Aim: This study was aimed to compare the efficacy of dietary Cordyceps militaris spent mushroom substrate (CMS) on growth performance, immunity, metabolic profiles, and antioxidant capacity in growing pigs.

Materials and Methods: Seventy-two crossbred growing pigs (Duroc×Landrace×Yorkshire) with an average initial body weight (BW) of 25.78±0.33 kg were allotted into two dietary treatments in six pens (six growing pigs each). Dietary treatments were (i) control and (ii) supplemented group with 2 g/kg CMS.

Results: Growing pigs fed with 2 g/kg CMS showed improvements in final BW (p=0.034) and average daily weight gain (p=0.039). Moreover, there were positive changes in immunoglobulin A (p=0.013), immunoglobulin G (p=0.019), total antioxidant capacity (p=0.001), and glutathione peroxidase activity (p=0.003), whereas decreased leukocyte percentage (p=0.002), cholesterol (p=0.023), and malondialdehyde (MDA) concentrations (p=0.002) were noted in the CMS supplemented treatment. Average daily feed intake, gain-to-feed ratio, glucose, aspartate aminotransferase, triglyceride, high-density lipoprotein, and low-density lipoprotein were unaffected by the treatments.

Conclusion: Supplementation of CMS at 2 g/kg of diet increases growth performance, immunoglobulin secretion, and antioxidant capacity, whereas it lowers leukocyte percentage, cholesterol, and MDA concentrations in growing pigs.

Keywords: antioxidant capacity, blood metabolites, Cordyceps militaris spent substrate, growing pigs, growth performance, immunoglobulins.