i honestly belive a lot will depend on where we got our birds from we have all seen the big fancy lofts some now have automatic cleaning or a fancier that full time cleaning drinkers the floor and so on well i don't belive u can take these into a environment where the loft is not cleaned as there constitution and imuinine system is not as strong how long would it take taking birds to excel from this clean environment to a deep litter system my own opinion would be generations could be wrong or course that why im not overly clean but do clean out but always when buying in look for lofts that are not to fancy