Fish bioenergetics: (Fish and Fisheries 13. Series ed. T.J. Pitcher) Malcolm Jobling Chapman and Hall, London, 1994 ISBN 0-412-58090-X, 24.99 Hard cover, acid-free paper, pp. xiv + 309, 31 tables, 61 figures Author, species and subject indexes

According to the UN Food and Agriculture Organization, aquaculture is growing more rapidly than all other animal food-production sectors (www.fao.org). Its contribution to global supplies of several species of fish, crustaceans and mollusks increased from 3.9% of total production by weight in 1970 to 33% in 2005. It has been estimated that fisheries and aquaculture supplied the world with about 110 million metric tons of food fish per year (FAO, State of World Fisheries and Aquaculture 2010.), providing a per capita supply of 16.7 kg (live weight equivalent). Of this supply, 47% is derived from aquaculture production. However, this production is hampered by unpredictable mortalities that may be due to negative interactions between fish and pathogenic bacteria. To solve this problem, farmers frequently use antibiotic compounds to treat bacterial diseases (Cabello 2006).

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Antibiotics in Aquaculture – Use, Abuse and Alternatives

Evaluation of commercial live bakers' yeast, Saccharomyces cerevisiae as a growth and immunity promoter for Fry Nile tilapia, Oreochromis niloticus (L.) challenged in situ with Aeromonas hydrophila

This study aims to present comprehensive notes for the use of probiotics in aquaculture. Probiotics have been proven to be positive promoters of aquatic animal growth, survival and health. In aquaculture, intestines, gills, the skin mucus of aquatic animals, and habitats or even culture collections and commercial products, can be sources for acquiring appropriate probiotics, which have been identified as bacteria (Gram-positive and Gram-negative) and nonbacteria (bacteriophages, microalgae and yeasts). While a bacterium is a pathogen to one aquatic animal, it can bring benefits to another fish species; a screening process plays a significant role in making a probiotic species specific. The administration of probiotics varies from oral/water routine to feed additives, of which the latter is commonly used in aquaculture. Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms. Encapsulating probiotics with live feed is a suitable approach to convey probiotics to aquatic animals. Dosage and duration of time are significant factors in providing desired results. Several modes of actions of probiotics are presented, while some others are not fully understood. Suggestions for further studies on the effects of probiotics in aquaculture are proposed.

The use of probiotics in aquaculture

Along with the intensification of culture systems to meet the increasing global demands, there was an elevated risk for diseases outbreak and substantial loss for farmers. In view of several drawbacks caused by prophylactic administration of antibiotics, strict regulations have been established to ban or minimize their application in aquaculture. As an alternative to antibiotics, dietary administration of feed additives has received increasing attention during the past three decades. Probiotics, prebiotics, synbiotics and medicinal plants were among the most promising feed supplements for control or treatments of bacterial, viral and parasitic diseases of fish and shellfish. The present review summarizes and discusses the topic of potential application of probiotics as a means of disease control with comprehensive look at the available literature. The possible mode of action of probiotics (Strengthening immune response, competition for binding sites, production of antibacterial substances, and competition for nutrients) in providing protection against diseases is described. Besides, we have classified different pathogens and separately described the effects of probiotics as protective strategy. Furthermore, we have addressed the gaps of existing knowledge as well as the topics that merit further investigations. Overall, the present review paper revealed potential of different probiont to be used as protective agent against various pathogens.

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Probiotics as Means of Diseases Control in Aquaculture, a Review of Current Knowledge and Future Perspectives.

Effect of dietary protein level, initial body weight, and their interaction on the growth, feed utilization, and physiological alterations of Nile tilapia, Oreochromis niloticus (L.)

Micrococcus luteus and Pseudomonas species as probiotics for promoting the growth performance and health of Nile tilapia, Oreochromis niloticus.

Compensatory weight gain and some hematological changes in starved Nile tilapia, Oreochromis niloticus (L.), were studied. Nile tilapia (8.9±0.2 g) were distributed randomly at a rate of 20 fish per 100-L aquarium. Water temperature was about 25±18C. Fish were classified into five groups and each group included three replicates. The control fish were fed throughout the experiment (13 weeks), and fish in the other four groups were subjected to food fasting for 1, 2, 3, or 4 weeks, and refed again up to the end of the experiment. Fish of fed groups were fed to satiation twice daily with dry pellets (30% crude protein). The fish growth decreased with increase of the fasting period except the fish group fasted for 1 week; however, its growth is enhanced after refeeding. Fish fasted for 2–4 weeks could not recover the lost weight after refeeding. The fish became hyperphagic after each fasting period. The duration of hyperphagia, which varied from few days (in W1) to several weeks (in W4), was dictated...

Compensatory Growth, Feed Utilization, Whole-Body Composition, and Hematological Changes in Starved Juvenile Nile Tilapia, Oreochromis niloticus (L.)

This study was carried out to evaluate the growth response of Nile tilapia; O.niloticus L. to dietary protein levels at two stocking densities. This study was bifactorial designed (3 protein levels x 2 stocking densities). Fish (1.8-2.5 g/fish) was randomly distributed into the aquaria at a rate of 15 or 30 fish/100 L. The temperature was adjusted at 27±1 °C. Fish of each density were fed either a diet containing 25%, 35% or 45% CP with a feeding rate of 4% of body weight twice daily for 5 days a week for 70 days,The obtained results showed that the final body weight, weight gain, weight gain %, specific growth rate (SGR)were positively affected by protein level and inversely affected by stocking density, but not affected by their interaction. Condition factor was significantly affected only with dietary protein levels (PO.05), while survival rate did not differ significantly by protein levels or stocking densities. The maximum growth was obtained with 45% CP at low density (10 J g/fish), whereas the lowest growth was obtained with 25% CP at high density (6.4 g/fish). On the other hand, the reduced growth at high density could be recovered by increasing the protein levelFeed intake increased significantly with increasing dietary protein level only (PO.01). Feed conversion ratio (FCR), protein efficiency ratio (PER) and protein productive value (PPV) were significantly affected by protein level and stocking density (PO.01), The best FCR was obtained with 45% protein diet at low density (1.72) and with 35% under low density (1.8.1) with insignificant: (1.72) and with 35% under low density (1.81) with insignificant difference (P>0.05). The highest values of PER and PPV were obtained with 25% CP at low (1.913 and 30.54%, respectively) and high density (1.720 and 26.64%, respectively) with significant difference (PO.01).Moisture was significantly affected by protein level only (PO.05), while crude protein, total lipids and ash were significantly affected by protein level and stocking density. The highest protein content in fish body was obtained with 45% CP at low and high densities (58.0% and 57.9%, respectively; P>0.05). The highest content of body lipids was observed in fish fed 25% protein diet at low and high densities (32,8 and 31.0%, respectively; P>0.05). The highest content of carcass ash was noticed in fish fed 45% protein diet at low and high densities with significant difference (15.6% and 16.8%, respectively; P<0,05).

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Effect of protein level and stocking density on growth performance, survival rate, feed utilization and body composition of nile tilapia fry (oreochromis niloticus l.)

ifferent doses of 17 a-methyltestosterone hormone (MT) used as I) growth promoter was administrated to Nile tilapia; Oreochromis niloticus in fishmeal based pelleted diet for 90 days. The obtained results showed that low doses of 0.5, L0 and 2.5 mg MT/kg feed were not effective meanwhile the dose of 5.0 mg/kg was the optimum effective one in promoting significant final weight, weight gain and SGR of Nile tilapia. HSI was insignificantly changed at low MT doses, and slightly increased at high MT doses. Male and female GSI was significantly decreased at high MT doses (10, 20 and 40 mg/kg), while insignificant changes were observed at low doses. Feed intake and FCR were slightly changed at different doses of MT. The higher PER was obtained with moderate MT doses and the least ones were obtained with 20, 40 mg/kg or control. The changes in erythrocyte counts, haemoglobin content, haematecrit value and plasma glucose showed insignificant differences at all treatments. A significant reduction of plasma total protein was observed in fish fed 40 mg MT/kg, whereas it was insignificantly changed with other treatments. in contrast, the highest level in plasma total lipids was obtained at 40 mg MT/kg. In fish plasma, the activity of ALT was the highest with control fish and that fed low doses of 0.5-2.5 mg MT/kg, while the least one was obtained with 40 mg/kg. In contrast, AST activity was significantly increased with high MT doses of 20 and 40 mg/kg, while there were no significant changes among other treatments. The higher

https://journals.ekb.eg/article_1736_26204bb4b0cf682d0f9b1bf4ebd16ca3.pdf

Yassir A.E. Khattab

Papers

Effect of dietary protein level, initial body weight, and their interaction on the growth, feed utilization, and physiological alterations of Nile tilapia, Oreochromis niloticus (L.)

Micrococcus luteus and Pseudomonas species as probiotics for promoting the growth performance and health of Nile tilapia, Oreochromis niloticus.

Compensatory Growth, Feed Utilization, Whole-Body Composition, and Hematological Changes in Starved Juvenile Nile Tilapia, Oreochromis niloticus (L.)

Effect of protein level and stocking density on growth performance, survival rate, feed utilization and body composition of nile tilapia fry (oreochromis niloticus l.)

EFFECTS OF 17 a-METHYLTESTOSTERONE ON GROWTH PERFORMANCE AND SOME PHYSIOLOGICAL CHANGES OF NILE TILAPIA, OREOCHROMIS NILOTICUS L.) FINGERLLNGS