Resumen de The effect of infra-red radiation on rectal, skin and hair-tip temperatures of rabbits.
An experiment was conducted on the effect of infra-red (i.r.) radiation on female NZ>/1/ rabbits. A 4x3x6 factorial design was employed in which the factors were: 4 intensities of i.r. radiant heating of O.O, 1.9, 2.1, 2.4 MJ/m2/h; 3 replicates and 6 rabbits. AII animals were watered and fed a standard ration ad libitum. Rectal temperatures differed (P<0.001) between treatments and were highest at the "high" level of i.r. radiation (1 ºC higher than far controls). At the "medium" and "low" levels of i.r. heating RT's were respectively 0.3º and 0.2ºC higher than in controls. In different i.r. treatments skin temperatura (ST) was significantly different (P<0.001), being highest at the "high" i.r. level, with values of 42.8 ± 0.5ºC. Under the "low" and "medium" levels, corresponding ST values were 37.8 ± 2.1 and 39.5 ± 3.0ºC, respectively. Skin temperatura differed with time of exposure (P<0.001), increased most rapidly (by 5.9ºC) in the first 20 minutes, but only by a further 0.8ºC in the subsequent 40 minutes. Between different level or i.r., hair-tip temperatura (HTT) was significantly different (P<0.001), values being highest under the "high" i.r. treatment. Comparad to controls, exposure to the "low", "medium" and "high" i.r. levels increased HTT by factors of 1.1, 1.3 and 1.6 respectively. Between different times of exposure, HTT also differed significantly (P<0.001) with most of this effect being in the first 20 minutes (a 1.6 fold increase). During the second 20-minutes interval a further significant increase was recordad, but of only 0.6ºC. From the above results it can be concluded that the higher the level of i.r. heating, the more stressed the animals was.
