Effects of stochastic food deprivation on energy budget,body mass and activity in Swiss mice

When small animals are faced with an unpredictable food supply,they can adapt by altering different components of their energy budget such as energy intake,metabolic rate,rate of non-shivering thermogenesis(NST)or behaviour.The present study examined the effect of stochastic food deprivation(FD)on body mass,food intake,resting metabolic rate(RMR),NST and behaviour in male Swiss mice.During a period of 4 weeks’ FD,animals were fed ad libitum for a randomly assigned 4 days each week,but were deprived of food for the other 3 days.The results showed that body mass significantly dropped on FD days compared to controls.Food intake of FD mice increased significantly on ad libitum days,ensuring cumulative food intake,final body mass,fat mass,RMR and NST did not differ significantly from controls.Moreover,gastrointestinal tract mass increased in FD mice,but digestibility decreased.In general,activity was higher on deprived days,and feeding behaviour was higher on ad libitum days suggesting that Swiss mice are able to compensate for stochastic FD primarily by increasing food intake on ad libitum days,and not by reducing energy expenditure related to RMR or NST.