Protective effects of zinc-bearing clinoptilolite on broilers challenged withSalmonella pullorum

This study was conducted to evaluate the effects of zinc-bearing clinoptilolite (ZnCP) on broilers challenged with Salmonella pullorum for a 21-d feeding trial. A total of 240 one-day-old chickens was allocated into 4 treatment groups: 1) nonchallenged control (CON) fed basal diet; 2) S. pullorum-challenged control (SCC) fed basal diet; 3) Salmonella challenge fed basal diet plus antibiotic (ANT); 4) Salmonella challenge fed basal diet plus 0.2% ZnCP (ZnCP). Compared with CON, Salmonella challenge caused adverse effects on ADG (P<0.05), ADFI, feed/gain ratio in broilers, Salmonella and Lactobacillus colonies at 7 d (P<0.05) and 21 d, and serum diamine oxidase (DAO) activity. Moreover, the relative weight of spleen of 21-d birds, malondialdehyde (MDA) content of jejunual and ileal mucosa at 21 d, and the superoxide dismutase (SOD) activity of ileal mucosa were also significantly negatively affected by SCC treatment (P<0.05). Supplementation of ZnCP in basal diet significantly improved ADG and reduced Salmonella colonies in cecal contents and serum DAO activity both at 7 and 21 d (P<0.05), compared with SCC. Furthermore, supplementation with ZnCP as well as ANT significantly decreased the relative weight of spleen at 21 d, reduced MDA contents of jejunual and ileal mucosa at 21 d (P<0.05), and improved the SOD activity of ileal mucosa at 7 d as compared with SCC (P<0.05). The results suggested that ZnCP addition in feed exerted protective effects on performance and gut health of broilers against S. pullorum infection.