The improvement of animal welfare also goes through the development of housing systems designed in such a way as to enhance species-specific natural behaviors and provide an environment capable of satisfying the physiology of the animals. But what is even more important when a new equipment is introduced in the animal facility is to verify the lack of impact on the standard physiological parameters.
The assessment for the verification of the achievement of these objectives is often made, in rodents, using the so-called welfare indicators. Some of these indicators are very simple, for example the trend of body weight over time, the consumption of feed and water, while others are much more complex, such as breeding performances and the impact on the anxious state of the animal.
At the Division of Laboratory Animal Medicine, Chapel Hill North Carolina a group of investigators compared the impact on breeding performances and the anxious state of Sprague Dawley rats using three ventilated cages, one of which is the bi-level (GR1800 Double-Decker, Tecniplast S.p.A, Italy) allowing this species of rodents to best express some natural behaviors (1).
Authors observed some breeding benefits and no impact on anxiety like behavior in rats housed in the bi-level Tecniplast caging.
(1) Lauren E Wimsey et al. Effect of Individually Ventilated Bi-Level Caging on Anxiety-Like Behavior and Breeding Performances in Rats. Research & Reviews: Journal of Veterinary Sciences Vol 3; Issue 1; p. 16-24. March 2017.