Hyperplasia in interrenal cells of adrenal glands after forced training of turkeys

The aim of this study was to see if there were any changes in the morphology of the adrenal glands of turkeys after varying levels of forced training. Birds of the first group had no training (Control); birds of the second group were trained from their second week of life to their eighth week (T 2-8) and birds of the third group were trained from their second week of life until 20 weeks of age (T 2-20). Training consisted of running 300 meters once per day, 5 days per week. At slaughtering the adrenal glands were taken out of ten animals per group, weighed, covered in Tissue Tek ® and stored at -20 °C until cutting. The adrenal glands were cut and stained, using an adapted protocol of Masson Goldner. From these slices pictures were made with a “AxioCam” camera (Zeiss). From the pictures the areas of adrenal cells and interrenal cells, as well as size of the total investigated area, were measured using a picture analysis program (AxioVision LE Rel 4.3.; Zeiss). Additionally the weight of the adrenal gland in relation to body weight was determined. Training improved the walking ability (T2-20), but in contrast the amount of interrenal cells was significantly higher in birds trained to 20 weeks compared to the control group (8.12 x 10-3 vs. 4.70 x 10-3, t27.2=2.84, p<0.05) with birds trained for 8 weeks in between (6.07 x 10-3). At this point of time we cannot say if the differences are physiological adaptations to the training or if this hyperplasia suggests that the animals were not able to cope with the highest level of training. It remains open, weather these unwanted morphological changes were due to the forced locomotion itself (duration, length, frequency), the handling procedure, or to the high weight and fast growth of the breeding line used in this investigation. Therefore further studies must be done. _______________________________________________________________________________________________________________________________