No way to know if they will work unless you research bloodlines and genetics and then it is a crap shoot on the rumen adjusting, overall fit, environmental acceptance, .... Cool weather is the best time to transfer but the time it takes them to acclimate is not short so I would only consider in late fall but have not even gone that route. Some research showed that it takes years for adult cattle to totally settle into a new environment. Like some said, the younger, the better. Feed a mineral with available and very good levels of Se, Cu, Zn to give them the best chance. Dilute fescue with legumes and other species like orchardgrass if this is a long term thought.
But you can do all you can and if the genetics are wrong, then it is not going to work. The ones that work the best are relatively short haired even in winter. Fuzzy Wuzzy was a bear, Fuzzy Wuzzy did not care (for fescue)!
