Evaluating the Effects of Sow Parity on Litter Performance

Growing populations and a rise in food demands have caused a need for more efficient production systems within the swine industry, prompting greater focus on maternal reproductive performance. One aspect that has been found to affect litter performance is sow parity. While numerous studies have evaluated sow parity effects on litter performance, most rely on commercial purebred herds, leaving a gap in understanding regarding mixed-breed show pigs housed in hybrid indoor/outdoor systems such as the Murray State University swine unit. This exploratory pilot study was designed to investigate the effects of sow parity on litter size, number born alive, birth weight, weaning weight, and average daily gain, and establish a standardized analytical and data-collection framework for an ongoing, long-term longitudinal herd investigation. Twelve sows, three farrowing in May 2026 and nine farrowing in July 2026, each having one litter, were studied. The sows were placed into three groups (P1,n=3;P3,n=4;P5+,n=5). Kruskal-Wallis tests and linear mixed models revealed no statistically significant difference across parity groups for any measured outcome. Due to the limited sample size, the study was underpowered for definitive population-level conclusions; however, it successfully validates the methodology and serves as the foundational pilot for continued longitudinal research at Murray State University.