The introduction of a new batch of feed to 400 pigs aged five to eight weeks resulted in 38 deaths and further morbidity associated with multiple haemorrhages. Signs abated within two days of withdrawal of the feed. Widespread haemorrhages were present in many tissues including the pancreas. Additional pancreatic lesions comprised focal necrosis, atrophy and fibrosis of exocrine tissue. The condition was reproduced experimentally in pigs and vitamin K protected mice against the injurious effects of the feed. The cause was not determined but it is speculated that more than one toxic factor and an imbalance of nutritional factors may have been present in the diet.