A project was undertaken to investigate the causes of inadequate sticking encountered during a survey of pig abattoirs. The results of the investigation identified the length of the sticking (exsanguination) wound as a major contributor to the problem. Experimental abattoir trials conducted on slaughter pigs comparing two sticking lengths indicated that the rate of bleed out was delayed with short sticking wounds. In addition, information about the identity of blood vessels severed following sticking was obtained. The results indicate that following head-only electrical stunning, a relatively long sticking wound should provide better welfare in slaughter pigs. The study has also highlighted the health and safety problems for the operatives as well as the welfare concerns associated with manual application of electrical stunning.