
I don't set much score by temperature taking either. And didn't bother, most of the time. I go by the number of days, from the first mating and never left my bitches to go over by more than 2 days without having my vet examine them.
As for all this giving the bitch puppy food - again I have no idea when, or why, this started. If the bitch has been on a good quality diet, always (!!) and certainly before being mated, why the need for 'puppy food' which is for PUPPIES!! And I didn't up the amount being fed until I knew how many puppies (live, on the ground) she was going to have to cater for. Again there is no more need to get a pregnant bitch fat, as a human pregnant mum. The puppies will take all they need, both before and after birth and once mum is into feeding them, then is the time to up her food intake, not before. It's way more important to feed a quality adult food throughout - and as the bitch increases in girth it is often necessary to split the daily intake into several small meals, concentrating on protein, not bulk.
Feeding a bitch 'puppy food' sounds like nothing more than a sales ploy to me.

ps - With our litters, the puppies tended to go less active during the final day before whelping - the first time this happened, I was really concerned, but it was just them moving into line ready to be born.