AU definition

[msdelin]

Hello. I am new to this board and definitely to cattle. I am so new that I do not have land or cattle at this time. However I am in the process of selling my current residence and moving to Northern Missouri and have a few head of cattle.

My question is regarding the term AU. My understanding is that is carrying capacity of an acre of pasture for a month. For example 1 AU/month is a 1000 lb cow on an acre of land for one month.

However, I do not understand the second month. Without taking into account rotational grazing and non growing months of grass (winter), etc, Does this mean that the 1000 lb cow can remain on the 1 acre month after month or does it need another acre for the next month. Therefore meaning that 12 acres are need for 1 AU per year?

I hope I didn't confuse myself further.

Thank you for your assistance. Over the previous months I have enjoyed reading this forum.

 

[bigbull338]

an AU refers to a cow or cow calf pair.an also the number of acres to carry that cow an her calf when she has 1 for a year.in MO you might could carry a cow/calf to 1.5 to 2.5acs.now my guess/figuring maybe a tad high on the acres but im figuring on the safe side.

 

[msdelin]

Thank you bigbull333.

For clarification, if I have a 2 acre pasture (and no additional land for rotational grazing), would 1 cow/calf pair get the feed it needs during the growing period of the grasses in the pasture.

 

[js1234]

An AU is an animal unit. One AU is one cow, a pair is 1.35 AU's and a yearling is .65 AU's, at least out west. And AUM is an animal unit for one month. If in your area an acre will support an AU, then that is it. If you were told 1 acre per AUM, then yes, multiply by 12. I'm guessing though that in MO you probably can run a cow year round on 3-4 acres but I'm not qualified to say for certain.
Stocking rate varies wildly based on where you are geographically and what your country is capable of specifically. As an example, our California ground takes 14-15 acres to run a cow year round and 4 acres to run a stocker from November to May. Our Nevada ground requires about 80 acres to run a cow year round. Our stuff up in Wyoming we don't run mother cows on but it takes about 7-8 acres to run a yearling from May to October.
All that said, a little ground that runs a mother cow every 3-4 acres sounds pretty good.

 

[bigbull338]

if you have a 2ac pasture you can carry a cow/calf till the grass runs out.an thats if you dont get timely rains.an if you run out of grass youll be feeding hay.

 

[msdelin]

Thank you for all of your replies.

I'm sure I will have additional question as the time grows nearer to moving.

 

[Chris H]

You got great answers, and they gave examples how things vary across the country. Dun is in Missouri and knows a lot about managing pastures. My advice is to look up his posts.