Feeding different dog breeds

Question
I have in my care a German Shepherd, 2 St Bernard's, And 3 Cross breeds basically called Boar Bulls (I think they are a kind of Bull dog/ Mastiff. Point is they don't seem to be putting on weight.  Both St Bernard's are 6months and 2months while the others are just over a year.  They have been feeding on home made food of Soya beans and maize flour and fish or sometimes meat, it was introduced to my boss but i don't think it's ok cause they don't seem to like it and as i said they are not putting on weight.  I need a proper diet that i can have access to any time cos i don't always have access to Pedigree. Basically i am asking if it is okay to make up a meal for them instead of buying tinned or processed food

Answer
The safest thing for the average dog owner is to feed a dry, commercial dog chow.  The Pedigree should be fine for all your dogs.  Eating an adult chow might slow the growth of the young St. Benards, but that is a good practice giving their bones and joints more time to develop before bearing the full weight of the adult's final size.  

I question whether what you are feeding is the diet growing large breed dogs need.  It may lack the calcium and other minerals dogs need.  Calcium is tricky, too much is just as bad as too little, and it need to have the right ratio to phosphorus.  Canned food may be the complete and balanced diet dogs need, but it doesn't give their teeth and jaws the exercise they need nor help scrape off the decay and bad breath causing tartar.  It is expensive too.  

What I would do is that if the Pedigree is the only dry chow available, I would try to stay ahead on it, buying several bags when it is available.  Check the date on the package, it should be good a long time after purchase.  There is only one store in the area that sells the Pro Plan I feed my one dog.  I am careful to buy before I run out so if they are out, I can still wait a few days.  

I won't say many people don't prepare their own dog diet, but my dogs are too important to me to experiment with their diet.  I prefer to have my dogs' diets tested on Purina's dogs, not my own.  Home made diets are very difficult to do, and I certainly would not risk your dogs on any diet I tried to formulate.  Do you know how much of what is in the soya beans, maize flower, etc.?  You need to know, to know what else to add.