The effect of stimuli emitted by sucklings on the course of their feeding by bitches.

A change in feeding behavior on the 15th and 16th day of the maternal cycle was observed in experimental bitches whose own litter was partly replaced, on the onset of the 15th day, by foster puppies 12-13 days younger. The number of feeding acts and the overall feeding time increased, as compared with the indices for 2 days preceding the exchange of puppies (the 13th and 14th day of the maternal cycle). In the control group, where puppies were not exchanged, no increase in the above behavioral indices was observed on the 15th and 16th day, and they remained at the level recorded on the 13th and 14th day of the cycle.