I have an arrangement with someone that gifted me a breeding pair. He wants a pair of the offspring back in exchange. The birds I took in are being particularly well cared for in a fashion he uses. When I go back to him next summer for the exchange, great care will be taken to keep the birds in good feather. They will also be kept in a quarantine area away from my other birds to reduce risk on his end. Birds I have are prone to fighting in transport and season for transport makes so I will be concerned about heat stress. This time of year it would be cold stress. The birds will be taken off feed day prior to transport although given continued access to water.I would not buy birds from a breeder that takes back birds.
BioNightmare.
I box my birds singly and have them over straw in box. We used to routinely transport subadult chickens in burlap sacks like SDM111 suggested although care was taken to keep them from overheating, piling up, or rolling in bed of pickup truck. Such transport messed up feathers. The currently available feed sacks do not allow good airflow unless perforated and they do not wick away moisture associated with defecation.