Piglets that miss the call because there is too much mechanical noise or they don't recognize their mother don't get their share of milk and colostrum, and get off to a slow start. Closed, insulated barns with deep straw packs maximize piglet survival but require high-volume air movement. The straw-manure mixture gives off heat and gases as it composts. Simply installing bigger fans caused too much noise for piglet-sow nursing communication. Farmers isolated fans and built quieter ventilation systems.
Peaceable interactions take planning and room.
Creating and managing these environments demands a depth of knowledge of hog tendencies and behaviors. The emphasis in conventional systems on technology, volume and isolation of individual sows provide younger farmers few chances to learn about natural hog instincts, says Halverson. Sows given freedom of movement and time to bond with their litters show strong maternal instincts through weaning, which is best done gradually to diminish stress for sows and piglets. Farmer Gunnar Ljungstrom of west-central Sweden incorporated these features in the system he developed to allow natural hog behaviors. In these Swedish barns, farmers have to get in and walk among their pigs at least once a day to develop mutual trust with the animals.