
For mum to be, she needs to be on the normal top quality diet she should always be having. Maybe as she gets bigger, dividing the daily intake into several smaller meals as there won't be as much room in her stomach, as 'normal'. I do not believe in feeding a pregnant bitch 'puppy food'. This is for PUPPIES, not mum. And I'd be careful she doesn't put on unnecessary weight prior to whelping as she needs to be lean and trim. Her puppies will take what they need before being born. Once you see how many she has to cater for, then you up her food intake, especially into the second week when the puppies will be taking the most. Too much milk early days and she could run into mastitis as newborn puppies don't need lashings of milk.
With feeding the puppies - when weaning started, we started supplementing using warmed goats milk 4 times a day, with a very tiny amount of raw lean mince once a day. The puppies loved that and the temptation was to give more, but early on, they should still be taking most of their nourishment from mum. Once they could lap, then I added a good quality puppy food, mixing it with either goats milk, or water, warmed, into a porridge. Mum was out of the box during feeding, going in to clean up afterwards and allowing 'comfort nursing' until she felt the sharp teeth, and wanted out - fast. We used a food that our new owners could access easily, so they didn't need to switch until later, if at all. With our heavy boned breed, we'd add scrambled egg, cottage cheese, raw mince and so on to the puppy food (not all at the same meal) and also gave them a goats milk drink mid-morning, mid-afternoon and last thing. None of that would be needed by all breeds!