Rate of blood loss and timing of exsanguination on prevalence of ecchymosis in fallow deer (Dama dama)

Abstract

Blood loss associated with four combinations of stunning and exsanguination methods was determined as part of studying prevalence of ecchymosis in slaughtered fallow deer (Dama dama). A fifth treatment simulated incomplete severance of the extended neck after captive bolt stunning. Predicted mean weights of blood collected from the five slaughter treatments, including electrical stunning followed by the thoracic stick method of exsanguination, captive bolt stunning followed by the thoracic stick, captive bolt stunning followed by the gash cut method of exsanguination, electrical stunning followed by the gash cut, and captive bolt stunning followed by incomplete severance of the extended neck, were 1458.7, 1072.7, 684.5, 463.7, and 228.5 g, respectively. The overall effect of exsanguination method was highly significant (p<0.001) with the thoracic stick resulting in the greatest weight of blood collection in the 10s period immediately after initiation. The overall effect of stunning method on blood loss was not significant, although there was a significant (p<0.05) stunning method by exsanguination method interaction. Ecchymosis of varying severity occurred in some carcases from all treatment groups. Using the total loin and round ecchymosis scores, when little or no ecchymosis (grades 0 or 1) was compared with some ecchymosis (grade 2) by logistic regression, castrated bucks were 9.8 times more likely (p=0.002) and does 4.2 times more likely (p=0.06) to have some ecchymosis than entire bucks. The results indicate that ecchymosis can be reduced in fallow deer carcases by thoracic stick exsanguination incorporated less than 10s after stunning.