Aquaculture: a promising solution for food insecurity, poverty and malnutrition in Kenya

Food insecurity remains one of the most visible dimensions of poverty. The increasing population amid competition for land and water resources means that the global demand for food will continue to increase. In Kenya, the food insecurity trend is worrying as the population is expected to hit 55 million by 2020 against an annually declining arable land per capita and consequent increase in food prices. The Kenyan agricultural sector has failed to either eliminate or reduce malnourishment for poor populations as the annual national production for both staple food and livestock products fall short of national consumption levels. The nutritional deficiency levels remain high among a significant segment of the Kenyan population. With increasing food production challenges such as dwindling capture fisheries and impacts of climate change becoming more eminent, solutions to food insecurity and malnutrition in Kenya must bring about quick results in food availability by stimulating more own-food production. Aquaculture has so far been recognized as an important opportunity to enhance household food security in developing countries. The existing literature reveals scattered but increasing evidence of the contribution of aquaculture to nutritional security through direct fish consumption and income stability among vulnerable groups through involvement in aquaculture value chain linkages. This paper reveals the status of food insecurity, poverty and malnutrition problems and discusses aquaculture initiatives as the remedial solutions. This paper also provides a framework for examining aquaculture’s value chain linkages to food and nutritional security and national economic growth by elucidating key pathways concerning the role of aquaculture in household food and income systems. The authors advocate for clear and sustainable national policies for aquaculture development to address food insecurity and poverty questions more sharply. More empirical evidence should be collected on the varied aquaculture opportunities to improve the income, employment and food consumption levels within the poor households.Key words: KMFRI, MDGs, Aquaculture, Food insecurity, Poverty, Kenya, Malnutrition, Fish, Agricultur

Profit Indices in Nile tilapia (Oreochromis Niloticus L.) Fed on Peanut-Based Meals as Alternatives to Dietary Fishmeal in GrowOut Earthen Ponds

Persistence of dietary fishmeal probably accounts for the low profitability in farmed Niletilapia in Uganda. A 24 week field study was conducted in Busoga sub-region of Eastern Uganda tocompare profit indices in pond cultured Nile tilapia fed on peanut-based meals as alternatives todietary fishmeal. It consisted of an experiment and sample survey that targeted fish biomassproduction and input-output valuation respectively. Each of the 12 earthen ponds measuring 12 cubicmeters were stocked with 48 ‘all male’ Nile tilapia (Oreochromis niloticus L.) fingerlings of meaninitial weight of 21.7 grams. Iso-nitrogenous diets containing 30% and 25% Crude Protein wereapplied for the first eight and last four respectively. Dietary treatments included fishmeal-based dietand two peanut-based diets; peanut meal-based diet and mixed plant-based diet. Profit indices for thefishmeal and mixed plant-based- diets were not significantly different (p0.05). On the contrary, theProfit index characteristic to the PNM-based diet was significantly lower (p≤0.05) than the other testdiets. Accordingly, the mixed plant meal should be used for complete substitution of dietary fishmealin pond cultured Nile tilapia

NUTRITIVE VALUE AND AVAILABILITY OF COMMONLY USED FEED INGREDIENTS FOR FARMED NILE TILAPIA (OREOCHROMIS NILOTICUS L.) AND AFRICAN CATFISH (CLARIAS GARIEPINUS, BURCHELL) IN KENYA, RWANDA AND TANZANIA

ABSTRACT Commonly utilized feed ingredients for culture of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) from Kenya, Tanzania and Rwanda were collected over a period of six months (January -June 2010) and evaluated for their nutritive composition through proximate analysis. Most of the fish feed ingredients were found in all the three countries except a few that were unique to one or two countries as detailed in the results. Feed ingredients of animal origin exhibited significantly (P<0.05) higher crude protein levels (407 -635 g/kg DM) compared to the feed ingredients of plant based origin. Freshwater shrimps (Caridina nilotica) contained the highest crude protein levels of 635 g/kg DM. Feed ingredients of animal origin had low ether extracts (EE) with an exception of Omena fish (Rastrineobola argentea). Crude fibre (CF) was generally higher on feed ingredients of plant origin and ranged between 55-368 g/kg DM while Nitrogen Free Extracts (NfE) and ash content were higher in the feedstuffs of plant origin with an exception of maize bran which had the lowest value. Omena fish and freshwater shrimp had higher ash content of 182 and 228g/kg DM compared to other feed ingredients of animal origin, which may indicate contamination with soil particles during drying process. Based on the feed ingredient availability, potential competition with other human uses, content of crude protein and crude fibre and the feasibility of removal of anti-nutritional factors, C. nilotica, blood meal, meat and bone meal, were identified as most promising sources of animal based protein. Cotton (Gossypium spp) and sunflower (Helianthus annuus) seed cakes provided the best option as source of processed plant based protein. Leaves of gallant soldier (Galisonga parviflora), sweet potato (Ipomoea batatus), cassava (Manihot esculenta) and papaya (Papaya carica) were identified as high potential feedstuffs of plant origin either processed or in raw form for small-scale fish farming. We recommend that in well fertilized semiintensive ponds, maize (Zea mays), wheat (Triticum aestivum) and rice (Oryza sativa) bran may be utilized where available to supplement natural pond food

Fish farming in Tanzania: the availability and nutritive value of local feed ingredients

An investigative field survey was performed to gather baseline data on locally available feed ingredients and fish farming practices in different regions of Tanzania. More than 80% of respondents relied on locally available feed ingredients as a major feed supplement for their cultured fish, with maize bran being the most commonly used feed ingredient in all regions. Crude protein content in most analyzed local feed ingredients was medium-high, while crude fat content was high in some animal and agricultural by-products, and medium-low in other ingredients. Most respondents were males and the majority of fish farms were owned by individuals. Earthen pond was the most common fish farming system in all regions except Dar es Salaam. Semi-intensively mixed-sex tilapia monoculture was the dominating fish farming practice. The results of the survey presented provide a good platform for future development of culture systems and feeding strategies for tilapia in Tanzania

Optimization of extruder cooking conditions for the manufacture of fish feeds using response surface methodology

Abstract A composite blend consisting of sunflower cake, maize germ, wheat bran, fresh water shrimps and cassava flour was extruded using a single‐screw extruder to produce expanded fish feed pellets. The effects of temperature (80–120 °C), die diameter (2–4 mm), and feed pre‐conditioning time (50–150 s; steam 400 kPa) on properties of the pellets (expansion ratio, bulk density, floatability, durability, water absorption, water solubility, water stability, and in‐vitro protein digestibility) were investigated using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The pellets extruded using a factor combination of 120 °C extruder barrel temperature, 2 mm die diameter, and 100 s of feed pre‐conditioning time gave most desirable pellet floatability (100%), durability index (99%), expansion ratio (2.64), water absorption index (4.12), water solubility index (9.31), water stability (87%), bulk density (479 g/L), and in vitro protein digestibility (69.97%) with a composite desirability of 0.88. Practical applications Extrusion is a modern feed processing method whose use is fast gaining popularity among small feed processors in developing countries. However, extrusion is a process that involves many parameters that need to be optimized for desirable end properties. These findings guide fish feed manufacturers on the optimum conditions for single screw extruders for production of feeds with desirable properties especially for the fish types that are top feeders. In addition, the results offer important insights on how temperature, die diameter, and feed pre‐conditioning, may be manipulated to influence properties of extruded aquafeed when using simple low‐cost small‐scale extruders

Blending fishwastes and chicken manure extract as low-cost and stable diet for mass culture of freshwater zooplankton, optimized for aquaculture

Abstract This study investigated the feasibility of fishwastes and chicken manure extract (CME) as cheap diet for mass culture of freshwater zooplankton. CME and fishwastes as well as carbon source were used to make fishwaste diets (FWD). Each diet was triplicated 3 days before inoculation with 5, 2 and 0.4 ind ml−1 of rotifers, copepods and cladocerans, respectively in each tank. About 5ml of water was done daily, from which the zooplankters were counted. Harvesting was done at the first exponential growth phase by replacing 50% of the water and FWD. There was a significantly higher density of zooplankton and SGR in FWDB than FWDA and control tanks. The zooplankton obtained highest densities on day 7 as follows: rotifers: 100.6±14.8, 146.3±7.0, and 60.0±7.9 ind ml−1 in FWDA, FWDB and the control tanks, respectively; the copepods: 8.0±11.1, 12.6±13.6 and 4.3±2.1 ind ml−1 in FWDA, FWDB and control tanks, respectively; the cladocerans: 3.3±6.0, 8.6±8.7 and 3.6±2.5 ind ml−1 in FWDA, FWDB and control tanks, respectively. The most abundant genera were Brachionus sp., Cyclops sp. and Daphnia sp. for the rotifers, copepods and cladocerans, respectively. This study offers an alternative to expensive on-site microalgal production toward a more cost-effective aquaculture.</jats:p

Dietary Fishmeal Substitution by Peanut-Based Meals in Nile Tilapia (Oreochromis Niloticus L.) : Effect of Pond Water Quality on Biomass Production: Effect of Pond Water Quality on Biomass Production

Abstract. A 16 week experiment was conducted in earthen ponds in Iganga District of Eastern Uganda to investigate the effect of water quality on biomass production in Nile tilapia (Oreochromis niloticus L.) fed on peanut-based meals as alternative dietary fishmeal. Iso-nitrogenous diets containing 30% and 25% Crude Protein were applied for the first 12 weeks and last four weeks while the control was a local diet for Nile tilapia of 25% Crude Protein throughout the experiment. Treatments included the fishmeal-based diet and two peanut-based diets; peanut meal-based diet and mixed meal-based diet. Each of the 16 pond units measuring 3.0 x 4.0 x 1.0 were stocked with 48 fish fingerlings of 21.7 grams mean weight. Significant differences (p≤0.05) in mean values occurred among targeted parameters; pH, Dissolved Oxygen, nitrite nitrogen and unionized ammonia with exception to temperature. Apart from the unionized ammonia, the significant variations (p≤0.05) in water quality parameters did not significantly affect (p≥0.05) biomass production because they were maintained in suitable ranges for Nile tilapia

Growth response of rotifers on a bacterial-based diet made from fishwastes

Abstract Fishwastes are potential low-cost diet sources for replacing microalgae, which is the popular diet for rotifers. Growth responses of rotifer were tested under different weights of the diet (i.e. 0.05, 0.1, 0.2 and 0.4 g/L), different culture containers (i.e. using small tall (ST), small-short (SS), medium-tall (MT) and large-short (LS) containers), different initial densities of the rotifer (i.e. 10, 50 and 200 rotifers/mL) and mass cultured trials for 15 and 30 days. Population densities of rotifers increased significantly (ANOVA, p=0.001) when providing 0.1 to 0.4 gr/L than those fed 0.05 gr/L of the diet (Tukey HSD test, p&lt;0.05). The densities also were significantly higher (ANOVA, p=0.001) when cultured using larger containers (LS and MT) than using smaller containers (ST, SS) (Tukey HSD test, p&lt;0.05), but it was not significant when inoculated at different initial densities (ANOVA, p&gt;0.05). The rotifers were successfully mass cultured for 30 days and were successfully harvested for 7 times at densities of about 2500 to 3300 ind./mL.</jats:p