Spotted pacas are a rodent species increasingly bred by small producers in Brazil as an alternative protein source. Despite their growing role in agriculture, not a lot is known about paca welfare in captivity. Evidence suggests that object play can enhance welfare by promoting mental and physical stimulation, reducing stress, and encouraging natural behaviors.

This study explored the potential of object play as an indicator of a positive emotional state in farmed spotted pacas. By introducing boomer balls to the pacas’ environment, this research set out to assess whether object play is associated with other positive welfare indicators, offering insights into how simple interventions can improve animal welfare in farming practices.

The study was conducted in accordance with Brazilian animal welfare laws, with approval from the Ethics Committee on Animal Use of the State University of Santa Cruz. It took place on a farm in Minas Gerais, Brazil, involving 18 adult spotted pacas (12 females, six males) who were born and raised in captivity. The pacas were housed in six groups, each with one male and two females. Their pens measured four square meters and contained a wooden shelter, a water tank, and three feeders.

The study had three phases: two without balls and one with balls to encourage the pacas to play. The researchers recorded their behavior using a camcorder positioned outside the pens, capturing 30 minutes of footage daily over three consecutive days for each phase. They observed behaviors such as friendly and aggressive interactions, object play, and exploration. They also recorded the pacas’ bark calls to study their sound characteristics. Data analysis used mixed linear models to compare behaviors across different phases.

The pacas played with the balls, mostly by biting them, for about 36 seconds on average. During the ball phase, pacas displayed increased friendly and exploratory behaviors, while aggressive behaviors decreased compared to phases without the balls. No significant difference was observed between males and females in their engagement with the balls or their behaviors, suggesting that both sexes were equally interested in the enrichment. Additionally, pacas emitted more bark calls during the ball phase. These were also quieter, which previous research has associated with a positive emotional state in this species. These findings suggest that adding objects like boomer balls to standard farm environments could help pacas by boosting their activity levels and stimulating their investigative behaviors.

The study had several limitations. The observation period was short, with boomer balls introduced for only 30 minutes daily, which may not capture long-term effects on behavior and welfare. The pacas had no prior experience with the balls, which might have influenced their initial reactions and play behaviors. The study focused solely on adult pacas, so the findings might not apply to younger animals. It is also important to note that the observed play behavior could have been the pacas’ response to their barren environment and may not necessarily reflect positive welfare overall.

The researchers concluded that adding boomer balls to the environment of farmed spotted pacas led to more object play. This increase in play was linked to more friendly and exploratory behaviors, fewer aggressive interactions, and quieter bark calls, all suggestive of a positive emotional state. Since adult spotted pacas rarely engage in play on their own, this study shows that using enrichment such as boomer balls can help stimulate this behavior and potentially enhance their well-being in captivity.