Effects of Dietary Sandarac (Tetraclinis articulata) Powder Supplementation on Growth Performance, Physiological Responses, Intestinal Histomorphology, and Oxidative Status of Heat-Stressed Broiler Chickens

Abstract

This study was conducted at the Poultry Research Unit, Department of Animal Production, College of Agricultural Engineering Sciences, University of Baghdad, Iraq, from 10 May to 14 June 2024. The objective of this study was to evaluate the effects of dietary supplementation with different levels of Sandarac (Tetraclinis articulata) powder on growth performance, carcass characteristics, serum biochemical parameters, and oxidative stress biomarkers of broiler chickens reared under heat stress conditions. A total of 180 one-day-old unsexed Ross 308 broiler chicks were randomly allocated to three dietary treatments, each comprising 60 chicks with four replicates of 15 chicks each. The dietary treatments consisted of G1, a basal diet without supplementation (control); G2, the basal diet supplemented with 0.1% Sandarac powder; and G3, the basal diet supplemented with 0.2% Sandarac powder. Birds were reared under identical management conditions for 35 days. The results demonstrated that dietary supplementation with Sandarac powder significantly improved growth performance. Broilers fed the 0.2% Sandarac diet (G3) exhibited the highest (P ≤ 0.01) final body weight and cumulative weight gain at 35 days of age, followed by those in G2, compared with the control group. Birds in G3 also recorded significantly higher (P ≤ 0.05) total feed intake and live body weight at slaughter. Feed conversion ratio (FCR) was significantly improved (P ≤ 0.05) during the finisher period (35 days), whereas cumulative feed conversion ratio was not significantly affected by dietary treatments. No significant differences were observed in dressing percentage or in the relative weights of the liver, gizzard, and spleen. However, significant differences (P ≤ 0.05) were detected in the relative weights of the heart and the bursa of Fabricius among the experimental groups. Dietary supplementation with 0.2% Sandarac powder significantly reduced (P ≤ 0.05) serum triglyceride and very-low-density lipoprotein (VLDL) concentrations, while other serum biochemical parameters and liver functions were not significantly affected. Regarding oxidative stress biomarkers, Sandarac supplementation significantly reduced (P ≤ 0.01) malondialdehyde (MDA) concentrations in both supplemented groups compared with the control. Superoxide dismutase (SOD) activity was significantly increased in both supplemented groups, with the highest activity observed in G2, whereas reduced glutathione (GSH) concentration was significantly increased only in G3. Catalase (CAT) and glutathione peroxidase (GPx) activities were not significantly affected by the dietary treatments. In conclusion, dietary supplementation with 0.2% Sandarac (Tetraclinis articulata) powder enhanced growth performance, improved antioxidant status by reducing lipid peroxidation and increasing glutathione concentration, and favorably modulated lipid metabolism in broiler chickens reared under heat stress conditions. These findings indicate that Sandarac powder could be considered a promising natural phytogenic feed additive for improving broiler productivity under heat stress.