Monday, April 29, 2013

Let's Talk About Sex -- Artificial Insemination That Is

Me [to my beloved roommate]: "What should I blog about tonight?"
My Roommate: "Sex."
Me: "Fair enough."

Tonight we're going to be talking about the benefits that AI (Artificial Insemination) has brought to the table since its introduction to livestock production in 1935.

So for everyone out there that isn't an expert on it, here's how it works. First, semen is collected from the male animal of choice. For large animals such as horses and cows, breeding mounts are typically used, with an artificial vagina in them so that the male can have his way with it, and the collection of semen is a little easier than trying to do the dirty deed by hand. (Note, however, that doing it by hand using a variety of methods from masturbation to vibroejaculation is usually how it's done with smaller animals such as wolves and dogs).

Those sassy male wolves

Here are some actually educational photos:
IA tools brought from the USSR by Dr. Ing. Luis Thomasset in 1935 to work at Cambridge Laboratories and South America.

A breeding mount with an artificial vagina for cattle and horse semen collection

Back to the technique, the semen of the animal is collected and "extended." Semen extender is a liquid dilute that preserves the fertility of the semen, makes fertilization possible with fewer sperm and allows it to be transported to the female if she is a long distance away. The semen are also cooled or frozen for the same reason. The tubes that frozen semen are stored in are referred to as "straws." In order to make sure that the semen are still fertile for awhile after it has been frozen, the semen is mixed with a solution containing glycerol or other cryoprotectants. Sometimes antibiotics (like streptomycin) are added to the semen in order to protect against bacterial venereal diseases. After the semen has been sent to the location of the female, it is manually introduced into her reproductive tract.

AI has grown to be a very useful tool since its beginning, especially in the cattle industry; it allows farmers to nearly hand pick the traits he would like to introduce into his herd. AI also circumvents things like injuries during conception that sometimes happen with large animals. As mentioned before, this process makes fertilization possible with fewer sperm, allowing for far more straws to be produced and multiple cows to be fertilized, rather than the fertilization of a single cow through physical conception. Additionally, the farmer does not have to take care of the bull as he would if it were his own, saving the farmer money on feed and veterinary expenses. Disease transmission between animals is decreased as well, especially since antibiotics can be added to the semen before use.

Now let's focus on the benefits associated with trait selection, the true genetic side of AI. Probably the biggest improvement since the introduction of AI is the less likelihood of inbreeding. Before AI, it was altogether too common to accidentally breed related animals to each other, bringing out unwanted mutations and diseases. Presently, it is much easier to track the bloodlines of breeding pairs and avoid crossing those that are related. Now, if a farmer knows his cows have less than desirable  feet and legs, utters, milk yield, fat and protein yield, capacity, or "dairyness" (a physical appearance that is associated with good dairy cows), he can choose bulls that have proven to improve any of those traits in his offspring with other cows. This in itself is a huge help to dairy farmers to increase their milk production and ensure that his cows can produce more milk over a longer period of time.

So, dairy cattle sex? Good. Artificial dairy cattle sex? Even better.

Thursday, April 11, 2013

Cloning -- Risky or Rewarding?

Alright, today we're going to be talking about cloning.

Now, for some out there, when you bring up cloning they immediately think of the "second" Star Wars movie. Wrong-o, Mary Lou.
 Now just to make sure we're all on the same page, cloning is where you take DNA -- just about any kind of DNA -- from an adult animal, and fuse the genetic information with electricity to a donor egg. The egg, containing the exact same genetic information as the adult from which the DNA was taken, is then placed in a surrogate mother and develops just as any other animal would, and is born just as naturally.

Now I'm going to stop right here and make this very, very clear. Human cloning should never be pursued by scientists. I'm merely going to discuss the merits and detriments of animal cloning.

As many know, Dolly the sheep was the first animal cloned, and since Dolly's birth there has been a wide variety of other animals cloned as well, ranging from ferrets to deer to the Pyrenean Ibex.

In my own home state, the Minnesota Zoo is the home to the first bovine ever cloned, a Holstein bull named "Gene." (Punny!!) Gene, along with a few Holstein heifers, were cloned by ABS Global of DeForest, Wisconsin (formerly known as the American Breeders Service). ABS Global donated the heifers for free, but Gene was worth a pretty penny; the Minnesota Zoo bought him to the tune of $20 million.

ABS Global said they let Gene go to the MN Zoo because "his genetic makeup was considered inferior to their other bulls." Now why would someone make a clone if they knew the clone wasn't going to be of any use to them?

Well to be honest, my best guess is that they made clones for the sake of making clones.
As I mentioned earlier, a lot of clones have been tried out, but the kicker is that there are a lot of issues with cloning animals. To sum up the University of Utah's webpage on animal cloning, clones have "a high failure rate, problems during development, abnormal gene expression patterns, and telomeric differences" with their original counterparts.

The page also mentions that "the success rate ranges from 0.1 to 3 percent" of animals cloned. Based on all of this information, one can see why a breeding company, such as ABS Global, would attempt to make clones, if only to see if they could.

Additionally for companies like ABS Global, if their scientists were able to find a way to successfully clone animals in a much higher rate, they could benefit greatly. The dairy industry, as an example, depends on cows that with high milk production. Not all cows are created equal, so if scientists could clone the top producers, farmers would have an even better edge on the market. The only trouble with that is that the clones are not quite identical to the original animal. Just like the aforementioned reason from the webpage above, clones can have abnormal gene expressions. This means that although the clones start off with the exact same genetic material as the original animal, the embryonic cells of the growing clones could differentiate differently, and not produce an "identical" clone.

On the other hand, cloning in the beef industry could make a huge profit -- if scientists can figure out how to clone cheaply. According to Irina Polejaeva (chief embryologist at ViaGen, a livestock-cloning lab in Austin, Texas) in "Cloned Beef: It's What's for Dinner," cloned beef cattle cost "around $15,000, versus $2,000 to produce a naturally bred animal. But the quality of the clone should be a surer bet." That's great for the companies with money to spend, but for everyday farmers, that's not a reality. So, like I mentioned before, if scientists can come up with a way to clone cheaply, then cloned cattle could take the market by storm. For the moment, I don't see it happening, at least for a little while.

Cloning is very interesting to me, and growing up, I've always been fascinated with Gene the cloned bull at the MN Zoo. I think that it's great that scientists have figured out a means to make clones, but they haven't quite perfected it yet. There could be unknown potential benefits to finding a sure-fire way to clone animals; I just can't think of any off the top of my head. All in all though, I'd say cloning is far more risky and expensive than it is rewarding, for the time being.

Thanks for reading!

(Oh and here's a picture of my favorite clone -- adorable, isn't he??)

(Courtesy of my_morgan on flickr)

Wednesday, April 10, 2013

A Quick Blurb on My Story

Hey readers,

I just thought I'd like to start off my first post by explaining how I came to be blogging about genetics. So, here we go!

I originally came to UW - Madison with every intention of being a genetics major. Additionally, I had hoped to become a genetic counselor after college. As great as my aspiring hopes were, things changed for the better, at least in my opinion. Through a communication assignment given to me by a really great TA, I got to know an amazing professor in the Department of Animal Sciences that let me in on a little secret: if I wanted to study genetics, I didn't have to confine myself to just the Genetics department. He let me know that the study of genetics can be found in a variety of other departments, including his own.

I'd always wanted to be able to study animal genetics, but I didn't realize until that very moment that if I actually wanted to do that, I'd be better off switching majors. So I did.

The real lesson from my little blurb is that if you're interested in something as a career, pursue it. No matter how crazy it might seem at first, go after it. Because if you're truly, deeply interested in whatever it is, you'll always be able to find a way to make ends meet while pursuing it. And as the old saying goes, if you love what you do, you won't have to work a day in your life.

That really great TA I mentioned? Well, she assigned a final project in which my class is to use a medium and communicate about something each of us is interested in. So, here I am, blogging about genetics. Really, though, this assignment is just an excuse to do something I'd always wanted to.

Thanks for reading, and I hope you enjoy my future posts!