Papers by Bobban Subhadra
Energy Policy, 2010
Algal biomass provides viable third generation feedstock for liquid transportation fuel that does... more Algal biomass provides viable third generation feedstock for liquid transportation fuel that does not compete with food crops for cropland. However, fossil energy inputs and intensive water usage diminishes the positive aspects of algal energy production. An integrated renewable energy park (IREP) approach is proposed for aligning renewable energy industries in resource-specific regions in United States for synergistic electricity and liquid biofuel production from algal biomass with net zero carbon emissions. The benefits, challenges and policy needs of this approach are discussed.
Aquaculture, 2006
We conducted a 12-week feeding trial with largemouth bass (LMB) to examine the interactive effect... more We conducted a 12-week feeding trial with largemouth bass (LMB) to examine the interactive effects of non-fish dietary proteins with different lipid sources on the performance of LMB (3.4 g ± 0.05 g). Practical diets contained poultry by-product meal (PBM) in place of fish meal on a digestible-protein basis, and 12% blood meal (BM). Diets were supplemented with 10% lipid as canola (CAN), chicken (CHK), CHK + MFO (50 : 50), menhaden fish oil (MFO) or CHK + CAN (50:50). A commercial trout diet (SC) was included as a positive control. Growth, survival, feed intake (FI), feed conversion ratio (FCR), protein efficiency ratio (PER), body composition, fatty acid composition of liver and muscle, hematological parameters and lysozyme and alternative complement activity (ACH50) were measured to assess diet effects. Weight gain (23.8 ± 1.8 g), survival (92 ± 4%), FI (44.3 ± 4.1 g), FCR (2.1 ± 0.1) and PER (1.3 ± 0.04) of LMB did not differ among the replacement diets. However, weight gain (38.5 ± 1.5), FI (53.9 ± 1.1), and PER (1.6 ± 0.1) of LMB fed the SC diet was higher and FCR (1.4 ± 0.1) was lower than that of fish fed the test diets. No signs of essential fatty acid deficiency were observed, although tissue concentrations of n-3 highly unsaturated fatty acids declined markedly in LMB fed diets without fish oil. Lymphocytes were elevated in fish fed diets with ≥ 7% n-3 fatty acids. Fish fed diets with 10% MFO or CHK + MFO had higher ACH50 than fish fed the diet with 10% CHK. There were no differences in serum lysozyme activity among fish fed the test diets. Hematocrit, hemoglobin, ACH50, and lysozyme activity were higher in fish fed the SC diet than in those fed the test diets. Regardless of lipid source, the ACH50 and lysozyme activity were greatly reduced in LMB fed PBM diets compared to LMB fed diets with 30% fish meal in a previous trial. The amino acid composition of the PBM was similar to that of fish meal. However, the availability of some essential amino acids from PBM to LMB may have been limited, and poor diet palatability caused by BM also may have reduced feed intake and performance of LMB.
Aquaculture, 2006
We conducted a 12-week feeding trial with LMB fed practical diets differing primarily in lipid so... more We conducted a 12-week feeding trial with LMB fed practical diets differing primarily in lipid source. We reduced the fish oil content of commercially solvent-extracted menhaden fish meal to 0.5-1.2%, and used it as the primary protein source in all test diets. Diets were supplemented with 10% lipid as canola (CAN), chicken (CHK), menhaden fish oil (MFO) or CHK + MFO (50/ 50%). An additional diet contained non-extracted fish meal and 10% CHK (NEF + CHK), and a commercial trout diet (SC) was also included. Growth, survival, feed utilization, body composition and health parameters were measured to assess diet effects. Weight gain, survival, feed intake, feed conversion ratio, and protein efficiency ratio of LMB fed the test diets did not differ. Weight gain of LMB fed the SC diet was higher than that of LMB fed the test diets. Muscle lipid of fish fed the diet with 10% MFO was higher than that of fish fed diets with an equal mixture of CHK + MFO or NEF + CHK, and muscle lipid of LMB fed the SC diet was higher than that of fish fed the test diets. The n-3 to n-6 fatty acid ratio of the test diets was lower than expected because the poultry meal contained 16% lipid (high in 18:2n-6). The ratio of n-3 to n-6 fatty acids was higher in muscle and liver of fish fed the SC diet than those of fish fed the test diets. Docosahexaenoic acid (22:6n-3) and 20:4n-6 were conserved in fish fed diets without HUFA, but 20:5n-3 declined sharply from initial values. The index of atherogenicity (IA) and the index of thrombogenicity (IT) of LMB fed the test or SC diets were below 1.0 (considered healthful). Lymphocytes were higher in fish fed diets with N 4% n-3 fatty acids, including the CAN diet without HUFA. There were no differences in the Hk, Hb, MCHC, or serum lysozyme of LMB fed the test diets, but lysozyme was lower in LMB fed the SC diet than those fed the CHK + MFO diet. Fish fed diets with 10% MFO or CAN had higher alternative complement activity than fish fed diets with CHK. Tissue concentrations of HUFA (especially 20:4n-6 and 22:6n-6) were not depleted in 12 weeks, possibly due to conservation of initial HUFA, synthesis of HUFA from 18:3n-3 and 18:2n-6, or both. Therefore, non-fish oils might reduce diet cost with few deleterious effects for at least a quarter of the production cycle of LMB.
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Papers by Bobban Subhadra