Junior or Adult Pellets?

Which would you suggest for a 13 weeks old Rex who's quite slow developing?

Any advice on exact brands of food and quantities appreciated! My doe was on an adult diet and has always only had an egg cupful a day but I am contemplating a different approach for this little chap as he's such a slow developer!

Mine had Junior Excel Pellets, right up untill they were about 6-8 months, then I slowly changed to adult pellets.

For a 13 week old bun, I would definantly use Junior Pellets, and can recommend Excel.