I don't think this is a good story, and also wonder about genetic issues here. Agree about possible heart issues.
About diet: do you check the mill date on each bag of food before buying it? It should be fed within two or at most three months of milling, as some vitamins deteriorate over time. Also, is it a crumble or whole grain feed? Birds will select the good stuff out of a whole grain feed and unbalance their diet.
Breeding stock should be healthy in every way, and not need special care to survive and thrive. If you want to keep him going as a pet, fine, but not as a breeder.
Mary