tailieunhanh - Báo cáo khoa học: " Minimising the stress of weaning of beef calves: a review"

Tuyển tập các báo cáo nghiên cứu về bệnh học thý y được đăng trên tạp chí Acta Veterinaria Scandinavica cung cấp cho các bạn kiến thức về bệnh thú yđề tài: Minimising the stress of weaning of beef calves: a review. | Enriquez et al. Acta Veterinaria Scandinavica 2011 53 28 http content 53 1 28 AVS ACTAVETERINARIA Sco ftoyi cc a SCANDINAVICA REVIEW Open Access Minimising the stress of weaning of beef calves a review Daniel Enriquez1 f Maria J Hotzel1 and Rodolfo Ungerfeld2 Abstract Weaning of beef calves is usually done abruptly and early compared to the natural weaning of the species and is associated with simultaneous exposure of calves to a range of social and environmental stressors. Behavioural and physiological responses to weaning indicate detrimental effects on the welfare of these animals. The development and assessment of weaning methods aiming at reducing or avoiding this problem must be supported by scientific knowledge of the morphological physiological and psychological mechanisms involved in the establishment maintenance and braking of the cow-calf bond. Solutions also depend on the understanding of the various stressors associated with weaning among which are the change in diet cessation of nursing separation from the dam the change to a new spatial environment and the need for social reorganization following removal of the adults from the group. This review discusses these issues and assesses the effectiveness of the methods so far proposed for improving the welfare of beef calves during the weaning period. Keywords mother-calf bond separation distress weaning practices behaviour animal welfare Introduction In extensive systems beef calves are usually weaned at around six months of age. The main objective is to improve the cow s body condition thus preparing her for the forthcoming lactation. Although increasing the reproductive and productive performance of the herd abrupt weaning is a source of stress for the cow 1-4 and calf 5-8 . This effect is especially acute and prolonged for the calf which at weaning is subj ected to multiple stressors such as the loss of the mother and access to the udder and milk and changes in the social and .