We raise a flock of 70 dairy and meat sheep on 185 acres on yhe central coast of CA on what I call an oak Mediterranean forest. The Dorpers are out 24/7 and the dairy girls are spoiled closer to home on rotationally grazed pasture. We don't have loads of grass here so the flock definitely eats mostly browse. The breed that has hands down been wonderful for us is the Dorper. They can utilize low quality feed and turn it into succulent meat and the amount of fat they have is seriously impressive. We have lots of toyon, ceanothus, thistle, CA sage, sycamore, and oak. The acorns in the fall and winter might be responsible for all that fat. There are loads of various types of plants I'm forgetting but I'm sure you get the picture. Our 8-10 month old lambs hang between 70 to 100 lbs which is really amazing. We've been running sheep for about 12 years so we've had a pretty good run at this and it seems to be a perfect match for us. I would say though that supplementing with kelp is always a good idea, given that it is cheap insurance that fills in any nutritional gaps and also helps remineralize the soil via those tidy little sheep poos.
The dairy girls get irrigated pasture most of the year and I focus on medicinal plants and herbs over grass but of course the seed bank is full of grass so we get that as a default as well. They love it all and clover is their absolute favorite but they eat chicory, dandelion, and I plant sorghum in the summer for them and they eat it, along with the malva, lambs quarters and mustard that pops up which they also love. Overall the sheep tell me grass is highly over-rated and they would rather eat the forbes.
Hope that helps!
Brieanne