Effects of surgical catheterization and degree of isolation on the behavior and exocrine pancreatic secretion of newly weaned pigs

The purpose of this study was to examine the effects of surgery and isolati on on behavior and exocrine pancreatic secretion of nursery pigs. Thirty-tw o pigs were weaned at 28 d (d 0) of age and assigned to one of four treatme nts that comprised the 2 x 2 factorial combination of surgery (surgically m odified, intensively handled animals or intact, minimally handled animals) and isolation (fully or partly isolated). The pigs were kept in metabolic c rates that provided full or partial isolation for 25 d after weaning. On d 3, one-half of the fully and partly isolated pigs were surgically fitted wi th a pancreatic catheter, whereas others were left intact. Exocrine pancrea tic secretions were collected from catheterized pigs beginning on d 7 and c ontinuing every 2nd d. Behavior of the pigs was video-recorded on d 6 and 1 3 from 0700 to 2230. There was no indication of treatment effects on the ex ocrine pancreatic secretion. The volume of pancreatic secretion increased f rom d 5 to 23, and during the same period the output of protein and enzyme activity also increased. Surgically catheterized pigs showed a passive beha vioral response in their undisturbed behavior, characterized by less time s pent active, fewer postural changes, less chain manipulation, fewer escape attempts, and less play behavior than their intact littermates. Furthermore , surgical catheterization led to less fear of humans and behavioral indica tions of an ability to distinguish between familiar and unfamiliar persons. Partial isolation led to increased activity, increased chain manipulation, and increased play behavior, indicating that the provision of limited soci al contact may help reduce the negative effects of individual housing in we aned pigs. These results suggest that it is important to be aware of effect s of housing, experimental surgery, and associated handling when interpreti ng results from intensive experiments.