An attempt to improve the reproductive efficiency of Nile tilapia brood stock fish

A field study was conducted on brood stock Nile tilapia to increase the propagation. Both sexes were individually stocked into Habas (enclosures) in an earthen pond and fed for 19 days on a basal diet supplemented with different additives at graded levels of each (0.5, 1.0 and 2.0 g Therigon^®; 1.0, 2.0, and 3.0 g Nuvisol Hatch P^®; 20, 40 and 60 mg Gibberellic acid and 700, 900 and 1,100 mg L-carnitine/Kg diet). The obtained results were evaluated, and the best treatment for each sex was chosen for mating. Results indicated that all pretreatments for male and female brood stocks of Nile tilapia positively affected the total count of the offspring produced. Yet, the Haba, in which the females were pretreated with 0.5 g Therigon^®/Kg diet and the males pretreated with 700 mg L-carnitine/Kg diet, gave the highest total count of the offspring comparing with the other Habas. But, because of the high feed cost due to the additives cost, 0.5 g Therigon^®/kg diet as pretreatment for ♀ only (3rd Haba), 2 g Nuvisol Hatch P^®/Kg diet as pretreatment for ♀ only (5th Haba), followed by 0.5 g Therigon^® and 700 mg L-carnitine/Kg diet for ♀ and ♂, respectively (4th Haba), respectively were the best economically.     

Utilization of live body weight,measurements, and eye muscle components to predict carcass performance of fattened Egyptian male buffalo calves

Tropical Animal Health and Production - Carcass performance of 12 fattened male buffalo calves equally grouped by slaughter weights of 300, 350, 400, and 450 kg was evaluated. Six...     

Some clinical, microbiological and molecular characteristics of Aeromonas hydrophila isolated from various naturally infected fishes

Heat-stable cytotonic enterotoxin gene (Ast) was detected by polymerase chain reaction (PCR) of twenty isolates of Aeromonas hydrophila isolated from various naturally infected fishes collected from both fresh and brackish water. These fishes were Nile tilapia and meagre, mullet and sea bream, respectively. Antibiotic susceptibility, pathogenic characteristics of these isolates and histopathological alterations of liver from experimentally infected tilapia fish with A. hydrophila which contained Ast gene were investigated. PCR technique for the detection of Ast as specific gene for A. hydrophila genomes showed that 90% of tested A. hydrophila (18/20) contained Ast gene, which is specific for A. hydrophila (SSU).The in vitro susceptibility of 18 strains of A. hydrophila (SSU) to 9 antibiotics was evaluated. Oxytetracycline only was an effective antibiotic for all tested isolates. On contrast, all these isolates were resistant to amoxicillin, ampicillin and penicillin. Pathogenicity assay in this study proved that 33.3% of the tested A. hydrophila (6/18) were pathogenic for tilapia in vitro with various levels of virulence where 2/6 were classified as strongly virulent according to the severity of mortality rate. Microscopically, A. hydrophila toxins apparently cause irreparable systemic damage to liver which leads to death.     

Detoxification and antioxidant effects of garlic and curcumin in <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> injected with aflatoxin B<Subscript>1</Subscript> with reference to gene expression of glutathione peroxidase (GPx) by RT-PCR

The present study aims to investigate the effects of both garlic and curcumin through evaluating their therapeutic properties as antioxidants on liver and kidney functions, hepatic antioxidants and GPx gene expression against aflatoxicosis of O. niloticus. In total, 180 of tilapia were divided into ten groups; T₁ represented the negative control fed on a basal diet, and T₂ was injected with a single intraperitoneal (i.p.) dose of AFB₁ (6 mg/kg b.w.). Fish in T₃–T₆ were fed on a basal diet supplemented with both garlic (T₃ and T₄) and curcumin (T₅ and T₆) at the two concentrations of 10 and 20 g/kg diet, respectively. Fish in T₇–T₁₀ groups were injected with AFB₁ and fed on the garlic (T₇ and T₈) and curcumin (T₉ and T₁₀) dietaries. The results showed that AFB₁ has significant potency for increasing the activity of plasma AST, ALT, creatinine and uric acid values, and hepatic MDA as well as for reducing the concentrations of plasma TP, AL, GL and hepatic activity of TAC, while AFB₁ led to up-regulated GPx gene expression when compared to the control (T₁). These harmful effects of AFB₁ were alleviated due to the garlic and curcumin dietaries in some studied parameters. Garlic reflected the highest induction of gene expression (T₇); however, curcumin showed significant down-regulated (T₉). These results concluded that the effects of garlic were better than curcumin at the two concentrations and the low concentration of them is more beneficial than the high concentration when it used against AFB₁ in O. niloticus.