Post-Parturitional Heat Responses of Newborn and Adult Guinea Pigs. Data on Parturition.

Abstract
Summary Ninety-two of 93 newborn females and 121 of 123 newborn males displayed a response when fingered which is similar to the heat response of adult females. The behavior is independent of the post-parturitional heat in the adult and does not depend on the presence of the maternal ovaries. In the adult post-parturitional heat was displayed by a smaller percent of animals and was shorter than normal heat. The preponderance of evidence suggests that post-parturitional heat is induced by factors associated with ovulation in the maternal ovaries. The interval between delivery of the first and last members of a litter was less than 30 minutes in 79 of 80 cases. The time of parturition in 99 animals was distributed about evenly throughout the 24 hours of the day.