We are still transitioning from dairy cattle to beef. We kept most of the dairy cows that we had, Holsteins and few of Latvian red breed (basically Danish red), and honestly I think that was a mistake. We should've sold them and bought cows of heifers of beef breeds instead.
So, Problems we've encountered:
1) Winters - Winter temperatures here can drop quite low, cows of dairy breeds just don't gain enough of fat before winter (compared to beef breeds), and although they haven't had any health problems because of that, I don't like to see cows being like that in winter.
2) Udder problems - Huge thing, lost two cows because of that. It seems that Holsteins are at higher risk of mastitis, and the calves only make it worse.
3) Too much milk - this is one of the causes for udder problems. We had few cows that produced milk so much that first few weeks we had to use a milking machine, to prevent udder problems. Once the calf gets bigger, it's not a problem anymore, but at the beginning there's a huge risk.
At the same time I have to admit that some of our Holsteins crossed with bulls of beef breeds gave us very, very good weanlings, since they got that big frame from mother and qualities from beef breed bulls. Also after the first month that milk production helps calf to grow faster.
In general I think it's too much of a risk to use Holsteins this way, and right now we have only few left, most likely we'll keep only one or two that accept orphaned calves.
At the same time we're still going to keep cows that are Holstein and beef breed crosses (Charolais, Angus, Simmental). They are much more balanced animals than pure Holsteins, they produce more milk than average cow of beef breed, but not so much that it causes problems. No udder issues so far. Their calves also have shown good growth.