I have bred a lot of greyhounds and would never give my pups Farrels kibble. I start them on weetbix and fine mince. As they get older they get puppy kibble pedigree them working dog mix. petigree or Bonnie. However I give them beef mince, chicken mince, , bones chicken necks yolk of egg. Also a stew once a week. Do not feed onions. A vet will tell you this.
I use calcium,magnesium and multivits with greys. Only use good worm pills. drontal etc. I found years ago that the ones you buy in supermarkets may be okay a couple times but then you are wasting your money. worming is very important.
I think show dogs would need the best but if only pets you may not need the vits etc.