Fat tire vs regular mountain bike in mud Looking to see which one is better suited for me. Mid 50's outta shape and heavy and need the exercise. Will be checking cows and fences. This is mostly flat pasture and hay meadows with lots of wallows from hogs tearing it up.Any help would be greatly appreciated.
Mud is even difficult for experienced riders. And a fat tires is not always better at mud.  If you need to dig down to get to solid ground a more narrow tire can be better.  

Sand is where a fat tire is nice.  But even soft deep sand is going to be a challenge on a fat tire.  

I would look for a 29" mountain bike that will take up to 2.4" tires. 
And there are are mud tires.  Mud tires does not just get better traction but they shed the mud better.