Infracrvena termografija za mjerenje promjena temperature kljuna kao odgovor na akutni stres u kokoši nesilica

The aim of this study was to investigate beak surface temperature changes to stress induced by fear resulting from tonic immobility using infrared thermography in laying hens. It was also examined whether beak temperatures differed among brown and white lines. The study was based on 89 hens from both lines: 45 White Leghorn birds and 44 Hy-Line brown birds. Beak temperature was measured with infrared thermography immediately before and after tonic immobility testing. The average temperature was obtained from the upper and lower beak area measurements. The beak temperature before tonic immobility had significantly higher temperature than after tonic immobility testing. Birds with shorter tonic immobility had lower temperature of beak than birds with longer tonic immobility. An interaction effect of stimulus (before and after tonic immobility) and tonic immobility time was significant. The upper and lower beak temperatures significantly (P<0.001) decreased in response to tonic immobility test in birds with shorter tonic immobility. Brown hens had higher lower-beak temperature compared to white hens. Based on these results, hens experienced tonic immobility resulting in beak surface temperature changes that were detectable using thermography. Therefore, infrared thermography could be used as a non-invasive technique to assess beak temperature changes in response to stress. Infrared thermography could improve ability to evaluate hens under potentially stressful conditions.Cilj ovog rada bio je istražiti promjene temperature površine kljuna u kokoši nesilica uzrokovane stresom zbog straha pri testu tonične imobilnosti. Mjerenja su obavljena infracrvenom termografi-jom. Istraženo je i razlikuje li se temperatura kljuna u smeđe i bijele linije. Uključeno je 89 kokoši obiju linija: 45 jedinki pasmine White Leghorn i 44 smeđe jedinke pasmine Hy-Line. Temperatura kljuna mjerena je infracrvenom termografijom neposredno prije te poslije testa tonične imobilnosti. Prosječna temperatura dobivena je mjerenjem gornjeg i donjeg dijela kljuna. Temperatura kljuna prije testa tonične imobilnosti bila je znakovito viša nego poslije testa tonične imobilnosti. Jedinke s kraćom toničnom imobilnošću imale su nižu temperaturu kljuna od ptica u kojih je tonična imo-bilnost dulje trajala. Interakcija podražajnog učinka (prije i poslije tonične imobilnosti) i vrijeme tonične imobilnosti bili su znakoviti. Temperatura gornjeg i donjeg dijela kljuna znakovito je snižena (P < 0,001) kao odgovor na test tonične imobilnosti u jedinki u kojih je test kraće trajao. Smeđe jedinke imale su višu temperaturu donjeg dijela kljuna u usporedbi s jedinkama bijele linije. Na temelju ovih rezultata, u kokoši u kojih je učinjen test tonične imobilnosti došlo je do promjene temperature površine kljuna koja je izmjerena termografijom. Infracrvena termografija mogla bi se stoga upotrijebiti kao neinvazivna metoda procjene temperaturnih promjena koje prate odgovor na stres. Navedeno bi moglo unaprijediti mogućnost procjene kokoši koje su izložene potencijalno stresnim uvjetima