Back in the Day when life was still Good, the wife (now ex wife) used to run Great Dane Rescue NSW, and we had afew Danes of our own, plus the Boxer, and a managary of rescue Danes and Dane Crosses over the years.
Now the staple for their diet was Blackhawk Kibble grain free(so we alternated the lamb and rice, chicken and rice, Fish and Potato...they would not touch the kangaroo ...the rescies did, ours were too fussy). There are different varieties for puppy, adult, working dog and dogs needing diets to loose lard.
https://www.petcircle.com.au/black-hawk
The trick with this is to get a really decent 25 Kg drum with an air tight lid, that keeps the kibble crunchy and fresh for 30 days.
We would also supplement with turkey wings, thighs and drumsticks (local butcher would put some aside in bulk for 3 bux a kg for us), chicken frames and chicken wings (all uncooked, as cooked bones splinter and shatter and are no good for doggy digestion system) and marrow bones.
They never got the taste for roo or bunny, so we kept it on what they would eat and kept them healthy with shiny coats.
Now the trick is to get a great scoop (a diagonally cut in half 29 liter square drum with a long handle on it worked here) and long shovel, a 63 liter bunnings bin with lid and top quality glad garden bags (do not skimp on bag quality otherwise bin day when transplanting the baggy to the big bi is a tormenting experience). Once a day mine sweeping and clearance into the baggy lined bin, and sorted.
Plus keeping plastic shopping bags for poop patrol when doing walkies. Just passing on these tips as the dog rocks here were industrial scale
Cheers