Evaluation of Various IVC Systems According to Mouse Reproductive Performance and Husbandry and Environmental Parameters

Abstract

IVC systems are marketed for improving the health and management of mouse colonies. The current study compared mouse reproductive performance and husbandry and environmental parameters among 3 high-density (HD) IVC rack systems (RS1, RS2, and RS3), which were present in separate but comparable rooms. Three breeding trios each of Swiss Webster (CFW) and BALB/c mice were placed in each rack (n = 36 female, n = 18 male). Reproductive indices were measured for 3 breeding cycles over 2 generations; indices included time to parturition, litter size and pup weight, survivability, and interbirth interval. Over 18 wk, personnel used scoring systems to evaluate each RS daily to every other week according to cage dirtiness, need for spot changing, ease of cage changing, daily health checks, and cage wash processing. Macroenvironmental parameters (temperature, relative humidity, noise, total particulate matter) were measured weekly over 14 wks. Microenvironmental parameters (temperature, relative humidity, NH3, CO2, O2) of 2 cages each of male and female CFW mice (4 mice/cage) on each RS were measured at 6 time points over 2 wks. RS1 had significantly smaller mean litter sizes of CFW mice (mean ± 1 SD, 6.5 ± 2.9 pups) as compared with both RS2 (9.5 ± 1.7 pups) and RS3 (9.3 ± 3.8 pups). RS1 scored as beingsignificantly easier to process through the cage wash. RS2 had significantly lower room noise levels (46.0 ± 5.0 dBA) but higher humidity (58.6% ± 8.9%) as compared with both RS1 (43.7% ± 9.9%) and RS3 (46.0% ± 12.0%) over the 2-wk cycle, particularly at 8 and 12 d after cage change. In conclusion, in terms of mouse reproductive performance and husbandry and environmental parameters, each system had at least 1 advantage over the other 2. Therefore, various factors should be considered when choosing an IVC system for mice.

Nest-building in breeding mice: Impact of macro- and micro-environment

“…Moreover, in ventilated cages housing mated breeding animals and their pups, ammonia and relative humidity appeared to increase when cages were changed less frequently (21 days) or when the ventilation rate was reduced (30 ACH). 22 Variations in cage humidity may be related to the IVC system 23 or to the volume of bedding available in the cage. 24 A further important aspect of high humidity is that it may give rise to an increase in the incidence of mortality in pups prior to weaning.…”

Supporting advancement of lab animal welfare and scientific integrity in developing countries: ACURET Cage Consortium (ACCON) Project

“…For this reason, and to maintain adequate ventilation, low relative humidity and reduced concentrations of ammonia and CO 2 in the cages, Individually Ventilated Cage (IVC) systems have been developed that aim to ameliorate these problems. [18][19][20][21][22] However, very few Institutions in Africa breed and use transgenic mice, hence the use of the open cages is still efficient and cost effective.…”