Differences in Fluid, Electrolyte, and Energy Balance in C57BL/6J Mice () in Metabolic Caging at Thermoneutral or Standard Room Temperatures.

The recommends mice be pair or group housed and provided with nesting materials. These provisions support social interactions and are also critical for thermoregulatory behaviors such as huddling and burrowing. However, studies of fluid and electrolyte balance and digestive function may involve use of metabolic caging (MC) systems in which mice are housed individually on wire-mesh floors that permit quantitative collection of urine and feces.

Short-term Housing in Metabolic Caging on Measures of Energy and Fluid Balance in Male C57BL/6J Mice ( ).

Metabolic caging is an important tool for quantitative urine and feces collection in rodents, although significant limitations and problems accompany its use. Despite strong opinions among investigators regarding the effects of metabolic caging on energy and fluid homeostasis, careful quantitative analysis of the impact of this caging type-particularly when used for mice-is lacking. The current study assessed the effects of metabolic caging, with or without modifications such as plastic platform inserts, on ingestive behaviors, energy expenditure, accuracy of urine and fecal collection, and ambulatory activities in male C57BL/6J mice.

Assessing Accumulation of Organic Material on Rodent Cage Accessories.

According to the 8th edition of the Guide for the Care and Use of Laboratory Animals (the Guide), rodent cage accessories, such as filter tops, should be sanitized at least once every 2 wk. We performed a study to test the hypothesis that organic contamination (measured by ATP content, expressed as relative light units (RLU)) of cage accessories (wire bar inserts and filter top lids) does not differ at 2 wk (14 d) as compared with 30, 60, and 90-d time points after cage change even when in constant use. An additional time point for filter top lids of 180 d after cage change was also evaluated.

Effect of Nearby Construction Activity on Endothelial Function, Sensitivity to Nitric Oxide, and Potassium Channel Activity in the Middle Cerebral Arteries of Rats.

The present study assessed the effect of nearby construction activity on the responses of rat middle cerebral arteries (MCA) to the endothelium-dependent vasodilator acetylcholine and the NO donor sodium nitroprusside (SNP) and the activity of MaxiK potassium channels in MCA smooth muscle cells from male Sprague-Dawley rats. Two monitoring systems were used to assess vibrations in the animal rooms during and immediately after construction activities near the research building where the animal facility is located. One was a commercially available system; the other was a Raspberry-Pi (RPi)-based vibration monitoring system designed in our laboratory that included a small computing unit attached to a rolling sensor (low sensitivity) and a piezoelectric film sensor (high sensitivity).

Rat Breeding Parameters According to Floor Space Available in Cage.

The cage floor space recommended for a female rat with a litter is greater in the 8th edition of the Guide for the Care and Use of Laboratory Animals than in previous editions. As a result, research institutions using commonly available cages to house rats may not offer the recommended amount of space for a breeding pair and litter housed in the same cage. We evaluated breeding parameters in rats housed in cages with 143 in(2) (922.

IACUC Considerations for the Use of Livestock in Translational Research.

Through its program oversight function, the institutional animal care and use committee (IACUC) plays a central role in ensuring the humane use and care of animals in research. To be effective in this role, the IACUC requires explicit knowledge of the species for which it bears oversight responsibility. Owing to a variety of species-specific factors, such as their relatively large size and range of acceptable housing environments, livestock present many special considerations for the IACUC.

The cost of self-imposed regulatory burden in animal research.

U.S. federal regulations and standards governing the care and use of research animals enacted in the mid- to late 1980s, while having positive effects on the welfare and quality of the animals, have resulted in dramatic increases in overall research costs.

PCR testing of a ventilated caging system to detect murine fur mites.

Rodents housed in microisolation caging are commonly monitored for infectious agents by the use of soiled bedding sentinels. This strategy relies on the successful transmission of rodent pathogens from the index rodents via soiled bedding to sentinel cages and the subsequent infection or colonization of sentinel rodents. When the prevalence of a pathogen is low or the target agent is not readily transmitted by soiled bedding, alternative testing methodologies should be used.