EFFECTS OF SHACKLING AND CONE RESTRAINING ON RESIDUAL BLOOD IN CARCASS AND PHYSIOLOGICAL STRESS RESPONSES OF BROILER CHICKENS

Abstract

The effects of restraint methods on stress hormones (corticosterone, adrenaline, and noradrenaline), blood biochemistry (glucose and lactate), and bleeding efficiency were examined in broiler chickens. Thirty 30 male Ross broiler birds were randomly allocated to either shackling or cone restraint prior to the neck cut. As measures of well-being, physiological data such as alterations in blood metabolites and hormone levels were assessed. Each bird's blood was calculated by comparing its initial body before and after the neck cut for 90 s. The amount of leftover blood was determined using the haemoglobin content of the Pectoralis major muscle. Compared to their shackled counterparts, the plasma levels of adrenaline, noradrenaline, glucose, and lactate were lower in the coned broiler chickens (p<0.05). Those shackled lost significantly less blood than those restrained in a cone. Coned broilers showed significantly less residual haemoglobin in their breast muscles than shackled broilers. It can be concluded that pre-slaughter cone restraint is preferable to shackle restraint. However, a feasible restraint device has not yet been developed.                                                   

Keywords

• broiler
• pre-slaughter restraining
• residual blood
• shackling
• welfare