Complimentary effect of exogenous enzymes, essential amino acids and essential fatty acids supplemented de-oiled rice bran (DORB) based diets on hematology, liver and intestinal histoarchitecture in Labeo rohita.

A 60-day feeding trial was conducted to study the hematology, liver, and intestinal histoarchitecture of Labeo rohita fed with a combination of exogenous enzymes, essential amino acids, and essential fatty acids to DORB (De-oiled rice bran) based diets. Three treatments viz., T1 [DORB + phytase and xylanase (0.01% each)], T2 [DORB + phytase (0.01%) + xylanase (0.01%) + L-lysine(1.4%) + L-methionine (0.4%) + EPA and DHA (0.5%)] and T3 [DORB + phytase (0.01%), xylanase and cellulase (0.075%) + L-lysine (1.4%) +L-methionine (0.4%) + EPA and DHA (0.5%)] were used in the present study. Serum total protein, albumin content and A/G ratio varied significantly (p < 0.05) among groups. Globulin content did not vary significantly among groups (p ≥ 0.05). The Hb content, RBC and MCV count varied significantly (p < 0.05) whereas MCH, MCHC content, WBC and lymphocyte count did not vary significantly among groups (p > 0.05). The liver and intestine examination revealed no visible alteration and showed normal histo-architecture. Based on the finding it is concluded that DORB supplemented with exogenous enzymes, essential amino acids and essential fatty acids with phytase (0.01%), xylanase and cellulase (0.075%), L-lysine (1.4%), DL-methionine (0.4%) and EPA and DHA (0.5%) improves the health of L. rohita.

Changes in weight gain, digestive and metabolic enzyme activities in Labeo rohita fingerlings in response to multiple stress exposure and dietary nutraceutical.

A feeding trial was conducted for 4 months to study the effect of a nutraceutical conglomerate at different levels (0, 0.1, and 0.5%) on stress-exposed (high stocking density, H and feed restriction, R) Labeo rohita fingerlings. Six isonitrogenous diets with a crude protein of 35% were prepared for the different treatments, viz. THR0, THR1, THR5, TNS0, TNS1 and TNS5. Stress significantly reduced the weight gain and feeding of 0.1% nutraceutical improved it in both stress-exposed and non-exposed groups from 3 months onwards. Two-and three-month stress-exposed groups exhibited lower (p < 0.05) protease activity, while amylase activity was significantly higher in 2-month stress-exposed groups. Higher lipase activity was found in stress-exposed groups irrespective of the duration of stress. Higher serum glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hepatic and muscle lactate dehydrogenase (LDH) activities were observed in the THR0 groups; however, THR1 showed a lower activity of these enzymes. Increased malate dehydrogenase (MDH) and glucose-6-phosphate dehydrogenase (G6PDH) activity was recorded in the 1st and 2nd months stress-exposed groups. However, THR1 group exhibited a reduced MDH and G6PDH activity compared to THR0 group in 1st and 2nd months. Hence, it can be concluded that the duration of multiple stress exposure adversely affected the digestive and metabolic enzymes activities and feeding of 0.1% nutraceutical conglomerates could restore the activities of digestive and metabolic enzymes in rohu fingerlings.

Exogenous phytase and xylanase supplementation of formulated diets for rohu (Labeo rohita): impact on haematology, histology and IGF I gene expression.

The present study aims to delineate the effect of exogenous enzyme supplementation of fermented or non-fermented de-oiled rice bran (DORB) on haematology, histology and expression of IGF I gene expression of Labeo rohita. Four test diets, namely, T1 (DORB), T2 (fermented DORB), T3 (DORB+exogenous enzyme) and T4 (fermented DORB+exogenous enzyme) were formulated and fed to the L. rohita for a period of 60 days. The test diets T3 and T4 were supplemented with 0.1 g kg-1 xylanase (16,000 U kg-1) and 0.1 g kg-1 phytase (500 U kg-1) enzymes. A total of 120 juveniles of L. rohita (average weight 5.01 ± 0.02 g) were stocked in 12 rectangular tanks with 10 fish per tank in triplicates. At the end of the experiment, haematology, histology and IGF I gene expression of the different groups were analysed. The haemoglobin (Hb) content, RBC count and WBC count of L. rohita varied significantly (p < 0.05) among different groups. T3 diet-fed group had the highest Hb content, RBC count and WBC count as compared to the other groups. The MCV content was significantly (p < 0.05) lower in T3 group. The DORB type, exogenous enzyme supplementation and their interaction have no significant (p > 0.05) effect on MCH, MCHC and lymphocyte content of the cultured fish. The group which were fed T3 diet had significantly (p < 0.05) higher IGF-I gene expression as compared to other groups. The histological examination of liver revealed no pathological alteration of this organ. Similarly, there were no pathological changes observed in intestinal tissue in any dietary treatment group. Based on the findings of the present study, it is concluded that exogenous enzyme supplementation of DORB-based diets improves the physiological status and growth performances of Labeo rohita.

Physio-metabolic and haematological changes of Labeo rohita fed with graded level of de-oiled rice bran-based diet.

A 60-day feeding trial was conducted with six experimental diets containing 260 g/kg crude protein and 70 g/kg lipid with varying level of de-oiled rice bran (DORB), viz., 33 (T33), 38 (T38), 43 (T43), 48 (T48), 53 (T53) and 58% (T58) to assess the digestive, metabolic and haematological responses in Labeo rohita. One hundred and eighty (180) fingerlings with ten fish per tank having an average weight of 9.8 ± 0.5 g were randomly distributed within six treatments in triplicates following a completely randomised design. The amylase and lipase activities in the whole intestine did not vary significantly (P > 0.05), but protease activity varied significantly with respect to DORB level in the diet. At higher (53 and 58%) inclusion level of DORB, the protease activities were lower. T33, T38 and T43 groups showed significantly (P < 0.05) higher aspartate aminotransferase (AST) activity compared to the other groups, whereas lowest activity was recorded in the group fed with highest inclusion level (58%). The oxidative stress enzyme like superoxide dismutase (SOD), catalase and glutathione-S-transferase exhibited significantly higher activities in liver of T58 group of L. rohita. However, the activity of catalase and SOD showed no significant variation in gill tissue. The haematological parameter values such as red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb) and packed cell volume (PCV) were lower in the highest DORB fed group (T58) as compared to their lower DORB inclusion counterparts. No change in NBT value was recorded irrespective of DORB inclusion level in the diet. Hence, from these results, it can be concluded that the dietary inclusion of DORB up to 43% in the diet of L. rohita at 26% crude protein and 7% lipid level is best for the optimal activity of digestive, metabolic and haematological parameters.

Solid state fermentation of de-oiled rice bran: Effect on in vitro protein digestibility, fatty acid profile and anti-nutritional factors.

An experiment was conducted to study the effect of solid state fermentation of de-oiled rice bran (DORB) with Rhizopus oryzae on in vitro protein digestibility, anti-nutritional factors and fatty acid profile. The fermentation of DORB with Rhizopus oryzae significantly reduced the in vitro protein digestibility of DORB (p < .05). The fermentation of DORB with Rhizopus oryzae increased the saturated fatty acid (SFA) content by 46.83%, while decreased the MUFA and PUFA contents by 14.01 and 8.76%, respectively. The n-6 fatty acid content of FDORB increased by 6.19%, while n-3 fatty acid content decreased by 53.92%. The fermentation of DORB resulted in significant reduction in phytate and trypsin inhibitor activity (p < .05). Based on the present result it is concluded that the fermentation of DORB with Rhizopus oryzae improves the n-6 fatty acid profile and brings significant reduction in the phyate and trypsin inhibitor content but fails to improve the in vitro protein digestibility and hence cannot be recommended as a suitable microbe for DORB fermentation.

Comparative evaluation of fermented and non-fermented de-oiled rice bran with or without exogenous enzymes supplementation in the diet of Labeo rohita (Hamilton, 1822).

A 60-day feeding trial was conducted to study the effect of exogenous enzymes (xylanase and phytase) supplementation in the non-fermented and fermented de-oiled rice bran (DORB)-based diet of Labeo rohita. Four test diets (T1-DORB-based diet, T2-fermented DORB-based diet, T3-phytase and xylanase supplemented DORB-based diet, and T4-phytase and xylanase supplemented fermented DORB-based diet) were formulated and fed to the respective groups. Test diets T3 and T4 were supplemented with 0.01% xylanase (16,000 U kg-1) and 0.01% phytase (500 U kg-1) enzymes. One hundred twenty juveniles of L. rohita, with an average weight 5.01 ± 0.02 g, were stocked in 12 uniform size plastic rectangular tanks in triplicate with 10 fishes per tank following a completely randomized design (CRD). Exogenous enzyme supplementation to the T3 group significantly improved the growth performance of L. rohita (p < 0.05). Fermented DORB fed groups registered significantly lower growth irrespective of the supplementation of exogenous enzymes. The carcass composition (except CP %), enzyme activities (except amylase activity), globulin, and A/G ratio did not vary significantly (p > 0.05). Based on the results of the present study, it is concluded that exogenous enzyme supplementation significantly increases the growth of fish fed with DORB-based diet.