Vocal communication plays an important role in establishing and maintaining social relationships in many mammalian species. For bovines, vocal communication in particular plays an important role in mediating mother-infant relationships, specifically during contexts of separation. Several species produce calls that are exclusively used to induce nursing behaviour. We therefore predicted that calf calls would affect the behaviour and biology underlying lactation in dairy cows. Playback of vocalizations were conducted at two dairies under controlled conditions. Exposure to calf vocalizations significantly increased milk production in experimental cows by 1-2% in the milking session immediately following the milking session in which playbacks were conducted. The playback of calf vocalizations in the milking parlor therefore increased overall milk production (but not immediate milk release or letdown) in dairy cows. In conclusion, this study suggest that the use of calf vocalization playback as bioacoustic tool provides a non-chemical alternative for increasing milk production in dairy cows.