Effects of Commercial and Locally Formulated Diets on Growth Performance of Juvenile <i>Oreochromis andersonii</i> in a Hatchery System

ABSTRACT In Namibia, the aquaculture sector faces significant challenges, mainly due to the high cost of imported commercial feed, which limits small‐scale farmers' productivity and food security. To address this, locally formulated feeds must be evaluated as sustainable alternatives. A study conducted at the Kamutjonga Inland Fisheries Institute assessed the effects of feed types on the growth and survival of Oreochromis andersonii over 9 weeks. Three locally formulated diets (pearl millet, maize and sorghum) were compared with a commercial pellet diet (control) in a randomised design with three replications. Growth performance indicators, including specific growth rate, weight gain, final body weight, feed conversion ratio and survival rate, were analysed using ANOVA. Results showed no significant differences among treatments; however, the pearl millet diet recorded the highest specific growth rate (3.94 ± 0.16%) and final mean weight (11.29 ± 0.67 g), while the sorghum diet showed the lowest growth rate (3.08 ± 0.40%) and maize resulted in the least weight gain. The pearl millet diet had the most efficient feed conversion ratio (1.92 ± 0.57). The economic evaluation further showed that the pearl millet diet had the lowest economic conversion ratio (N$13.27 per kg biomass gain), making it the most cost‐effective diet, whereas commercial pellets recorded the highest feed cost (N$27.58 per kg biomass gain). Survival rates were high across treatments, particularly in pearl millet and commercial diets. These findings indicate that pearl millet–based feed can support growth and survival comparable to commercial pellets while substantially reducing feed costs, making it a promising and economically viable alternative for small‐scale aquaculture production in Namibia.