I have a walnut tree in my pasture. What can I do with the walnuts as

are they english or black walnuts? Need more information. What animals graze in the pasture?

I'm not sure what the rest of your question was, but you can do lots with them. Gather and ripen them. Crack them and roast the meats and soak the shells to make natural dyes. Post them for sale, either separately or whole, on places like etsy. There are a lot of yarn dyers that would love a reasonable source for walnut shells for their dying purposes.

I'm not sure what kind of walnut you have but here is an article that might help - https://www.thebalance.com/how-to-harvest-english-walnuts-1388177

If they're Black Walnuts, crack them and use the meats in your cooking or to eat fresh. They are sooooo much better tasting than English Walnuts. Check out Lehmans.com to see the price of just one pound of Black Walnut meats; they are $19.99 per pound! We have about 7 acres of Black Walnut trees and not one nut goes to waste; also, the meats can be frozen in air-tight jars and used months {even 2 yrs} after they have been frozen without any loss of flavor and without any freezer burn.

Or let your local bakery and food stores know that you have home grown walnuts for sale. I know I like to buy nuts/fruits and vegetables from local growers!

Crack them open and freeze the meats. Nuts contain oils and they can go bad just aging on a shelf, so if you can, freeze them. Perfect for holiday baking and just snacking.