Evaluation of Aspalathus linearis Tea Extract as a Functional Ingredient in Mozambique Tilapia (<em>Oreochromis mossambicus</em>) Culture

Abstract

Supplements in fish nutrition can help alleviate pressure on the wild stock; however, there is limited information on the benefits of rooibos tea extract in aquafeed. This study aimed to determine the effect of rooibos tea extract inclusion in the commercial diet on the growth performance of larval fish. Fish were reared on three diets: a commercial diet with 30% fermented or green rooibos extract and a commercial tilapia diet (control). Fish (initial weight of 0.54 &amp;plusmn; 0.008 g and length of 2.22 &amp;plusmn; 0.01 cm) were randomly distributed into recirculating aquaculture systems in triplicates at 100 fish per tank. Fish was hand-fed thrice daily for eight weeks at 2% body weight. After that, samples were withdrawn to measure growth parameters. Fish-fed fermented, and green tea extracts exhibited a significantly (p ˂ 0.05) higher weight gain than the controls. The feed conversion ratio was higher in the control group, fermented (1.50 &amp;plusmn; 0.25 cm) and green tea (1.41 &amp;plusmn; 0.07 cm). Similarly, the control group exhibited the highest condition factor (K=13.14 &amp;plusmn; 4.87). The two treatment groups were comparable (p &amp;amp;gt;0.05) in growth performance. Overall, the evidence indicates that adding rooibos tea extracts to the basal diet can improve fish growth.