You don't necessarily need a set of "trekking poles", but I HIGHLY recommend using something for a third point of contact when sheep hunting. Before trekking poles, guys used walking sticks, staffs, or walking ice axes to good effect. I still use (and prefer) a good spruce stick over trekking poles, but anything that gives you another point of contact will pay dividends at the end of the day with a heavy pack. The advantages (as I see them) are:
1. My legs are less tired when climbing because they don't have to do as much work "balancing" when I take each step.
2. Great as a brace when crossing fast mountain streams
3. Easier on your knees when descending, especially with heavy a pack.
Worth the weight to me and I'm about your age. In fact, my main piece of advise would be to consider sturdiness before weight when picking something out. My preference is to just use one pole (I like the free hand), but using two has it's advantages also.
I don't believe I've met many sheep hunters here in Alaska that don't use some sort of walking support. Try it. You will like it.
Yk