EXPERIMENTAL-STUDY OF THE FIRST SUCKLING EPISODE - RAT PUPS INGEST FLUIDS THROUGH A SURROGATE NIPPLE

The present study reported a new technique in which pups ingested flui ds from a surrogate nipple. Cesarean-delivered pups tested before suck ling experience showed oral grasp responses and ingested milk from the surrogate nipple. Pups ingested equal amounts of distilled water and milk and rejected saline. After ingesting milk from the surrogate nipp le, pups remained attached to an empty surrogate nipple, while pups ex posed to distilled water or saline did not show sustained attachment. Brief experience with milk from an oral cannula or from a surrogate ni pple elicited sustained attachment to an empty nipple. Pups ingesting milk from a surrogate nipple showed increased intake of water and sali ne from the nipple when tested subsequently. The surrogate nipple prov ides a new technique for experimental study of early suckling behavior . The results suggest that initial experiences with milk may reinforce components of early suckling behavior.