I spent the weekend at a 2 1/2 day grazing workshop (called the California Grazing Academy) put on by the University of California Cooperative Extension at the Sierra Foothill Research and Extension Center. The workshop covered grazing plans, forage assessment, fencing, and implementation of theory into practice. That is, I got to fence assess an area to determine how much area a cow (pregnant, dry heifers at about 1,000 lbs) would eat in 24 hours. I then fence an area sufficient for 20 cows with 1 strand electric polywire, put them in for 24 hours and see how close I came. I then estimated another, adjacent paddock and tried again for 24 hours. The top photo cows munching on yellow starthistle, an invasive plant. The second is the fence line after 24 hours.
Poison oak shrub after 24 hours:
Along with the grass species that I expected the cattle to eat, they really went for poison oak, yellow starthistle and russian olive (the large shrubs around the poison oak). They didn't seem interested in the interior live oak (which is good) and purple needlegrass. Rachel really doesn't get along with poison oak.