Statistical Analysis of the Leakage Situation in the Automated Watering System for Mice in Tsinghua University Laboratory Animal Resources Center

Abstract

Objective To calculate the leakage rate of the automated watering system in Tsinghua University Laboratory Animal Resources Center, to evaluate the safety of the system, and provide references for selection, maintenance, and management of automated watering systems in animal facilities. Methods This study investigated the automated watering system installed in South and North Barriers of Tsinghua University Laboratory Animal Resources Center (Phase II). Water leakage monitoring was conducted over two periods, one over a period of 3 years and the other over 1.5 years. The occurrence of water leakage events at the two barriers during the monitoring period was statistically analyzed, classifying the causes into four categories: mishandling by personnel, animal behavior, obstruction by foreign objects, and deformation of fittings. The total daily leakage rate due to these causes and the daily leakage rate caused by quality issues, i.e. obstruction by foreign objects and deformation of fittings were calculated. Further analysis and discussion focused on the causes of water leakage and its impact on the facilities. At the same time, the number of caretakers at the end of the monitoring period in the Phase I facility without automated watering system and the Phase II facility with automated watering system were counted. Finally the difference in the number of cages per capita under the two watering systems was calculated. ResultsA total of 52 water leakage incidents occurred in both areas during the monitoring period, with a total daily leakage rate of 0.000 13%. Among them, 31 were caused by personnel mishandling, accounting for approximately 60% of total leakages. Enhanced training, supervision, inspection, and effective reminder measures could reduce leakage caused by personnel mishandling. There were 2 cases of water leakages caused by animal behavior, 0 leakage due to obstruction by foreign objects, and 19 leakages due to system quality issues, with a daily leakage rate of 0.000 07%. According to the operation data of Tsinghua University Laboratory Animal Resources Center, the average number of cages managed per person in facilities equipped with the automated watering system was 908, compared to 570 cages in facilities without the automated watering system. This represents an approximate 59% increase in the number of cages managed per person with the adoption of the automated watering system. Conclusion The daily leakage rate of the automated watering system in the Tsinghua University Laboratory Animal Resources Center is significantly lower than the theoretical design rate of 0.003%, which demonstrates the system's safety and effectiveness. Additionally, the adoption of an automated watering system can significantly enhance caretaking efficiency. While initial investments in the system are required, the subsequent increase in efficiency leads to a continuous decrease in labor costs, thereby reducing the total operational expenses of the facility. In the context of modernizing animal facility construction, automated watering systems are becoming an essential consideration in facility design and operation.

Keywords

• laboratory animal
• animal facility
• automated watering system
• leaking rate
• mice