Suitability of conventional ingredients used for aqua feed production in East Africa

Abstract

The ambitious aquaculture production targets aiming at producing 1,000,000 mt, 700,000 mt, 50,000 mt and 160,000 mt in Uganda, Kenya, Tanzania and Rwanda respectively by 2030; calls for increased fish feed production. However, fish farmers are challenged by limited access to quality fish feeds that are commercially competitive and environmentally friendly. Small scale fish farmers are challenged by high feed cost and logistics associated with feed importation that limit their access to quality feeds. Accordingly, there is growing interest to promote backyard aqua feed formulation. Traditionally, feed formulators focus on nutrient composition (more so proximate composition) and cost of feed ingredients and pay less attention to several factors that affect sustainability, including pollution potential, environmental/ecological impacts, competing uses, socio-cultural considerations, yield and fertilizer requirements among others. A broad range of factors that may affect the suitability of a feed ingredient (including those related to environment, nutrition content and utilization, unit nutrient cost and socio-economics among others) for five commonly used protein ingredients (i.e., fishmeal, bone meal, soya bean meal, sunflower meal and cotton seed meal) and four conventional energy ingredients (i.e., maize bran, sorghum grain, wheat bran and rice bran) in East Africa were examined. The results indicated that soya bean and cotton seed meals are the most viable plant-based protein ingredients with an average rank of 1.8 compared to sunflower meal average of 2.0. Among the animal-based protein ingredients, fish meal (mukene) out performed bone meal. However, continued use of fishmeal in feed formulation seems unsustainable because of the allied ecological and environmental impacts. Maize bran remains the most viable energy ingredient, outperforming wheat bran, rice bran and sorghum respectively. Overall, animal ingredients are the most suitable protein sources for farmed fish species. However, their use is associated with ecological and environmental impacts that culminate into outstanding negative impacts to the aquatic ecosystem than plant protein ingredients