Effects of complex trace mineral blend on growth performance, antioxidant status, and immune response in weaned...

Trace minerals are essential micronutrients that play important roles in swine nutrition and physiology. This study evaluated the effects of different sources and levels of trace minerals on growth performance, antioxidant capacity, and immunity in piglets. A total of 96 weaned Duroc × Landrace × Yorkshire piglets (8.52 ± 0.26 kg) were randomly assigned to four dietary treatments in a 2 × 2 factorial arrangement, with eight replicate pens per treatment and three piglets per pen. The experimental factors were trace mineral source (inorganic trace minerals [ITM] vs. hydroxychloride and organic trace mineral blends [HOTM]) and supplementation level (low vs. high). HOTM supplementation significantly increased average daily gain from d 15-49 and overall and improved gain-to-feed ratio from d 0-14 (P < 0.05). High mineral supplementation level reduced diarrhea during the first 2 wk (P < 0.05) and tended to increase early ADG (P = 0.06). HOTM also improved nutrient digestibility of crude protein, dry matter, and ash (P < 0.05), strengthened gut barrier integrity (higher Occludin expression, P < 0.05; ZO-1 trend, P = 0.07), and elevated serum copper and zinc concentrations (P < 0.01). Bone weight and liver antioxidant capacity (GSH-Px) were increased in HOTM-supplemented piglets, while oxidative stress markers declined (P < 0.05). Immune responses were enhanced with HOTM, showing higher IL-4, IgA, and IgM and lower IgG compared with ITM (P < 0.05). These findings suggest that HOTM are more effective than ITM in improving growth performance, antioxidant status, and immune function in weaned piglets.