@article{oai:soar-ir.repo.nii.ac.jp:00010823, author = {YOSHIDA, Motokazu}, issue = {2}, journal = {信州大学農学部紀要}, month = {Dec}, note = {Effects of the age of pups and the number of days after delivery on retrieving behaviour were examined using the procedure of continuous cross-foster nursing. The procedure included the foster mother which reared either 1-2, 7-8, or 13-14 day old pups repeatedly from 1 to 14 days after delivery. Results obtanined were as follows. 1) The difference in the latency of retrieving among the age of pups was significant but that among the number of days after delivery was not. The mean latency of retrieving of the mother reared 13-14 day old pups was longer than those of the mothers reared 1-2 and 7-8 day old pups. 2) The difference in the duration of retrieving among the age of pups was significant but that among the number of days after delivery was not. The mean duration of retrieving in the mother reared younger pups was shorter than that reared older pups. 3) Mothers of 2 days after delivery was slower to begin retrieving than those of above 4 days after delivery in all groups. 4) The variance of the latency was larger than that of the duration of retrieving. The fact demonstrated that the time to begin retrieving was more influenced by many environmental conditions. 5) It was concluded from these results that retrieving behaviour observed over the period of 14 days after delivery, was effected by the age of pups and was stimulated more strongly by younger pups, independently with the age of the foster mother., Article, 信州大学農学部紀要 12(2): 53-60(1975)}, pages = {53--60}, title = {Effects of the Age of Pups and the Number of Days after Delivery on Retrieving in Mice}, volume = {12}, year = {1975} }