The effects of pen design for farrowing and boar breed on reproductive traits of sows

Abstract

Modern pig production increasingly requires compliance with welfare-oriented housing standards, prompting farms to modernize farrowing systems while maintaining productive performance. This study aimed to evaluate the effects of farrowing pen design during the suckling period and boar line on the reproductive performance of sows, piglet growth, and survival under industrial conditions aligned with contemporary animal welfare requirements. The experiment was conducted using a 2 × 2 factorial design involving 192 sows (Large White × Landrace) of second to fourth parity and 2,443 piglets obtained through terminal crossbreeding with Maxter and PIC 337 boars. Animals were fed complete diets and housed under controlled microclimate conditions. Reproductive traits, piglet survival, and sow backfat thickness were assessed using standardized methods and subjected to statistical analysis. Sows housed in fixed traditional farrowing pens exhibited superior reproductive performance compared with those kept in improved welfareoriented pens. The boar line significantly affected the total number of piglets born and the number born alive, with the highest total number of piglets born (14.1 piglets) recorded in sows inseminated with PIC 337 semen. Farrowing pen design had a significant effect on litter size, litter uniformity, stillbirth rate, litter weight at weaning, sow backfat thickness, and piglet weaning weight. The highest average daily gain and piglet live weight at weaning were observed in Group 1, whereas the lowest values were recorded in Group 4. Piglet survival to weaning was the highest in Group 3 (97.3%). A combined effect of farrowing pen design and boar line was identified for milk performance (defined as total milk output estimated from litter weight gain), litter uniformity index (reflecting within-litter variation in piglet body weight), and piglet survival. The practical significance of these findings lies in providing science-based recommendations for selecting farrowing pen configurations and boar lines that support welfare-compliant and efficient pig production systems in Ukraine. The study demonstrates a performance-welfare trade-off, whereby traditional pens improved piglet growth parameters, while welfare-oriented improved pens enhanced sow mobility. This balance should be considered when implementing welfare-compliant farrowing systems.