?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Placentophagia+in+Nonpregnant+Rats%3A%0D%0AInfluence+of+Estrous+Cycle+Stage+and+Birthplace&rft.creator=Kristal%2C+Dr.+Mark+B.&rft.creator=Graber%2C+Gary+C.&rft.subject=Behavioral+Biology&rft.subject=Psychobiology&rft.subject=Comparative+Psychology&rft.subject=Animal+Behavior&rft.description=Prior+parturitional+experience+and+genotype+have+previously+been+found+to+affect+the+proportion+of+nonpregnant+female+rats+and+mice+that+will+eat+foster+placenta.+The+present+series+of+experiments+was+designed+to+investigate+the+influence+of+estrous+cycle+stage+on+placentophagia+in+rats.+Foster+placenta+was+presented+to+nonpregnant+Long-Evans+females%2C+purchased+from+a+commercial+breeder%2C+for+15+min+on+5+consecutive+days.+We+found+that+virgin+placentophages+were+most+likely+to+have+eaten+placenta+on+the+first+presentation%2C+unless+the+first+presentation+occurred+during+proestrus.+In+fact%2C+virgins+would+not+eat+placenta+for+the+first+time+during+proestrus%2C+regardless+of+test-day.+However%2C+once+they+had+eaten+placenta%2C+either+in+a+nonproestrus+stage%2C+or%2C+in+the+case+of+primiparae%2C+during+parturition%2C+they+would+eat+placenta+during+proestrus.+Long-Evans+rats+born+in+our+laboratory+differed+from+the+purchased+rats%2C+manifesting+an+incidence+of+placentophagia+that+was+too+low+to+be+analyzed+by+stage+of+the+estrous+cycle%3B+when+tested+as+primiparae%2C+however%2C+there+were+no+differences+between+the+two+groups.&rft.publisher=Pergamin+Press+and+Brain+Research+Publ.&rft.date=1976&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F6219%2F1%2Festrous.pdf&rft.identifier=++Kristal%2C+Dr.+Mark+B.+and+Graber%2C+Gary+C.++(1976)+Placentophagia+in+Nonpregnant+Rats%3A+Influence+of+Estrous+Cycle+Stage+and+Birthplace.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F6219%2F