Aquaculture by-product meal as a fishmeal replacer in African catfish (Clarias gariepinus) diet: Effects on serum biochemistry, innate immune response, and oxidative stress markers

The effect of feeding aquaculture by-product meal (ABP) to African catfish (Clarias gariepinus) was investigated in a 56-day feeding trial using serum biochemistry, innate immune response, and oxidative stress markers as indices of assessment. Fishmeal protein in control diets was replaced at a rate of 15, 30, 45, and 60% by aquaculture by-product meal protein. Each experimental diet was randomly distributed into triplicate tanks containing catfish fingerlings (n = 15 fingerlings/replicate, 5.58±0.05 g). The primary haematological parameters (haemoglobin, packed cell volume, red blood cell count) and secondary haematological parameters (MCH, MCV, and MCHC) were similar with the control. The white blood cell count and its differential of the fish group fed ABP meal was numerically higher than control but not significant, except in fish fed D30T that had high lymphocyte count. The platelet count in all the dietary groups was similar. There was no significant variation in some of the serum biochemistry parameters: total protein, albumin, globulin and albumin/globulin ratio, urea, HDL-C and LDL-C. Creatinine values of the D60T fed group were significantly higher than all other dietary treatment groups including the control. Triglyceride's level was statistically similar with control up to 30% replacement level, while there were no significant variations in the cholesterol levels of the blood of C. gariepinus fed the different dietary treatments. Except for catalase, there were no significant differences in other oxidative stress biomarkers under study, primarily SOD, GSH, and GPx. Catalase enzyme activities of the fish group fed D30T were statistically higher than other fed groups. Some serum electrolytes, such as calcium and chloride ions of the differently fed fish groups, were not significantly different. Lastly, serum potassium ions were significantly higher among D60T fed group though statistically similar to D45T-fed group. No stress conditions were recorded among the dietary groups.  These results showed that the health status and immunity of African catfish were not degraded by feeding aquaculture by-product meal to the fish

Toasted Jatropha curcas seed meal in Nile tilapia (Oreochromis niloticus) diet: Effect on growth, economic performance, haematology, serum biochemistry and liver histology

The effect of dietary inclusion of differently timed dry heat-treated Jatropha curcas on the growth and economic performance of Nile tilapia, Oreochromis niloticus, was evaluated in a 56-day feeding trial. Five isonitrogenous and isolipidic dietary treatments (35% crude protein and 10% crude lipid) were made consisting of soybean meal (control) which was replaced by J. curcas seed meal toasted either 5 min or 10 min at 20 and 40% to make other four test diets. A total of 225 juveniles of O. niloticus were acclimatized for a week, weighed and allotted into five dietary treatments. Each treatment was replicated three times with fifteen fish per replicate. Fish were fed 5% body weight on two equal proportions per day for 56 days. Growth data were collected at two-week intervals. The results from the study indicated that there was significant difference (P0.05) in the different growth and economic performance parameters of fish fed CTR and fish fed D520T (5 min toasted, 20%). There was significant reduction in haematological and biochemical parameters of the blood of O. niloticus fed the different dietary treatments containing J. curcas seed meal. Based on economic and physiologic performance, soybean meal in Nile tilapia diet could be replaced up to 40% by 5-minute toasted J. curcass seed meal

Sensory quality of smoked Clarias gariepinus (Burchell, 1822) as affected by spices packaging methods

Effect of packaging materials and spices on the sensory quality of smoked Clarias gariepinus (Burchell, 1822) was evaluated. The smoked C. gariepinus treated with garlic, ginger, garlic–ginger homogenate, and the control (unpreserved) was stored for 112 days at ambient temperature inside plastic (polyethylene terephthalate) and nylon (polythene). The four groups garlic, ginger, garlic–ginger homogenate spiced fish, and the control (unpreserved) fish samples comprising 216 fish in each group totaling 864 fish (226 ± 23 g) were euthanized, gutted, cleaned, and hot-smoked using Nigeria Institute for Oceanography and Marine Research (NIOMR) smoking kiln, packaged, and sampled at 14-day intervals for a period of 112 days at ambient temperatures (27 ± 2°C). Organoleptic assessment was carried out by a semi-trained taste panel. Data obtained were subjected descriptive statistics (mean) and virtual analysis (bar chart). The results indicated that garlic–ginger homogenate preserved catfish was rated as having the best odor (mean score 9.25) at the onset of the experiment, followed by ginger-preserved catfish (mean score 7.58). However, control was rated as having the best texture (mean score 8.25), followed by garlic–ginger homogenate (mean score 7.17). Plastic (polyethylene terephthalate) was established as a better packaging material than nylon (polythene) as the scores allotted by taste panelists started decreasing earlier for the odor and texture of the smoked fish samples with increased storage time when packaged inside nylon. Garlic–ginger homogenate was recommended as both preservative and spices of C. gariepinus, while plastic was recommended as better packaging material at room temperature

EVALUATION OF HETEROCLARIAS QUALITY WITH INCREASED STORAGE TIME USING QUALITY INDEX METHOD (QIM)

The quality of Heteroclarias with increased storage time using Quality Index Method (QIM) was evaluated. 140 live samples of Heteroclarias (average weight 230 + 7g) were used for the study. QIM was used to evaluate the key parameters in fish deterioration, twenty semi-trained assessors was used for the sensory evaluation. Data obtained were subjected to appropriate statistical tools using SPSS 16.0 version. Quality Index (QI) of Heteroclarias increases with increased post slaughter time when the fish was left at ambient temperatures (27 + 3°C) indicating decrease in fish quality with time. High correlation of (r=0.993) with a high coefficient of determination (R2=0.986) was obtained indicating that 98.6% of the variation in post slaughter time was explained by quality attributes; the regression equation was significant F(9, 130)=1080 (p Practical Applications :Fish is highly perishable despite its nutritional value, consumers becoming increasingly interested in the quality of fish they consume and the physical attributes of the fish is very vital for on the spot assessment of fish quality. This study provide quality index that could be used for prediction and estimation of fish quality using sensory evaluation

Effect of processing methods on consumer's acceptability and proximate composition of yellow croaker (Larimichthys polyactis)

Effect of processing methods on consumer’s acceptability and proximate composition of yellow croaker was investigated. The experiment was completely randomized design where the treatments were the various processing methods employed. 12kg frozen yellow croaker fish were purchased, cut into chunks, divided into 4 groups of 3kg each, each group was salted and then subjected to different processing methods including: sun drying, deep- frying, solar drying and smoking. After processing, the products were subjected to organoleptic assessment using hedonic scale while the proximate composition was determined using standard experimental procedures.  The result of this study indicates that the odour and flavour of smoked fish product were significantly (p < 0.01) preferred by consumers above other products. Solar dried fish product had highest percentage crude protein followed by smoked fish product while smoked fish product had the highest crude ash. This study suggests that it is better to process yellow croaker by solar drying and smoking so as to get good nutrients

EFFECT OF STORAGE TIME ON THE QUALITY OF SMOKED HETEROCLARIAS

Effect of storage time on the quality of smoked heteroclarias was studied. 108 samples of heteroclarias (average weight 210 + 15g) was used. Analysis carried out include: proximate, mineral composition (Ca, Na, Fe and Mg), biochemical, amino acid and sensory evaluation. Data obtained was subjected to Analysis of Variance (ANOVA) while the sensory data was subjected to nonparametric test (Kruskal Wallis test). Smoked heteroclarias have good nutritional quality in terms of proximate, mineral and amino acids all of which decrease with increase in duration of storage at ambient temperatures. Glutamic acid  was the most predominant amino acid and the highest non-essential amino acid (NEEA), lysine was the most predominant EAA. There was higher concentration of non-essential amino acids than essential amino acids, EAA/NEAA ratio (0.86 – 0.93) recorded indicates that the fish have excellent protein quality; its the predicted protein efficiency ratio (P-PER) ranged between 3.44-3.61 and its biological value ranged between 79.84 -75.04. Its chemical score and TEAA decrease with increase in storage time. Its texture quality reduced significantly (χ2 = 12.207, p<0.01) with increased storage period. It is therefore recommended that smoked heteroclarias be consumed as soon as it is smoked and regularly for good healthy conditions especially among children, aged and other vulnerable groups

Effect of dietary cinnamon supplementation on the growth in length, haematology, serum biochemistry, intestinal microbiota and enzymes and histomorphological changes of the intestine, liver and the kidney of Heteroclarias (Clarias gariepinus ♀ × Heterobra

The effect of dietary cinnamon supplementation on the growth, haematology, serum biochemistry, intestinal microbiota and enzymes and histomorphological changes of the intestine, liver and kidney of juvenile heteroclarias (Clarias gariepinus ♀ Heterobranchus bidorsalis ♂) was assessed in a 56-day feeding trial. Five 38% crude protein experimental diets were formulated to contain a cinnamon powder that was included at a rate of 0% (DT1), 0.5% (DT2), 1% (DT3),1,5% (DT4) and 2% (DT5). Each diet was allotted to a triplicate group of fish (n=15 fish/ replicate tank 8.55± 0.12 cm average length) in a completely randomized design. There was a significant increase (p0.05) among the dietary groups. Bacteria counts were heightened significantly (p<0.05) with cinnamon supplementation when compared to the control. The contrast was the results for fungi count with diversity indices in favour of DT4 dietary group. The amylase, cellulase and trypsin activity of the cinnamon-fed group was significantly (p<0.05) elevated when compared to those of the control group. The intestine, liver and kidney microstructures were well preserved with no features of injury recorded