Brown propolis extract in feed as a growth promoter of Nile tilapia (Oreochromis niloticus, Linnaeus 1758) fingerlings

This study assessed the use of increasing levels of brown propolis extract (BPE) as a growth promoter in Nile tilapia fingerling feeds. In a complete randomized design, 75 Nile tilapia fingerlings with 60 days on average and weighing 4.1 +/- 0.1 g were assigned to 25 aquaria (60 L) and subjected to 5 treatments in 5 repetitions for 30 days. Propolis from Serra do Araripe, Cariri Region, South Ceara State - Brazil was used to produce the BPE. The treatments involved the addition of BPE to feed samples (0.91, 1.83, 2.74 and 3.65 g kg(-1)) and feed control (without BPE). The final mean weight and the percentage of weight gain varied quadratically with the increase in BPE (P < 0.01), with a maximum of 2.22 g kg(-1). The other evaluated parameters were not affected by the treatments (P > 0.05). The level of best performance parameters was 2.22 g kg(-1), between the levels of 1.83 and 2.74 g BPE kg(-1) feed inclusion. These results indicate the potential to use the brown propolis extract as a growth promoter to Nile tilapia fingerlings.