Looks to me like the math is not in your favor. If 4 of the larger pigs in that picture are sows then that is a minimum of 80 piglets per year. That number would triple the next year. They get smart quick. You may have to get some hounds or even rent a helicopter.

Yup.

Too thick for helicopters to work. I am afraid dogs will end up on neighbors land. I am hoping this is seasonal.

I know one thing. They are getting read to be on the receiving end of some rifles and shotguns.

Pour cow mineral salt on the ground, water it down if you can, or let rain and mother nature let it seep...It will last forever..the build a hog proof fence around it, about 10 x 10, I use sheep fencing wire fence, its about 3.5 to 4 ft. high. deer will jump in and out, hogs can't jump that high..Another trick is use and old wood coke box, fill it with corn inside the fenced area and fill it with corn..deer have small noses and can get the corn but only one kernel at a time, not much else can get to it, other than Javalina as far as I know..I bury it ground level. Folks used this prior to fancy feeders on a timer, today the feeders are inside the wire fence and go off and scatter corn at 6am and 4 PM, some hogs show up but can't get to the corn...Just some ideas that have worked for me then and now...

Salt does not work here. My ranch is so close to the Gulf that I can hear the boats. We have an abundance of naturally occurring salt in the ground. They totally ignore salt blocks and salt licks.

Amazing what you can find on you tube. Check out the video where they use 100 pounds of tannerite at a feed station.

https://www.youtube.com/watch?v=QFUNXKATbJg

I have actually thought about that. I have thought about gluing ball bearings on three sides. Might be interesting.

If you go the ball bearing route I suggest you stick with the "Claymore" design. I do not know how critical the curvature is, but I'm betting it is there for a good reason.
I could see ball bearings on three sides resulting in balls going in directions you never imagined

May want to check with your local Game and Fish. Imagine trying to explain that one to the Bureau.! "Well Sir, It all started with these damn wild pigs!"

On private land, wild hogs are the property of the land owner. One can kill them however they want, whenever they want.

I would be careful saying I was going to build a homemade claymore. I'm not sure if that would be legal. They would probally fall under the destructive device regulated by the NFA. I do understand wantimg to reduce the hog population on you're farm. Good lick and if you do end up creating some device I along with others would like to see a video of the results. Ammonia nitrate and aluminu powder can be used to make homemade tanner ire.