Texas Pastures Need a Break
Wade Hibler

In case you have not noticed Texas is way over grazed for the most part.  Of course most of the blame will go on the drought we just came out of but the bottom line is this “We are overgrazed”.  Now that the rains have returned we need to think about changes we can make to bring back our pastures as well as create a rangeland condition that will be more conducive to helping us retain “capture” the rains runoff that will come this year. 

The first term we need to understand is Animal units.  I get the call all the time as to how many cows, goats, sheep, etc. that can be put on a place.  Of course their next statement is always “I want to keep my Ag. Exemption” (there is no such thing as an Ag. Exemption.  The correct term is a 1-d-1 open space designation for rangelands).   An animal unit can be designated as 1 Cow with calf, 7 goats, 7 sheep or 1 horse.  This term is generic and can be different in other areas.

Now the other part of the answer to the question of “how many animals” rest on the pastures condition.  If it is covered with ashe juniper (we call it cedar) there is no way you could stock it and not hurt the land.  But if it is a cleared, grass established, pasture with no other inputs you might be able to handle 1 animal unit for 20 acres.

Another way to look at Animal Units is to think of it as commonly defining the average amount of forage consumed by a cow/calf production unit during a year as equal to 26 pounds of dry matter per day.  I know some 20 acre fields in this county so over grazed you couldn’t find 26 lbs of grass over the whole place.

Here are some other warning signs of overgrazing:

• Abundance of unpalatable plants.  Even toxic plants will thrive when nothing will eat them.  When you see lots of pricklypear and other cactus plants you are overgrazed.
• Distinct browse lines on woody plants.  When those animals are hungry they will begin to browse heavily.  If you can knell down and see the neighbors property through the brush your over grazed.
• Pedestaled plants is a condition that occurs when run off washes away soil around the base of a plant.  This makes it look like it is on a pedestal.
• Steep gully banks occur when the slope is enough that rainfall runoff moves with great velocity.  That water begins to cut the soil as it erodes it away and the faster the water runoff the steeper the gully gets.
• Low plant vigor can occur where the grass plants have been grazed so much that a deficit of carbohydrates occur in the root system.  It’s simple, no leaf to produce the plants food, the weaker the plant becomes.
• Increased need for supplementation pastures become so poor that we need to go buy other feed to compensate for the loss of forage.
• Increased livestock use of unpalatable plants happens when there is simply nothing left for them to eat.  Out of desperation they will eat lower quality plants.
• Losses of livestock to toxic plants is the end result.  This happens when the animal is left with no other alternative but to consume toxic plant material.

When you think about practicing a grazing management plan here are some simple rules of thumb.

With proper grazing only 25 percent of each year's annual forage production is consumed by livestock.  After a wet year you might have a few extra head but watch how much of the pasture they consume.  If you are getting more that 25 percent of the forage, back off on stocking rate.

And don’t forget your livestock are not the only things out there.  Insects, wildlife, trampling, etc. consume 25 percent of each year's annual forage production.  So if your grazing 25% and other things in the pasture are taking 25% you should be able to see about half of the forage left at any given time of the year.

2010 will be great year to catch up.  Control weeds now because they are coming with a vengeance this year, and reduce the stocking rate so our pastures can simple catch up.