Open AccessOptimum Dietary Protein Level and Protein‐to‐energy Ratio for Growth of Juvenile Parrot Fish, Oplegnathus fasciatus
Author(s) -
Kim KangWoong,
Kim KyoungDuck,
Han Hyon Sob,
Moniruzzaman Mohammad,
Yun Hyeonho,
Lee Seunghan,
Bai Sungchul C.
Publication year - 2017
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12337
Subject(s) - biology , juvenile , zoology , dietary protein , fish <actinopterygii> , feed conversion ratio , protein efficiency ratio , juvenile fish , weight gain , body weight , fishery , ecology , endocrinology
An 8‐wk feeding trial was conducted to estimate the optimum dietary protein level and protein‐to‐energy (P/E) ratio in juvenile parrot fish, Oplegnathus fasciatus . Eight experimental diets were formulated with two energy levels and four protein levels for each energy level. Diets containing crude protein ( CP ) at 35, 40, 45, and 50% had either 12.5 or 14.6 kJ /g of energy. Fish averaging 7.1 ± 0.06 g (mean ± SD ) were fed one of the experimental diets for 8 wk. At the end of the feeding trial, weight gain ( WG ) of fish fed 45 and 50% CP in the 12.5 kJ /g diet was significantly higher than fish fed the 35% CP diet ( P < 0.05). WG of the fish fed 45 and 50% CP in the 14.6 kJ /g diet was significantly higher than fish fed the 35 and 40% CP diets ( P < 0.05). Fish fed the 14.6 kJ /g diet had a higher WG compared with fish fed the 12.5 kJ /g diet at all CP levels. Feed efficiency ( FE ) and specific growth rate ( SGR ) showed a similar trend to the WG . WG , FE , and SGR improved with increasing dietary protein levels up to 45% and remained constant at 50% CP for both energy levels. However, protein efficiency ratio was negatively related to dietary protein levels. The results suggested that the optimum level of protein and the optimum P/E ratio for juvenile parrot fish should be 45% and 31.1 mg protein/ kJ , respectively, in a diet containing 14.6 kJ /g energy.