Veterinary and Animal Science 14 (2021) 100197 Available online 18 August 2021 2451-943X/© 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Boosting animal performance, immune index and antioxidant status in post-weaned bull calves through dietary augmentation of selective traditional medicinal plants A.B.M. Rubayet Bostami a, * , M. Rokibul Islam Khan b , A.K.M. Zilani Rabbi c , M. Nurealam Siddiqui d , M. Tofazzal Islam e a Department of Animal Science and Nutrition, Faculty of Veterinary Medicine and Animal Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur-1706, Bangladesh b Department of Animal Science, Faculty of Animal Husbandry, Bangladesh Agricultural University (BAU), Mymensingh-2202, Bangladesh c Agricultural Training and Management Development Institute, Dhaka, Bangladesh. d Department of Biochemistry and Molecular Biology, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur-1706, Bangladesh. e Institute of Biotechnology and Genetic Engineering (IBGE), Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur-1706, Bangladesh A R T I C L E INFO Keywords: Traditional medicinal plant Feed additives Growth performance Blood assay Immune index Antioxidant status ABSTRACT Traditional medicinal plants (TMP) are considered valuable alternatives to hazardous synthetic chemical utilized as animal growth promoters. This study aimed to evaluate effects of dietary supplementation of seed and leaf powder (75:25) of three Bangladeshi TMP viz. Emblica offcinalis Gaertn., Terminalia bellirica Gaertn. Roxb., and Terminalia chebula Retz. on growth performance, digestibility of nutrients, hematological indices, immune index and antioxidant status in post-weaned bull calves. Dietary treatments: TMP1 (basal diet = green grass + concentrate), TMP2 (basal diet + 0.5% mixture of seed and leaf (75:25) of E. offcinalis Gaertn.), TMP3 (basal diet + 0.5% mixture of seed and leaf (75:25) of T. bellirica Gaertn. Roxb.), and TMP4 (basal diet + 0.5% mixture of seed and leaf (75:25) of T. chebula Retz.). Supplementation of TMP signifcantly (p < 0.10) improved weight gain without affecting digestibility. Hematological indices did not change much by treatment of TMP except for enhancement of monocyte (p < 0.10) and platelet percentage (p < 0.05). A reduction in IGF, enhancement (p < 0.05) of lymphocyte proliferation, and IgG were recorded in TMP2, TMP3 and TMP4 compared to TMP1. Decreasing (p < 0.05) trend of interleukins-1 and 6, and an elevation of TNF-α and antioxidant status were recorded in the TMP2, TMP3, and TMP4 in comparison to TMP1. An elevated level of total antioxidant and glutathione peroxidase activities were found in calves treated with TMP2, TMP3, and TMP4 (p < 0.05) relative to TMP1. Taken together, our results indicate that supplementation of feed with Bangladeshi TMP promoted growth and some health indices like immune-advocating effcacy of post-weaned bull calves. 1. Introduction Various factors such as genetics, nutrition, management, pre- and post-slaughter conditions impacts the performance and on meat quality of animals (Bostami, Mun & Yang, 2018; Taberlet, Coissac, Pansu & Pompanon, 2011). To satisfy the increasing demand for animal products due to the rapidly increasing world population, animal production has been intensifed. Consequently, for the increase of productivity and quality of animal meat, breeding and nutritional research approaches are also being continued in both developed and developing countries. The intensifcation of animal production is often limited by both avail- abilities of inadequate indigenous feed and desired breed of animals in most of the developing countries (Eastridge, 2006; Kamanzi & Mapiye, 2012). Therefore, novel sources of low-cost feed supplementation are needed for ruminant’s feed and rumen or digestive system manipulation to maximize ruminant productivity. In the animal industry, feed com- prises by far the largest component of input cost. Hence, the effciency of feed utilization in terms of herd output is the primary consideration in any technological development. Addition of synthetic growth promoters, antibiotics, anabolic * Corresponding author at: Department of Animal Science and Nutrition, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur-1706, Bangladesh. E-mail address: rubayet@bsmrau.edu.bd (A.B.M.R. Bostami). Contents lists available at ScienceDirect Veterinary and Animal Science journal homepage: www.elsevier.com/locate/vas https://doi.org/10.1016/j.vas.2021.100197 Received 9 April 2021; Received in revised form 16 August 2021; Accepted 16 August 2021