Can early weaned pigs adapt to changes as well as their later weaned counterparts? Iowa State University researchers seem to think so.

The study's objective was to determine whether early weaning alters the pigs' abilities to respond to stress or affects their well-being.
Six pigs from each sow (eight sows per treatment) were either weaned at 10 days of age or at 30 days of age. Using time-lapse photography and direct observations, researchers monitored pigs for five days after weaning and again at eight weeks of age. They used a video to record howmuch time the pigs spent lying around, eating and performing other normal behaviors. Researchers personally observed and recorded the animals' vocalizations, social interactions and fighting behaviors.

At 12 weeks of age, one pig from each litter was isolated from the others and placed in a 24-inch x 24-inch box. Researchers collected blood samples and checked heart rates at 0, 15, 30, 45, 60 and 90 minutes. White-blood-cell counts were determined for the 0-, 30- and 90-minute blood collections to determine the pigs' stress levels.

Researchers found that the late-weaned pigs spent more time eating during the five days after weaning, but less time drinking than the early weaned pigs.

The early weaned pigs had greater average daily gain soon after weaning, but this advantage disappeared by 165 days of age.

At eight weeks of age, the early-weaned pigs tended to fight and root more compared to late-weaned pigs. During the isolation stress, heart and vocalization rates were similar for pigs from both treatments. White-blood-cell counts also were similar for pigs from both treatments. However, the early-weaned pigs did express elevated plasma cortisol concentrations, which indicates slightly higher stress levels.

Although early weaning altered the pigs' stress responses and some behavior patterns during development, it appears that the pigs adapted well to their environment. Therefore, early weaning did not affect the pigs' overall well-being.