Calf sheds need to fit certain criteria.

Adequate space ( 1.5 square m minimum per calf )

Pens should preferably be isolated from each other by using corrugated iron etc so noses can't touch.

This is critical to stop disease spreading right through a shed

Calves should be all in, all out of a pen not mixed.

Good ventilation but no drafts.

Clean warm bedding in the form of straw or wood chips / saw dust. THIS NEEDS MAINTAINED.

Access to clean water. Ensure they can't shit into the water and create disease.

Access to concentrates of high protein % ( 20% or more ) Ensure they can't shit into the feeders and create disease.

Access to good quality hay.

You need a clean feeding system.

Feeding needs to be consistent. It doesn't if matter if it's once a day, ad lib or twice a day it just needs to be an adequate volume and consistent.

BUT NEWBORN CALVES DON'T LIKE COLD MILK AND TAKE MUCH LONGER TO FEED. Make sure milk is collected without going through plate coolers to feed these calves.

Teaching calves to feed is much easier in small pens with small groups of 5 or 6. You can temporarily break up big pens with gates and take them down once they know how to feed. Or put up barriers to break groups up.

There are many calf diseases that can infect humans. YOUR HYGIENE IS CRITICAL.