Environmental Enrichment for Sucker and Weaner Pigs: The Effect of Enrichment Block Shape on the Behavioural Interaction by Pigs with the Blocks

Abstract

Simple SummaryHow often do intensively-housed pigs interact with enrichment devices, especially smaller pigs during the sucker and weaner phases of production? Understanding whether smaller pigs use such devices, whether habituation occurs, and whether device-shape influences the level of interaction by pigs are all relevant questions surrounding justification for including enrichment devices in pig pens. We provided litters of pigs from 10 to 60 days old with one of three different shaped enrichment blocks (cube, brick, or wedge) and recorded oro-nasal contact with the blocks on two days each week. Fresh blocks were provided weekly. While pig interaction with blocks was infrequent before about 25 days of age, contact with the blocks steadily increased thereafter. Brick-shaped blocks were used more than the other shapes, possibly because the brick-shape presented a wider surface for contact, allowing multiple pigs to simultaneously interact with the block. Pigs interacted more with 1-day-old (i.e., ‘fresh’) than 4-day-old blocks, suggesting that habituation to the blocks may have occurred.AbstractThis experiment tested the effect of enrichment-block shape on oro-nasal contact by young pigs, and possible habituation to the blocks. Nineteen litters (197 piglets) were randomly allocated to one of three block-shape treatments: Cube, Brick, or Wedge. Oro-nasal contact with blocks was infrequent before 25 days of age. Thereafter, contact steadily increased, suggesting enrichment blocks may not need to be provided until week 4 of lactation. Brick-shaped blocks attracted more oro-nasal contact than the cube and wedge shapes (p = 0.002). Oro-nasal contact was more frequent (p < 0.001) during the first 24 h after block introduction than when blocks were four days old. From 25 to 60 days of age, oro-nasal bouts were longer (p = 0.014) during the first 30 min of exposure to a fresh block, than for the remainder of the 24 h, or on day 4 after block replacement. Therefore, habituation to blocks may have occurred by 24 h after block introduction. Brick-shaped blocks may present a wider surface for oro-nasal contact, where multiple pigs could simultaneously interact with the block. We speculate that simultaneous interaction with brick-shaped blocks may be similar to a litter co-operatively massaging the sow’s udder prior to suckling bouts.

Enrichment in the Sucker and Weaner Phase Altered the Performance of Pigs in Three Behavioural Tests

“…Enrichment blocks were replaced weekly and the cubic-shaped blocks provided were increased in size between the sucker and weaner stage to match piglet size. The enrichment blocks were a “nutritional lick block” developed by Ridley Agriproducts (Toowong, Queensland, Australia) and were specifically formulated for use with sucker and weaner pigs [ 14 ].…”

Developing and testing a new feed block for the gut health and welfare of the weaning pig

“…The differences between the feed blocks could be ascribed to a different time to adaptation to the different formulations. In general, it has been seen that brick-shaped blocks disappear more in suckling piglets than cube-shaped blocks (Winfield et al 2017) and that the oro-nasal interactions are more intense the first day of provision of the blocks (Winfield et al 2017). Regarding the 'sleep' parameter, the subjects of the F6 groups rested for a percentage of time significantly higher than those of the control and of the F7 groups, while the value of the F8 group did not differ significantly from that of the other three groups.…”

“…The blocks were brick-shaped and of average size: 13 cm  10 cm  7 cm. This shape was considered to favour the simultaneous physical interaction of more than one piglet, because it presented a wider surface than the other shapes (Winfield et al 2017). The blocks were dried in a stove using forced ventilation for 24 hours at 37 C.…”

“…It was hypothesised that feed blocks (smaller than those frequently used for ruminants) such as cookies, could satisfy, multiple functions: stimulate the instinct of play, and reduce competition and aggressive behaviour, stimulate early intake of solid feed (piglets like gnawing and rooting - Studnitz et al 2007) and favour the post-weaning maintenance of a well-shaped gut mucosa. Feed blocks have already been tested in weaning pigs (Nannoni et al 2016;Winfield et al 2017) and in grouped sows (Muller et al 2015). However, in these cases no specific attention was paid to the formulation of the feed blocks.…”

“…In one case, the feed blocks were formulated to contain lucerne meal, molasses and minerals (Nannoni et al 2016). Winfield et al (2017), focussed on the importance of different shapes of the block. Thus, the first aim of the present study was to evaluate, by means of an acceptance test, the attractiveness of several formulations of supplemental feed blocks in pigs at weaning.…”