Effects of different volumes of a water-soluble and biodegradable nesting material on behavior, pain, glycemia, farrowing traits, and performance in crated sows.

This study evaluated the effects of providing 3-15 kg of a soluble and biodegradable biopolymer-based enrichment material (blend of biodegradable polymers and natural fibers) to prepartum sows housed in farrowing crates. Fifteen sows were blocked by body weight and backfat thickness and assigned to three treatments: no enrichment material (CONT), 3 kg of enrichment material (BN3), or 15 kg of enrichment material with added nutritional value (BN15; 14.50 MJ ME/kg; composition: a blend of biodegradable natural polymers and natural fibers). The material was supplied 24 h before the expected farrowing date. Behavioral observations were performed during the 18 h preceding farrowing. Sow and piglet blood glucose concentrations were determined from venipuncture of auricular vein. Pain-related facial expressions, piglet birth intervals, and litter performance parameters were also evaluated. Behavioral analysis revealed significant differences between treated and control sows, with BN3 and BN15 sows showing reduced ventral lying, redirected nest-building behaviors, floor interaction, and postural changes during the pre-farrowing period (p < 0.05). A quadratic relationship was observed between piglet birth order and birth interval (p < 0.001), birth interval was longer early in parturition, decreased in the middle stages, and increased at the end of parturition. In addition, compared with CONT sows, BN15 sows provided exhibited shorter birth intervals (p = 0.030), while BN3 sows showed a tendency toward shorter birth intervals (p = 0.084). Sows in BN15 tended to have higher glycemia at farrowing onset than CONT (96.6 vs. 80.2 mg/dL; p = 0.022). Piglets from BN3 and BN15 tended to have higher birth glycemia than CONT (44.06 and 43.79 vs. 37.92 mg/dL; p < 0.10). Pain scores assessed through facial expressions/grimace score were lower (p < 0.10) in BN3 and BN15 than in CONT between 120 and 240 min after farrowing onset. Overall, providing biopolymer-based enrichment material, improved behavioral and physiological indicators associated with sow welfare.