Veterinary session

It is well-known that the different tools of environmental enrichment influence the behavior and physiological state of laboratory animals. In the present work two trials have been carried out. In the first the effect of every day’s occupation on the rat behavior. Two groups of three CR (W1)BR, FELASA SPF male rats were raised from the age of week 5 under physically identical environmental conditions, but the members of the experimental groups received individual personal care, whilst the controls get only minimal human contact. Tests were carried out in the age of 15-week-old.

1: 8-hour-long ethogram of randomly chosen individuals of both groups was taken, registered the sleeping/rest, eating/drinking, grooming and inquisitor behavior. There was no expressed difference between the daylight activity of the two groups.

2: 5-minute-long open-field test has been made with each individuals. Socialised rats shown more activity. Differences are not significant (p>0.05).

3: hiding in running time has been made with each individuals, three times, in 2 minutes intervals. In a corner of the vivarium a hiding place has been put and it was studied the frequency and duration of running and staying in of the newly placed in animal. The first running into the hiding place of the control rats occurred every occasion later), but the average staying of the socialized and control individuals and the number of running in did not differ significantly.

4: the reaction of rats on an unexpected stimulus has been registered. Animals were observed individually during six minutes in the experimental vivarium and the open-field behavior patterns registered. At the end of the third minutes rats were exposed to a strong vocal stimulus (handclap) and observed the duration of getting erect (startling time) and the changes in the ethogram. The socialised animals get frozen for less period of time owing to the handclaps, plus their behavior pattern significantly changed, contrary to the control rats’ one.

In the second trial the effect of faster, “rodentized” human music on the rats’ behavior has been studied. Ten weaned, experimentally naive male rats have been used in a simplified open-field test. After having recorded the 5-minutes-long basal behavior, animals were exposed to the ten-times faster version of “Sonata for Two Pianos in D Major K 448” piece of Mozart, known in the human psychology. Rats unanimously perceived the music, their basal behavior change, but owing to the great individual deviations the differences are not significant.

In summation it can be concluded that in case of rats, above the physical environmental enrichment tools, both the human socialization and the human music may improve the animals’ welfare as an enlargement of the third “R”, the refinement. To find the most efficient methods and the most suitable music further research is required.