Grazing lessens the intensity of wildfires by reducing fuel load. Historically, grazing by large herds of wild ungulates kept fuel loads down in between human-induced cultural burns, reducing the intensity of those fires and leaving us with a landscape abundant in old-growth oak trees. Below are links to various articles that discuss the positive impacts of grazing as a fire mitigation strategy.
from UCCE Livestock and Range Topics
from Lisa M. Krieger, Bay Area News Group (pause ad blocker to read)
from UCCE Fire in California