Effects of feeding level and access to rooting material on behaviour of growing pigs in situations with reduced feeding space and delayed feeding

Abstract

Seventy-two pigs, housed in groups of four, were allocated to either (1) ad libitum feeding with access to wood chip, (2) restrictive feeding with access to wood chip or (3) restrictive feeding without access to wood chip. The effects of feeding level (treatment 1 vs. 2) and access to wood chip (treatment 2 vs. 3) were investigated in a normal situation, a competitive situation (reduced feeder space) and a conflict situation (delayed feeding). During normal days the pigs without access to wood chip manipulated the floor more, both on a 24 h basis and during the first hour after feed allocation, but the level of manipulating floor in these pigs did not reach the level of manipulating wood chip among pigs on treatment 2. During normal days restrictively fed pigs spent less time feeding on a 24 h basis, but more time feeding during the first hour after feed allocation than ad libitum fed pigs. When feeder space was reduced restrictively fed pigs stood more and were more aggressive during the first hour after feed allocation, but when feeding was delayed restrictively fed pigs were less aggressive during the first hour after normal feeding time. Generally, access to wood chip stimulated explorative behaviour and reduced manipulation of floor and pen mates. However, it had no effect on the response to reduced feeding space or delayed feeding. On the other hand, restrictive feeding increased aggression when feeder space was reduced.