Effect of phosphorous supplementation in the formulated fish feed on carcass quality of Nile tilapia Oreochromis niloticus L.

A study was conducted to evaluate the effect of phosphorus supplementation in the formulated fish diet on carcass quality of Nile tilapia in net-cages suspended in fertilized earthen ponds. In the experiment 3% di-calcium phosphate (DCP), 3% triple supper phosphate (TSP) and 7% 16:20 inorganic fertilizer were added as phosphorous sources to three diets containing fish meal as main protein ingredient. Feeding tilapia in net-cages with these diets significantly (psupplementation and fish given no feed. The final body composition and bone phosphorous content of Nile tilapia fed with DCP, TSP and 16:20 grade fertilizer supplemented diets were comparable.

Effect of zinc and manganese supplementation to tricalcium phosphate rich diet for tiger puffer (Takifugu rubripes)

Effects of zinc (Zn) and manganese (Mn) supplementation to a tricalcium phosphate (TCP) rich diet for tiger puffer have been investigated. A TCP supplement to the diet decreased the growth of fish compared to the control diet with a Ca supplementation from Ca-lactate. However, addition of either Zn or Mn to the TCP supplemented diet could not improve the growth of tiger puffer. Addition of both zinc and manganese to the TCP supplemented diet improved the growth of tiger puffer.

Effect of dietary supplementation of tocoferol acetate alone and with varying combinations on growth, survival and fatty acids profile of Macrobrachium rosenbergii larvae through Moina micrura enrichment

A study was carried out to determine the effect of tocopherol acetate along with cod liver oil astaxanthin enriched Moina micrura (MC- control, Ml- tocopherol acetate enriched, M2-tocopherol acetate combined with cod liver oil (CLO) enriched and M3- tocopherol acetate combined with astaxanthin enriched) on growth, survival and fatty acid composition of M. rosenbergii (de Man) larvae (TC- unenriched Moina fed larvae, Tl- tocopherol acetate enriched Moina fed larvae, T2- tocopherol acetate + CLO enriched Moina fed larvae to T3 – tocopherol acetate+ astaxanthin enriched Moina fed larvae). Growth was expressed as the time taken in to the settlement of 95% post larvae. Maximum growth i.e., the lowest time taken to the 95% PL settlement (40 days) and the maximum survival percentage (61%) was observed in both T2 and T3 treatments fed with M2 and M3 Moina respectively. Minimum growth and survival was observed in unenriched Moina fed larvae (TC). In larval treatments T2, (larvae fed with (M2) vitamin E + CLO enriched Moina), showed a higher percentage of EPA, DHA and higher HUFA level than other treatments.

Effects of dietary supplementation of commercial human probiotic and antibiotic on the growth rate and content of intestinal microflora in ornamental fishes

The effects of dietary supplementation of commercial human probiotic, Lactobacil and antibiotic, oxytetracycline on the growth, survival, disease resistance and content of intestinal microflora in two ornamental fishes, viz., goldfish, Carassius auratus and swordtail, Xiphophorus helleri were studied. The total wet weight gain, food conversion ratio and specific growth rate of C. auratus did not vary significantly (p>0.05) among treatments. While in X. helleri, significant differences existed in the total wet weight gain, survival, food conversion ratio and specific growth rate among treatment groups (p<0.05). The counts of antibiotic resistant bacteria in fish gut increased with days of culture in all the treatments and the increase was more in antibiotic fed fishes. A reduction in the development of antibiotic resistance among the bacterial flora of fish gut was noticed in probiotic fed groups of C auratus and X. helleri. The results of the present study revealed that the effects of human probiotic on the growth, survival and disease resistance of ornamental fishes are variable and difficult to reproduce the similar effect on different species.

The effects of Moina artificial diet and nutrase xyla supplemented artificial diet on growth and survival of Clarias gariepinus larvae

An experiment was carried out to investigate the effects of Moina, artificial diet (55% CP) and nutrase xyla supplemented artificial diet on growth performances and survival rates of Clarias gariepinus larvae. A combination of Moina and artificial diet (with or without nutrass xyla) resulted in higher growth performance and survival rates during a 12-day nursing time with specific growth rates of 30.04-32.15% d super(-1) and survival rates of 87.5-90%. Best growth performance and survival rate was obtained with a combination of Moina and artificial diet supplemented with nutrias xylem. Feeding of Moina and artificial diet supplemented, with nutrias xyla alone to the larval led to a lower growth performance of 25.60-27.04% d super(-1). However, the survival rate of Monia of larvae fed a combination of Moina and artificial diet (with or without nutrias xylem supplementation) artificial diet without nutrias xylem addition proved relatively less suitable for larval rearing of Clarias gariepinus owing to a low survival rate of 69% and growth performance of 19.7% d super(-1). This study showed the feasibility of feeding a combination of Moina and nutrias xylem supplemented artificial diet to the larvae of Clarias gariepinus

Integrating fish and azolla into rice-duck farming in Asia

Several countries in Asia practice integrated rice-duck farming. On-farm resources such as duck manure and feed waste are not adequately used and recycled in the system. This indicates the potential for research to increase the productivity of the rice-duck system. The integration of fish and the nitrogen-fixing aquatic fern azolla show promise for increasing the production potential of the system. Fish, azolla and ducks integrated with rice farming can result in nutrient enhancement, pest control, feed supplementation and biological control. Some of the results of a case study on integrated rice-fish-azolla-duck farming systems conducted in the Philippines are presented in this paper.

Effects of physiological doses of vitamin D sub(3) (Cholecalciferol) on induced molting and growth in giant freshwater prawn, Macrobrachium rosenbergii (de Man)

Effects of three different doses of vitamin D sub(3) on molting, growth, and calcium and phosphate composition of tissue and molt during the grow-out of the giant freshwater prawn Macrobrachium rosenbergii (average weight 10.56 ± 0.20 g), obtained from a grow-out pond, were studied. Intramuscular doses of vitamin D sub(3) (100, 500 and 2000 IU/kg body weight) were given on the 1st, 3rd, 5th, 7th, 9th, 11th, 13th, 15th, 20th, 25th and 30th days. All the experimental animals were fed with a basal diet containing fish meal, shrimp meal, wheat flour, groundnut de-oiled cake, soybean meal and wheat bran at 3% of the body weight. The numbers of molts were recorded as 20±0.50, 29±1.16, 51±1.87, and 30±1.60 in control, 100, 500 and 2000 IU/kg body weight physiological doses, respectively. Maximum growth was recorded in prawns given 500 IU/ kg dose. Survival was between 58.33 ± 9.13 and 77.77 ± 8.61%. The ash content and calcium level increased significantly (p<0.05) and recorded the highest values in 500 IU/kg physiological dose. However, the inorganic phosphate (P sub(i)) content recorded the highest values in tissue in 2000 IU/kg dose (p<0.05, F = 50.60613). There is no significant difference in calcium contents (p>0.05) in both tissue and molt at 500 and 2000 IU/kg doses. It was found that a higher physiological dose (2000 IU/kg) of vitamin D sub(3) increased the rate of mortality. Results have shown that vitamin D sub(3) has a positive impact on the growth and survival of M. rosenbergii and it interferes with the metabolism of Ca and P sub(i), in tissue, and alters molting frequency. Results on physiological dose suggest an alternative and effective dietary supplementation method of vitamin D sub(3) in the grow-out phase of M. rosenbergii.

Probiotics and nutrient supplement in artificial feed of gold fish (Carassius auratus)

The efficacy of three feeds incorporated with different probiotics -Lactobacil, Vizylac and Cyfolac as nutrient supplement was evaluated in an ornamental fish, Carassius auratus (Linn.). The basal diet (40% protein) was prepared and the probiotics were incorporated at different levels viz. Lactobacil at 8x10 super(7)/100g and 12x10 super(7)/100g, Vizylac at 8x10 super(7)/100g and 12x10 super(7)/100g and Cyfolac at 12x10 super(7)/100g. Feeding trial was conducted for a period of 4 weeks. At the end of the experiment, bio-growth parameters and proximate composition of the fishes were studied. The growth, survival and protein content were improved in all the probiotic fed fishes compared to control. The maximum growth (0.74 g) and survival (85%) were observed in fishes fed with Lactobacil at 12x10 super(7)/100g. It emphasizes that supplementation of feed with probiotics has a positive impact on the growth, survival and the body composition of goldfish.

Feeding stimulatory effects of Cyperus rotundus tuber on Cirrhinus mrigala

Traditionally tubers of cyperus (Cyperus rotundus) and its extracts have been used for alluring fish during harvesting in India. An experiment was conducted to evaluate its feeding stimulatory activity and effect on the growth of a commercially important freshwater fish, Cirrhinus mrigala. Three isonitrogenous and isocaloric formulated diets viz. plant ingredient based control and control supplemented with cyperus tuber (CS) at 1% and 5% levels were fed to the fingerlings of mrigal, C. mrigala (2.68+0.20 g) for a period of 45 days. The growth performance and the activity of metabolic enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), in liver, gill and muscle tissues of mrigal were studied during every 15 days interval. Highest relative growth (72.28%) was obtained in the mrigal fed with the diet containing 5% cyperus (5% CS), while the relative growths were 66.18% and 43.40% for the fish fed with the 1% CS diet and control respectively. The activities of AST and ALT were significantly higher (p<0.01) in both 1% and 5% CS diets as compared to the control in all the tissues studied. Higher aminotransferase activities were observed in the tissues of 5% CS group than in those of 1% CS group throughout the experimental period. The observed higher enzymatic activity was concomitant with the higher growth rate in fish. The results suggested that cyperus tuber supplementation increased feed palatability and growth.

Effects of dietary phosphorus and zinc levels on growth artd bone mineralization in fingerlings of rainbow trout, Oncorhynchus mykiss

A laboratory based 2 x 2 factorial experiment was conducted to investigate the influences of dietary phosphorus and zinc levels on growth and bone mineralization in fingerlings of rainbow trout for 21 weeks. Two levels of phosphorus (19 and 30 mg/g) and two levels of zinc (55 and 103 Ag/g) in the dry diets were tested. Duplicate tanks of 30 rainbow trout (average weight 1.56 ± 0.24 g) per 60L glass tank were fed experimental diets three times a day to apparent satiation level at 15 to 24°C water temperature. The results of the present study demonstrated that dietary phosphorus supplementation influenced the growth and bone mineralization whereas zinc levels significantly (p<0.05) influenced bone mineralization in rainbow trout. Further investigations in this area with different size and age groups of this fish are broadly needed.

Alternative phosphorus sources for formulated fish feed

An experiment was conducted to evaluate the possibility of using inorganic fertilizer triple super phosphate (TSP), inorganic fertilizer 16:20 (a 16:20 grade fertilizer contains 16 percent N and 20 percent P20 5), rice-bran and duck-manure as phosphorus sources in formulated fish feed for Nile tilapia ( Oreochromis niloticus). Experiment was conducted for a period of 2 months in net-cages suspended in fertilized earthen ponds and all male sex-reversed Nile tilapia (9.39- 10.37 g) were used in the experiment. Seven treatments including one non-feed treatment were used in this experiment. Treatment 1 (non-feed), treatment 2 (-P) where fish fed with phosphorus non-supplemented diet acted as control 1 and treatment 3, 4, 5, 6 and 7 where fish fed with 3% di-calcium phosphate (DCP), 3% triple supper phosphate (TSP), 7% 16:20 inorganic fertilizer, 30% rice-bran and 30% duck-manure supplemented diet, respectively. Results showed that the TSP and 16:20 grade inorganic fertilizer supplementation in diets as phosphorus sources were equivalent to DCP (Di-calcium phosphate) supplementation in terms of growth performance, feed utilization efficiency and final body composition of Nile tilapia. Ricebran and duck-manure were not found as good phosphorus sources.

Utilization of frog waste

Commercial frog waste samples have been converted into meals by cooking at 0.7 kg/sq. cm for 30 min, draining off the stick water and drying the press cake either in the sun, tunnel dryer under controlled conditions or hot air oven. Yield of the meal varied between 18.6 to 21.5% of the fresh frog waste. Chemical analyses of the meals have shown that the meals prepared from frog waste conform to standards prescribed for fish meal and livestock feed and can therefore be used for supplementation of poultry/animal feed.

Nutritional evaluation of some freshwater fishes

The proximate composition, amino acid composition and the PER values of Rohu (Labeo rohita), Mrigal (Cirrhina mrigala) and Calbasu (Labeo calbasu) are reported. The proximate composition of all the three fishes was similar. However the amino acid composition varied considerably. Protein quality index of the three fish proteins calculated from the amino acid composition are also reported. The nutritional quality of the 3 types of proteins to meet the growth requirements of infants, children and adult human beings is discussed. The possibility of substantial improvement in nutritional quality of the three fish proteins to suit the requirements of infants and children by marginal supplementation with valine/valine-rich food for rohu and valine and isoleucine/food rich in valine and isoleucine for mrigal and calbasu is also discussed. The results indicate that of the three fishes rohu is the best in protein quality followed by mrigal and calbasu. All of them have a better amino acid make up than casein to meet the amino acid requirement of adults.

Influences of dietary lipid and phosphorus levels on retention and excretion of phosphorus and nitrogen in fingerlings red sea bream, Pagrus major

A laboratory based 2x3 factorial experiment was conducted for 12 weeks to investigate the influences of dietary lipid and phosphorus (P) levels on retention and excretion of phosphorus and nitrogen (N) in fingerling red sea bream. Two levels of lipid (210 and 260 g/kg) and three levels of phosphorus (17, 14 and 12 g/kgˉ¹) in the dry diets were tested. Duplicate groups of 25 red sea bream (average weight 3.74±0.07 g) per 60L glass tank were fed experimental diets three times a day near to satiation level at 22 to 28°C water temperature. A reduction in dietary fish meal from 500 to 300 g/kg dry diet, corresponding to a supplementation in both dietary lipid and P resulted in significant increase in both P and N retention which resulted in the reduction of their excretion by red sea bream. The overall results of the present study demonstrated that both lipid and phosphorus supplementation are necessary for developing less-polluting feed which in turn, reduce fish meal level in the diet of fingerling red sea bream. Further studies in this regard with different size and age groups of red sea bream are warranted.

Necessity of dietary calcium supplement in file fish (Monacanthus cirrhifer)

File fish, Monacanthus cirrhifer, juveniles with initial mean body weight of 0.27g were fed purified diets with or without calcium (Ca) supplement for 10 weeks at a water temperature of 27.0±1.4°C. Growth was significantly low in fish fed diet without Ca supplement than fish fed diet with Ca supplement. Feed efficiency and condition of fish were also significantly decreased in absence of a dietary Ca supplementation, Minerals contents of bone were similar in both the treatment groups and did not appear as a suitable indicator of Ca requirement. It appeared that Ca supplement to the purified diet is necessary for file fish for their proper growth and feed utilization.