The effects of lactation and ambient temperature on the body temperature of female Norway rats.
Norway rat dams were placed in an ambient temperature of 4 degrees C, 22 degrees C, or 28 degrees C. Body temperatures were recorded over a two hour period on three days; each female was observed on Day 4 and Day 10 of lactation and three days after lactation was stopped. Body temperatures were initially higher during lactation than after lactation had stopped. Dams were less able to maintain their body temperatures in the 28 degrees C ambience on Day 4 of lactation than after lactation, and on Day 10 of lactation, were even less able to maintain their body temperatures than on Day 4. During lactation, dams were able to maintain and even increase their body temperatures in the 4 degrees C ambience. The data support the hypothesis that the acute hyperthermia encountered by rat dams during contact with their litters may be due to a physical restriction on maternal heat loss.
D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation; D005260:Female; D007774:Lactation; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013696:Temperature