Natural occurrence of citrinin in rice grains and its biocontrol byTrichoderma hamatum     

E. F. Abd-Allah  S. M. Ezzat 《Phytoparasitica》2005,33(1):73-84

Paddy rice was sampled from El-Sharkia, El-Gharbia, El-Dakahlia and Kafr El-Shekh governorates, Egypt. Of the 30 samples taken, ten were contaminated with the mycotoxin citrinin. An average of 6.79 × 10⁴ fungal spores per gram rice was found. The isolated fungi represented 47 species and 28 genera. The predominant genera wereAspergillus, Cladosporium andPenicillium. Aspergilli were represented by 22 species;Aspergillus niger andA. flavus had the highest occurrence.Penicillium viridicatum produced the highest amount of citrinin on glucose ammonium nitrate salts broth and rice grains, and hence this isolate was selected as a good producer of citrinin in this study. The presence ofTrichoderma hamatum reduced the amount of citrinin produced byP. viridicatum compared with its respective control. The excessive growth ofT. hamatum onP. viridicatum was increased with time. Viability ofP. viridicatum conidia decreased byT. hamatum with an increase in the incubation period. Chitinases and 1,3-β-glucanase enzyme activity ofT. hamatum increased with extending the incubation period onP. viridicatum mycelia up to maximum values at 72 and 84 h, respectively.T. hamatum led to a decrease in the production of citrinin byP. viridicatum on rice grains compared with the respective control values. http://www.phytoparasitica.org posting Dec. 19, 2004.  相似文献   

Combined effects of dietary mannan‐ and fructo‐oligosaccharide on growth indices,body composition,intestinal bacterial flora and digestive enzymes activity of regal peacock (Aulonocara stuartgranti)          下载免费PDF全文

S. S. Mirzapour‐Rezaee  M. Farhangi  G. Rafiee 《Aquaculture Nutrition》2017,23(3):629-636

A 56‐d feeding trial was conducted to investigate the effect of dietary mannan‐oligosaccharides (MOS) and fructo‐oligosaccharide (FOS) on growth indices, body composition, intestinal bacterial community and digestive enzymes activity of regal peacock. A total of 240 fish were randomly distributed to 15 experimental units (40‐L aquariums) of 16 fish each. These replicates were randomly assigned to one of five treatments in a 2 × 2 + 1 factorial arrangement. The treatments were control diet (no MOS and FOS), diet A (2 gkg^?1 MOS + 1.5 g kg^?1 FOS), diet B (2 g kg^?1 MOS + 3 g kg^?1 FOS), diet C (4 g kg^?1 MOS + 1.5 g kg^?1 FOS) or diet D (4 g kg^?1 MOS + 3 g kg^?1 FOS). The results showed that feeding diet C increased specific growth rate and protein efficiency ratio and decreased feed conversion ratio compared with control diet. Higher intestinal trypsin activity and increased Lactobacillus counts were observed in fish fed diets B and C. All diets significantly elevated body protein deposition and intestinal amylase activity compared to the control diet. In conclusion, the diet supplemented with 4 g kg^?1 MOS + 1.5 g kg^?1 FOS was advantageous over other MOS + FOS‐supplemented diets, with respect to growth performance and health benefits of regal peacock.  相似文献   

The influence of the herbicide paraquat ‘Gramaxon’ on growth and metabolic activity of three chlorophytes     

Ezzat A. Ibrahim 《Water, air, and soil pollution》1990,51(1-2):89-93

The acute toxicity of commercial herbicide, Paraquat was determined by 96-hr static bioassay on the freshwater chlorophytes Scenedesmus dimorphus (Trup.) Kuetz., Scenedesmus quadricauda (Trup.) de Brebisson and Ankistrodesmus falcatus (Cord) Ralfs. The 96-hr EC50 values of Paraquat for reducing growth and metabolic products of the three algae were determined. The number of days required for cell division increased with increasing Paraquat concentration. The three algae and their test parameters respond differently to Paraquat. Scenedesmus dimorphus was the most susceptible alga and the chlorophyll a was the most sensitive response parameter. On the other hand, the dry weight of the test algae was the most resistant parameter. It was observed that Paraquat has inhibitory effect on the primary producers.  相似文献   

The first linkage map for a recombinant inbred line population in cotton (Gossypium barbadense) and its use in studies of PEG-induced dehydration tolerance     

Abdelraheem Abdelraheem  Ezzat Mahdy  Jinfa Zhang 《Euphytica》2015,205(3):941-958

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Enhancement of the adrenocortical response to metyrapone by L-dopa in the chicken (Gallus domesticus)     

A R Ezzat 《British poultry science》1988,29(1):167-170

1. Eight-week-old chickens were treated with a single intravenous injection of saline, L-dopa (20 mg/kg body weight), metyrapone (60 mg/kg) or a combined dose of L-dopa and metyrapone. Serum corticosterone was measured by radioimmunoassay at 30, 60 and 90 min after the treatment. 2. L-dopa did not alter the corticosterone concentration during the experiment, whereas metyrapone increased it at 60 and 90 min. 3. When L-dopa and metyrapone were given together there was a gradual increase in corticosterone and the hormone concentrations were significantly greater than control values at all times. 4. It was concluded that L-dopa is not a potent stimulator of adrenocortical cells in chickens, but it enhances the response to metyrapone. This may be achieved through the release of endogenous ACTH by stimulating central dopamine receptors.  相似文献   

Effects of dietary protein level on spawning performance of Nile tilapia (Oreochromis niloticus) broodstock reared at different water salinities     

Abdel-Fattah M. El-Sayed  Cathrine R. Mansour  Altaf A. Ezzat 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):619-632

Effects of dietary protein level and water salinity on spawning performance of Nile tilapia broodstock and growth of their larvae were studied. Four isocaloric (400 kcal/100 g) diets containing 25%, 30%, 35% and 40% crude protein were prepared. The diets were fed to broodfish (25.7 g) reared at three water salinities (0‰, 7‰ and 14‰) at a female/male ratio of 3:1, to satiation twice a day for 195 days. The size at first maturation increased with increasing dietary protein at all salinities. At 25% and 30% protein levels, broodstock reared at 0‰ reached their sexual maturity at bigger sizes than those reared at 7‰ and 14‰. At 0‰, spawning intervals were not significantly affected by dietary protein levels. At 7‰ and 14‰, spawning intervals significantly decreased with increasing dietary protein level. Spawning frequency and number of eggs per spawn were increased with increasing dietary protein level. The total number of spawnings per female and absolute fecundity were better in fish fed 40% protein in freshwater than at 7‰ and 14‰ salinity. The relationship of dietary protein and water salinity on egg size was significant, but showed irregular patterns. The chemical composition of broodstock muscles, eggs and fry were not significantly affected by dietary protein and water salinity, except for body water and crude protein of broodstock which were significantly affected; but showed irregular trends. At each water salinity, egg hatchability was linearly increased with increasing dietary protein level. Eggs produced from broodstock fed 25% protein at 7‰ and 14‰ needed more time for hatching and yolk-sac absorption and resulted in poorer larval weight than those reared in freshwater. Fry growth was improved with increasing protein level at all salinities. This result revealed that 40% dietary protein is required for optimum spawning performance of Nile tilapia reared at 0‰, 7‰ and 14‰ salinity. It also indicated that spawning performance and larval growth were better in freshwater than at 7‰ and 14‰.  相似文献   

Application of ERIC-PCR for the comparison of isolates of Haemophilus parasuis   总被引：9，自引：0，他引：9  

Rafiee M  Bara M  Stephens CP  Blackall PJ 《Australian veterinary journal》2000,78(12):846-849

Objective To validate a polymerase chain reaction (PCR) based method, Enterobacterial Repetitive Intergenic Consensus‐PCR (ERIC‐PCR), for the fingerprinting of Haemophilus parasuis strains and to use that method to differentiate isolates from apparently related outbreaks of Glässers disease on three pig farms. Design ERIC‐PCR was evaluated by comparing 15 different strains that represented all 15 recognised serovars in the Kielstein‐Rapp‐Gabrielson (KRG) scheme for serotyping H parasuis. Next, ERIC‐PCR was used to examine 14 Australian field isolates of H parasuis; 12 collected from three farms suffering apparently related outbreaks of Glässers disease and two from two other farms with no known connection. Results The 15 serovar reference strains all gave unique, reproducible ERIC‐PCR fingerprints. The 12 isolates from the three apparently related outbreaks all gave a single fingerprint, which was distinct from any seen in the 15 serovar reference strains and the two other Australian field isolates in the studied farms. The confirmation that all 12 isolates were the same strain allowed the development of a prevention and control program that has prevented the emergence of any further outbreaks of Glässer disease on the three farms. Conclusion ERIC‐PCR is a suitable technique for the differentiation of unrelated strains of H parasuis. The finding that the 12 field isolates of H parasuis all shared the same fingerprint is strong evidence that there was a common source of infection on all three farms. This study has shown, for the first time, that ERIC‐PCR is a suitable technique for the sub‐typing of H parasuis and useful for studying the epidemiology of outbreaks of Glässers disease.  相似文献   

Effect of lemon verbena powder and vitamin C on performance and immunity of heat‐stressed broilers          下载免费PDF全文

F. Rafiee  M. Mazhari  M. Ghoreishi  O. Esmaeilipour 《Journal of animal physiology and animal nutrition》2016,100(5):807-812

An experiment was conducted to investigate the effect of lemon verbena powder and vitamin C on performance and immunity of broilers under heat stress. The experiment was carried out with a total of 160‐day‐old male Ross 308 broiler chickens in a completely randomized design. From 25 days of age, the birds were assigned to four diets including control diet and treatment diets which were supplemented with 2 levels of lemon verbena (0.5% and 1.0%) and one level of vitamin C (250 mg/kg) in 16‐floor pens with 10 chickens each and reared to 42 days of age. To induce chronic heat stress, birds were exposed to an ambient temperature of 35 ± 2 °C for 8 h daily (from 09:00 AM until 17:00 PM) between 25 and 42 days of age. At the end of experiment, one chick/pen was randomly selected, and the performance and blood parameters were evaluated. Dietary supplementation of 1.0% lemon verbena increased (p < 0.05) average weight gain and feed intake by 5.81% and 3.29%, and reduced feed conversion ratio by 2.59% respectively compared to control group. Birds fed diets containing 1.0% lemon verbena had significantly higher relative weight of bursa of fabricius and breast (p < 0.05). LDL decreased by 15.85% and 17.57%, for birds fed 0.5% and 1.0% lemon verbena respectively. The ratio of heterophyl to lymphocyte was reduced (p < 0.05) by 20.68% via significant decrease in heterophyl by 15.55% and significant increase in lymphocyte by 4.51% in birds fed lemon verbena at the rate of 1.0% compared to those fed the control diet. 1.0% lemon verbena and vitamin C elevated (p = 0.0005) the level of glutathione peroxidase by 51.81% and 27.90%, respectively. In conclusion, lemon verbena and vitamin C improved some performance data and blood metabolites which somehow suppressed the negative effects of heat stress.  相似文献   

Validation of CFD simulation for ammonia emissions from an aqueous solution     

Li Rong  Basman Elhadidi  H. Ezzat KhalifaPeter V. Nielsen  Guoqiang Zhang 《Computers and Electronics in Agriculture》2011,75(2):261-271

In order to model and predict ammonia emissions from animal houses, it is important to determine the concentration on the emission surface correctly. In the current literature, Henry's law is usually used to model the mass transfer through the gas-liquid surface (e.g. manure or aqueous solution). The objective of this study is to investigate the accuracy of three models for Henry's law constant (HLC) as well as functions derived from experimental vapor-liquid equilibrium (VLE) properties of ammonia water to determine the concentration on the liquid ammonia solutions surface in order to be used as boundary condition for CFD prediction of ammonia emission.The accuracy of CFD simulation depends on many factors. In this study, the effects of appropriate geometry model, inlet turbulent parameters and three turbulence models (low-Reynolds number k-? model, renormalization group k-? model and Shear Stress Transport k-w model) on ammonia emissions are investigated and discussed. Then the concentration boundary condition determined by different HLC models and the VLE model is validated by ammonia emissions and concentration profiles measured in the boundary layer. The results indicate that the current HLC models generally over-predict the ammonia emissions from aqueous solution in this study whereas VLE gives better agreement between simulated and measured results. A linear relation is observed between ammonia mass transfer coefficient obtained from the VLE relation and those from HLC models.  相似文献   

Comparative analysis of reproductive performance between spring and autumn forms of Persian sturgeon,Acipenser persicus,Bordin, 1897: with an emphasis on sex steroids and milt quality     

Saeed Hajirezaee  Gholam Reza Rafiee 《Aquaculture Research》2012,43(5):641-648

To compare the reproductive performance of spring and autumn forms of Persian sturgeon males, Acipenser persicus, the relative abundance of spermiating and non‐spermiating males, milt quality, sex steroids and cortisol were investigated after pituitary preparation (PP) treatment and at the time of spermiation. Our results showed that higher numbers of spring males are spermiated after PP treatment than autumn individuals. The autumn spermiating males had higher and lower values of sperm density and duration of motility than spring males respectively. The milt volume was higher in spring males than in autumn individuals. The percentage of motility was statistically equal in both the groups examined. In both forms of brooders, the serum levels of testosterone (T), 11‐ketotestosterone (11‐KT), progesterone (P), 17α, 20β, 21‐trihydroxy‐4‐pregnen‐3‐one (20βS) and cortisol (C) increased after PP treatment, although such increases did not occur in non‐spermiating males. Our results showed the probable involvement of 20βs, P, T, 11‐KT and C in the final maturation of Persian sturgeon. In addition, it was demonstrated that the spring form of Persian sturgeon shows better reproductive performance than the autumn form in terms of a response to artificial induction and milt quality.  相似文献