It depends on the individual situation. Bred cows are so high right now that it would take a lot of years to have them be profitable.
I'm not too great with the math, but we've alwasy figured a calf is worth $500 on averqage. In todays market that's way low, but in some years it's way high, so we just work from the average. I don't know the actual dollars in forage, vaccination, supplements, minerals, water if you have to pump it, depreciation and all those other variables. But the figures I've seen claim that a cow cost $325-350 a year. So at the best with those figures you have to figure $1500 profit a year, and the studies actaully show it's more like $75-100. Bred cows around here are going in the $900-1200 range. That works out to around 6 years, maybe a little less because of salvage values, before a cow has paid for herself. Now in my book, that's a long time for an investment to pay for itself. I'm talking commercial cows, if you're doing registered stuff you might hit the jackpot with a bull or a heifer that brings in some big bucks. But you can't plan on that, plus that really good registered cow will cost you more upfront to get in your pasture.
dun