if you're looking to milk only once a day, consider keeping the calf on for half the day, and penned separately for half the day. all cows go through changes in their production as the calf grows, and many dual-purpose cows, although they don't produce like the production dairy breeds, still need to be milked twice daily to not have mastitis or damage to their udder. at least for some part of their lactation. sharing the milk with a calf solves the problem and lets you milk once a day. we do this with our high-production dairy goats as well - we separate the kids at night and milk in the morning, then the kids run with the does during the day, so there's no evening milking required. and you're raising a beef calf at the same time, so there's a bonus.
with goats, we let the kids have the first 30 days of milk, and share after that... it gives the kids the best start and we're not in the milk production business so it works fine. depending on your purpose, you might start sharing earlier, especially if you have a high-production cow. some of our dairy does bag up early and we actually start milking a month before they kid to prevent damage to the udder and mastitis. don't know if this happens in dairy cows or not.