At 12 months (3months time yet) it says on the breeders diet sheet:

680 grams - Adult complete dry food and

400 gram - butchers tripe can

divide in to two meals a day

that would total 1080 grams a day for a 12 months old rottweiler

does it seems like too much?

I have 12 month old pups at present. They are fed a natural diet which consists of between 3-4lb fresh meat a day as well as a natural mixer (about a mug). They also have supplements and veggies over the week.  I have never fed a complete food nor tinned but Im sure someone on here might be able to advise. It does seem to me that 1080 grams is not enough though.  Obviously the amount of food given is based on the amount of exercise the dogs do.  My older dogs are on approx one and a half pound of meat a day since they have less exercise