Study of an anti-GnRF vaccine as a more welfare friendly method of castration for ram lambs

Abstract

Castration of male lambs is performed in all major sheep producing counties as a standard management practice. The reasons to castrate may be different and will depend on the size and type of the farm. Castration gives more control over genetics of the flock, stops inbreeding, unwanted pregnancies and behaviours. It also gives improved carcass characteristics. However, it has been shown that castration is painful and distressing to the animals. Different techniques are used to castrate sheep at the present time such as rubber ring, Burdizzo, combined, short scrotum, and surgical castration. Due to changing attitudes towards animal pain and unnecessary suffering there is a need for further development and implementation of new castration methods, efficient pain assessment techniques, animal welfare codes of practice and legislative requirements to improve lamb well-being. Recent increase of public concern regarding animal welfare is putting pressure on many government bodies to strengthen research in this area and increase attempts to regulate by law unnecessary suffering during standard livestock management practices. Immunocastration with an anti-GnRF vaccine has the potential to be an alternative to common physical castration methods. Nonetheless there is little or no information about the impact of vaccination against GnRF on the physiology of lambs (rams’ reproductive tract, endocrine regulation), emotionality (possible changes to normal behavioural patterns like increased aggression, anxiety) and health (is the vaccine safe to be used and if there are any adverse effects of vaccination like tissue damage, swelling, lesions etc.). There is also little or no information on how the vaccine affects sheep at the time of injection. This study investigates three main questions: Is Immunocastration a pain free alternative to traditional physical methods of castration? Is Immunocastration safe and practical to use? Does Immunocastration influence the male reproductive system in a way to achieve sterility without any negative impact on the ram natural behaviours, wellbeing and health?