Browsing by Subject "Common carp"

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Development of supplemental diets for carp in Vietnamese upland ponds based on locally available resources
(2010) Nguyen Ngoc, Tuan; Focken, Ulfert
Cyprinids play very important role in aquaculture, especially in Asia and Pacific regions. Vietnam is not an exception. Although aquaculture in Vietnam increased dramatically recently, its high value products such as catfish, tiger prawn seem to be unaffordable for the people in rural areas, especially for the mountainous ethnic minority in the North who are more independent to herbivorous and omnivorous fish such as grass carp, Indians carp, and common carp. Yen Chau is a district of Cyprinids play very important role in aquaculture, especially in Asia and Pacific regions. Vietnam is not an exception. Although aquaculture in Vietnam increased dramatically recently, its high value products such as catfish, tiger prawn seem to be unaffordable for the people in rural areas, especially for the Son La province, located in mountainous region in North-Western Vietnam. In this district, Black Thai ethnic minority accounts for approximately 54% population. Besides producing huge amount of grain and tuber crop such as maize and cassava for selling, aquaculture in a small poly-culture pond system is also a very typical activity which supplies an important nutritional source for human consumption and income generation as well. However, even though most of farmers in Yen Chau own at least one pond each, the demand on the local market cannot be covered (Steinbronn, 2009). Recently, unknown diseases causing high mortalities could be the reason of the decrease of grass carp production. To avoid risk from losing grass carp, farmers are tending to change the composition of the fish species stocked in favour of e.g. common carp and mud carp without having an appropriate feed base for these species. So far, no high quality feed was applied into the pond system. Therefore, the study entitled ?Development of supplemental diets for carp in Vietnamese upland ponds based on locally available resources? was conducted to not only contribute to an improvement of income and food security in the region but also meet the appeal of improvement of scientific knowledge on cyprinids which is inadequate with their great contribution. In the study, most of the possible feed ingredients were collected and analyzed for nutritive and non-nutritive values. Based on the results of the analysis a number of diets were formulated for 30% of CP and 10% of CL then tested by common carp. In total, four experiments were designed. The first was conducted in laboratory in which common carp were fed by local pelleted feed with 25, 50, and 75% protein derived from local ingredients. Results of this trial were confirmed by the trial 2 which was implemented under pond condition at Hanoi University of Agriculture. Trial 3 was conducted to compare different protein (full fat soybean meal and soybean cake) and carbohydrate sources (maize and cassava powder). Furthermore, sweet potato leaves were preliminarily investigated in fish feed inclusion. The last trial, trial 4, was carried out to evaluate the use of earthworm for common carp. Trial 1, 3 and 4 were designed for a recirculation system in which five common carp were stocked in each aquarium of 40 l with 3 replicates. Water flow through the aquaria was maintained at 6-7 litters per minute. Water temperature, DO and pH were kept at 25-27°C, above 4 mg/l and around 7.0-8.0, respectively. The photoperiod was set up at 12 hrs light:12 hrs dark. Fish were fed daily five times metabolic body mass requirement for eight weeks. The trial 2 consisted of four feeding groups (3 test diets and 1 control), each having three replicates. In each net, 45 common carp were stocked, Fish were fed three times per day (8h, 12h, and 16h) at a feeding rate of 5 times of maintenance requirement manually. Feed amount was adjusted every ten days after taking the weight of fish. The total trial lasted for 2 months. Analytical results show that all of local materials have good nutritive values, similar or better that those in other regions. Besides, fish meal and many other ingredients can be used as source of protein such as full fat soybean meal, soybean cake, meat meal, as well as earthworm powder. This earthworms Perionyx excavatus show a suitable quality for fish feed, high protein (71% of DM) and amino acids in comparison with many conventional protein sources, including fish meal. Replacement of 70% of protein (~ 20% of DM) by earthworms can significantly improve growth of fish. However, it is still unclear in full replacement fish meal by this material. Using maize and cassava in Yen Chau is also feasible because these materials not only are cheap but also are the most available. Among all plant materials, full fat soybean seems to be the best ingredient with high protein and lipid content. In contrast, fish seem to be deficient of nutrient by feeding sweet potato leaf inclusion diets. In conclusion, except for sweet potato, all of local ingredients can be used for fish feed formulation. The local feeds were well digested, utilized by omnivorous common carp. Despite local feed ingredients did not give the best growth of fish, they gave the best results in term of economic return. Local ingredient feed gave the lowest cost of feed as well as the lowest cost of fresh fish produced. The field trial fish performance seems to be better than in the laboratory due to receiving certain amount of natural food. Thus, fish utilize feed more efficiently resulted in reduction of feed conversion ratio as well as cost of feed per unit of fish produced. Transfer knowledge about low-cost feed to the local farmer together with basal techniques of producing, storing, and effective using fish feed is an important issue which could help farmers to improve production of fish in the region as well as contribute to poverty alleviation in the rural areas in Vietnam.
Evaluation of suitability of non-toxic and detoxified Jatropha curcas L. meal as feed for fingerling common carp, Cyprinus carpio L., with reference to phytase application
(2012) Richter, Nahid; Becker, Klaus
Jatropha curcas L. is a hardy plant which can thrive on marginal degraded lands. Jatropha seeds contain about 300-350g kg-1 oil, which is used as fuel or in transesterified form as a substitute for diesel; they also have considerable protein quality. However, Jatropha contains antinutrients such as lectins, trypsin inhibitors and phytic acids at high levels and in toxic varities phorbolesters cause detrimental effect. Common carp fed heat-treated non-toxic Jatropha meal (JM) has been shown to have higher weight gain and protein efficiency ratio than those fish fed untreated JM. However, these parameters were significantly lower in the aforementioned trial when compared to fish fed a fish meal (FM) based diet. Reduced growth performance in fish fed non-toxic JM might be attributable to the deficiency of some essential amino acids such as lysine, to high levels of phytic acids or the presence of antinutrients. These may indicate the need for additional processing of JM for common carp. This work was therefore conducted to test various ways of further improving the nutritional quality of JM to increase the levels of inclusion in diets for common carp. In the first experiment, four diets based on 50% replacement of FM with defatted non-toxic JM were formulated, one with no further JM treatment, the second with 80% aqueous ethanol extraction before diet formulation, the third supplemented with 1% L-lysine and the fourth with 500 FTU phytase (5000G, Natuphos). These were compared to a standard, FM based diet. The results showed that diets with 500 FTU/kg phytase or 1% L-lysine could maintain common carp?s growth performance at a level comparable to fish fed a FM diet. Fish fed diets containing JM and ethanol treated JM had significantly lower growth performance than the control. The addition of 1% L-lysine or 500 FTU phytase enhanced percent body weight gain, food conversion efficiency and specific growth rate to a level comparable to those of the control. Furthermore, the addition of 500 FTU phytase significantly increased whole body Mg, P and K to the levels of those fish fed Diet Control. When the level of JM replacement was increased from 50% to 75% while at the same time supplementing the diets with inorganic phosphorus (Experiment 2), however, a significant decrease in body weight gain of common carp was observed both with and without 500 FTU phytase. In a third experiment, the effect of JM diets with added phytase but without phosphorous supplementation was therefore investigated in more detail. At the end of the eight week trial, phytase supplementation had not affected body mass gain (BMG), food conversion ratio (FCR) and specific growth rate (SGR) of fish. However, whole body phosphorous (P), P gain and P retention were significantly improved in fish fed JM with phytase supplementation when this was compared to the fish fed JM without phytase. Moreover, fish fed JM diets indicated higher O2 consumption per gramme body mass gain than carp fed FM diets. Energy expenditure per gramme protein retained was significantly higher for fish fed JM with or without phytase addition, indicating that the utilisation of JM was associated with higher energy costs for the fish. In the final experiment, the nutritional quality of non-toxic JM was compared to that of the toxic variety once appropriate measures had been taken to detoxify the latter. FM was replaced with either of the two at 75% of total dietary protein, for each Jatropha variety once without further supplementation and once supplemented with 500 FTU phytase and 1% lysine. The results of this experiment indicated that there was no significant differences in final body mass (FBM), % BMG, feed intake (FI), FCR and specific growth rate (SGR) of fish fed diets Control and non-toxic, supplemented JM. However, fish fed diets based on detoxified or non-toxic, unsupplemented Jatropha showed significantly inferior growth parameters when compared to carp fed the first two diets (p<0.05). Whole body P was significantly higher in fish fed the Control and non-toxic JM diets (with/without phytase and lysine) than fish fed either of the two detoxified JM diets (p<0.05). The depressed growth performance in the group fed detoxified JM could imply that the detoxification process was not complete and traces of phorbolesters may still be present in the diets. This work has shown that, given proper treatment, JM can act as a suitable replacement for FM at high levels in diets for common carp. The results of this work suggest that phytase addition to enhance phosphorous availability and lysine supplementation to correct the essential amino acid imbalance are two factors that have significant effects in improving JM suitability for common carp.
Jatropha meal and protein isolate as a protein source in aquafeed
(2011) Kumar, Vikas; Becker, Klaus
As aquaculture continues to develop, there will be an increasing need to use alternative plant proteins in aquaculture diets so that aqua eco-systems will be sustainable. Jatropha (DJKM, H-JPKM and DJPI) can be used as protein rich sources in the diets of fish and shrimp. There is a high potential for the safe use of DJKM, H-JPKM and DJPI in diets for fish and shrimp without compromising performance, provided that these ingredients are free of toxic factors. The detoxification process developed in Hohenheim is simple and robust and produces products that are safe and of good quality. Their addition to fish and shrimp diets gave excellent performance responses without any ill effects on animal health or safety. Effects on growth and nutrient utilization: ? Detoxified Jatropha kernel meal, H-JPKM and DJPI could replace 50%, 62.5% and 75% fish meal protein respectively without compromising growth performance and nutrient utilization in fish. In addition, DJKM could also replace 50% fish meal protein with no adverse effects on growth and nutrient utilization in shrimp. If the replacement levels are exceeded, the producer must examine the nutrient profile of the feeds carefully to ensure that desired production levels can be achieved and fish and shrimp health maintained. ? High inclusion (>50% fish meal protein replacement) of DJKM decreased the efficiency of conversion of feed to body mass. This could be explained partly by the increased mean feed intake which was possibly a reaction to the reduced protein retention, measured as protein efficiency ratio and protein productive value. No such effects were seen with the use of DJPI in common carp diets. ? Increased DJKM inclusion in diets caused a significant lowering of protein, lipid and energy digestibilities. No such effects were seen when DJPI was used in common carp diets. Effects on energy budget: ? Feeding DJKM and H-JPKM to common carp and Nile tilapia respectively did not change the major components of the energy budget (routine metabolic rate, heat released and metabolisable energy) compared to fish meal and soybean meal fed groups. These results revealed that dietary protein sources DJKM and H-JPKM can be efficiently utilized for growth by common carp and Nile tilapia respectively, as well as soybean meal and fish meal. Effects on expression of growth hormone and insulin-like growth factor-1 encoding genes ? As the level of DJKM inclusion increased in the common carp diet, growth rate decreased. The expression of Insulin-like growth factor-1 (IGF-1) in liver also decreased with increase of DJKM in the diet and that of the growth hormone in liver decreased. Effects on clinical health parameters and gut health: ? No mortality and unaffected haematological values suggested the fish were all in normal health. Alkaline phosphatase and ALT activities; urea nitrogen, bilirubin and creatinine concentration in blood were in the normal ranges which showed that there was no liver or kidney dysfunction. ? The measured plasma nutrient levels gave no indications of stress, but increasing the level of plant protein in the diet decreased plasma cholesterol. This may be related to high NSP content or reduced dietary intake of cholesterol. Decrease in muscle cholesterol level is also expected which could be considered good for human health. ? Histopathological evaluation of organs showed no damage to the stomach, intestine or liver of common carp or rainbow trout. Effects of Jatropha-phytate in Nile tilapia The defatted Jatropha kernel meal obtained after oil extraction is rich in protein (58−66%) and phytate (9 −11%). The phytate rich fraction was isolated from defatted kernel meal using organic solvents (acetone and carbon tetrachloride). It had 66% phytate and 22% crude protein and its inclusion in fish diets showed the following: ? Negative effects on growth performance, nutrient utilization and digestive physiology (nutrient digestibility and digestive enzymes). ? Adverse influences on biochemical entities such as metabolic enzymes (alkaline phosphatase and alanine transaminase) and electrolytes/metabolites. Salient changes include decreased red blood cell count and hematocrit content, decreased cholesterol and triglyceride concentrations in plasma and decreased blood glucose levels. The adverse effects observed may be due to the interaction of phytate with minerals and enzymes in the gastro intestinal tract, resulting in poor bioavailability of minerals and lower nutrient digestibility. The level of phytate used in the present study (1.5 and 3.0%) corresponds to 16.5% and 33.0% of DJKM in the fish diet. The DJKM at levels > 16.5% in the diet would exhibit adverse effects in Nile tilapia. Addition of phytase to the phytate containing diets would mitigate the adverse effects of at least up to 3% Jatropha phytate (or 33% DJKM) in the diet. Addition of phytase (1500 FTU/kg) in diets containing DJKM is recommended to maximize their utilization by Nile tilapia.