Magdy A. Soltan

Evaluation of Essential Oil of Fennel and Garlic Separately or Combined withBacillus licheniformis on the Growth, Feeding Behaviour, Hemato-biochemicalIndices of Oreochromis niloticus (L.) Fry

A total of six treatments, i.e., negative control group (D1), B. licheniformis 7×107 CFU g−1 diet (D2); 1ml essential fennel oil (EFO) kg-1 diet (D3); 1 ml essential garlic oil (EGO) kg-1 diet (D4); B. licheniformis 7×107 CFU g−1 +1 ml EFO kg-1 diet (D5) and B. licheniformis 7×107 CFU g−1 +1 ml EGO kg-1 diet (D6) were added to the diets of Nile tilapia, Oreochromis niloticus to investigate the effects of the respective treatments on the growth, feeding behaviour, hematological and biochemical indices. Fish (1.88 ± 0.12 g) were distributed at a rate of 20 fish per 100-L aquarium and three aquaria have been assigned for each treatment. At the end of the experiment (84-day), results indicated that the highest survival, weight gain and specific growth rate were recorded by fish fed D5 and D6 being statistically different (P<0.05) from other treatment groups. Whereas, the best feed conversion ratio and protein efficiency ratio were observed in D3, D4, D5 and D6 compared with other treatment groups. Fish feed D6 were higher in mouth wrestling and chasing behavior. Fish fed D5 and D6 significantly higher (P<0.05) hematocrit and hemoglobin values also, was effectively enhanced aspartate aminotransferase, alanine aminotransferase, total protein and globulin in comparison to the other treatments. No significant differences were found in the chemical composition of whole body of fish fed different tested diets.

Response of Nile tilapia (Oreochromis niloticus) to diet acidification: Effect on growth performance and feed utilization

ABSTRACT A 12-week feeding trial was undertaken to assess growth, nutrient utilization, some hematological parameters, and proximate composition of Nile tilapia (Oreochromis niloticus) fed diets supplemented with graded levels (0.5%, 1.0%, and 1.5%) of two blends of organic acids or organic salts. Seven isonitrogenous (300 g CP kg−1) and isocaloric (19.0 MJ gross energy kg−1) diets were formulated. The control diet (D1) contained neither added blend of organic acids nor organic salts. Three diets (D2, D3, and D4) were supplemented with 0.5%, 1.0%, and 1.5% of malic acid + oxalic acid blend (OAB), respectively. The other three diets (D5, D6, and D7) were supplemented with 0.5%, 1.5%, and 1.5% of calcium lactate + sodium acetate blend (OSB), respectively. Fingerlings (7.05 ± 0.02 g) were randomly distributed into 21 glass aquaria (160 liter), with each aquarium holding 15 fish. At the end of the feeding trial, O. niloticus offered the control diet showed lower growth and feed utilization than all those fed the organic acids or organic salts blends supplemented diets. Fish fed the diet D3 showed the highest body weight (BW), body length (BL), weight gain (WG), specific growth rate (SGR), feed intake (FI), and the best feed conversion ratio (FCR) and protein efficiency ratio (PER). Fish fed diet supplemented by 1.5% OAB (D4) showed the highest serum protein content, while control group (D1) showed the lower level of total lipids compared with the other treatments. Fish group fed the diet supplemented with 0.5% of OSB (D5) showed the highest protein and ash contents and the lowest lipid content of the whole fish body, while the control group showed the lowest protein and the highest fat content. The present observations suggest that the growth, feed utilization, and health status of juvenile O. niloticus can be enhanced with a supplementation of 1% of OAB or OSB in the diet.

A Comparative Study of Growth, Feed Utilization and Gonad Development of Diploid and Triploid Nile Tilapia, Oreochromis niloticus

A 16 week experiment was conducted to evaluate growth performances, gonads development, carcass and proximate analysis of diploid and triploid Nile tilapia, Oreochromis niloticus. Triploid were induced by inhibiting the second polar body formation in fertilized eggs using heat chock. Newly hatched fry were transferred into reared in 5 liter aquaria for three weeks and then transferred to 80 L indoor aquaria, provided with a recirculated for 8 weeks. After the rearing period diploid and diploid fingerlings transferred into 300 liter tanks and fed 30% protein diet to apparent satiation. At the end of feeding trial (16 weeks), triploid O. niloticus had significant heaviest, longest and deepest bodies compared with diploids and the same trend was also observed for weight gain and specific growth rate. Triploid O. niloticus showed the best feed conversion ratio and protein efficiency ratio compared to diploids. Gonado-somatic indices (GSI) of triploid males and females were significantly smaller than diploids. On the other hand, Hepato-somatic indices, (HSI) of triploid O. niloticus males were larger than that of diploid with significant differences between the two groups. However, HSI of triploid females were smaller than that of diploid females but the differences were insignificant. Carcasses of triploids O. niloticus had the highest percentages of dressing and flesh and the lowest by-products compared to diploid. Also, triploid flesh contained the highest (P 0.05) affected by ploidy induction in O. niloticus.

Inclusion of fermented fish by-product silage in the diets of the Nile tilapia, Oreochromis niloticus

A feeding trial was conducted to study the possibility of replacing the fish meal (FM) with fermented fish by-product silage (FBS) as non-conventional ingredients in the diets of the Nile tilapia, Oreochromis niloticus fingerlings. Five isonitrogenous (300 g CP kg -1 dry matter, DM) and isocaloric (19 MJ gross energy kg -1 DM) diets were formulated and FM was replaced by FBS in five increased levels, 0, 25, 50, 75 and 100% g to formulate the five experimental diets, FBS0, FBS25, FBS50, FBS75 and FBS100, respectively. Three hundred O. niloticus fingerlings (18.53±0.70g) were randomly distributed into 15 glass aquaria (160 liter), and were divided into five groups (three aquaria for each group) and each aquarium holding 20 fish. Experimental fish were fed onon the formulated diets for 84 days. Replacing of FM with FBS up to 25% did not significantly (P<0.05) affected growth and feed utilization parameters, while the other substitution levels (50,75 or 100%) significantly (P<0.05) reduced growth and feed utilization parameters. Fish offered the control diet exhibited the highest significance (P<0.05) average body weight (BW), body length (BL), weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER). Fish group fed onon FBS25 gained the highest significant protein content and the lowest fat and ash content of carcasses compared to the control and the other fish groups Generally, replacing 25% of FM by FBS did not significantly affected growth and feed utilization parameters and reduced feed costs by 7.93% for tilapia fingerlings.

Agricultural Drainage Water as a Source of Water for Fish Farming in Egypt

In Egypt, the reuse of agricultural drainage increases the country’s available water resources by 20%. The aim of this study was to assess the impact of agricultural drainage water on accumulation of heavy metals and pesticide residues of Nile tilapia (Oreochromis niloticus) reared in earthen ponds. Six earthen ponds (2 hectare for each) in two fish farms located at the same area (3 ponds for each farm). The first pond group irrigated by fresh irrigation water (IW) and the 2nd group (in another fish farm) supplied by agricultural drainage water (ADW). Each pond was stocked with 40000 fish (2.22±0.1 g) and fed on 25% CP diet at a daily rate of 3% of the total fish biomass. At the experiment end (7 months) results showed that, physico-chemical parameters for IW and ADW remained in the favorable range for Nile tilapia growth. ADW had higher density of phytoplankton and zooplankton in comparison to IW. Accumulation of heavy metals in liver and gills were higher than in muscles and ranked as liver>gills>muscles. Iron had the highest concentration values of metals content in liver, gills and muscles of fish reared in two water types and the sequence of metals was as follows: Fe&gtZn&gtCu&gtMn&gtPb. All pesticides residues under permeable limits in fish reared in the two types of water. Fish reared in agricultural drainage water showed the lowest significant (P<0.05) red blood cells (RBCs), haemoglobin (Hb), hematocrit and (Ht) total protein and the opposite trend was recorded for glucose and amino transferases, AST and ALT. ADW ponds produced the highest significant body weight, weight gain specific growth rate and fish yield compared to IW.

Effect of oxytetracycline and florfenicol drugs on the physiological activities and its residues of Oreochromis niloticus

The present study was carried out to study the effect of different doses (40, 80, 120mg/kg basal) diet of oxytetracycline, (OTC) and florfenicol, FF (7.5, 15, 22.5mg/kg basal diet) on growth performance, feed utilization, physiological activities and residues of Oreochromis niloticus (7±0.66g). Fish fed the diet supplemented by 40mg OTC/kg basal diet showed the highest final body weight (BW), weight gain (WG), condition factor (K), specific growth rate (SGR), protein efficiency ratio (PER) and the best FCR, while the lowest final BW, WG, K values were achieved by fish fed the diet 120mg oxytetracycline/kg diet. Fish fed the diet supplemented by 22.5mg FF/kg diet showed the highest final BW, BL, K, feed intake (FI) and the lowest final BW, BL, WG and K values were fed the diet 7.5mg FF/kg diet compared with control group and other doses of FF, for fishes. Liver transaminase enzymes, Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased with increasing the doses OTC and FF. the fish fed the diet supplemented by 40mg OTC/kg recorded the highest value of ALT, AST and insignificant decrease in total protein (TP) and the fish fed the diet supplemented by 15mg FF/kg basal diet recorded the highest value in the ALT, AST and TP compared with control group and the other doses of FF. The fish fed the diet 120mg OTC/kg diet recorded the highest value in the haemoglobin (Hb), white blood cells (WBCs) and significant increase in red blood cells (RBCs) while the fish fed the diet supplemented by 40mg OTC/kg basal diet recorded the lowest value of Hb, WBCs and RBCs compared with other OTC doses with insignificant increase in Hb, RBCs compared with control group. Fish fed the diet supplemented by 7.5mg FF/kg diet recorded the highest value of Hb, RBCs and insignificant decrease in WBCs but the fish fed the diet 22.5mg FF/kg diet recorded the lowest value in Hb, WBCs and RBCs compared with control group and the other FF doses. Residues of OTC and FF in fish tissues showed that all the doses of oxytetracycline and florfenicol after 21 days have no risidue in tissues while at the experimental end all samples were positive and the dose 40mg OTC/kg diet and the dose 7.5mg FF/kg diet caused the lowest values in fish tissues compared with other doses.