[The effect of short-term fasting on sleep in pigs]

Trials were conducted with twelve piglets of the German Large White breed, intended for fattening. Their age was 56 +/- 2 days and their average weight was 21 +/- 3.7 kg. The piglets were studied for the effect of short fasting on the time and nature of sleep. After 18 hours of fasting (skipping the morning feeding), the piglets were fixed to obtain a combined record, including the electroencephalogram (EOG). This record was used for analyzing the time of waking and sleep, both the NREM stage and REM episodes. The same observations were performed in the piglets after feeding. The differences in the obtained data between the groups of animals were subjected to statistical evaluation. The fasting animals slept for about 15% of all the time under study and their sleep included short NREM periods interrupted by waking. No REM sleep was observed in the fasting piglets. After feeding the piglets slept significantly longer (p less than 0.01), more than half the period of study. Episodes of REM sleep occurred repeatedly in four animals. It is indicated by the results that fasting reduces the length of sleep and the nature of sleep.