In a milking cluster of teat cups, each teat cup (1) has a port in the form of a nozzle (13) disposed in the head portion (6) of the flexible liner (3) of the teat cup. The milking cluster includes a distributor (111) having a fluid inlet (114) aid outlets (115) connected to the nozzles (13) of the cups. The distributor inlet is connected to a supply (130) of filtered air under atmospheric pressure by a first valve (132) which is operable to admit air to the distributor in order to regulate the level of vacuum present in the teat cup liners (3) during a milking cycle. It is connected to a delivery line (112) for supplying sanitising fluid, which is utilised to treat the teats and teat cups in a cleansing cycle following the milking cycle, by a second valve (126) operable to maintain the delivery line (112) primed with sanitising fluid preparatory to initiation of the cleansing cycle.
