my suggestions"
if you tie them at the feed bunk, make sure they can't jump in. they will hang themselves.
perimeter fence around working area.
200 amp circuit service?
220 circuits
plenty of 110 so you don't overload circuits
slight depression on egress areas and french drains at doorways
base rock/gravel on approach areas
base rock pile somewhere for repairs
gutters routed away from barn
exits for air movement in roof or eave
pressure pump for washing
gfi near water
corn cooker
office
fire extinguishers
locked room for grain and good grain bins
extra mister emitters
pit for manure composting
wash rack with high walls
turnout pens attached to smaller pen for low stress easier haltering
more than one convenient entrance so they don't get used to using just one entryway
etc etc