INTRAPERITONEAL TEMPERATURE OF PIGLETS IN THE FIRST 3 POSTNATAL WEEKSAS MEASURED BY RADIOTELEMETRY

Intraperitoneal temperature (IT) was determined in early-weaned piglet s of both sexes to day 21, using radiotelemetry. Ten piglets (five wea ned on the second, five on the third day after birth), were used in th e study. They were reared individually in cages, offered a liquid diet for suckling at 2-h intervals 9 times a day. They were placed in a te mperature-controlled room with L:D regime of 12:12 h. Audio signals fr om intraperitoneally implanted transmitters Minimitter Co., Sunriver, OR, USA) were converted to body temperature using calibration data. A total of 1,963 daily measurements taken between 06.00 and 22.00 h show that in the first two postnatal weeks the mean daily IT rose signific antly (P < 0.05) with advancing age from 39.8+/-0.1 degrees C to 40.5 degrees C.At the beginning of the second week, there was a transient I T decrease, followed by another increase; IT did not change thereafter . There were also diurnal changes in IT observed in the light phase, e specially during the morning hours. IT was also affected by gender. In males the mean daily IT was higher, though not significantly, during the entire experimental period. During dietary intake there was a smal l temporary increase in IT. An IT elevation occurred in several piglet s suffering from transient diarrhoea. Radiotelemetric procedures with unrestrained animals exclude measurement errors resulting from direct contact with the measuring techniques/devices and the excitement due t o contact with experimenters. Radiotelemetry opens new technical possi bilities of a reliable, undisturbed recording of body temperature in p iglets.