Land requirements for grass raised cattle

Asked March 22, 2016, 8:51 AM EDT

Hi,

I have a question about pasture raising cows. I live in El Paso County and have thought about raising cows here. If we did so, I would want to have them exclusively grass/pasture fed (with hay fed in the winter only). So before we consider getting any though, I would like help finding 2 things out. And I realize that these will vary considerably throughout the areas in the county, and between wet/dry years. I am mainly looking for an good average.

First, what is the average cow days per acre in this area (# of days a cow can eat off one acre of grass during its growing season and be satisfactorily fed before needing additional feed of any kind)?

Second, how many acres per cow are required to feed them an exclusively grass diet during the year on average (with hay in the winter only) for this area? Thanks!

-Will

El Paso County Colorado

5 Responses

Will~
I am unsure about the exact number of acres to "run" a cow in your area. There are a number of factors in determining this number - precipitation (amount and timing), historical harvest (grazing and mechanical), soil type, etc. In Pueblo County, the range is 20 to 100 acres per cow per grazing season.

I suggest you contact the USDA Natural Resources Conservation Service in El Paso County. The people there will be able to provide you more specific information.

Jeff

Thank you for the response. I will look them up!

-Will

Hi again. So I thought I might go ahead and post the response I got from the NRSC. I figure that there is likely someone else out there that will also be looking for help with this topic at some point. This guy was a huge help and gave me more information then I had even hoped for. "Hi Will, For your area of El Paso County the estimated production for smooth brome pasture would be in the neighborhood of 1500 pounds per acre depending on the condition of the grass. Allowing for 50% use of the forage means that you can graze about 750 pounds per acre. A standard Animal Unit (i.e. ~1000 pound mature, moderate frame, moderate milk production cow) requires approximately 3% of her body weight per day which would be 30 pounds per day for an AU. Based on the above grass production estimate of 750 pounds per acre, your pasture would support about 25 Animal Unit Days per acre (750 divided by 30). For the 5 acre pasture you would have 125 Animal Unit Days of carrying capacity. That equates to one AU for 125 days or 2 AU's for 62 days, etc. Of course you would need to adjust for the kind and size of the livestock you're actually planning to run on the pasture if different than an AU. The table below show the commonly used conversion factors for different kinds and classes of livestock. ANIMAL UNIT CONVERSIONS AU = +/-1000 lbs. beef cow Animal Unit Category Beef Cow (yr. long avg) - 1.00 Beef Cow (Dry) - 0.90 Beef Cow (Milking) - 1.20 Bull (Mature) - 1.25 Calf (Weaned) - 0.50 Heifers (13-18 mo.) - 0.70 Bred Heifers (19-24 mo) - 0.85 Steers (13-18 mo.) - 0.70 Steers (19-24 mo.) - 0.85 Horse (Mature) - 1.25 Ewe (Mature) - 0.20 Lamb (1 yr.) - 0.15 Ram (Mature) - 0.25 Goat (Mature) - 0.20 Bison - 1.00 Bighorn Sheep - 0.20 Deer (Mule) - 0.15 Deer (Whitetailed) - 0.15 Elk - 0.70 Antelope - 0.20 The grass production ESTIMATE is based on the total annual production (TAP) in an average growing season at the end of the growing season without any influence of grazing during the growing season. You may realize more production than TAP IF proper rotational grazing followed by adequate rest/recover opportunity is applied to a pasture during the growing season. Hope that answers your question. Good luck with your grazing program! For more direct on the ground assistance please contact the NRCS office in Colorado Springs at 719-632-9598 ext 101. Greg Langer is the manager of that office. Ben Berlinger Rangeland Resource Specialist SRM Certified Professional in Rangeland Management NRCS – ACES 318 Lacey Avenue La Junta, CO 81050 Ben.berlinger@co.usda.gov 719-384-5408 x104 (O) 719-469-3895 (C)" Thanks again for directing me to this resource! -Will

Sorry about that post. Let me try it again. For some reason it posted without the spaces between lines.

So I thought I might go ahead and post the response I got from the NRSC. I figure that there is likely someone else out there that will also be looking for help with this topic at some point. This guy was a huge help and gave me more information then I had even hoped for.


"Hi Will,

For your area of El Paso County the estimated production for smooth brome pasture would be in the neighborhood of 1500 pounds per acre depending on the condition of the grass. Allowing for 50% use of the forage means that you can graze about 750 pounds per acre.

A standard Animal Unit (i.e. ~1000 pound mature, moderate frame, moderate milk production cow) requires approximately 3% of her body weight per day which would be 30 pounds per day for an AU. Based on the above grass production estimate of 750 pounds per acre, your pasture would support about 25 Animal Unit Days per acre (750 divided by 30).

For the 5 acre pasture you would have 125 Animal Unit Days of carrying capacity. That equates to one AU for 125 days or 2 AU's for 62 days, etc.

Of course you would need to adjust for the kind and size of the livestock you're actually planning to run on the pasture if different than an AU. The table below show the commonly used conversion factors for different kinds and classes of livestock.



ANIMAL UNIT CONVERSIONS
AU = +/-1000 lbs. beef cow

Animal Unit Category

Beef Cow (yr. long avg) - 1.00
Beef Cow (Dry) - 0.90
Beef Cow (Milking) - 1.20
Bull (Mature) - 1.25
Calf (Weaned) - 0.50
Heifers (13-18 mo.) - 0.70
Bred Heifers (19-24 mo) - 0.85
Steers (13-18 mo.) - 0.70
Steers (19-24 mo.) - 0.85
Horse (Mature) - 1.25
Ewe (Mature) - 0.20
Lamb (1 yr.) - 0.15
Ram (Mature) - 0.25
Goat (Mature) - 0.20
Bison - 1.00
Bighorn Sheep - 0.20
Deer (Mule) - 0.15
Deer (Whitetailed) - 0.15
Elk - 0.70
Antelope - 0.20

The grass production ESTIMATE is based on the total annual production (TAP) in an average growing season at the end of the growing season without any influence of grazing during the growing season. You may realize more production than TAP IF proper rotational grazing followed by adequate rest/recover opportunity is applied to a pasture during the growing season.

Hope that answers your question. Good luck with your grazing program!

For more direct on the ground assistance please contact the NRCS office in Colorado Springs at 719-632-9598 ext 101. Greg Langer is the manager of that office.


Ben Berlinger
Rangeland Resource Specialist
SRM Certified Professional in Rangeland Management
NRCS – ACES
318 Lacey Avenue
La Junta, CO 81050
Ben.berlinger@co.usda.gov
719-384-5408 x104 (O)
719-469-3895 (C)"



Thanks again for directing me to this resource!

-Will