Objective To explore whether the adaptation period needs to be introduced in the living cage experiment used for the detection of metabolic function of mice, and how to judge and set the length of the adaptation period.
Methods The data of 31 mouse living cage experiments from 2016 to 2017 were collected. A 3-day (72-hour) adaptation period was set for each experiment, and data such as drinking water, diet, heat production rate, and body weight were recorded, and the formal detection was started after 72 hours. The collected data of drinking water, diet, heat production rate and body weight were analyzed by 24 h subsections to judge the adaptation effect of mice.
Results About 12% of the 356 mice drank less than 1 mL of water at the end of the 96-h experiment, and there were significant differences in water intake, food intake, heat production rate and body weight between 24-48 h and 48-72 h ( There was no significant difference in water intake, heat production rate and body weight between 48-72 h and 72-96 h (P>0.05), but there was still a significant difference in food intake (P<0.05). The food intake adaptation of each experiment was independently verified, and it was found that there was a significant correlation between the food intake adaptation and the body weight of mice (P<0.05).
Conclusion About 12% of the mice were still unable to adapt to the new water bottle after the 72-h adaptation period, and it is necessary to consider increasing the number of samples when designing the experiment. If food intake data is not a key research direction, a 48-h acclimation period is sufficient to obtain stable results.