Evaluation of processed groundnut (Arachis hypogaea) cake meals in the feeding of Clariid catfish, Clarias gariepinus, fingerlings

Groundnut cake (GNC) meal is an important source of dietary protein for domestic animals with a cost advantage over the conventional animal protein sources used in aquaculture feed production. It would be useful to evaluate the effects of GNC processing methods on the density and nutritional values of processed GNC meals. The use of processed GNC meals in the diets of Clarias gariepinus fingerlings was evaluated. Seven iso-proteic and iso-caloric diets were formulated, replacing fish meal with roasted and boiled GNC meals, each at three inclusion levels of 30%, 35%, and 40%. Diet I is 100% fishmeal, Diet II is 30% roasted GNC meal, Diet III is 35% roasted GNC meal, Diet IV is 40% roasted GNC meal, Diet V is 30% boiled GNC meal, Diet VI is 35% boiled GNC meal and Diet VII is 40% boiled GNC meal. Results showed that the crude protein content of GNC meals was 40.5% and 40.8% in boiled and roasted GNC meals respectively; the lower protein content for processed GNC meals might be due to heat denaturation of the seed protein, with boiled GNC meal being more adversely affected. The mean weight gain of fingerlings fed roasted GNC meals ranged between 5.29 – 5.64 while for boiled GNC meals, it was between 4.60 – 5.22. Generally, fish performed better when fed diets containing roasted GNC meals, than boiled GNC meals, and compared favorably with fish fed fish meal based diet. Body mass increase, total feed increase, protein efficiency ratio and specific growth rate by C. gariepinus fingerlings in all diets, showed no significant differences, suggesting that processed GNC meals could partially replace diets for C. gariepinus fingerlings without adverse consequences. This study showed that processed GNC meals could partially replace fish meal up to 30% without significantly influencing fingerling growth and health. It is recommended that the use of fish meal as the main basal ingredient for fingerlings could be discontinued, since GNC meal was a cheaper alternative, and could replace fish meal up to 35%, without any significant adverse effects on the fingerling performance. KEYWORDS: Clarias gariepinus, Fingerlings, Groundnut cake meal, Nutrient utilization, Performance.

Effects of feeding carnitine and ractopamine on rainbow trout (Oncorhynchus mykiss, Walbaum 1972)

L-carnitine is required for the transfer of long-chain fatty acids from the cytosol to the mitochondrial matrix for 13-oxidation of them and ractopamine, beta adrenergic agonists, have potential stimulating lipolysis and altering rates of protein degradation and synthesis. Present study was carried out to improve lipid body oxidation and protein-sparing action of fish through addition of L-carnitine and ractopamine to diet of rainbow trout, Oncorhynchus mykiss, Walbaum 1972. An eight-week feeding trial was carried out to evaluate the effects of supplementation of tree levels of L-carnitine tartrate (0, 1 and 2 g/kg) and two levels of ractopamine hydrochloride (0 and 10 ppm) on growth performance, fillet muscle fatty acid compositions and blood biochemical parameters in 288 juvenile rainbow trout (130 g) at 3X2 factorial experimental design. Ractopamine and 1 g/kg carnitine improved the specific growth rate, feed conversion ratio, protein efficiency ratio and weight gain at the end of experiment. The protein and lipid contents of fillet muscle were affected by the inclusion of 10 mg/kg ractopamine in the diet, increasing crude protein and reducing crude fat (P<0.05) of fish fillet muscle. The highest protein and lowest fat contents of fish fillet were observed in diet that contains 2 g/kg carnitine plus ractopamine. Ractopamine and carnitine increased levels of albumin, total protein and globulin in fish blood serum, but carnitine increased triacylglycerol and cholesterol. Fatty acids compositions of fish fillet were also affected by ractopamine and carnitine. All fatty acids except for eicosapentaenoic acid and docosahexaenoic acid, were increased by dietary supplementation of ractopamine. Total saturated fatty acids were not affected by carnitine. Supplementation (P>0.05). However, total n-3 poly unsaturated fatty acids were reduced by carnitine supplementation. A significant interaction was observed between ractopamine and carnitine supplementation regarding the saturated (P<0.01) and n-3 poly unsaturated fatty acid (P<0.001) of fish fillet. This study shows that supplementation of 1 g/kg carnitine and 10 ppm ractopamine could improve performance of juvenile rainbow trout and their combination in diet results in protein increment, fat reduction and change in profile of fatty acids in fillet muscle.

Optimum dietary carbohydrate to lipid ratio in stinging catfish, Heteropneustes fossilis (Bloch, 1792)

A feeding trial of 8 weeks was conducted in a static indoor rearing system to investigate the optimum carbohydrate to lipid ratio (CHO:L ratio) in stinging catfish, Heteropneustes fossilis. Five iso-nitrogenous (35% crude protein) and iso-energetic (17.06 kJ gˉ¹ gross energy (GE)) fish meal based diets with varying carbohydrate to lipid (CHO:L g/g) ratios of 0.60, 0.98, 1.53, 2.29 and 3.44 for diets 1-5, were tested, respectively. The diets containing a fixed protein to energy ratio (P:E ratio) of 20.50-mg protein kJˉ¹ GE were fed to triplicate groups of 40 fish (per 70-L tank). Fish were fed 5% of their body weight per day adjusted fortnightly. Diet 1, containing 10% carbohydrate and 17% lipids with a CHO:L ratio of 0.60 produced the poorest (p<0.05) growth rates, feed and protein efficiency. Increasing carbohydrate content in the diets to 26% concomitant with a reduction in lipid content to 11% with a CHO:L ration of 2.29 of diet 5 significantly improved (p<0.05) growth rates, feed and protein efficiency. But did not differ with diet 4, containing CHO:L ratio 2.29. A further increase in dietary carbohydrate up to 31% and a decrease in lipids levels to 9% with a CHO:L ratio ranging from 2.29 to 3.44 (diet 4-5) did not significantly improve the fish performance. Apparent net protein utilisation (ANPU) of fish fed diet 5 was higher (p<0.05) than for diets 1 and 2 but did not differ from diets 3 and 4. Higher lipid deposition (p<0.05) in whole body was observed with decreasing dietary CHO:L ratios as increasing lipid levels. Whole body protein of fish fed varying CHO:L diets did not show any discernible changes among the dietary treatments. This study revealed that H. fossilis can perform equally well on diets containing carbohydrate ranging from 26 to 31%, with 9 to 11% lipid or at CHO:L g/g ratio of 2.29-3.44.

Growth performance of Clarias gariepinus fingerlings fed earthworm meal (Lumbricus terrestis)

An investigative study was carried out on the growth performance and nutrient utilization of (Clarias gariepinus) fingerlings fed earthworm meal as a replacement for fish meal. A large collection of earthworm was done during the peak of rainy season (July-August) within the University environment. They were then ovens dried. Used as test ingredients were 0% (Diet 1) 50% (Diet 2) and 1000% (Diet u). The trials were conducted in plastic bowls (40-L capacity) under laboratory conditions. The diets were fed at 5% body weight to fish; the fish were stocked at 10 fish per bowl. The evaluation of the growth parameters showed that there was no significant difference (P>0.05) in mean weight gain (MWG) specific growth rate (SGR) food conversion ratio (FCR), protein efficiency ration (PER) and survival among the fish fed the experimental diets

Effect of stocking density on the growth of Thai pangas, Pangasius sutchi (Fowler) in net cage fed on formulated diet

A three month long experiment was conducted to observe the effect of stocking density on the growth of Pangasius sutchi in net cages. The size of each cage was 1m³.The three stocking densities used were 40, 50 and 60 fishes/m³ and designated as treatment T1, T2 and T3 respectively. Each treatment had three replicates. All the fishes were of same age group having mean length and weight of 7.13 ± 1.37 cm and 2.46 ± 0.12 g respectively. The fish in all the net cages were fed a diet containing 34% protein. The result of the study showed that fish in the treatment T1 stocked at the rate of 40 fish/m³ resulted the best individual weight gain followed by T2 and T3 respectively. The specific growth rate (SGR) ranged between 3.51 and 3.09, the food conversion ratio (FCR) values ranged between 1.73 and 2.04 with treatment T1 resulting the lowest FCR. The protein efficiency ratios (PER) values were 1.69, 1.16 and 1.43 for treatment T1, T2 and T3 respectively. There was no significant (P>0.05) variation among the survival rates of fish which ranged between 92 and 95%. The net productions in different treatments were 2189, 2343, and 2283g for treatment T1, T2 and T3 respectively. The result of the present study indicated that the best individual growth of P. sutchi was obtained at a density of 40 fish/m³ but the highest total production was obtained at a stocking density of 50 fish/m³ in net cages.

Effect of feeding three different formulated feeds having different protein levels on the growth of angel fish (Pterophyllum scalare) juveniles

Experiment was conducted to study the effect of dietary protein level on growth and nutrient utilization by angel fish (Pterophyllum scalare) juveniles. Fifty-four juveniles (average wt. 2-2.5 g) were equally divided in three treatments with each of three replicates. Three formulated diets with graded protein levels, T1 (35% CP), T2 (40% CP) and T3 (45% CP) were fed to juveniles for 45 days. A trend of higher weight gain %, SGR, FER and PER was found with the increased CP level in the feed. Feed intake was similar in all the groups. T3 group fed with 45% CP registered highest weight gain % (43.26 ± 2.07), SGR (0.78 ± 0.04), FER (0.29 ± 0.01), which were significantly higher (P<0.05) than the T1 and T2 groups. Protein digestibility of T2 and T3 groups was significantly higher than the T1 group. Survival was similar in all the experimental groups. Diet with 45% CP with protein energy ratio of 112.62 mg protein/K cal. is ideal for juvenile angel fish for indoor rearing.

Comparative effect of Pediococcus acidilactici and Lactococcus lactis on growth performance, survival and enzyme activity of western white leg shrimp (Litopenaeus vannamei)

This study was done in Shahid Kiani Marine Aquaculture Development Center, Choebde, Abadan in order to evaluate the effects of Pediiococcus acidilactici, Lactococcus lactis and vitamin C on growth performance, survival, enzymatic activities and immune responses of L. vannamei during three months. Treatments were included control group, Pediiococcus and Lactococcus treatments which fed with diet containing 1×10P9P cfu gP_1P bacteria and vitamin C. At the end of the experiment, the growth factors, immune parameters, digestive enzymes, intestinal, histology of intestine, carcasses and microbial flora (bacterial total count and lactic acid count) were evaluated. The results indicated that administration of lactobacillus had significant effects on the growth factors as the highest weight, increase specific growth rate, relative growth rate, feed conversion ratio and protein efficiency in the shrimps received pediococcus and then Lactococcus (P<0.05). The best immune function was also observed in the shrimps fed by probiotics, so that proteins and hemoglobin̛ hemolymph, phenoloxidase activity and challenged with V. parahaemolyticus showed a statistical difference comparing to the control group and the group received vitamin C (P<0.05). Some digestive enzymes, in pediococcus treatment showed a significant increase when compared to other treatments (P<0.05). Significant changes in bacterial intestinal flora were observed in probiotic groups compared with control and vitamin C groups (P < 0.05). Histological results showed the positive effects of probiotics in the gut (P < 0.05). While these supplements cannot caused to significant impacts on the shrimp carcass composition (P ˃ 0.05). As a result pediococcus group had the best performance among treatments.

Preliminary investigation on growth responses of Cyprinus carpio L. fed on locally formulated artificial diets

The growth rate and feed conversion ratios of the common carp, Cyprinus carpio were measured for five test diets in 14-day replicate laboratory studies. The young carp were fed with artificial test diets with crude protein contents ranging from 14.50 to 21.42 per cent. Within this range of feed characteristic optimum growth rates were obtained with diets containing 20.25 and 21.42 per cent crude protein. The study of the effect of varying ration levels showed that growth rates increased with increases of ration size, but the food conversion efficiency and protein efficiency ratios decreased markedly as ration size was increased

Digestibility and nutrient utilization of soybean milk concentrate based diets in Oreochromis niloticus

The digestibility and utilisation of two fresh soybean milk concentrate based diets, two stale soybean milk concentrate based diets and two Fishman based diets serving as control, at optimal (30%) and suboptimal (20%) protein levels were evaluated in Oreochromis niloticus. The diets were as follows: Diet I (control) - fishmeal based diet at 30% crude protein, Diet II (control) Fishman based diet at 20% crude protein, Diet III - fresh soybean milk concentrate based diet at 30% crude protein, Diet IV - fresh soybean milk concentrate based diet at 20%, Diet V - stale soybean milk concentrate based diet at 30% crude protein, Diet VI-stale soybean milk concentrate based diet at 20%. Dry matter digestibility differed not significantly with variation in diets (P:0.05). A significant variation was recorded in the protein, lipid and ash digestibility. Proteins were more digestible at optimum than suboptimum level. Ash digestibility was lowest of all the nutrients. Variations in the utilisation of the diets in terms of weight gain, specific growth rate, food conversion ration, protein efficiency ration and apparent net protein utilization were insignificant (P: 0.05). All diets compared favourably with the standard control diet Diet I. This findings suggest the suitability of stale soybean milk concentrate utilisation as protein supplements in the diets of late fry Oreochromis niloticus

Comparison of extruded and non-extruded soy meals in the diet of genetically improved mudfish Heterobranchus longifilis juveniles

Raw soybeans were subjected to three different processing methods viz Parboiling, Toasting and Extrusion with an Intra Pro Extruder. The processed soybean meals were thereafter incorporated at equal levels into the diets of genetically improved mudfish Heterobranchus longifilis juveniles. The fish were fed the experimental diets in triplicate at 5% of their body weight for eight weeks. The growth performance and food utilization indices, namely Mean Weight Gain (MWG), Food Conversion Ratio (FCR), Specific Growth Rate (SGR%) and Protein Efficient Ratio (PER), were monitored bi-weekly. The results show that fish fed the control fishmeal diets were highest in growth performance, which was significantly different (P>0.05) from others. Among the fish fed the test diets, those fed toasted soybean had higher MWG, SGR, FCR and PER than juveniles fed the parboiled soybean diet. The juveniles fed the extruded soybean diet recorded the least growth performance. The implication of these results in diet formulation is discussed

Community metabolism, P/R ratio and photosynthetic efficiency of a brackishwater farm

The productivity level of a brackishwater fish culture farm consisting of 25 ponds, with a water spread area of 2.5 ha, was studied. Gross community photosynthesis of the farm was found to be 46.32 Kcal/m2/day, which is equivalent to the release of 13.23 of O2/m2/day, or the fixing of 4.10 gC/m2/day. Respiratory demand of the farm was estimated to be 44.66 kcal/m2/day, which is equivalent to the uptake of 12.76 g O2/m2/day or the utilization of 3.95 gC/m2/day. Photosynthetic efficiency of the farm was high at 2.26%. The P/R ratio was 1.04, showing eutrophic nature.

Studies on the optimum protein to energy ratio of African catfish (Clarias batrachus Burchell)

A laboratory trial was conducted to determine the optimum dietary protein to energy (P/E) ratio of African catfish, Clarias gariepinus. The experiment was carried out in a flow-through system for 6 weeks. There were 12 treatments each with two replicates having 10 fish each with a mean initial weight of 1.80 ± 0.02g. Twelve semi-purified diets were formulated with four digestible crude protein levels (23, 26.5, 30 and 33.5%) and three digestible energy levels (2.25, 2.75 and 3.25 Kcal/g). The fish were fed three times daily at satiation level. The results of the study showed that, diet containing 33.5% digestible protein and 2.75 kcal/g digestible energy with a protein to energy ratio of 121 .8 (mg protein/kcal) appeared to be best utilized for growth.

Nutrient digestibility coefficients of diets with varying energy to protein ratio for Japanese flounder, Paralichthys olivaceus

A laboratory trial was conducted in a sea water recirculatory system to study the nutrient digestibility coefficients of diets with varying energy to protein ratios in Japanese flounder Paralicthys olivaceus. Six different experimental diets with two protein levels (45 and 55%) having six different energy to protein ratio of 87, 90, 94, 107, 110 and 114 were formulated using white fish meal and casein as protein sources. The results of the study showed that the apparent protein digestibility (APD) value ranged between 90.59 to 91.61% and there were no significant differences (P>0.05) between the APD values of diets 1, 2, 3, 4 and 6. The apparent lipid digestibility (ALD) values of diets ranged between 88.24 to 90.18%. The apparent energy digestibility (AED) values ranged between 80.55 to 87.52% with diet 3 producing significantly the highest AED value. In general, except in diet 1 the ALD and AED values increased with the increase of dietary lipid at both protein levels. The results of the present investigation indicated that Japanese flounder can efficiently digest the dietary nutrients at varying energy to protein ratios.

Dietary protein and energy interations: an approach to optimizing dietary protein to energy ratio in walking catfish, Clarias batrachus

An 8 weeks feeding trial was conducted in a static indoor rearing system to investigate protein to energy ratio (PIE ratio) in walking catfish Clarias batrachus. Six fishmeal based diets of two protein levels (25 and 35%), each with three lipid levels (5, 10 and 15%) resulted in P/E ratios ranging from 13.57 to 21.97 mg protein kJˉ¹ gross energy (GE) were fed to 50 fish in triplicate. Fish were fed 6% of their body weight three times per day adjusted fortnightly. Significantly higher (p<0.05) growth rates in terms of weight gain, % weight gain and specific growth rate (SGR) were evident in fish fed with higher protein diet. The highest growth rate was found by fish fed 35% protein, 17.06 kJˉ¹GE with a P/E ratio of 20.55 mg protein kJˉ¹GE. Significantly better (p<0.05) feed conversion ratio (FCR) was also evident in fish fed with higher protein diet and best FCR was found by fish fed 35% protein, 10% lipid, 17.06 kJˉ¹GE with a P/E ratio of 20.55 mg protein kJˉ¹GE. Significantly indifferent (p>0.05) values of protein utilisation were found in between the both (higher and lower) protein diets. Higher lipid deposition (p<0.05) in whole body was observed with increasing dietary lipid level at each protein diet and as higher (p<0.05) for the lower protein diets. The study reveals that C. batrachus performed best the diet containing 35%, 17.06 kJ gˉ¹ and 20.55 mg protein kJ gˉ¹ GE protein, gross energy and P/E ratio respectively.

An appraisal of the efficiency of fish marketing system in Lake Chad basin

Fish products from the Chad Basin Lake play important role in meeting fish protein needs of Nigeria: they contribute not less than 25% of the total domestic fish supply and are significant in determining the availability of processed products and reduction of post-harvest losses. Processors, marketers and consumers are the major actors in appraising a marketing system. The results show that most sellers (4-7.5%) are within the age range of 30-39 years. Desires for more earnings led the markets to diversify their business activities to food stuff trading (37.5%), dried meat/livestock sales (37.5%), farming (12.5%), and transportation (12.5%). 65% of traders dispose off their products mostly in the mornings and evenings, 70% of the products are sold smoked while 50% of products are sold to individual consumers. Lake Chad fish products have a long distribution chain. There is also a high degree of buyers and sellers concentration in the primary fish markets and secondary (urban) markets. The products have a vertical regional movement with southern traders (82.5%) dominating the business, thus making the products popular all over Nigeria. Product differentiation with imperfect pricing policy is common occurrence. Lake Chad fish marketing system has distortions that impede its efficiency, recommendations are made on how to ensure a better efficiency of the system