A trailer (1) for round bales of fodder material comprising a bed (19) and a pick-up mechanism (35) for transferring bales from the ground onto the bed (19). A lifting mechanism (38) adjacent the front end (10) of the bed (19) is provided with first and second receiving elements (39,40) for receiving four bales sequentially from the pick-up mechanism (35). The lifting mechanism (38) is urgeable by a main drive ram (60) from a first state adjacent the front end (10) of the bed (19) in a rearward direction for transferring four bales on the lifting mechanism (38) to an intermediate framework (26) of the bed (19). The next four bales on the lifting mechanism (38) urge the bales already on the intermediate framework (26) onto the rear framework (27) as those bales on the lifting mechanism (38) are being urged to the intermediate framework (26), and so on until the trailer has been loaded with sixteen bales. The rear framework (27) is pivotally coupled to the chassis (3) from a hauling state to a discharge state for discharging the bales onto the ground with the longitudinal central geometrical axis of the bales extending vertically.