Placentophagia in rats is modifiable by taste aversion conditioning

An aversion to placenta was conditioned by pairing ingestion with LiCl-induced illness, in virgins, in nonpregnant primipara, and in primipara during the first parturition. Persistence of the aversion was assessed at the subsequent parturition, immediately after the subsequent parturition, and two weeks after the subsequent parturition. The results indicated that (a) female rats can learn an aversion to placenta, (b) the aversion was expressed during parturition, (c) previous parturitional experience reduced retention of the aversion, but not acquisition, (d) rats can distinguish between their own normally delivered placenta and donor placenta, and (e) an aversion to placenta at parturition did not appear to have a major effect on pup care.