ASSESSMENT OF ALTERNATIVE PROTEIN SOURCES AS FISHMEAL REPLACEMENTS ON THE GROWTH PERFORMANCE OF JUVENILE Tor tambroides (BLEEKER 1854)

Abstract

Fishmeal has traditionally been a primary protein source in aquafeeds due to its high nutritional quality. However, declining availability and rising costs have driven interest in alternative protein sources. This study aimed to evaluate the effects of replacing fishmeal with different protein sources on the growth performance of juvenile Malaysian mahseer, Tor tambroides. Four experimental diets were used and formulated using Danish fishmeal as Diet 1 (Control), soybean meal (SBM) as Diet 2, Black Soldier Fly Larvae meal (BSFL) as Diet 3, and poultry by-product meal (PBM) as Diet 4. Juvenile T. tambroides were reared in outdoor tanks (triplicate groups per diet) over a five-month feeding trial. Growth performance metrics, including body weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and hepatosomatic index (HSI) were assessed. Results indicated that fish fed the Diet 2  achieved the highest weight gain which is 32.66 ±0.18 g compared to fish fed with Diet 3 (30.29 ±1.41g) and Diet 4 (25.54 ±1.51g). Meanwhile, for SGR, the fish fed with Diet 3 showed highest result (0.42±0.02%/day) compared to those fed Diet 2 (0.41±0.02%/day)  and Diet 4 (0.38±0.02%/day). However, the differences were not statistically significant (P>0.05). Notably, the Diet 2 (1.06±0.001)resulted in significantly higher PER values (P<0.05) compared to the Diet 1 (control)(0.97±0.001). No significant differences (P>0.05) were observed in FCR across the different diet treatments, HSI values did not differ significantly among the treatment groups. These results highlight the potential of SBM and BSFM as viable substitutes for fishmeal in juvenile T. tambroides diets, while emphasizing the need for additional studies on protein utilization and long-term effects.