Assistant Laboratory Animal Technician (ALAT) Practice Exam

At what temperature might one expect behavioral changes in laboratory animals due to thermal stress?

1. Above TNZ

2. At LCT

3. Below TNZ

4. Within TNZ

The correct answer is: Below TNZ

Behavioral changes in laboratory animals due to thermal stress are most often expected when temperatures fall below the thermoneutral zone (TNZ). The thermoneutral zone is the range of temperatures in which animals can maintain their body temperature without expending additional energy for heating or cooling. When temperatures drop below this zone, animals begin to experience cold stress, which can lead to a variety of behavioral changes. These may include increased activity as they try to generate heat, seeking shelter, or changes in feeding behavior as they utilize energy to stay warm. In contrast, levels above or within the TNZ generally do not trigger the same level of stress responses. At lower critical temperatures (LCT), while animals begin to expend energy to maintain body temperature, the most significant behavioral changes are observed once they are significantly below the TNZ, as they struggle to cope with the cold environment. Thus, temperatures below the TNZ are critical for understanding thermal stress and its impact on behavior in laboratory settings.