Effect of feed quality restriction followed by realimentation on growth, nutrient utilization, biochemical changes and haematological profiles of Indian major carp, rohu (Labeo rohita H.)

To investigate the effect of protein restriction with subsequent re-alimentation on nutrient utilization, hematological and biochemical changes of Indian major carp, Rohu (Labeo rohita H.), 150 acclimatized Rohu fingerlings (average 20.74 ± 0.13 g) divided into five experimental groups (30 fingerlings in each groups with three replications with 10 fingerlings in each) for experimental trial of 90 days using completely randomized design. Control group (T sub(CPR)) was fed with feed having 30% crude protein at 3% of body weight for 90 days trial period. Other experimental groups T sub(1PR) was alternatively 3 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(2PR) was alternatively 7 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(3PR) was alternatively 15 days fed with feed having 20% CP and 30% CP at 3% of body weight and T sub(4PR) was alternatively 25 days fed with feed having 20% CP and 30% CP at 3% of body weight during 90 days trial period with daily ration in two equal halves at morning and afternoon. It was noticed that retention of different nutrients was almost similar among all treatment groups indicated improvement of digestibility of nutrients might not be the mechanisms for recovery growth in carps. Increased percent feed intake of body weight (hyperphagia) (4.14 ± 0.30 or 4.94 ± 0.46 and 3.33 ± 0.29), improved specific growth rate (1.86 ± 0.09 or 2.26 ± 0.05 and 1.43 ± 0.01), absolute growth rate (1.57 ± 0.08 or 1.84 ± 0.18 and 1.36 ± 0.12), protein efficiency ratio (1.19 ± 0.11 or1.16 ± 0.12 and 1.05 ± 0.09) were the important mechanism showing better performance index (21.60 ± 1.09 or 23.80 ± 0.21 and 19.45 ± 0.37) through which the experimental groups which were protein restricted and re-alimented at 3 or 7 days alternatively during 90 days trial period could able to compensate the growth retardation and to catch up the final body weight of control (128.68 ± 11.53 g/f) but other experimental groups failed to compensate during 90 days trial period. Result of the present study indicated that deprived fish i.e., fish received alternate 3 or 7 days protein restriction and re-alimentation showed recovery growth had still lower values of Hb (10.21 ± 0.02, and 9.88 ± 0.04 g/dl), hematocrit value (30.62 ± 0.05 and 26.64 ± 0.11%), total erythrocytic count (3.40 ± 0.01 and 3.29 ± 0.01 X10super(6) mm³), plasma glucose (126.93 ± 0.20 and 126.67 ± 0.05 mg/dl), total plasma lipid (1.04 ± 0.01 and 1.02 ± 0.01 g/dl) and liver glycogen (290.10 ± 0.80 and 288.99 ± 0.95 mg/kg) in comparison to control (10.56 ± 0.08 g/dl, 31.68 ± 0.24%, 3.52 ± 0.03 X10super(6) mm³, 128.23 ± 0.25 mg/dl, 1.07 ± 0.01g/dl and 292.00 ± 0.23 mg/kg) at the end of 90 days trial but total plasma protein in deprived group was compensated with advancement of trial period. All hematological and biochemical parameters studied were proportionately lowered in the experimental group got higher degree of deprivation. These findings suggested that with the increase of trial length complete compensation of hematological and biochemical profiles of rohu might be achieved. The results indicated that the implementation of alternative 7 days low and high protein diet feeding during aquaculture of carps could make economize the operation through minimizing the feed input cost.

Preliminary studies of the dual role of cotton-seed cake as fish feed and fish pond fertilizer in aquaculture

Many locally available fish feeds have been tried in fish culture. These include guinea corn, soya bean, groundnut cake and rice bran. Cotton seed cake has been successfully used as a fishpond organic fertilizer at Ado-Ekiti Government fish farm. Three fishponds stocked respectively with common carps, Heterotis, Tilapia spp., Clarias lazera and Heterobranchus were fed with cotton seed cake. Carps, Tilapia and Heterotis increased rapidly in weight and length while the catifishes did not grow

The use of locally available materials in fish feed production

In Nigeria, the culture of fish is gaining importance, but local fish farmers face a set back because of the stoppage on importation of fish feed. Locally available raw materials such as yam, plantain, banana, cowpeas, macuna, maize, cassava, millet, sorghum, groundnut, sunnhemp seed and brewery wastes are considered as potential materials for fish feed. These have been examined on their minimum protein contributions since this is the most expensive part of the fish feed. Alternative sources to animal proteins are also examined. Plant protein from groundnut, melon, mucuna and others compare favourably with bloodmeal mixture and thus can be used to replace the more expensive animal proteins. Pellet feed can be produced on a small scale or commercial basis from the locally available raw materials and the fish farmer is advised to seek assistance from qualified fisheries personnel

Investment prospects in fish feed technology

The author endeavours to analyse the recent trend in the local production of fish by sector over a period of 5 years, 1980-1985 and the data available to the author on the Nigerian fish imports. The present and future deficit in fish production in Nigeria could only be met from the capture fishery and the fish farm industry but more likely from the latter. The production techniques involved in fish feed industry are illustrated in this paper with standard feed formulations to arrive at a suitable fish diet. Associated problems of fish feed industry and their possible solutions are highlighted. A case study of investment prospects in fish feed industry as well as the production of brine shrimps are suggested as possible areas of investments in the industry. The unit production cost of fish feed is about 700/ton, while in the case of artemia (brine shrimp), the estimated unit cost if about 400/ton

Protein and amino acid requirements of warm-water fishes: a tool to efficient and low-cost fish feed production in Nigeria

Numerous investigations have utilized various semi-purified and purified diets to estimate the protein and amino acid requirements of several temperate fishes. The vast literature on the protein and amino acid requirements of fishes has continued to omit that of the tropical warm water species. The net effect is that fish feed formulation in Nigeria have relied on the requirement for temperate species. This paper attempts to review the state of knowledge on the protein amino acid requirements of fishes with emphasis on the warm water species, the methods of protein and amino acid requirement determinations and the influence of various factors on nutritional requirement studies. Finally evidence are presented with specific examples on how requirements of warm water fishes are different from the temperate species and used this to justify why fish feed formulation in Nigeria are far from being efficient

On-farm feed: the potential for improving profitability in aquaculture

The urge to develop a standard practical diet for farmed fish in Nigeria has been on the increase since the last decade. Since ages diets has ever represent the largest single cost item of most fish farm operations. This is the reason why careful selection of feed ingredients for use in aqafeed plays a vital role in the resultant nutritional and economic success of farmed fish. In an attempt to meet the objectives of culturing fish two main sources of fish feed have been identified for meeting the nutritional requirements of fish. These include 'on-farm feeds' and 'commercial feeds'. However, 'on-farm feed' takes the lion share out of the total annual national aquafeed product which amounts to about 70% of the estimated total of 3,570 tones of fish feed produced in year 2000. This paper takes a look at the important of non-conventional feed resource in 'on-farm feed', the place of vitamins in 'on-farm feed', the need to develop and encourage on-farm feed production and feeding strategies if aquaculture will grow further to meet the projected million metric tones production within this decade

Growth response, feed conversion rate and cost benefits of hybrid catfish fed maggot meal based diets in outdoor tanks

The growth response, feed conversion ratio and cost benefits of hybrid catfish, Heterobranchus longifilis x Clarias gariepinus fed five maggot meal based diets were evaluated for 56 days in outdoor concrete tanks. Twenty-five fingerlings of the hybrid fish were stocked in ten outdoor concrete tanks of dimension 1.2mx0.13mx0.18m and code MM sub(1)-MM sub(5) in relation to their diet name. Five isonitrogenous and isocaloric maggot meal based diets namely MM sub(1)-0% maggot meal, MM sub(2)-25% maggot meal, MM sub(3)-50% maggot meal, MM sub(4-)75% maggot meal and MM sub(5-) 100% maggot meal were used for the experiment. The higher the proportion of maggot in the meal, the higher the ether extract and crude fiber. No significance difference P>0.05 exists between ash content of the experimental diets. Diet MM sub(2) had the best growth performance and highest MGR with a significant difference P<0.05 with other diets fed fish. No significance differences P>0.05 exists between the growth parameters for diets MM sub(1), MM sub(3), and MM sub(4). A positive correlation (r=1.0) exists (P<0.05, 0.25) between the growth parameters for the different experimental diets. Highest correlation r super(2)=0.9981 exists P<0.05 between MGR within the treatments. However, there no significant (P>0.05) difference in expenditure but there is between the profit indices and incidence of cost between the trials. MM sub(2) has the best yield cost and net profit. Without any reservation, inclusion of maggot based meal diet is recommended as feed of hybrid catfish to 75% inclusion for growth and profit incidence

Preliminary investigation into implication of a single cell organism in fish feed bouyancy and flotation

Two Isocaloric Isoproteic 30% crude protein diets were formulated for Clariid catfish and Tilapia with wheat grain starch (WGS) and cassava tuber starch (CTS) incorporated at 10 percent as binding agents. Saccharomyces cerevisiae was included at 2% as floating additive. The water stability, nutrient retention and flotation of pelleted feeds were observed for 60 minutes. There were generally decreasing trends in stability and retention at increasing time of immersion in water. The lipid retention was higher (P>0.05) than proteins in both diets. WGS diet was better (P>0.05) than CTS diet in flotation, which has attributed to the presence of gluten protein in wheat products. It is envisaged that a break through in floating feed development in Nigeria aquaculture would save the Nigeria economy from extruded (floating) feed importation

Feed conversion, protein efficiency, digestibility and growth performance of Oreochromis niloticus fed Delonix regia seed meal

Oreochromis niloticus fingerlings (mean weight 5.27~c0.29g) were fed raw and boiled Delonix regia seed meals following standard procedures. The weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), net protein utilization (NPU) were determined as growth indices. Diet formulated with seed boiled for 80 minutes showed significantly (P<0.05) high values for the growth indices. Carcass nutrients composition were significantly (P<0.05) higher than in the control (raw) diet. Delonix regia seed meal when boiled has high potential of being utilized efficiently by O.niloticus. The implications of the respective index in fish metabolism are discussed

Potentials of castor seed meal (Ricinus communis L.) as feed ingredient for Oreochromis niloticus

The potentials of castor seed (Ricinus communis) meal as feed ingredient for Oreochromis niloticus was determined by using boiled seeds to prepare five diets which were fed to the fish species. The effects of the experimental diets on the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, apparent net protein utilization, digestibility and carcass composition were investigated. The best of these growth factors were obtained with feed formulated from R. communis seeds boiled for 50 and 65 minutes. The highest carcass protein content was observed with fish fed with 65 minute-boiled seeds

Application of ipil- ipil leaf meal (IILM) as feed Ingredient for Monosex tilapia fry (oreochronis niioticus) : In terms of growth and economics

The Ipil-ipil (Leucaena leucocephal) leaf analyzed for crude protein (CP), fat, crude fibre (CF), ash content, moisture content and nitrogen free extract (NFE). The CP 23± 0.12 % , fat 8 ± 0.11 %, CF 18 ± 0.15 % , ash 10 ± 0.13 %, moisture 14. ± .16% and NFE 29.± 1.10 % were recorded. A twenty one days experiment was conduced to assess the response of juvenile monosex tilapia with different iso-nitrogenous formulated diets for find out the feasibility study of using ipil-ipil leaf meals as feed ingredient for juvenile tilapia. Three experimental diets were formulated by using fish meal, soybean meal, rice bran and ipil ipil leaf meal. One control diet was formulated by using fish meal, soybean meal and rice bran. Considering the high demand, limited availability of fish meal and soybean meal, ipil ipil leaf meal was incorporated in juvenile tilapia feed. Among plant protein ingredients ipil ipil leaf meal was considered as the most nutritive plant protein source after soybean meal. However, high concentration of toxic element limited the incorporation level of ipil ipil leaf meal in fish feed. Use of 15 % ipil ipil leaf meal in fish feed was more significant from the view of growth performance and economics. The higher Absolute Growth was 1119.26 gm, higher Specific Growth Rate was 6.52% /day higher Feed Conversion Efficiency was 41.23% , higher Protein Efficiency Ratio was 1.178 and higher Average Daily Growth rate was 14.00% recorded in diet-4 ( which contained 15% IILM). The lower Feed Conversion Ratio 2.42 and lower cost for per unit production 34.65 taka/kg were recorded in diet-4. The higher cost for per unit fish production 45.6 tk./kg was recorded for diet-1 where no ipil ipil leaf meal.. The results suggest that tree legumes Ipil-ipil (Leucaena leucocephal) leaf has potential and excellent source of feed ingredients as protein supplements for juvenile monosex

Determination of optimum stocking density of Macrobrachium rosenbergii larvae using multiple feed in a commercial hatchery at Cox’s Bazar, Bangladesh

Experimental stocking density of Macrobrachium rosenbergii in larval rearing was conducted in A.G. Aqua Hatchery, Chakaria, Bangladesh to study the effect of different stocking densities on growth, survival rate and diseases stress under hatchery condition. The research work was conducted using six cemented rectangular tanks having 3m3 capacity (1.5mX2mX1m) each. Stocking density were maintained in three experimental setup as 200, 150 and 100ind/L of the T1, T2 and T3 respectively with one replicate each. The larvae were fed with Artemia nauplii, Custard, Maxima and brine shrimp flakes. Water quality was maintained by exchanging 20-30% (12ppt saline water) daily. During the study period, temperature, pH, DO, salinity, nitrite-nitrogen, ammonia and alkalinity were maintained from 28.5-31.5ºC, 7.5-7.8, 5.8-5.9mg/L, 12-13ppt, 0.14-0.2 mg/L, 0.22-0.3mg/L, and 140-160mg/L respectively. The growth rates of larvae at 11th stage were recorded in terms of body length 0.115, 0.136, and 0.169 mm/day whereas body weight were observed 0.000115, 0.000180, and 0.000240g/day. The survival rate of larvae were found 21.8%, 30.4% and 51.3% in treatments T1, T2 and T3 respectively. PL was obtained as 43, 45, and 51PL/L and days required of 41, 38 and 34 days in stocking density of 200, 150, and 100ind/L respectively. It was found that the minimum of 34 days was required to attain the PL (12th stage) using the stocking density of 100 individuals/L. Cannibalism, Zoothamnium, Exuvia Entrapment Disease (EED), and Bacterial Necrosis (BN) were found to be the threat to the commercial hatchery operation that might responsible for potential larval damages which can be reduced by lowering the stocking densities in larval rearing tank that also increased the survival and growth rate.

Flood circulation in oligomictic lakes: an undervalued reason for restriction of zooplankton production [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 22 9-52, 1967]

Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.

Comparing the identification of southern California juvenile rockfishes (genus Sebastes spp.) by restriction site analysis of the mitochondrial ND3/ND4 region and by morphological characteristics

Rockfish (Sebastes spp.) juveniles are often difficult to identify by using morphological characters. This study independently applies morphological characters and a key based on mitochondrial restriction site variation to identify juvenile rockf ishes collected in southern California during juvenile rockfish surveys. Twenty-four specimens of Sebastes were examined genetically without knowledge of the morphological assignment. Seventeen fish were identified genetically as S. semicinctus, S. goodei, S. auriculatus, S. jordani, S. levis, S. rastrelliger, and S. saxicola. Identities for the remaining fish were narrowed to two or three species: 1) three fish were either S. carnatus or S. chrysomelas; 2) one fish was either S. chlorosticus, S. eos, or S. rosenblatti; and 3) three fish could have been either S. hopkinsi or S. ovalis, the latter for which we now have distinguishing mitochondrial markers. The genetic and morphological assignments concurred except for the identity of one fish that could only be narrowed down to S. hopkinsi or S. semicinctus by using morphological characters. Genetics excluded more species from multispecies groupings than did the morphological approach, especially species within the subgenus Sebastomus. Species in the genetically unresolvable groups may be similar because of recent divergence or because of interspecies introgression.

A key to selected rockfishes (Sebastes spp.) based on mitochondrial DNA restriction fragment analysis

Larval and juvenile rockfishes (Sebastes spp.) are difficult to identify using morphological characters. We developed a key based on sizes of restriction endonuclease fragments of the NADH dehydrogenase-3 and -4 (ND3/ND4) and 12S and 16S ribosomal RNA (12S/16S) mitochondrial regions. The key makes use of variation in the ND3/ND4 region. Restriction endonuclease Dde I variation can corroborate identifications, as can 12S/16S variation. The key, based on 71 species, includes most North American taxa, several Asian species, and Sebastolobus alascanus and Helicolenus hilgendorfi that are closely related to rockfishes. Fifty-eight of 71 rockfish species in our database can be distinguished unequivocally, using one to five restriction enzymes; identities of the remaining species are narrowed to small groups: 1) S. polyspinis, S. crameri, and S. ciliatus or variabilis (the two species could not be distinguished and were considered as a single species) ; 2) S. chlorostictus, S. eos, and S. rosenblatti; 3) S. entomelas and S. mystinus; 4)S. emphaeus, S. variegatus, and S. wilsoni; and 5) S. carnatus and S. chrysomelas.