| Biosafety individually ventilated cage(Biosafety IVC)is the hardware foundation of high-level animal biosafety laboratory,and it is one of the important primary protective barriers to protect workers and the external environment.In this study,by observing the physiological,behavioral,and reproductive performance indicators of ICR mice reared in biosafety IVC,we explored the effects of biosafety IVC on the physical health and welfare of ICR mice.The main findings are as follows:1.ICR mice were divided into three groups according to the feeding environment: barrier environment as the control group,IVC-1 as the D group,and IVC-2 as the J group.Temperature,relative humidity and ammonia concentration in the environment and cages were monitored,and the weight,organ coefficient,blood physiological index,stress hormone and immune factor of mice in each group were measured.The results show that temperature,relative humidity and ammonia concentration of the cages in group D and J are higher than those in the control group,but they are all within the requirements of relevant standards.There is no significant difference in body weight and organ coefficient of ICR mice between the groups(P> 0.05).Compared with the control group,there is no significant difference in corticosterone,adrenaline and growth hormone between group D and J.There is no significant difference in leukocytes,lymphocytes,monocytes and neutrophils of mice in each group(P> 0.05).Compared with the control group,there is no significant difference in the contents of Ig A,Ig G,Ig M,CD4 and CD8 molecules between group D and J(P> 0.05).2.All day behavior of ICR mice was recorded by infrared camera and video recorder.Through video playback,active,inactive,exploration,grooming,ingestion and abnormal behavior frequency of mice were observed and recorded manually.Finally,anxiety state and motor ability of mice were evaluated by forced swim test,tail suspension test,open field test,light and dark box test and elevated cross maze test.The results show that compared with the behavior frequency of light cycle,the behavior frequency of moving,climbing,grooming,exploration and cage top creeping of ICR mice in each group increase significantly(P< 0.05),and the behavior frequency of sleep and rest decrease significantly(P < 0.05).Central area entry times in group D is significantly higher than that in the control group(P< 0.05),while central area stay times in group D is significantly lower than that in the control group(P< 0.05).Open box stay times in group D is significantly lower than that in the control group(P< 0.05),and shuttle times is significantly higher than that in the control group(P< 0.05).There is no significant difference in indexes of elevated cross maze of mice in each group(P< 0.05),and there is no significant difference between forced swimming immobility times and tail suspension immobility times(P< 0.05).3.The 8-week-old ICR mice cohabited for a long time in a 1: 1 ratio of male and female.The litter size,weaning size,and birth time of the mice in 4 fetuses were recorded,and the weaning rate,fetal interval,and the weight changes of the pups during and after lactation were calculated.The results show that there is no significant difference in litter size,weaning size,and weaning rate of ICR mice between group D and J in the 1-4 litter compared with the control group(P> 0.05),and there is no significant difference between the first birth interval and the mean fetal interval in each group(P> 0.05).The growth curves of the pups in each group are basically similar,and there are no significant differences in birth weight,weaned weight,and final weight(P> 0.05).In summary,this study show that the biosafety IVC have no adverse effect on the health and welfare of ICR mice.This work is conducive to the improvement and popularization of biosafety IVC,and to the research needs of highly infectious pathogenic microorganisms in high-level animal biosafety laboratory. |
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