TİCARİ HİNDİLERDE KORKUNUN KESİM ÖNCESİ YAKALAMA STRESİ ÜZERİNE ETKİLERİ
Project no. 334 · Status: Kapanmış · 2015
Summary
The study aimed to investigate growth and later pre-slaughter stress responses of male turkeys differing in their fear responses to human at 7 wk which measured by voluntary approach (VA) test under commercial conditions using two flocks of the same company. Turkeys were grouped according to their responses to observer as approached-low fear (LF) or aversive-high fear (HF) at 8 observation-areas/flock. At each observation area, first 5 (Flock1) and 3 (Flock2) birds/area that approached to the observer were marked as LF (n=64) using leg bands. The same number of aversive birds were marked as HF (n=64). Fear groups were kept together in their own flock but in an experimental pen. Tonic immobility (TI) was tested on 15 birds/group/flock. At 7 and 17 wk of ages, bloods were collected from 10 birds/group to measure H/L ratio, leucocyte differentiation and corticosterone hormone as stress measures. At 17th wk, beside blood sampling for basal physiology, blood samples were collected after a 30 minutes crating stress in transport cages. Body weights were measured at 7 and 17 weeks, individually. Slaughter weights of male turkeys significantly differed between fear groups being higher in LF (16.65±0.22 kg) group than HF (14.75±0.22 kg). Significantly lower H/L ratio (0.54-0.67)but higher lymphocyte (53.67-46.80 %)was observed in LF group as compared with HF (P?0.05) which was associated with the lower stress response. Tonic immobility responses of turkeys and plasma CORT levels were not significantly varied between the fear groups. Although it could not be associated with TI responses in this study; VA test could be used to define less fearful and less susceptible individuals to stress in male turkeys. Higher slaughter weight together with lower H/L ratios measured in LF group seemed to be promising to improve our understanding regarding to the relations among the behaviour, performance and welfare in commercial turkeys.