PSXIII-6 Dietary Scutellaria baicalensis and Lonicera japonica extracts enhance the growth performance of broilers by reducing heat stress in summer.

Abstract The dietary inclusion of phytogenic feed additives to improve the performance and health status of broilers is safe, effective, and environmentally friendly, thus gaining growing popularity among new strategies. Herein, we aimed to conduct a 49 days growth trial using three groups of 360, 1-day-old ROSS 308 mixed-sex broilers [1080 total birds initial body weight (BW) 47.79 ± ± 0.05 g] to assess the impact of herbal extract mixtures (HEM, Scutellaria baicalensis and Lonicera japonica) on growth performance, nutrient digestibility, gut lesion score, serum biochemical and hematology, and heat stress protein 70. Pens of birds (18/pen) were randomly allocated into one of three dietary treatments in a randomized design with 20 replicates per treatment. The test diets were corn-soybean meal-based basal diet (CON) with the addition of none, 0.05%, and 0.10% of HEM. The diets were fed in three phases: starter, from days 1-7; grower, from days 8-21; and finisher, from days 22-49. All data was analyzed using the GLM procedure of the SAS, and polynomial contrast was used to determine linear and quadratic effects on the graded level of HEM in pigs. P < 0.05 and at 0.05 > P ≤ 0.10 were considered as significant and tends, respectively. During the starter phase, there was no evidence of a difference (P > 0.10) in broiler growth performance; however, during the grower phase, broiler-fed graded levels of HEM supplementation showed linearly increased body weight gain (BWG) than CON. Moreover, the increasing level of HEM supplement had linearly increased (P < 0.05) BWG and feed intake (FI) during the finisher and overall experimental period. Furthermore, HEM-treated groups showed linearly increased (P < 0.05) N digestibility at the end of day 49. Correspondingly, serum cortisol, malondialdehyde (MDA), and heat stress protein 70 (HSP70) levels were linearly reduced in broilers receiving HEM supplement. Also, the biochemical variables such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) were linearly (P < 0.05) increased in broilers fed increasing HEM supplementation with Nil effect on nitric oxide. In summary, supplementing broilers with increasing levels of HEM, consisting of Scutellaria baicalensis and Lonicera japonica, could be a potential option to improve their growth performance, nutrient digestibility, and reduce heat stress without negative effects on gut lesion score.