Effects of treated walnut green husk on broiler growth performance, gut health, and meat quality

This study evaluated the effects of treated walnut green husk (WGH) on growth performance, cecal microflora, jejunal morphology, nutrient digestibility, blood biochemistry, and meat quality in broiler chickens. A total of 180 day-old Ross 308 broilers were assigned to three dietary treatments for a 42-day trial, with six replicates (10 birds per cage). The dietary treatments consisted of a basal diet (control), the basal diet supplemented with 2.1 g/kg fermented WGH (FWGH), and the basal diet containing 2.0 g/kg WGH plus 0.1 g/kg multi-enzyme (EWGH). Both FWGH and EWGH improved broiler growth performance during the grower, finisher, and overall periods, as indicated by enhanced feed conversion ratio and European production efficiency index, with FWGH producing marginally greater improvements. Both treatments reduced cecal total aerobic bacteria, while FWGH additionally increased Lactobacillus spp. and decreased Clostridium perfringens. Jejunal villus height increased in both WGH-treated groups, whereas villus surface area improved in FWGH group. Both FWGH- and EWGH-supplemented diets increased ileal digestibility of dry matter, while FWGH also improved organic matter digestibility. Both FWGH and EWGH had a modulatory effect on blood parameters by increasing lymphocyte (L) percentage and decreasing WBC count, percentage of heterophil (H), H:L ratio, total cholesterol, low-density lipoprotein (LDL), and alkaline phosphatase (ALP) levels. In addition, FWGH increased high-density lipoprotein (HDL) level and reduced alanine transaminase (ALT) activity. Both FWGH and EWGH improved meat quality by reducing breast muscle press loss and malondialdehyde content in thigh muscle, while EWGH further decreased malondialdehyde and increased pH in breast muscle, and enhanced water-holding capacity and pH in thigh muscle compared with the control. Overall, the dietary inclusion of treated-WGH improved growth performance, intestinal health, nutrient digestibility, blood lipid profile, and meat quality in broiler chickens, with FWGH showing slightly superior effects.