Enhanced Farrowing Efficiency and Sow Performance with Escherichia coli-Derived 6-Phytase Supplementation During Late Gestation and Lactation.

Phytase releases phosphorus from phytate and may confer extra-phosphoric benefits in sows. We tested whether Escherichia coli-derived 6-phytase during late gestation and lactation improves sow and litter outcomes. In a randomized complete block trial, 186 TN70 sows received a phytase-free positive control (adequate Ca and available P) or Ca- and P-reduced diets with 500, 1500, or 2500 FTU/kg. Outcomes included sow body condition, lactation feed intake and feed conversion ratio (FCR), farrowing duration and blood glucose, piglet weaning performance and diarrhea scores, maternal serum Ca and P (farrowing, weaning), and piglet glutathione peroxidase (GPx) and superoxide dismutase (SOD; day 14). Phytase increased lactation intake by 4.4-5.6%; farrowing duration was shorter at all doses (-24.2, -23.8, and -14.8 min; up to -8.1%). Litter weaning weight rose by 6.1-8.2%, and piglet average daily gain increased by 9.1% at 2500 FTU/kg. Maternal Ca and P increased dose-responsively, especially at weaning (Ca +73% at 500-1500 FTU/kg; +140% at 2500; P +55%, +59%, +118%). Diarrhea counts declined at selected doses (e.g., scores 1-2: -17% at 500 FTU/kg), and piglet SOD decreased with dose (-8.6% to -39.3%); GPx showed modest modulation. Sow body weight, backfat, and the weaning-to-estrus interval were unchanged. In Ca- and P-reduced diets, conventional and super-dosed phytase enhanced mineral bioavailability and peripartum efficiency, supporting heavier litters without compromising sow condition.