After looking at some pig game sprites, most I found don't have a bounce. Probably due to pigs having such short legs.
And looking at your images, I want to say that maybe on the side view you should make the but a little more rounded and move the tail down just a pixel or two and reflect those changes on the back view.
And maybe raise the head by 1-4 pixels on the side and front view.
As for the walk cycle, I suggest watching some videos of pigs walking and slow them down if you can.
Edit:
Actually, here's my modifications since I'm not sure if I explained things right.
And looking at your images, I want to say that maybe on the side view you should make the but a little more rounded and move the tail down just a pixel or two and reflect those changes on the back view.
And maybe raise the head by 1-4 pixels on the side and front view.
As for the walk cycle, I suggest watching some videos of pigs walking and slow them down if you can.
Edit:
Actually, here's my modifications since I'm not sure if I explained things right.
