Effect of Light Regiment on Farrowing Performance and Behavior in Sows

SIMPLE SUMMARY: When sows approach birthing in most commercial farms, they are often exposed to continuous light to help farm workers monitor pig health and progress. Being in constant lighting may have a negative effect on sows as mammals often prefer a quiet environment with low stimulation during birthing. In our study, we placed 15 sows in a 12 h light/12 h dark environment, and 15 sows in 24 h light. Sows were watched for ease of farrowing (measured in total time farrowing, birthing interval, and behavior during farrowing). We also measured total piglets born alive and stillborn piglets. Overall, we observed that sows who received darkness gave birth earlier in gestation. Light availability had no effect on total piglets born alive, farrowing behavior, or total length of time giving birth. It was observed that there were more stillborn animals for the sows who received darkness. Overall, it is possible that light availability could have an impact on farrowing behavior and health; however, more factors should be considered in the environment. ABSTRACT: The purpose of this study was to investigate the effects of light exposure on farrowing performance in sows. Thirty sows were moved to the farrowing unit at d 110 of gestation and assigned a treatment: 12 h light/12 h dark cycle (Dark) or 24 h light (Light). Treatments began upon entry into the farrowing unit. Video was recorded continuously from initiation of the treatments until completion of farrowing. Data collected included duration of farrowing, birthing interval, and behavior during farrowing. Additionally, the number of total born, liveborn, and stillborn piglets was recorded. Gestation length was different between treatments, with a shorter gestation in Dark treatment sows than Light treatment sows (116.4 vs. 117.1 ± 0.2 d, respectively; p = 0.027). The total duration of parturition and number of liveborn did not differ (p = 0.393). Number of stillborn piglets between treatments did differ (p = 0.018). Dark had more stillborns compared to Light treatment sows (1.5 vs. 0.7 ± 0.2 piglets, respectively). Neither the interval between piglets nor farrowing behavior differed between treatments (p > 0.100). The results from this experiment indicate that a sudden change in photoperiod has the potential to impact the gestation length of sows and number of stillborn pigs.