Productive performance, body measurements, and meat composition in Nile tilapia juveniles supplemented with fresh duckweed

Abstract Lemna minor (LM) or duckweed is a cheap and sustainable protein source, mainly for use by small fish farmers. In this study was determined the composition of the used fresh LM and evaluated its effect on performance, body measurements, and meat composition of Nile tilapia. One hundred sixty juveniles were used in a completely randomized design with four treatments and four replicates. Treatments comprised a control group (commercial ration) and three experimental groups (90%, 80%, and 70% of the daily ration amount in the control group + 10%, 20%, and 30% of fresh LM, respectively). The used LM showed 96.55% of moisture, 17.24% of ash, 5.56% of total lipids, and 29.78% of crude protein. The 30% supplementation with LM reduced the feed intake and, consequently, the protein intake (P≤0.05) compared to the control group, resulting in a better feed conversion rate (g ration/g weight gain), and lower cost of fish kilo. There was no effect (P ≥ 0.05) of the supplementation with fresh LM on body measurements and the contents of moisture, protein, fat, and minerals in the juvenile meat. It was concluded that Nile tilapia juveniles can be reared with 70% commercial ration + 30% fresh LM, reducing the costs of fish kilo.