The Addition of the Hormone Thyroxine (T4) to the feed to Accelarate the Growth of Bronze Featherback (Notopterus notopterus, Pallas 1769)

Bronze featherback (Notopterus notopterus, Pallas 1769) are freshwater fish whose population in nature has decreased. This population decline is due to fishing activities carried out by local fishermen in the wild that do not consider the size of the fish. As a result, fish that are small and not consumed are also caught. Also often found caught fish that are in the spawning season. Efforts that need to be done to prevent the extinction of these fish in nature are by cultivating fish. One of the weaknesses in current Bronze featherback farming is the slow growth of the fish being kept. To accelerate the growth of fish in this maintenance, it is necessary to try the addition of the hormone thyroxin in the feed given to fish. This research was conducted in Sungai Paku Village, Kampar Kiri District, Kampar Regency, and Riau Province from July to August 2020. The design used in this study was a completely randomized design (CRD) with one treatment and three replications. The treatment used in this study was the addition of thyroxin hormone at different doses given to feed (trash fish) consisting of P1 (0 mg thyroxin/kg feed), P2 (2 mg thyroxin/kg feed), P3 (4 mg thyroxin/kg feed) and P4 (6 mg thyroxin/kg feed). The results showed that the best treatment of thyroxin hormone was 6 mg/kg feed with an absolute weight growth value of 59.96 g, an absolute length growth of 14.3 cm, a specific growth rate of 3%, and a survival rate of 95%.