Dietary Fish Oil and a Flavor and Multi-Enzyme Complex Supplementation Improved the Reproductive Performance, Nutrient Metabolism and Health of Primiparous Lactating Sows and Piglets

This study was conducted to investigate the effects of dietary polyunsaturated fatty acid (PUFA) levels and FME (flavor and multiple enzymes) on the reproductive performance, nutrient digestion, and metabolism, immunity, and antioxidant capacity of sows and piglets. Forty primiparous sows [Duroc × (Landrace × York)] were randomly assigned from day 107 of gestation to day 7 post-weaning to one of four dietary treatments, low PUFA (4.6% tallow, LP), high PUFA (4.6% fish oil, HP), and LP and HP, each supplemented with 600 mg/kg FME (LP + FME, HP + FME). Results showed that dietary HP + FME supplementation significantly alleviated sow backfat loss during lactation (<i>p</i> < 0.05). Dietary FME supplementation significantly increased milk lactose and solids-non-fat (<i>p</i> < 0.05) on day 15. Meanwhile, milk protein and true protein contents were significantly lower in the LP treatment than in the LP + FME and HP treatments. The apparent total-tract digestibility (ATTD) of ash and phosphorus was improved (<i>p</i> < 0.05) by both HP diets and FME supplementation. The ATTD of energy and dry matter was significantly higher in LP + FME treatment than in LP and HP + FME treatments (<i>p</i> < 0.05). HP diets increased serum malondialdehyde (MDA, <i>p</i> < 0.01), total superoxide dismutase (<i>p</i> < 0.05) in sows, and increased serum MDA and decreased hydrogen peroxide (H₂O₂) contents in piglets (<i>p</i> < 0.05). Dietary FME supplementation decreased serum H₂O₂ contents and increased serum catalase activity of sows and/or piglets (<i>p</i> < 0.05). The serum immune markers, lipid, and protein metabolites of sows and piglets were altered (<i>p</i> < 0.05 or <i>p</i> < 0.10) by HP diets and/or FME supplementation. In conclusion, dietary fish oil (4.6% of diet replacing tallow) and FME (600 mg/kg) supplementation improved lactating performance by improving nutrient digestibility, body reserve mobilization, antioxidant capacity, and health state of sows and piglets.