Abstract: A milk liner of a milking apparatus has a resiliently deformable sleeve extending between a mouthpiece and an outlet pipe. The sleeve forms a cavity for receiving a teat of an animal to be milked. The sleeve incudes a first portion having a plurality of ribs, where the ribs extend longitudinally along and transversally outward from the first portion. The longitudinal extent of each rib terminates at a proximal end of the first portion. The transversal extent of each rib terminates in a flange for engaging with a shell. A second portion is located between a proximal end of the first portion and the outlet pipe. Both portions are configured to sequentially and progressively collapse inwards, where the progressive inward collapse is directed towards the distal end of the sleeve when a pressure difference is within a predetermined range, resulting in a peristaltic massage directed upward of the teat.