[An economic comparison of replacement decisions for sows in the field and in model conditions]

On twelve farms in the Netherlands, using the VAMPP herd health and management information system, were collected and analysed detailed sow culling data over the period from 1985 to 1986. A total number of 1617 sows were culled, resulting in an annual culling rate of 50 percent, more than half of which was due to reproductive problems (34 percent) and low productivity (17 per cent). When the calculated model recommendations and the actual decisions were compared, there was a striking resemblance for sows culled because of low productivity. With regard to reproductive problems, however, sows not showing any heat were culled too early after weaning and sows which failed to conceive too late. The total calculated losses due to premature disposal were found to average Dfl. 124,- per culled sow, or Dfl. 9,300,- per year in a 150-sow herd.