Soil testing is a regular practice for many crop producers. Some livestock operations regularly check feed samples, but why shouldn't both be done? I have noticed that many cattle producers have never tested their soils or feed, yet still expect maximum efficiency & productivity from their forages.
I think this article http://cattletoday.com/archive/2002/May/CT205.shtml is a great read for all cattlemen & women. If we don't have a good handle on what the soils are able to support, and we don't know what the forages are testing, how can we manage?
When I was growing up, there were many local farms with cattle. Today most of those operations are no longer present, and many of the current producers continue to practice management techniques that have served them well in the past, but not necessarily today. Soil & forage testing is every bit as valuable to livestock producers, as it is to row crops.