Estratégias de enriquecimento ambiental para leitões em creche e eficácia na plasticidade do interesse

Abstract

The present research was carried out aiming to evaluate different environmental enrichment strategies on the behavior of pigs in the nursery stage, maintenance of animal interest by the enrichment objects, and their reflexes in face of emotionally negative situations. 425 piglets were randomly assigned in a completely randomized design with five treatments and 85 replicates per treatment. The treatments employed were: T1- Control with no enriching object (C); T2 - Wooden box with popcorn and wood shavings (WB); T3 - Objects made of plastic tubing (PT); T4 - WB and PT concomitantly (WB+PT); and T5 - WB or PT on alternate days (WB/PT). Behavioral observations were made over ten days for 8 h a day divided in two 4 h periods. By the end of the behavioral evaluations, four distinct tests were performed: a) aggressiveness against an unknown member in the group, b) proximity with humans, c) unknown area, and d) new object. No effect (p>0.05) was found of the type of enrichment provided or strategy adopted on the time piglets interacted with the enrichment objects. Animals kept in an environment with no stimulus had higher frequency (p<0.05) of undesirable behaviors (sucking, belly nosing, and agonistic behavior) compared to the other treatments, regardless of the enrichment type or strategy adopted. Those piglets, when isolated in a new environment, had higher frequency of behaviors of defecating, urinating, and attempting escape, besides more and longer vocalization events (p<0.05). Piglets reared in an enriched environment had higher frequency and duration of interaction with a new object, besides shorter latency time for the first contact (p<0.05). The use of enrichment objects in the rearing environment of piglets in nursery stage reduces undesirable behaviors and makes the animals less reactive to unknown situations, which reduces fear and anxiety and may improve their psychological well-being.