I think having two breeds is very do-able if you have smaller herds of each breed. There is absolutley nothing wrong with doing this. I have had two breeds on several occasions that were bigger herds( over 100 head of each breed) and what I found was that I was spread too thin between each breed. It was hard for me to prepare two show herds, attend as many breed shows, sales, and breed functions, as I felt I should be attending, etc etc . This could have been a situation that many others would not have, and it was mainly because I only had my father at home to do the work while I was away. I don't think you should have any problems if you are thinking of keeping two herds with smaller numbers. I have alway said that the Shorthorn breed could see huge growth if every Shorthorn breeder would give two heifers to someone with another breed of cattle, and provide them with free semen, with the only payment required being a promise that they register the offspring.