Hi Hector
There are all sorts of reasons why they might have gone AWOL, other than that they have come to harm. They may be males. Males have bigger ranges than females so they don’t always turn up every night to all food sources. Also once the females are around, large amounts of their time can be taken up with circling females. Then someone may have repaired fences along their route (bearing in mind that males can travel 2 miles a night there is a fair amount of scope for that), or as Cecil hinted at, they may be being offered food nearer to where they’re coming from.
Hopefully eventually some hogs will return, so I would keep offering food and water in case. Good luck
