Inclusion of dietary nontoxic sulfur on growth performance, immune response, sulfur amino acid content and meat characteristics in growing-finishing pigs

Objective: This experiment was conducted to evaluate the inclusion of dietary nontoxic sulfur (NTS) on growth performance, immune response, sulfur amino acid composition and meat characteristics in growing-finishing pigs. Methods: A total of 140 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight of 34.73±0.66 kg were used for the 12-week feeding trial. Experimental pigs were allotted to one of 5 treatments in 4 replicates of 7 pigs per pen in a randomized complete block (RCB) design. The experimental treatments were as follows (0%, 0.1%, 0.2%, and 0.4% NTS levels): i) Control, corn soybean meal (SBM)-based diet; ii) NTS 0.1, basal diet + NTS 0.1%; iii) NTS 0.2, basal diet + NTS 0.2%; iv) NTS 0.4, basal diet + NTS 0.4%. Results: Body weight increased linearly as dietary NTS levels increased up to 0.2% (linear; p = 0.04) in the early finishing phase (9 weeks). During the whole experimental period, body weight and average daily gain linearly increased as the dietary NTS level increased in the diet (linear; both p = 0.01), but quadratic responses in body weight and average daily gain were observed with the addition of NTS 0.4% (quadratic, both p = 0.01). In the late finishing period, the IgG concentration increased linearly (linear; p = 0.01) as the dietary NTS level increased up to 4%. In the finishing period, a linear response was observed as a dietary NTS level was added (linear; p = 0.03), and supplementation with 0.2% NTS resulted in a higher methionine content than the other treatments (quadratic; p = 0.01). NST 0.2% had a lower value of thiobarbituric acid reactive substances (quadratic; p = 0.01). Conclusion: Consequently, supplementation with dietary NTS up to 0.2% could improve growth performance, amino acid composition in hair and meat antioxidation capacity.