Where are you located? I'm gonna go out on a limb here and guess that you're in the western US somewhere and those are lodgepole pine (Pinus contorta) we're looking at. Assuming I'm right:
I agree with Al. If they weren't planted as a windbreak they were definitely cultivated as one. Lodgepole pine is a prolific wind-blown self-seeder after disturbance, so the fact that they're all clumped together there in the center of the clearing with nothing around the edges screams "management" of some kind. Windbreak makes the most sense as they aren't typically grown for Christmas trees. The remaining useful life of your windbreak will be pretty short, though. Relatively speaking, their leaves are photosynthetically inefficient, so the lower branches will begin to self-prune in a few years. I'm guessing 5 to 8. You could extend that windbreak functionality by planting some shrubs upwind of them to force the air up over the top of the
canopy instead of allowing it to funnel through beneath.
It's a short-lived species. Very prone to insects and disease, especially if not thinned, and prone to wind throw if thinned. Fencing will be about your best use. Young lodgepole is great for making zig-zag
fence, or jack-leg if you don't need something critter-proof. Except in some high elevation areas where lodgepole is the climax species they seldom grow large
enough to make much mill-able timber. Squirrels and birds will eat the nuts but I don't know of anything that uses it as browse. I've never raised either animal but I HIGHLY doubt pigs would eat it. I have no idea for goats. I hear they'll eat just about anything that isn't nailed down, including old socks...
If it was my land, I'd leave them in place for now while I established a new windbreak in the area where that truck is parked. Then I'd mow them all down, lop and scatter or
compost the branches, make fencing with the trunks, and expand the garden into the area where they were growing. For that matter: are you standing in the opposite tree line taking that first picture? If so, I'd seriously consider whether you even need a windbreak in such a narrow clearing.
I'm with you: that close to the house I'd rather be growing vegetables than
fence posts, and that's about all you're likely to get from lodgepole.