Friday, June 24, 2011

Dirty jobs: Breeding cows

Welcome to a joint Real Farmwives of America & Friends post!

RFOAbadge
The theme for this post is…

Dirty Jobs.

There is no shortage of dirty jobs on the farm.

Every spring, we breed our certified Angus cows to bulls that we select for their genetic potential. We are looking for things like a relatively low birth weight with a relatively high weaning weight (born small so they are easy for the cow to give birth to, but they grow quickly), rate of gain (growth), and meat quality. There is great data on these (and more) characteristics on many registered bulls. We have the luxury of being able to choose the bulls that we breed our cows to, and we can select different bulls for different cows.

How?

We artificially inseminate our cows every year.

Some of this is going to sound a little odd. But, believe it or not, this is pretty similar to what women go through with hormone therapy and in vitro fertilization when they are having trouble getting pregnant. Read on, and keep an open mind!

First, we bring the cows into the barn and run them, one at a time, in the head gate.


Before we can breed them, we need to synchronize their heat cycles so they are all ready to get pregnant at the same time. Otherwise, we would need to spend a lot of time watching each individual cow to see when she was most likely to get pregnant. This way, we can work with all the cows at once, and not have to stress them out by handling them too many times.

These are called CIDRs (Controlled Intrauterine Drug Release). They contain a synthetic progesterone. This is what we use to synchronize the heat cycles in our cows. You know how women living together will synchronize their periods? We’re doing this for them.


Look familiar? Have you seen the commercials for Mirena on TV? Those are a much smaller version than this. The hormone is even similar, but it is slightly different. Mirena are intrauterine birth control devices for women. CIDRs for cattle (stays in the vagina) and Mirena for women (stays in the uterus) accomplish essentially the same thing – they slowly release hormones, and keep the ovaries from cycling.


We insert the CIDR into each cow’s uterus with an applicator.


And 7 days later, we take the CIDRs back out (that’s what the blue string is for). With the CIDR out, the cow’s progesterone level falls, and she starts to cycle again. We have a pretty short window here, and we need to make sure we plan ahead. 60-66 hours after the CIDRs are removed, every cow should be ready to ovulate. This is when we breed them to have the highest chance of conceiving.

We get catalogs with pictures and statistics of the bulls. Before we start this whole process, we look through the catalog and choose the bulls we want to breed our cows to. We order the semen, and it is delivered to us, frozen, in a tank full of liquid nitrogen.



The liquid nitrogen tank has a Styrofoam insulator, and there are 5 different mini-canisters down inside the tank. This tank can actually hold 6 – the silver sticks poking out of the opening are the handles to each of the mini-canisters. Each mini-canister can hold up to 12 samples of semen. The semen is stored in small tubes, called straws.


We take out one straw at a time, and place it in this heated water bath. It is important to warm the semen up at just the right rate – if you warm it up too slowly or too quickly, the sperm will die and the cows won’t get pregnant. If it gets too warm or not warm enough, the sperm won’t be as active as they should be, and the cow’s won’t get pregnant. It’s a bit tricky.


After the semen is thawed, we cut the end off the straw.


The straw is loaded into the artificial insemination pipette. (That’s my father-in-law. He’s a veterinarian, too.) 


Then, using the pipette, the semen is put into the cow’s uterus.



Can you see the shiny stuff hanging down from the back end of this cow? This is mucus from her vagina. Kind of gross, I know, but this is a good sign for us. When cows are in heat, and ready to get pregnant, they produce a lot of stretchy mucus. We’d like to see this stretching all the way down to the ground. Then we know she’s really ready to conceive.


Three weeks after the artificial insemination, we turn a bull out in the pasture with the cows. We call him the “clean up” bull. His only job is to get any cows who aren’t pregnant yet, pregnant. He has a pretty cushy life – eat, sleep, and, well, play.

Around 45 days after the artificial insemination date, we will check to see if the cows are pregnant. This is done by a rectal examination – we palpate the cows uterus and can tell by the amount of fluid and any “lumps and bumps” (little bitty babies) in the uterus if the cow is pregnant or not. Forth-five days is one of the earliest times that a veterinarian can tell if a cow is pregnant or not; before then there is not much difference in the feel of the uterus. Vets who have been doing this for years can get quite good, and can often tell earlier.

When the cow is confirmed pregnant, we are done, and all she has to do is eat and grow a baby. If she is not pregnant, we will check her again 45 days after the bull leaves. Hopefully, the bull will “clean up” the rest of the herd.

Dirty job? Yes. Absolutely. But we sure do love the calves we get nine months later!

Don’t forget to check out the other Dirty Jobs posts from the Real Farmwives of America & Friends today!

4 comments:

  1. We have done this in the past on our farm too! Although I have never helped with the process, I have observed it!
    I never really understood what the CIDRs were for, although I know my hubby used them. Thanks for the explanation! It makes sense to me now.

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  2. WOW! I learned a lot today. I knew all about AI in general terms, but you did an awesome job filling in all the blanks!

    Great post!

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  3. Dirty job for you, fun job for the bull. Funny, how all mammals have similar systems, etc...

    I did LOTS of research about getting pregnant prior to my pregnancy. And I felt like a cow too...all that pumping...haha!

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