Acta Scientific Veterinary Sciences (ISSN: 2582-3183) Volume 6 Issue 3 March 2024 Spleen Indices of Mixed Breed Rabbits Fed Graded Levels of some Common Forages in the Coastal Savannah Ecological Zone of Ghana DY Osei 1,2 *, P Asiedu 3 , FO Sarkwa 4 , EC Timpong-Jones 4 and D Amedorme 1 1 Council for Scientific and Industrial Research - Animal Research Institute, Frafraha, Ghana 2 Department of Animal Resources Development, CSIR College of Science and Technology, Accra 3 Department of Animal Production and Health, University of Energy and Natural Resources, Sunyani, Ghana 4 Livestock and Poultry Research Centre, School of Agriculture, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana *Corresponding Author: DY Osei; Council for Scientific and Industrial Research - Animal Research Institute, Frafraha, Ghana. Research Article Received: January 16, 2024 Published: February 24, 2024 © All rights are reserved by DY Osei., et al. Introduction Abstract This study sought to examine the immune response of rabbits fed different dietary levels of four common forages in Coastal Savan- nah Ecological Zone of Ghana. A total of 48 eight-week old mixed-breed rabbits were offered–– concentrate containing graded levels of 0, 10, 20 and 30% Brassica oleracea outer leaves or Musa paradisiaca leaves, Megathyrsus maximus, and Stylosanthes guianensis aerial parts for one week and 12-weeks adaptation and testing periods respectively. Spleen from 8 representative rabbits from each treatment group were harvested at the end of the feeding period and used to determine the spleen indices. No significant differ- ences were found in the body weights, 1926 to 2314g, spleen weights, 1.00 to 1.50g, and spleen indices, 0.05 to 0.07g of rabbits fed concentrate containing the graded levels of the leaves. Rabbits fed diets containing 10% inclusion level of Brassica oleracea had the highest body weight, while the highest spleen weight and spleen index were found in rabbits fed 30% inclusion level of Musa paradi- siaca leaves and Stylosanthes guianensis aerial parts. The study concludes that feeding diets containing up to 30% inclusion level of Brassica oleracea outer leaves, Musa paradisiaca leave and Megathyrsus maximus and Stylosanthes guianensis aerial parts to growing rabbits enhance the immune response of the animals thereby ensuring good performance and health. Keywords: Body Weight; Brassica Oleracea; Dietary Level; Megathyrsus Maximus; Musa Paradisiaca; Stylosanthes Guianensis The spleen is the largest secondary immune organ in the body [1,6] and is responsible for initiating immune reactions to blood- borne antigens and for filtering the blood of foreign material and old or damaged red blood cells [1]. It has a wide range of immuno- logic functions alongside its roles in hematopoiesis and red blood cell clearance. The physical organization of the spleen allows it to filter blood of pathogens and abnormal cells and facilitate low- probability interactions between antigen-presenting cells and cog- nate lymphocytes [6]. It also plays a modulatory role that balances pro- and anti-inflammatory responses [9]. Brassica oleracea outer leaves, Megathyrsus maximus and Sty- losanthes guianensis aerial parts and Musa paradisiaca leaves are among the common forages fed to rabbits in the Coastal Savannah ecological zone of Ghana [10]. Stylosanthes guianensis is a short- lived, erect or semi-erect perennial legume that can reach a height of 1-1.5 m. The fresh aerial parts contain 22.1% dry matter (DM) as feed, crude protein (CP) 14.0% DM, crude fibre (CF) 31.2% DM, ether extract (EE) 2.4% DM, ash 8.8% DM and MJ/kg gross energy (GE) 18.5% DM [3]. Megathyrsus maximus (Guinea grass) is a fast- growing leafy grass with a good nutritional value. The grass has DM 22.7% as feed, CP 11.2% DM, CF 37.3% DM, and GE 18.1 MJ/kg Citation: DY Osei., et al. “Spleen Indices of Mixed Breed Rabbits Fed Graded Levels of some Common Forages in the Coastal Savannah Ecological Zone of Ghana". Acta Scientific Veterinary Sciences 6.3 (2024): 67-71. DOI: 10.31080/ASVS.2024.06.0839