting board with slices of ...
Plastic cutting board (Photo credit: Wikipedia)
A bit of a change from my usual animals and agriculture theme. A friend posted a link to this blog touting wooden cutting boards as better than plastic, and I had to do some checking.  I figured that my fabulous readers might enjoy the information I found too.

If you're like me you have at least one plastic cutting board in your kitchen.  I love that I can toss it in the dishwasher and it comes out clean right?  Apparently not so!

A wooden chopping board with a chef's knife.
A wooden chopping board (Photo credit: Wikipedia)

My mother has always preferred wooden boards for making bread dough, but not for messy foods.  However, several articles I found state that the cellular structure of wooden cutting boards actually wick the bacteria to a centimeter or so under the surface of the wood, thus reducing the bacteria on the surface that might transfer to other food.  You can find a good summary of these (and other kitchen bacterial haunts here). 

Wood is better than plastic especially when the surface gets nicked by a knife or two.  Plastic cutting boards with knife nicks have bacteria present in those cuts even after washing!

If you want to try out a wooden cutting board, you need to know a couple things.  Pine and ash were shown to have the best anti-microbial properties of the woods tested.  Some woods were no different from plastic in bacterial contamination.  For cleaning, I've been told not to use soap on unsealed wood as it (like the bacteria) gets into the wood making food taste soapy.  Also, the same properties that make wood antimicrobial can break down bleach, making it ineffective as a wood cleaner.  What does work, is getting the wood wet and then microwaving it for about 5-10 minutes.  Crazy but cool!

I'll be consider a wooden cutting board soon.  How about you?

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Monday, 15 October 2012

More reasons to test forages

Beyond knowing the nutriet composition of forages it is also important to be aware of harmful compounds that may be in feeds and forages.  Here's a good article on both how and why we need to take extra care to test in drought years like this one.

Wednesday, 10 October 2012

The fiber of forages

Relative feeding value, neutral detergent fiber, lignin.  These are all terms that can be found on any hay or grass analysis.  But what do they mean and how are they determined? 

Let's start at the beginning.  Sending in your forage to be analyzed is very important when developing a feeding plan for any species.  The values you get back tell you how the forage is lacking so that you can fill in the gaps without overfeeding nutrients that the animal won't be able to utilize.

In this post I'm going to focus on the fiber portions of forage analysis.  We'll get to protein and energy later.  Fiber in this sense refers to the structural portions of the plant cells.  The compounds that make plant cell walls rigid.  These are also the least digestible compounds in forages, thus they are important in indicating how well animals can use the nutrients in the forage.

The big three fiber categories are neutral detergent fiber (NDF), acid detergent fiber (ADF), and lignin.  NDF and ADF refer to several types of fiber and the names come from how they are analyzed.  The forage sample is 'washed' in a detergent solution, that solution is either of a neutral pH or an acid because of the chemicals used in each 'wash'.   Each of these procedures removes a set or components from the plant material, leaving only specific fiber types.  But what do they represent?
Plant cell components (image from University of Minnesota)

The neutral detergent removes soluble carbohydrates, sugars, etc.  This leaves us with only the cell wall components, lignin+cellulose+hemicellulose.  NDF value is a general indicator of intake ability.  As NDF increases voluntary intake generally goes down.

The ADF procedure removes hemicellulose, leaving only cellulose and lignin.  It is a general indicator of digestibility.  Cellulose is not digested by any mammalian enzymes, only by the microbes in the rumen of cattle and sheep or the hindgut of horses, rabbits, etc.  As ADF increases digestibility goes down.

Finally lignin, which is almost completely indigestible.  As lignin increases so does ADF and NDF, which means that both intake and digestibility go down.

Generally fiber can also be used a general indicators of maturity.  As plant age (maturity) increases the percent lignin and cellulose go up, decreasing the quality of the forage. 

That's fiber in a nutshell, what portions of nutrition do you want to hear about next?

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Monday, 1 October 2012

Nutrition and Breeding

This is a topic that has come up for me several times in recent weeks, so I thought I'd put a few notes on (virtual) paper.  Specifically, the conversations have ranged around the topic of how nutrition relates to EPDs and bull (or cow) selection.

Expected progeny difference, or EPDs are a tool used in the cattle industry to measure genetic potential.  They are a prediction of how the progeny of an animal are expected to perform relative to the progeny of other animals in the same index.  Each breed produces their own EPDs and they can't be compared between breeds without some extra math.  It sounds a bit confusing at first, but they are a great tool.

As an example: if Bull A has a weaning weight EPD of +60 and Bull B is +75, then you would expect the calves from Bull B to weigh 15 pounds more at weaning on average (this assumes comparable maternal genetics between the two calf groups).

So, where does nutrition play into this?  Well, in order for those calves from Bull B to live up to their potential they are going to need the right nutrition.  If Bull A's calves are our on lush pasture, crepe fed, and the dams are producing lots of milk, they'll grow great.  If at the same time Bull B's calves are out on poorly maintained fields with low quality grasses, the mother's milk production is going to be lower and the calves aren't going to be getting the nutrients they need to grow thier very best.  It is very asy to waste genetic potential by providing poor nutrition.

Set them both up right by balancing
genetics and nutrition.
Now, that doesn't mean that everyone needs to have perfect pastures and management.  As our extension reproduction specialist says "I don't care what your nutrition plan is, but be honest about it and pick the appropriate bull"  If I know that I'm not going to supplement my cows and calves with grain, then I choose bulls with lower frame scores, lower weaning weights, and lower milk productions (if keeping the heifers as replacements).  They don't have to be bottom of the barrel, just appropriate.  Said another way:  There is no single best bull, only the best one for each situation.

Questions?  Comments?  I'd love to hear your thoughts on the relationship between nutrition and genetics.

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