Soy isoflavones supplementation improves reproductive performance and serum antioxidant status of sows and the growth performance of their offspring

Abstract A total of 60 sows (Landrace × Yorkshire, average parity was 1.39) were used to evaluate the effects of soy isoflavones (ISO) supplementation on reproductive performance, serum antioxidant enzyme parameters, and milk compositions of sows, and the growth performance of offspring. Sows were randomly assigned to 4 groups based on the parity. There were 15 replicates per treatment. Dietary treatments were based on a corn‐soybean meal‐based basal diet and supplemented with 0, 10, 20, or 40 mg/kg ISO. With the increase of the ISO dosage, average daily feed intake of sows increased linearly; oestrus interval decreased linearly and quadratically. In addition, on day 10 of lactation, linear increases in serum superoxide dismutase levels, linear and quadratic increases in serum total antioxidant capacity, and linear decreases in serum malondialdehyde levels were observed in increasing ISO dosage in the diet of sows. The body weight on day 10 and 21 and the average daily gain during days 3–10 and 3–21 of offspring increased linearly at graduated doses of ISO increased. Therefore, feeding sows with graded levels of ISO containing diet during late‐gestation and lactation periods improved the reproductive performance of sows and the growth performance of their offspring in a dose‐dependent manner.