Study on the biomass yield of Duckweed (Lemna minor) (L.) in hydroponic cultures containing different concentrations of aquaeous extract of chicken manure

The biomass yields of duck week (Lemna minor(L) was monitored in hydroponic media prepared by variously extracting 0.50, 1.00 and 2.00g of dried chicken manure per liter of city water (tap water) supply. The culture media consisting of aqueous extract of the various manure treatments were made up to 12 liters in all cases with tap water as control. Plastic baths of 25 liters capacity with 0.71 super(m2) surface area were used as culture facility. Each bath was stocked at a density of 30g super(m-2) with fresh weed samples (i.e 21.30g/bath). Maximum yields were obtained at all treatment levels and control on day 3 and based on the highest yield of 0.37gm super(-2)d super(-1) (dry matter) obtained at 1.00gL manure treatment which was however not significantly higher (P>0.05) than the 0.36gm super(-2)d super(-1) (dry matter) at 0.05gl super(-1) media manure content, an average manure level of 0.75l super(-1) was selected and used to determine the operational plant density. Thus fresh weights of 30 to 300gm super(-2) was grown in triplicate at 30g intervals for a period of 3 days. A regression equation of Y=2.6720+0.0021x with a corresponding maximum density or operational plant density of 266gm super(-2) and yield of 0.98gm super(-2), d super(-1) (dry matter) were obtained. Further growth trials were carried out at the operational density and manure levels of 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00gl super(-1) media manure concentration giving a significantly higher yield (P<0.05) of 17gm super(-2), d super(-1) (dry matter). This yield was however doubled to between 2.21 and 2.24gm super(-2) d super(-1) (equivalent to 7.96 to 8.06mt.ha-1, Yr-1 dry matter on extrapolation) if 25% and 75% respectively of the total weed cover were harvested daily within the experimental period. The role of some dissolved plant nutrients (DPN) were also discussed

The commercial use of chicken processing wastes to raise hybrid catfish (Clarias gariepinus) x Clarias macrocephalus) in Thailand

The article highlights the commercial use of chicken processing wastes on nursery and growout operations of hybrid catfish (Clarias gariepinus x Clarias macrocephalus) farm in Thailand.

Effects of organic manuring (chicken droppings) on growth of Labeo rohita Ham. spawn

An experiment was conducted in six nursery ponds to determine the effect of different doses of organic fertilizer (chicken droppings) on growth and survival of Labeo rohita spawn. Ponds were stocked with four-days old L. rohita spawn at a density of 25 g/decimal and reared for 25 days. Three doses of organic fertilizer viz. 20kg, 10 kg and 5kg per decimal were tried in treatments Tp T2 and T3 respectively with two replication each. Fry were fed twice a day with a mixture of fine mustard oil cake and rice bran at the ratio of 1:1. The highest growth (6.33 em and 3.33 g) and survival rate (72.30%) were observed for the treatment T2. Physico-chemical and biological parameters were found within the productive range for all the treatments.

Population dynamics of a cladoceran zooplankter, Daphnia magna, in two poultry-cum-fish (duck-fish and chicken-fish) integrated ponds

The population dynamics of Daphnia magna was studied in two integrated fish-cum-poultry ponds (duck-fish and chicken-fish). The seasonal changes in the population of D. magna were recorded. Peak population of the zooplankter was recorded in the month of January in both ponds. The birth rate (b), growth rate (r) and death rate {d) of D. magna were studied in field as well as in the laboratory. Three temperatures and three different food concentrations were selected for laboratory study. The maximum values of (b) and (r) were recorded during December-January in field. Under laboratory conditions, highest birth and death rate occurred at lowest temperature (15 °C). Both food and temperature were found to affect the population dynamics of the species; longest life span and maximum population were recorded at lowest temperature and maximum food concentration.

Investment potentials in shellfish culture in Nigeria

Shellfish are a major but cheap protein source for human consumption as well as source of income for coastal towns and villages of the Niger Delta in Rivers State, Cross River, and Lagos States. A research into the nutritive value of some of these marine shellfish viz: bivalves (oyster - Crassostrea gasar and cockle - Anadara senilis); gastropods (periwinkle - Tympanotonus fuscatus, obtuse periwinkle - Semifusus morio and the giant whelk - Thais callifera) and mangrove crabs (green crab - Goniopsis pelli, ghost crab - Cardisoma ormatum, and common blue crab - Callinectes latimanus) was carried out to compare their quality and cost with beef, chicken meat, pork and egg in order to identify those most suitable for commercial culture. Results show that all shellfish had at least 16% crude protein except blue crab (13.38%). All shellfish had higher protein content than egg (13.36%). Cockle with protein content 25.47% compared favourably with beef, (29.60%). Beef, chicken meat and pork cost 11.50, 9.00 and 8.00 per kilo respectively while oyster, periwinkle and the common blue crab cost 3.50, 3.00, and 1.50 per kilo respectively. Oysters and Cockles are recommended for commercial culture based on the findings of this research

Changes in consumer tastes in the demand for fish and meat in Malaysia

In this article the demand for fish and its substitute was estimated using a very flexible demand function, the Almost Ideal Demand System (AIDS) developed by Deaton and Muelllbaeur (1980), incorporating the habit formation variable to measure the impact of the changes in tastes in comsumer demand for fish and meat products from 1960 to 1990 in Malaysia. Information on price and income elasticities for these meat groups was also obtained. To incorporate consumption habit variables, the dynamic translating procedure proposed by Pollak (1970) and Pollak and Wales (1981) has been adopted. The overall results of the maximum likelihood estimates of the dynamic AIDS model are quite good where 19 of 30 coefficients are significantly different from zero and the minimum budget shares, the constant, are between zero and one for each meat type. Consumers tend to purchase and consume fish, chicken, and pork almost daily. Beef and mutton are only consumed occassionally since they are relatively more expensive. This finding is consistent with the trend observed in the per capita consumption and budget share where fish, chicken, and pork tended to dominate over beef and mutton from 1960 to 1990.

Aquaculture technology transfer to smallholder farmers in Malawi, Southern Africa

Details are given of activities conducted in Zomba, Malawi, in order to demonstrate new aquaculture technologies and encourage their use by smallholder fish farmers. The following technologies were introduced: napier grass as a pond output; use of a reed fence for harvesting fish; developing a high-quality compost as a pond input; vegetable-pond integration; chicken-pond integration; smoking kiln; pond stirring; and rice-fish integration. The reactions of the farmers to these technologies and their testing by the farmers are outlined briefly.

Trade and Management: Exclusive Economic Zones and the Changing Japanese Surimi Market

The United States' increasing competitive advantage in international seafood trade in Alaska walleye pollock. Theragra chalcogramma, has contributed to higher prices for surimi-based goods and structural changes in seafood production and trade in Japan. The objectives of this analytical investigation include: 1) Evaluation of the role reversal of Japan and the United States in international seafood trade and 2) quantification of the impact of rising prices of frozen surimi on household consumption of surimi-based foods in Japan. This study documents Japan's regression from "seafood self-sufficiency" to increasing dependence on imported products and raw materials. In particular, Japan's growing dependence on American fishermen and seafood producers is described. Surimi production by the United States, and its emerging dominance over Japanese sources of supply, are especially significant. Results of the analysis suggest that Japanese consumer demand for surimi-based food stuffs correlates directly with "competitive" food prices, e.g., pork, chicken, and beef, and inversely with personal income. Also revealed is how rising household income and relative price shifts among competing animal protein sources in the Japanese diet have contributed to declining household consumption of surimi-based foods, specifically, and a shift away from seafoods in favor of beef, in general. The linkages between, for example. Japanese domestic seafood production and consumption, international trade in marine products, and resource management decisions in the U.S. EEZ present a picture of a changing global marketplace. Increasingly, actions in one arena will have perhaps profound implications in the others.

Effects of some selective supplemental feeds on the survival and growth of catfish (Clarias batrachus Lin.) fry

Feeding experiments were conducted for 21 days to study the effect of live food (Tubifex sp.) and three prepared supplemental feeds on the growth and survival of 13 day old magur (C. batrachus) fry. It was observed that the growth of fry varied significantly (p<0.05) with different diets. The best growth was shown by the fry fed with Tubifex sp. followed by those fed with the diet containing yeast (30%), milk powder (30%) and chicken eggs (30%). The poorest growth rate was given by the fry fed on yeast (45%) and fish meal (45%). There was no significant difference in survival rates and condition factors among the fry fed with live food and prepared feeds.

Effect of different feeds on growth, survival and production of African catfish (Clarias gariepinus Burchell)

An experiment was conducted to study the effect of different feeds on growth survival and production of African catfish (C. gariepinus) in six cemented tanks (3m² each) over a period of 120 days. Three different feeds namely Feed A (Saudi-Bangla fish feed, 33.43% protein), Feed B (formulated feed, 40.12% protein) and Feed C (chicken raw intestine, 59.58% protein) were applied to treatments I, II and III respectively. Each of the tanks was stocked with 24 fry with mean initial body weight of 2.56±0.06 g. Feeds were supplied to the fish ad-libitum daily in two instalments. Significantly highest weight gain was obtained in treatment III, however, survival rate was low compared to other treatments. The feed conversion ratio (FCR) values ranged from 2.52-6.4. Survival rate of fish varied between 83 and 96%. Treatment II yielded the highest (5000 kg/ha/120 days) production with the highest survival rate of fish. On the basis of survival rate and production, it is suggested that the formulated feed (Feed B) is suitable for the culture of C. gariepinus in cemented tanks.

Studies on the preparation of fish silage. 3. Dried silage products

An investigation was undertaken on the production of dried products from silver belly (Leiognathus splendens) silage mixed with plant filter materials. Silages produced using hydrochloric acid and/or formic acid when mixed with rice bran or maize meal and dried, yielded powders having an acceptable appearance and a pleasant odour, which are suitable for use in compounded chicken feeds.

Bioactivity of epidermal secretion of two marine catfish from Mumbai

Crude mucus and its partially purified fractions from two marine catfish from Mumbai, Arius dussumieri and Osteogeneiosus militaris were assayed for their crinotoxicity through assays for hemolysis and haemagglutination of chicken erythrocytes, formation of paw edema in mice, and antibacterial activity against one gram-positive and four gram-negative bacteria. Assays were also done to block the edema using Phineramine maleate, Piroxicam, and Atropine sulfate. Crude toxin as well as their fractions from both the fishes exhibited haemolytic and haemagglutinating activities on chicken blood, besides edematous activity in mice models. The edematous activity was blocked by Phineramine maleate and Piroxicam but enhanced by Atropine sulfate; however, all these activities, either blocking or enhancing, were statistically insignificant. Antibacterial activity was absent in all the extracts tested.

Effect of chitin and prawn shell on the growth of albino rat

The effect of addition of pure chitin from prawn shell, deproteinised prawn shell, demineralized prawn shell and dry prawn shell in casein based control diet on albino rats was studied. The diets contained 0.5% chitin and 10% protein. The results obtained in the studies show that the weight gain and feed conversion were maximum in the control diet. While addition of pure chitin slightly brought down the weight gain, addition of deproteinsed prawn shell have the minimum weight gain showing that presence of minerals adversely affects both feed consumption and weight gain in the case of albino rats. Although it was reported that addition of pure chitin at 0.5% in the commercial feed of broiler chicken gave increased weight, in the case of albino rats the weight gain was slightly reduced compared to control diet.

Noxious euglenophytes bloom in fertilized fish ponds

A study was carried out in nine fertilized fish ponds under three treatments at Bangladesh Agricultural University, Mymensingh, Bangladesh, to record the influence of different fertilizers on noxious euglenophytes bloom. Some water quality parameters (viz., temperature, pH, phosphate-phosphorus, nitrate-nitrogen and chlorophyll-a) and phytoplankton populations were monitored at certain intervals. During the study period, three genera of euglenophytes such as Euglena, Phacus and Trachelomonas were recorded of which Euglena was most dominant. Significantly (p<0.05) higher cell density of euglenophytes was observed in the ponds treated with chicken manure followed by the ponds treated with both cow dung and chicken manures and the ponds treated with only cow dung. The higher cell density of euglenophytes was explained by acidic pH (around 6.5) and higher phosphate-phosphorus (1.37 mg/1) and nitrate-nitrogen (1.47 mg/I) concentrations. The population size of euglenophytes showed positive correlation with phosphate-phosphorus and nitrate-nitrogen concentration while negative with pH. Nutrient enrichment and acidic pH enhanced the growth of euglenophytes but reduced the growth of chlorophytes and bacillariophytes.

Shrimp (Penaeus monodon Fabricius) production in brackishwater ponds applied varying fertilizer combinations

Details are given of the production of Penaeus monodon in the Philippines reared in brackishwater earthen ponds applied with different fertilizer combinations, namely diammonium phosphate, urea and chicken manure. Results show that the shrimp showed higher yields in fertilized ponds, but increasing the concentration of fertilizers did not give a marked increase in yield - the excess fertilizer was wasted.