Nutrient Composition of some Tropical Legumes Capable of Substituting Fish Meal in Fish Diets

Sword beans (Canavalia gladiata); Jackbean (Canavalia enciformis (L)); Mucuna bean (Mucuna pruriens); Mucuna cochiunensis; Bambara (Voandzeia subterranea) and Limabean (Phaseolus lunatus) are the tropical legumes considered in this paper. They have been used in the feed of ruminants but very scarcely considered in fish feed. Information about their nutrient composition are also scarce. Results from this study show that the protein contents of the test seeds ranged from 19.94% dry matter (DM), (Bambara) to 36.95% DM (Mucuna cochiunensis). Considering the high protein level required by fish for maximum growth and the presence of some ANFs, the seeds may not be able to be used in isolation without supplementing them with other food stuffs having higher protein value. The relatively high content of Nitrogen Free Extract (+ fibre) seem to suggest that the test seeds can be used in a semi-intensive setting to supply carbohydrate in fish diets. The seeds contain considerable amount of linoleic acid (18:2 n-6). The highest occurring in Lima beans. Sword beans and Jack beans are rich in oleic acid (18:1n-9). Palmatic acid (16:0) is high, while stearic acid (18:0) and myristic acid (14:0) are low. The amino acid compositions of the test seeds are not very adequate. Sword beans had a better amino acid profile though it seems deficient in some of the amino acids. The amino acid contents of Jack bean, Mucuna bean, Bambara and Lima bean look inadequate to provide a possible alternative to fish meal on individual basis. If to be used in fish feed formulation, combinating them with other protein sources, possessing higher contents of the limiting amino acids is strongly suggested. The potentials of these seeds in fish feed formulation seem high

Influence of dietary protein deficiency on amino acid and fatty acid composition in tilapia, Oreochromis niloticus, fingerlings.

Abstract The influence of dietary protein deficiency on the amino acid and fatty acid compositions of tilapia (Oreochromis niloticus) fingerlings was studied. Two experimental diets (0.81% and 33.32% protein, dry matter) were prepared. The protein content of fish fed diet 1 (0.81% protein) decreased from 57.14% to 49.18% in eight weeks. Fish fed diet 2 (33.32% protein) had higher protein and amino acid contents. The lipid content of fish fed diet 1 was higher than that of fish fed diet 2, suggesting that carbohydrates transformed into lipids. The levels of fatty acids 16:0 and 18:2 n-6 in fish fed diet 1 remained nearly unchanged and did not reflect the diet, demonstrating that fatty acids in diet 1 may not have been incorporated into the triglycerides of the tissues. Possible impairment of lipid secretion from the liver, caused by depletion of protein in the blood lipoprotein, may have affected the transport of lipids to the muscles. A dietary protein deficiency results not only in a deficiency of essential amino acids in the body but also affects transport and storage of lipids within the fish

Influences Of Dietary Protein Deficiency On Amino Acid And Fatty Acid Composition In Tilapia, Oreochromis Niloticus, Fingerlings

The influence of dietary protein deficiency on the amino acid and fatty acid compositions of tilapia (Oreochromis niloticus) fingerlings was studied. Two experimental diets (0.81% and 33.32% protein, dry matter) were prepared. The protein content of fish fed diet 1 (0.81% pro- tein) decreased from 57.14% to 49.18% in eight weeks. Fish fed diet 2 (33.32% protein) had higher protein and amino acid contents. The lipid content of fish fed diet 1 was higher than that of fish fed diet 2, suggesting that carbohydrates transformed into lipids. The levels of fatty acids 16:0 and 18:2 n-6 in fish fed diet 1 remained nearly unchanged and did not reflect the diet, demonstrating that fatty acids in diet 1 may not have been incorporated into the triglycerides of the tissues. Possible impairment of lipid secretion from the liver, caused by depletion of protein in the blood lipoprotein, may have affected the transport of lipids to the muscles. A dietary pro- tein deficiency results not only in a deficiency of essential amino acids in the body but also affects transport and storage of lipids within the fish

Alternative Protein Sources As Substitutes For Fishmeal In The Diet Of Young Tilapia Oreochromis Niloticus (LINN.)

Fifteen test diets were theoretically formulated to contain 33.32% dietary protein, dry matter, using a mixture of alternative protein sources and fishmeal in various proportions. Test diets were fed to fingerlings (initial weight 3.2±0.2 g) in triplicate tanks for eight weeks at 5% body weight per day in three portions. At the end of each experimental phase, fish carcass from the feeding groups was homogenized. Freeze-dried samples of fish at the beginning and end of the experiments as well as samples of the test diets were analyzed for proximate composition. Fish fed diet 1 containing 43% fishmeal recorded the highest weight gain, highest specific growth rate (SGR, 3.46%/d) and lowest food conversion ratio (FCR, 1.11). When part of the fishmeal was substituted with 18% soy- bean meal and 5% blood meal (diet 8), SGR and FCR were 3.02%/d and 1.34, respectively, not significantly different from diet 1 at 0.05 probability. Results showed that proper combination of alternative protein sources can provide 42-45% of the protein required by Oreochromis niloticus (33.32% dietary protein, dry matter). In such a combination, soybean meal can replace up to 25% of the fishmeal as a protein source. Blood meal exceeding 6%, groundnut cake beyond 10%, soy- bean meal above 20%, and wheat bran beyond 10% retarded fish growth. High mortality was gen- erally observed when these levels were exceeded, even in only one of the protein sources

Microplastic pollution: An emerging contaminant in aquaculture

Aquaculture largely contributes to aquatic products and consequential dietary protein for many households. Aquaculture, just like every other food sector, is faced with enormous challenges such as unfavorable climatic events, environmental stressors and contaminants. Microplastics (MP) are emerging contaminants in aquaculture following their perturbing occurrence in cultured fish, fishmeal and aquafeed. Several MPs pathways into aquaculture facilities include wastewater, pipe-borne water, dilapidated aquaculture facilities, fish gears, and aquafeed stuff (fishmeal). Techniques for the digestion, identification and characterization of MPs are critical to understanding their pathways, bioavailability and bioaccumulation patterns in aquaculture species. The impacts of MPs on cultured fish species are identified as impaired growth, oxidative stress, neurotoxicity, reproductive toxicity, immunotoxicity, embryotoxicity, and histopathology. Bioaccumulation of MPs in tissues and biological systems have been evidenced in several cultured fishes. Mitigation efforts cum strategies such as upgrade of wastewater treatment facilities, screening of inlet pond water, screening of aquafeed stuff, regular maintenance and repair of culture facilities, could be effective to eradicate MP contamination in aquaculture. Additionally, regulatory policy on the use of plastics is key to mitigating the impact of MPs and ensure cleaner and sustainable aquaculture

Housefly Maggot Meal as a Potent Bioresource for Fish Feed to Facilitate Early Gonadal Development in <i>Clarias gariepinus</i> (Burchell,1822)

Food security is threatened by the global increase of human population, climate change, inequality of wealth distribution, the state of natural resources, peace and sustainability, among others. Aquaculture has become an important part of the food supply, hence contributing to food security. Sustainable fish production, which represents an important affordable protein supply, should therefore involve feed formulation and production techniques that are not dependent on fish meal as the protein source. It is on this basis that bioeconomy becomes very important to promote the resourceful use of biomass for feed, food, biomaterials, and bioenergy. This study presents housefly maggot meal as an efficient alternative protein source to fishmeal and a valuable bioresource. Clarias gariepinus fingerlings (male and female) were fed maggot meal supplemented diets for 24 weeks and we assessed their growth and gonadal development. The findings of this study revealed that maggot-meal-enhanced diets promoted growth and faster gonadal development in fish. Maggot meal represents a quality alternative protein source to fish meal and an excellent bioresource, which can help us attain sustainable aquaculture production

Counting the cost: The effect of COVID-19 lockdown on households in south east Nigeria

The present study measured household hunger in South-East Nigeria amidst the COVID-19 lockdown. A total of 1209 households (urban and rural locations) were sampled. Household hunger was determined using the Radimer-Cornel hunger scale. Results show that before the COVID-19 lockdown, hunger prevalence in the urban areas was 85.5%, whereas prevalence in the rural areas was significantly lower, at a prevalence of 79.9% (7.3% level of association-X-2 = 6.499, p = 0.012). During the COVID-19 lockdown, the prevalence of hunger in the urban areas rose to 98.0% and 99.2% in the rural areas (4.9% level of association was X-2 = 2.888, p = 0.089). It was also observed that the COVID-19 lockdown significantly affected food prices. The major coping strategy employed by households was relying on less expensive foods (81.14%). High household hunger was identified as a short-term cost of the COVID-19 lockdown in South-East Nigeria. Only a few households (16.3%) benefited from the food aid programs and 16.9% from the government palliative cash transfer. It is recommended that the government setup a formidable unit that will develop physical and digital plans for effective implementation during a COVID-19 lockdown situation or other emergencies

Tropentag 2011 Development on the margin The Parasites of Cultured and Feral Nile Tilapia (Oreochromis niloticus) in Umudike

Abstract Fifty eight specimens of Nile tilapia (Oreochromis niloticus) were collected between the months of August and November with the use of siene net from the culture ponds of Michael Okpara University of Agriculture, Umudike and the water reservoir of National Root Crops Research Institute, Umudike impounded from Ohii Stream. Vital morphometric data of the specimens were recorded with the aid of calibrated metre rule while visual examination of the external part of the fish specimens were carried out immediately with the naked eye and hand lens for ectoparasites. This was followed by dissecting the specimens to obtain the internal organs which were properly labeled and preserved in 4% formalin for further examination. The preserved organs were subsequently sliced separately into piece, mixed with water and examined under stereo microscope for endoparasites. The recovered parasites were placed on covered slides and examined under the light microscope. The parasites obtained from each specimen were then properly counted and classified. No significant difference was observed in the level of parasitic infection between the pond cultured (89.65 %) and the wild (93.10 %) O. niloticus. This may be because both the ponds and reservoir have Ohii Stream as source of water. Trematodes, Cestodes and Copepods were the major parasites found on O. niloticus from both habitats. Trematodes and Cestodes constituted 48.8% and 41.38% respectively for cultured O. niloticus, while the feral O. niloticus had 13.8%, 17.2% and 62.0% Trematodes, Copepods and Cestodes respectively. The Cestodes were found in the intestine of O. niloticus while the Trenatodes and Copepods were found on the gills. Among the size groups 11-15 cm in the culture ponds had the highest occurrence of Trematodes (24.14%) while 6-10 cm class of feral habitat had the highest occurrence of Cestodes (58.62%). Similarly 6-10 cm class of reservoir O. niloticus had the highest (10.34%) infection of Copepods

Housefly Maggot Meal as a Potent Bioresource for Fish Feed to Facilitate Early Gonadal Development in Clarias gariepinus (Burchell,1822)

Food security is threatened by the global increase of human population, climate change, inequality of wealth distribution, the state of natural resources, peace and sustainability, among others. Aquaculture has become an important part of the food supply, hence contributing to food security. Sustainable fish production, which represents an important affordable protein supply, should therefore involve feed formulation and production techniques that are not dependent on fish meal as the protein source. It is on this basis that bioeconomy becomes very important to promote the resourceful use of biomass for feed, food, biomaterials, and bioenergy. This study presents housefly maggot meal as an efficient alternative protein source to fishmeal and a valuable bioresource. Clarias gariepinus fingerlings (male and female) were fed maggot meal supplemented diets for 24 weeks and we assessed their growth and gonadal development. The findings of this study revealed that maggot-meal-enhanced diets promoted growth and faster gonadal development in fish. Maggot meal represents a quality alternative protein source to fish meal and an excellent bioresource, which can help us attain sustainable aquaculture production