Influence of providing objects to piglets before and after weaning on behaviour and weight gain
Barren rearing environment and early weaning of piglets can lead to a high level of distress, behavioural disturbances and reduction in weight gain. The main aim of this thesis was to study the effects of potential enrichment objects on piglet?s behaviour and weight gain during the pre- and post-weaning period. The second aim was to examine what type of object stimulated the highest frequency of interaction.
The study was carried out at the Swedish Livestock Research Centre in Lövsta where a batch of litters from 10 first-parity Yorkshire sows were used. Sow and piglets were housed in individual farrowing pens and were provided with approximately 1 kg of chopped straw each day. Weaning was performed at the mean age of 33 days by removing the sow from the pen. The 10 litters were randomly assigned to two treatments. Five litters were provided with objects (object litters) whereas the remaining five were not provided with objects (control litters). Objects selected for the study were a knotted rope, a vanilla scented rubber ball and a rubber tire. The study was divided into two periods, the pre-weaning period and the post-weaning period. During the pre-weaning period, the object litters received two objects of the same type at three different ages (13-16, 20-23 and 27-30 days). A new type of object was provided during each age so that at the end of the pre-weaning period, piglets had been given access to all three types of objects. Each day, objects were provided at 9.00 and taken out at 15.00. During the post-weaning period, piglets had access to all three types of objects simultaneously. The objects were introduced on the first day after weaning and then they had 6 days of continuous access to them. The behaviours of four focal piglets from each litter were observed with direct observations (n=20 piglets/treatment). Observations were performed from 10.00-15.00 during the same days that piglets had access to the objects. Piglets were weighed within 24 h of birth, at weaning and at 11 days post-weaning and the average daily pre- and post-weaning weight gains (ADG) were calculated. Statistical analysis was done with Generalized Linear Models.
During the pre-weaning period, piglets in the object litters performed less behaviours directed at the pen fixtures (P