Feeding higher level of de-oiled rice bran causes stress to Labeo rohita fingerlings.

Abstract

A 60-day feeding trial was conducted with different inclusion levels of de-oiled rice bran (DORB) to study the digestive enzyme activity, physio-metabolic changes and oxidative stress in Labeo rohita fingerlings. Six iso- nitrogenous (30% crude protein), iso-lipidic (6% crude lipid) and iso-energetic (380.14 Kcal/100 g) semi-pur- ified diets were prepared with the graded levels of DORB viz. 0 (control), T20 (20%), T30 (30%), T40 (40%), T50 (50%) and T60 (60%). Three hundred and fifteen (315) fingerlings with an average weight of 8 ± 0.5 g were distributed randomly in seven treatments in triplicates, following a completely randomised design (CRD). The digestive enzyme, protease and amylase activities were higher in 20, 30 and 40% DORB fed groups but the Lipase activity did not vary significantly whereas, SOD and GST activity was significantly lower (p < 0.05) in the same groups. The T50 and T60 groups showed significantly higher (p < 0.05) hepatic LDH (Lactate de- hydrogenase), GST (Glutathione-s-transferase) and SOD activity, while RBC (Red blood cell) and WBC (White blood cell) content were found significantly lower in these groups. The catalase activity did not vary significantly (p > 0.05) among treatment group. Serum glucose content was higher in the T40, T50 and T60 groups, while serum total protein, albumin, NBT (Nitroblue tetrazolium) and haemoglobin levels were not significantly dif- ferent among the treatments. From the study, it can be concluded that DORB causes stress to fish when fed at higher inclusion level (50 & 60%).