Effects of Supplemental Potassium Magnesium Sulfate on Performance, Antioxidant Capacity and Immune Function in Sows During Late Pregnancy

【Objective】The experiment was carried out to study the effects of potassium magnesium sulfate (PMS) on sow performance, plasma biochemical indicators, antioxidant capacity and immune function in late pregnancy.【Method】By using simple factor design of the experiment, sixty sows (Landrace×Yorkshire) with 3-4 parity, good health and similar expected delivery in the third trimester of pregnancy (85th day of pregnancy) were randomly divided into 4 groups (15 replicates in each group and 1 sow in each replicate). The experimental groups during gestation were supplemented with PMS 0 (CK), 5, 10 and 15 g/d for each sow, respectively. After delivery, all sows during lactation were fed the same commercial lactation feed. The experiment ended on the 18th day of lactation.【Result】(1) Supplemental PMS had no significant effects on litter size, healthy litter size, back fat thickness, labor, body weight, feed intake in sows during lactation, and newborn weight of piglets, number of weaned piglets and number of deaths of lactating piglets. Compared with the control group, the fecal score of sows during late pregnancy after PMS supplementation showed a linear increase (Plinear < 0.05) and 10 g/d group had significant effects (PANOVA < 0.05); After supplementation with PMS, it showed a linear increase (Plinear < 0.05) in newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets (PANOVA < 0.05). Compared with the control group, the newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets in the 10 g/d group were increased by 16.27%, 24.42%, 35.14% and 31.64%. Except for newborn litter weight, all other indicators showed quadratic effect (PQuadratic < 0.05) and significant differences were found between groups (PANOVA < 0.05); (2) It showed a linear increase in the contents of triglyceride (TG), cholesterol (CHO), low-density lipoprotein (LDL) and insulin (INS) in plasma of sows supplemented with PMS (Plinear < 0.05). The contents of TG, CHO, LDL and INS in the 10 g/d group increased by 50.00%, 28.35%, 25.00% and 31.98% compared with the control group; TG and LDL had a quadratic effect (PQuadratic < 0.05). (3) Linear changes were found in contents of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM) and glutathione peroxidase (GSH-Px) (Plinear < 0.05) in the plasma of sows after supplementation with PMS, and they were increased by 17.10%, 20.34%, 8.00% and 15.04% in the 10 g/d group, compared with the control group. (4) It showed a linear increase (PANOVA < 0.05) in fat content of colostrum of sow with PMS supplementation (Plinear < 0.05), with significant increase. Non-fat milk solids, lactose and protein were linearly increased (Plinear < 0.05) and had an increasing trend (0.05 < PANOVA < 0.1). The fat content of colostrum supplemented with 10 g/d were increased by 51.42% compared with the control group.【Conclusion】PMS supplementation in late preganancy can significantly improve the fecal scores of sows, relieve sow constipation, and improve sow performance and body health, with 10 g/d supplementation as the optimal dose.