EN
The goal of the study was to evaluate the magnitude of lamb stress reaction by means of measurements of blood cortisol level changes during weaning and short pre-slaughter transport depending on the breed and their age. Fifty- and hundred-day-old Pomeranian (P), Ile de France (IdF), and crossbreeds of F1 generation (PIdF) ram lambs were used in the present study. The blood was collected from the jugular vein three times a day: I before weaning; II 15h after weaning and III after short transport to the slaughterhouse. The results indicate that the blood cortisol concentration in IdF was significantly higher than in P lambs (49.19 nmol/l and 44.43 nmol/l respectively) while in PIdF the authors determined a moderate level of the hormone studied (46.56 nmol/l). Irrespectively of the breed and collecting time, 50-day-old ram lambs showed a higher (P£0.01) level of cortisol (51.98 nmol/l) than 100-day-old ones (41.46 nmol/l). Moreover, the collection time significantly influenced the cortisol content, which increased from 26.20 nmol/l before weaning to 41.10 nmol/l 15h after weaning and finally to 72.83 nmol/l after transportation. However, different trends of cortisol level changes with respect to the age of animals should be noted. Fifty-day-old ram lambs of all studied breeds indicated a higher hormone release after weaning then after the short transport to the slaughterhouse.