THE ART OF OESTROUS CONTROL IN GROUP-HOUSED SOWS - A VIDEO PRESENTATION

摘要

New animal welfare legislation's were introduced in Sweden in 1988 and in Norway in 2000, both prohibiting fixation of sows. As a consequence, sows have to be kept loose during pregnancy, during lactation and after weaning. During the 1990ies a changein the pig industry evolved in both countries and batch production was introduced in piglet producing herds. As all-in-all-out is the main way to raise fatteners, large groups of sows have to be weaned at the same time. Consequently, a large number of sows have to be bred in a short time and artificial insemination is the dominant way for breeding sows. As the use of injecting reproductive hormones to induce farrowing or oestrus is not possible in Sweden and Norway, due to public opinion, a good knowledge about the normal oestrous behaviour is necessary. The main challenge to achieve good reproductive results with group-housed loose sows is knowledge about the interaction between the sows within the group and the interaction between the sows and the boar during the oestrous period.