Raw Beef Necks

I had been buying Welsey raw bison bones at the Dog Bakery (I am not sure what area of the bison - but looks like a knuckle bone to me) for recreational chewing - he does eat the whole thing over time - he is a voracious chewer and it takes him about 4 chewing sessions of about 45 minutes to eat it (I throw out the end so he doesn't choke)...  I was at the butcher recently though and saw some beef neck bones, they are a WHOLE lot cheaper than the bison, so I figured - hey, why not try...
 
A few questions - (i) do I just let him eat the whole thing at once - the ones I got are a little bigger than my fist and he weighs about 45-50 pounds; (ii) since they have a bunch of meat on them, I am going to make some caloric adjustments elsewhere - should I be aware to cut certain things and not others to keep him nutritionally balanced (he eat one meal of homecooked - Glenda's recipe - thanks Glenda!!! and one meal TWO); (iii) anything in particular to watch out for with these?
 
Thanks everyone!!  Canine nutrition is really really complicated - so important and so hard to feel like you are effectively parsing through all the information and doing what is best for your dog!!!