He's a little EE so I would say that's not too far off the mark. I have Ameraucana and the roos are a little slow to develop mass like other breeds. I think yours has a lot more Ameraucana in him than whatever he was bred from. Casportpony is right though, watch the scale. I would also stop all of his additives like ACV for now too. [been thinking about this all day, lol.] Baytril makes their system acidic if I remember correctly and with the ACV it might be too much right now. what I've done in the past for birds that had to be on an antibiotic is make them up some oatmeal with an egg and just a touch of molasses in it. Very little molasses, just a touch. For some reason this seems to tighten things up a bit.Alrighty he weighed about 5 lbs. Just curious...is that a healthy weight for a 9 month old Rooster?