Abstract: To investigate the effects of different doses of Poria cocos polysaccharides (PCPs) added to the diet on growth performance, feed nutrient digestibility, and immune response in growing-finishing pigs, thereby providing experimental evidence for the application of Poria cocos polysaccharides as a novel feed additive in swine production. A total of 180 Duroc × Yorkshire × Landrace crossbred barrows were randomly divided into 5 dietary treatments; each treatment contained 6 replicate pens and 6 pigs per pen. Dietary treatments included a control diet and 4 PCP diets. The CON diet group was fed a basal diet, the PCPs treatment group was fed 25 (Group 1), 50 (Group 2), 100 (Group 3), and 200 (Group 4) mg/kg PCP supplemented with the basal diet. The result showed that supplementing the growing-finishing pig diet with 0～200 mg/kg Poria polysaccharides did not cause diarrhea or mortality in the pigs. Compared to the control group, at a Poria polysaccharide level of 50 mg/kg, the average weight of finishing pigs increased by 3.55 kg, average daily gain increased by 0.05 kg, and feed conversion ratio decreased by 0.13 (P＜0.05). Apparent digestibility of calcium and total phosphorus increased by 10.31% and 5.86% , respectively (P＜0.05). Concurrently, it elevated red blood cell count and hemoglobin content in blood, reduced serum low-density lipoprotein and aspartate aminotransferase levels (P＜0.05), increased serum immunoglobulin IgA, IgG, and IgM levels along with cytokine IL-2, IL-4, and TNF-α content (P＜0.05), thereby enhancing the body's antioxidant and immune capabilities. The results showed that supplementing feed with Poria cocos polysaccharides promotes growth in finishing pigs, enhances antioxidant capacity and immune function, with an optimal dosage of 50 mg/kg.

Key words: poriacocos polysaccharides, growing-finishing pigs, growth performance, blood indicators, immune indicators