Date Full Report Received09/09/2020
Date Abstract Report Received09/09/2020
InvestigationInstitution: University of Pennsylvania
Primary Investigator: Dr. Thomas Parsons VMD PhD
Co-Investigators: Dr. Maria Camila Ceballos, Dr. Karen Camille Rocha Gois, Dr. Meghann K. Pierdon
Funded ByPork Checkoff
Individual crates have been the predominant farrowing environment in the last 50 years in the United States as well as globally. Unfortunately farrowing crates limit the sow’s ability to perform many natural behaviors during parturition and lactation. Concerns about the welfare of sows in farrowing crates continues to grow, given the physical and behavioral restriction on the sow, the compromise of natural maternal behaviors and physical comfort, creating a need for an alternative farrowing and lactation housing. A wide variety of alternative farrowing systems have been developed, trying to address sow’s needs, including temporary crates. However, alternatives can be problematic because of reports of increased pre-weaning mortality, which is one of the major economic and welfare concerns related to piglets in all farrowing and lactation systems. Here, we performed two studies using temporary or hinged farrowing crates, which is a hybrid between a crated and a pen based farrowing system. In this study, we evaluated its effect on sow welfare and piglet mortality, by opening them in two time points, at 4 and 7 days post-farrowing. In the first study, 36 sows and their litters were examined for behavioral, physiological and physical indicators of animal welfare. We found after opening the crates at 4 or 7 days post-farrowing, sows utilize the additional space provided to them, and spent more time active and performing motivated maternal behaviors (such as interacting with their piglets and exploring the environment). In the opened crates, sow salivary cortisol decreased post farrowing and sows had less teats lesions compared with the closed crates sows. A second study focused on piglet mortality during lactation and examined 630 sows and their litters. The total piglet mortality following crate opening was not different from the crated control. Laid on and low viability were the two most common reasons for piglet death with each comprising about 1/3 of the total mortality. There was no difference in the risk of being laid during the period 1-3 days post farrowing when all crates were closed. However, this risk increased whenever the crate was opened. Perhaps unexpectedly the risk associated with several other causes of mortality also increased when the crates were opened at day 4 but not at day 7. No association was found between treatment and physical measures of welfare (body condition scoring, lameness and shoulder sores), but there was a higher risk for teat lesions in crated sows at weaning. In summary, both behavioral and physical measures of welfare employed in this study indicate that the opening of a hinged farrowing crate contributes to improving the welfare of lactating sows. However, the piglet mortality data suggest that only opening the crate after 7 days post-farrowing, and thus avoiding the period when piglets are most vulnerable to crushing and other causes of death in the absences of a crate, has the potential to maintain total risk of mortality at levels similar to crated sows while still providing welfare improvements to the sow.