Additive effects of <i>Bridelia ferruginea</i> leaf meal as a partial replacement for soybean meal on nutrients digestibility, growth performance, and carcass characteristics of weaner rabbits

Abstract Background Protein is a crucial nutrient for enhancing livestock performance and productivity, traditionally sourced from soybean and fish meal. However, issues like erratic availability and rising prices necessitate exploring alternative protein sources. Tropical plants, especially leaf meals, are being considered to replace or supplement conventional protein sources in rabbit diets. Bridelia ferruginea, a plant abundant in West Africa, is recognized for its medicinal properties, but its potential as an animal feed is largely unexplored. This study aims to evaluate the impact of graded levels of Bridelia ferruginea leaf meal (BFLM) as a partial substitute for soybean meal in the diets of weaner rabbits. Materials and methods The experiment was conducted at the Animal Science Department of Kwame Nkrumah University of Science and Technology in Ghana. BFLM was obtained by air-drying harvested leaves and milling them. Four diets were formulated, with BFLM partially replacing soybean meal at levels of 0%, 10%, 20%, and 30%. Representative samples of BFLM and all formulated diets were analyzed for their proximate composition and detergent fibre fractions. Twenty-four weaner rabbits were assigned to these diets in a Completely Randomized Design. The study covered a 10-week period, assessing growth performance, nutrient digestibility, carcass characteristics, and economics of production. Results The chemical composition of BFLM revealed favorable attributes for rabbit feeding, with 20.5% crude protein and 92.6% dry matter. Growth performance declined at 30% BFLM inclusion, indicating a possible impact of anti-nutritional factors. Feed conversion ratio increased at higher BFLM levels. Nutrient digestibility showed a decline in dry matter digestibility at 30% BFLM. Carcass characteristics were affected at higher BFLM levels, with dressing percentage decreasing. Weights of internal organs were generally not negatively affected by the inclusion of BFLM. Economic analysis indicated a linear reduction in feed cost with increasing BFLM inclusion. Conclusion The study suggests that BFLM can be incorporated up to 20% in weaner rabbit diets without compromising productivity, nutrient digestibility, or dressing percentage. Beyond 20%, adverse effects on growth performance and some carcass characteristics were observed. Economically, BFLM incorporation up to 20% lowered feed costs without compromising feed efficiency. Incorporation of BFLM up to 20% in weaner rabbit diets had no adverse effects on the weights and functions of the heart, liver, and kidneys. Overall, BFLM presents a promising alternative protein source for weaner rabbit diets, contributing to cost-effective and sustainable livestock production.