Friday, 31 August 2012

Carbon and Rotational Grazing

Grazing (Photo credit: EricMagnuson)

I'm a frequent reader of Mother Earth News for the recipes of nothing else.  Today I was rather pleased with this article that talks about how the correct management of cattle grazing patterns can improve soil carbon sequestration.  In some cases more so than leaving the land fallow

Mob (high-intensity) grazing is nothing new, but in recent years I've been hearing about it more and more frequently.  Here at the University of Kentucky there have been several studies looking at very high stocking rates on pastures and strip grazing corn.  Do you use high-intensity rotational grazing?  What are your thoughts?
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Monday, 27 August 2012

Feeding the Rumen

Warning:  I'm going to try to keep this simple, but it's not an easy subject once you get past the intro.  Feel free to ask questions if you want clarification or more info, I'm happy to to explain anything in more depth.

I come across articles about feeding cattle fairly regularly on various news agencies.  More so in the past few months than usual, probably due to the drought this summer and concern over food costs.  Each time I do, I try to make my way through the comments to see how people are responding and what they think.  Almost every time I see several comments in the vein of "cattle should only eat grass not [grain...candy...byproducts...etc]."

While there is a whole host of reseach out there about the differences between grass and grain fed beef, that's a dscussion for another day.  And one I'm more than willing to have.  You might be suprosed about this beef nutritionist's thoughts.  (Hint:  I like both and think they both have a place).

Rumen diving at it's finest.
The bigger point for me here comes when comments like the example above are followed by some statement about how the cattle need the grass because the other feed is unhealthy or not natural.  And this my readers is where we dive back into the rumen.

The rumen basically just functions as a fermentation tank for a plethora of microorganisms.  Bacteria, fungi, and protozoa love that place!  One of the first tenets of feeding cattle (or any ruminant) is that you aren't.  What you are doing is feeding the microbes.  The microbes digest the food the cattle eats, turning it into the nutrients the animal absorbs and utilizes for energy, muscle building, etc.

Now, I'm not saying that we can't alter the microbial products by altering the diet.  We can and do.  But, the microbes are not overly particular about the form of their nutrients.  They really just want the carbon and nitrogen and other elements to pull off for their own needs.  Everything else is waste, which is rearranged by a series of reactions into a fairly standard set of molecules that the cattle then use.

This is where that warning comes in.  This is a whole semester of ruminant nutrition as short and sweet as possible. 

For example:  Let's say I feed my cow some grass.  The microbes don't really care that it's grass.  They digest the cellulose and other starches to get into the center of each tiny cell in that grass.  That's where the good stuff is.  Proteins, amino acids, and so much more.  When the cellulose is broken down it is rearranged into several products.  The most important of which are volatile fatty acids (especially acetate, propionate, and butyrate).  These are the main players for energy in cattle.

I know here's a lot going on in this image. 
Sorry, it's just not easy to find a good, clear graphic. 
The relevant part for this post is up at the top.  Click to see the original in full size.
The big picture here is that the microbes don't care about the original source of the carbon and nitrogen they stick back together to make VFAs.  It just happens.  You or I can eat meat or beans.  The proteins from either get broken down to amino acids either way.  The microbes in the rumen are similar, they just happen to break down materials that you and I never could becuase they have a different set of enzymes.
As always, there is my caveat that this is not a simple process.  The diet fed to cattle still has to have the right balance of proteins, carbohydrates, minerals, vitamins, etc.  Without that we do end up with unhealthy animals.  No one wants that.  I and every farmer I know hates having sick animals.  We feel for them when they are hurting. But we can continue to create that balance using unusual feeds to provide safe, healthy meat; when they are available, cost effective, and fit the needs of the animals and producer. If they don't go to cattle or other animals, they go to the land fill.  At least this way the waste fills a niche and leaves more corn, wheat, etc for straight human use.

That's my 5 minute ruminant nutrition lesson for the week, thanks for stopping by.  As always, let me know if you want more!
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Sunday, 26 August 2012

The middle.

As of this morning the last samples of period 2 are in the bag.  Or rather the freezer and drying oven.  

Now I enter two weeks of lab work before repeating the whole process.

Friday, 24 August 2012

Inside the Walls

This fabulous video by Dr. Temple Grandin came across my news feed today.  Take a few minutes and see the inside of a properly run beef slaughter facility, as explained by the best in the business.    The video shows what a processing plant is.  No hype, nothing trying to make it better (or worse) than it is.  Dr. Grandin has been recognized for her commitment to animal welfare and humane handling by both the livestock industry and groups such as HSUS. 

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Wednesday, 22 August 2012

Drugs, Hunger, and Obesity

My snack drawer after a week of munchies.
I've been on prednisone for a week now, after something in the garden didn't agree with my face.  Puffy rash, itchy-ness is now under control.  Unfortunately, I definitely got the hunger side effect.  Normally not a big deal, fresh fruit and veggies out of the garden, more food, but good for me food.  Unfortunate thing  part two?  This is one of my intensive research weeks.  I'm living at the beef farm, eating almost exclusively out of a microwave or other easy to manage foods.  Not a recipe for good nutrition.  I think the point of the low calorie ice-cream is defeated after the 2nd serving in a day.  Ah well.  Only a couple more days of the prednisone and I can go back to eating normal amounts and trying to make it healthy foods.

In a tangentially related note, I've been reading up on nutritional immunomodulation, growth promotants, and various other fun topics while working on some research plans and my dissertation.  So, when this NPR article about a possible connection between antibiotics and obesity came across facebook today I just had to check it out.

For many in the meat industry, this seems like something that perhaps should have been looked at sooner.  As the article says:
"Since the 1950s, farmers have known that small amounts of antibiotics increase the weight of livestock by as much as 15 percent. But exactly how these drugs fatten up cattle, pigs and chickens is a bit mysterious."
If we know that livestock grow faster and typically gain more fat when on antibiotics, why wouldn't the same be seen in other species?  Beyond that, we know that antibiotics alter digestion, metabolism and other body systems.  For both animals and microorganisms.  They have far-reaching effects.  This may be some of the first published research showing that there is a 'nutritional downside' to antibiotic use in people, but I don't imagine that anyone is overly surprised by the outcome.

Some of our current big boys.
Now, I'm not saying we should never use antibiotics, they have their place, and play an important role in managing disease.  But they do need to be used carefully, as much in humans as in livestock.  I've often heard the call for reducing or removing all antibiotics from cattle, but just like us, animals get sick.  I can't see any reason to deny them treatment that would save them or better their quality of life just to produce an organic or all-natural product.  Judicious use is important.  Making sure that the doses given are the minimum effective, and that they are given only when needed is crucial.

A big take home for me here is that there is still a need for more and better collaboration between human and animal researchers.  Because we can do more intensive research in animal models and we have focused on how to get livestock to grow to their full potential, there is a lot of information out there that if reverse engineered might provide insight into promoting lean gain and reduced weight in people. 
What other correlations do you see between human and animal health research?

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Tuesday, 14 August 2012

Getting Inside the Rumen

I wrote before about what the rumen is and a bit about how it functions.  Recently I ran across mention of fistulated/cannulated cattle on another blog.  My freinds tend to refer to them as my washing machine cows.  I see these guys every day, they are my research steers.  But I was reminded that not everyone knows about them or understands why and how they come to be.  Cannulas can be placed in other locations, but 90% of the time with cattle we are talking about rumen cannulas, so that's what I'll discuss here.

So, let's begin with just a bit of terminology.  A fistula is a hole.  Specifically it is a connection between two organ or other structures that does not normally exists.  These can occur naturally or can be created by trauma or surgery.  The cannula is the rubber or plastic piece that is inserted to keep the fistula open for access.  The tubes used for tracheotomies?  Those are cannulas.  Just much smaller than the ones we use with cattle.

The next question is always why.  Why do we need cannulated animals?  The simple answer is research.  The long answer is complicated.  Cannulated animals most commonly give us access to the rumen of the cow or steer.    This allows us to take samples from or place things into the rumen.  There are a wide variety of reasons for doing this.  Using some of the research here at the University of Kentucky for a few examples:

1) In my research, we place fescue seed directly into the rumen to induce fescue toxicosis.  Relying on the animals to eat the seed is problematic as it doesn't taste very good and one of the complications of toxicosis is reduced intake.  By placing it into the rumen through the cannula we know exactly how much each animal is receiving each day. This makes the resarch more repeatable and reliable.

2) In situ research.  In situ is Latin for in place.  By placing feed in mesh bags on strings and 'hanging' them in the rumen, we can see how much of the feed is digested over a specific amount of time under controlled circumstances.  Changing the animal's diet, the room temperature, etc changes how the feed is digested.  Better digested feed = less needed to provide the same amount of nutrients.

3) In vitro fermentation.  Again, we scientist types like Latin.  In vitro refers to experiments that simulate animal conditions in the lab.  Most often, we do gas production measurements.  By incubating rumen fluid with various feeds or additives and examining gas production (carbon dioxide & methane) we can predict how these things will affect an animal.  As bloat is a huge issue in the cattle industry, finding natural gas suppression methods is a big deal.

This video from Kansas State gives a good view inside:

I hope this helps answer a few questions.  As always, let me know if you want more information, something doesn't make sense, etc.  It's easy to forget that what I do is unusual when I have done it almost everyday for years.
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