Monday, February 2, 2015

The Average Age of a Dairy Cow...

"What is the average age of a dairy cow?"

I've been asked this question numerous times, and never had a really good answer.  So this morning when I was asked again, I decided to figure out what the average age of the lactating cows on our dairy farm is.

I went to the trusty old "heifer book".

This is where we write down all the information about our animals.

As each heifer calf is born, she is assigned an ear tag number, which is simply a chronological record of each heifer born here.  She gets her own line in the heifer book, where we record her birth date, her sire's identification...her dam's identification, and a list of all the genealogy that we have on file for her.

This is a sample of the genealogy side of the book.  (If you are a dairy farmer, some of these sires' names might look familiar to you. Mascot...Peti...Trifecta...Belltone...they were really good bulls in their time, but are only now a distant memory)  We bought the cows from Jim's dad over twenty years ago, so the genealogy list barely fits on the page any more...

We keep a lot of other information in this book as well.  Such as...any illness that a young calf may have that could affect her health or milk production as a cow, and how and why each cow is sold.

Ok...back to the question at hand..."What is the average age of a dairy cow?"

I checked to see how old each of our lactating cows are right now...

We have Dirty Pig...who is almost twelve years old...

We have the Twin...who is herself a twin...who has had three sets of twins...and who will be ten in a few months...

(interesting tidbit on those first two cows...they're both aggressive (not mean) and know how to hold their own among their herd mates.  Don't make them wait for their food, and don't boss them around!  Maybe that's why they're still going strong and two of our highest producers at their age?)

We have a handful of cows who are seven or eight years old...

And then there are fourteen first calf heifers (between two and three years old) and another big cluster in the four to five year range.

The answer to the question here...on our an average age of about 4 1/2 years.  

I was surprised...I really thought that the average would be a bit older than that, but all those first calf heifers really lowered the average.  Then I googled the average of dairy cows in the United States, and guess what?

It's four years!


  1. Oh we have records of our cows from the beginning too it is interesting to look back. That is a good average considering the new heifers. I think our average of Cows is around 5 or six now. Some as old as 10. Calving is coming up though:) Hug B

  2. Wow! I love statistics, and it's so crazy what they will tell you... I would love to know the story behind Dirty Pig's name!

    1. :) I figured somebody might ask about her name! It's simple...she stands back in the gutter, and then back up into her stall, and makes herself all dirty! Here's a post I did a long time ago, about how some of our cows earn their names...

  3. wow. a hard working life, i guess. and i know milk production is a hard job for the cows and for you!

  4. I'm glad to see you care about your animals enough to give them real names and know their personalities and stories. I often hear about dairy farmers who just number their cows and treat them like they are a production machine to be used and then tossed.

    We had a cow named Maude. She was a cranky stubborn old girl. Mom warned us not to yell at her or call her names because the pasture was just across the road from a neighbor named Maude. ;-)

  5. Interesting information, Alicia, thanks for sharing. I always think an old dairy cow as being 5 or 6. I don't know why or how I came up with that number, mostly thinking of the effect of concrete on feet and legs.

  6. Now I want mom to figure the average age of their beef cows. I know we had a couple of family bottle raised pets that made it to a pretty ripe old age. Actually, 4 is older than I anticipated.

  7. That is really interesting. I guess I never thought about how old they get. I would think it was older too. I had a milk cow a Jersey, my grandparents bought her for me when I was five. She had a bull calf every year, the one year she had a heifer calf, it died and my grandparents went to the dairy and tried to get a calf just like the one that died and tried to tell me it was the same calf. I knew it wasn't because I would have got to keep the heifer. They would sell the calf and put it into my college account. I always thought it was such a sweet thing to do. She was an old cow, by the time I graduated from high school, and one day she was gone. I never asked where she went. My Mom sold her milk and butter and buttermilk to all of her customers. You can't do that anymore. Cows just become such a part of your life don't they? I like your stories, sorry this one is so long, I bet I have already told you. I hope it isn't too cold for you all right now.

  8. That is really interesting and I learned a lot. If I were to guess the average age, I would probably guess 5 or 6 - maybe 7 years old, forgetting to factor in the young cows coming up. That's a good idea to keep a good record. Probably comes in handy too if you want to sell a couple of cows. How long to cows normally live?

  9. Thanks for looking into that, it is quite interesting!


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