Borzoi - nearly four months. Like with many big breeds, they need to be watched for their up and down growth spurts and fed accordingly.
My adults have raw mince with a basic dry food plus bones and canned fish a few times a week, also sometimes leftovers etc. I have tried expensive dry foods with poor results. My young ones alternate between adult, puppy and mature dry food depending on how they're travelling, normally with raw meat, bones and canned fish.
I had a young saluki once whose bottom jaw outgrew her top one within a week causing her to become undershot. We cut meat and any extra protien and she went on mature "fat camp" dry food for over a month and it corrected. She grew into a healthy adult and was never undernourished.