Nutritional evaluation of protein isolate from rubber seed in the diet of Labeo rohita : Effects on growth performance, nutrient utilization, whole body composition and metabolic enzymes activity

Abstract

a b s t r a c tThe nutritional potential of protein isolate from rubber seed (RPI) in the diets of Labeo rohita (initial average weight 4.45 ± 0.01 g) was assessed in a 60 days feeding trial. Five isonitrogenous (32.62 ± 0.13 CP Kg −1 ) and isocaloric (18.47 ± 0.08 MJ kg −1 ) experimental diets were formulated with graded level of RPI like 0%, 25%, 50%, 75%, or 100% in replacement for soybean protein isolate (SPI), and designated as Control, RPI25, RPI50, RPI75, RPI100, respectively. The RPI contributed 0%, 13%, 26%, 39% or 52% of the total dietary protein in the diets. Each diets were randomly assigned to 15 experimental tanks containing 12 fish in triplicates and fed to satiation twice daily at 10:00 h and 18:00 h. At the end of the feeding trial, the growth performance and nutrient utilization indices such as percent weight gain (WG%), specific growth rate (SGR), daily growth coefficient (DGC), feed intake (FI), protein efficiency ratio (PER), feed conversion ratio (FCR) and protein retention (PR) values were not significantly (p > 0.05) affected by the dietary treatments irrespective of inclusion levels of RPI. A significantly higher (p < 0.05) hepatosomatic index (HSI) was recorded in the control and RPI 50 group compared to other treatment groups (p < 0.05). The intestinal somatic index (ISI) and Survival rate were similar (p > 0.05) in all the groups. The apparent digestibility coefficients (ADCs) of dry matter and protein for fish fed the control and RPI 100 diets were found to be similar, while RPI 50 and RPI 75 groups exhibited a significantly lower value corresponding to the protease enzyme activity. The whole body compositions and digestive/metabolic enzymes activities among the various groups did not differ significantly (p > 0.05). The serum cholesterol and triglyceride levels were found to be significantly higher (p < 0.05) in the control compared to the RPI fed groups. Significantly higher serum glucose level was recorded in RPI 50, while a reverse was seen in the liver glycogen contents. Overall, this study clearly showed that RPI from rubber seed can serve as alternative protein source in the diets of L. rohita fingerlings without any adverse effects on growth, nutrient utilization and physio-metabolic responses.

Effects of detoxified Jatropha curcas protein isolate on growth performance, nutrient digestibility and physio-metabolic response of Labeo rohita fingerlings

“…The similar feed intake observed among the various groups indicates that the diets were well accepted by the fish and no palatability‐mediated feed rejection was noticed during the feeding trial. Also, the insignificant differences observed in the FCR, PER and PPV values among the various groups signify optimum utilization of the dietary protein fed without any inhibitory effects of ANFs and are in line with other studies (Fawole, Sahu, Jain, Gupta, Shamna, Phulia, et al., ; Kumar et al., ). In contrast, Shamna et al.…”

“…This may be due to the release of phosphorus from the phytate-bound phosphorus. Furthermore, the insignificant variation observed in the ADC of lipid among the various groups agrees well with the results of Kumar et al (2012) and Fawole, Sahu, Jain, Gupta, Shamna, Phulia, et al (2016) in L. rohita and common carp fed detoxified Jatropha and rubber protein isolates, respectively.…”

“…() and Fawole, Sahu, Jain, Gupta, Shamna, Phulia, et al. () in L. rohita and common carp fed detoxified Jatropha and rubber protein isolates, respectively.…”

“…The procedures for faecal sample collection were similar to those described in our previous study (Fawole, Sahu, Jain, Gupta, Shamna, Phulia, et al, 2016). Analysis of crude protein and lipid contents was carried out according to AOAC (1995).…”

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“…The digestibility study was carried out by indirect method using the chromic oxide (Cr 2 O 3 ) marker (Alexander et al, 2010;Fawole et al, 2016). The experimental feeds were prepared as specified earlier by incorporating 0.5% chromic oxide (Cr 2 O 3 ).Before starting the digestibility trial the fishes were acclimated for a period of 10 days to the respective diet.…”