When you say rib bars do you mean vertical lines around the rib area - sorry sounds a stupid question but I didnt know whether you were getting confused with chaining along his back?
Now for the important bit......5 days old? - dont panic! most look heavily barred at this age - over time the norm is for the lines to break up into spots and then rosette. My little girl I have looked striped when born - I thought I had a toyger
then after a full week I saw it was actually that she was born rosetted so what I was actually seeing was those but joined up - as she grew the space in between grew and lines went
Its far to early to see - and also look at the parents if they are not heavily barred I wouldnt worry toooo much - also if the bars rosette then again this isnt a major problem either.
But again it depends whether you have bought breed, show or pet quality too