Assistant Laboratory Animal Technician (ALAT) Practice Exam

What is the lower critical temperature (LCT) range for rats?

1. 20-25°C

2. 25-28°C

3. 26-30°C

4. 30-35°C

The correct answer is: 26-30°C

The lower critical temperature (LCT) is an important concept in understanding the thermal regulation of laboratory animals, including rats. For rats, the LCT range is typically around 26-30°C. This range indicates the temperature below which the animal must expend energy to maintain its core body temperature. When the environmental temperature falls within this range, rats require additional metabolic energy to generate heat, as they are unable to maintain thermal comfort without adequate insulation (like fur) or additional heat sources. This is a crucial consideration in laboratory settings, as it impacts husbandry practices, including housing conditions and environmental controls to ensure the well-being of the animals. In contrast, the other ranges provided do not accurately reflect the physiological needs of rats regarding temperature. The specified range of 26-30°C is based on established research and standards for animal welfare in laboratory settings.