Pigs weaned early have been known to develop behavioral vices. This fact has produced restrictions on weaning age in several countries.
No one has known if this behavior extends into grow-finish and questions have been raised whether diets are contributing to continuation of these vices such as belly nosing.
Researchers at Prairie Swine Centre in Saskatchewan, Canada investigated the effects of early weaning on behavior through the nursery and grow-finish periods.
Two treatment groups were compared: weaning at 21 days or 12 days of age. Pigs were housed in separate, but identical, on-site nursery rooms and within the same, grow-finish rooms.
Result was that pigs weaned at 12 days of age were slower in developing normal eating patterns than their counterparts weaned at 21 days of age. But the younger weaned pigs developed more normal eating behavior by 48 hours after weaning (See Figure 1).
The eating patterns of the two groups are depicted in Figure 1. The 21-day-old weaned pigs gradually increased eating over each 12-hour period following weaning.
In contrast, pigs weaned at 12 days old did very little eating before 36 hours postweaning. For the next 5-6 weeks, those early weaned pigs spent more time eating and drinking, but also in nosing other pigs and chewing on objects. This behavior persisted into grow-finish.
The Canadian researchers argue the fact that the higher level of chewing and nosing persists into grow-finish proves the behavior developed in an early weaning environment may have a lasting impact on animal behavior. There was no impact of behavioral vices on productivity in the study.
Attempts at eliminating these behavior-related concerns have not proven successful. Steps have included addition of plasma protein in the diets.
Researchers: Harold W. Gonyou, Eduardo Beltranena, Lee Whittington and John F. Patience, Prairie Swine Centre, Saskatoon, Saskatchewan, Canada. Phone Gonyou at (306) 373-9922.