Potential applications of biological filtration media in changing water properties and subsequent effects on common carp (Cyprinus carpio) in recirculating aquaculture systems     

Sadam Mohamad Hassan  Ahmed Ramadhan Muhaimeed  Hazem Sabri Abedalhammed  Najlaa Salah Madlul  Tan Tiek Aun 《Aquaculture Research》2021,52(1):345-355

This work aims to develop a suitable aquaculture system to solve issues pertaining to water quality in recirculating aquaculture systems (RAS) thereby improving fish growth performance and their feed conversion ratio (FCR). It is known that the efficiency of nutrient decomposition depends on the amount and species of bacteria present in the filter, and these can in turn be regulated by the pH. Our study shows that the significant increase in pH from 7.45 to 7.51 and 7.47 is achieved after the water was filtered through sawdust and wood wool respectively. At the same time, nitrite concentrations were found to have significantly decreased from 0.06 ppm in the control to 0.01 ppm in the sawdust treatment. Changes in the physical–chemical properties of treated water affect the biological properties of the organisms. It was found that the average final body weight for fish in the wood wool treatment 30.96 g and fish in the sawdust treatment 31.44 g was significantly higher compared to that for the fish in the control treatment 28.42 g. The use of sponge, wood wool or sawdust resulted in significantly lower FCR and therefore better fish productivity in RAS. At the same time, the red blood cell count, plasma urea, plasma creatinine, plasma albumin, and GOT and GPT were significantly higher in fish in the plastic, sponge, wood wool or sawdust treatment compared to the control treatment. In summary, this study demonstrates the benefits of using sponge, wood, wool and sawdust as biofilter media for aquaculture.  相似文献   

噪音对家禽的危害   总被引：1，自引：0，他引：1  

董海亮 《国外畜牧学(猪与禽)》2006,(3):36-37

关于噪音对家禽生长、产蛋和健康的影响,一直就很少有人研究。本文指出,长时间的过量噪音对家禽产是有害的,因而必须采取措施来减少这一有害作用  相似文献   

Degradation of atrazine and isoproturon in surface and sub-surface soil materials undergoing different moisture and aeration conditions   总被引：1，自引：0，他引：1  

Issa S  Wood M 《Pest management science》2005,61(2):126-132

The influence of different moisture and aeration conditions on the degradation of atrazine and isoproturon was investigated in environmental samples aseptically collected from surface and sub-surface zones of agricultural land. The materials were maintained at two moisture contents corresponding to just above field capacity or 90% of field capacity. Another two groups of samples were adjusted with water to above field capacity, and, at zero time, exposed to drying-rewetting cycles. Atrazine was more persistent (t(1/2) = 22-35 days) than isoproturon (t(1/2) = 5-17 days) in samples maintained at constant moisture conditions. The rate of degradation for both herbicides was higher in samples maintained at a moisture content of 90% of field capacity than in samples with higher moisture contents. The reduction in moisture content in samples undergoing desiccation from above field capacity to much lower than field capacity enhanced the degradation of isoproturon (t(1/2) = 9-12 days) but reduced the rate of atrazine degradation (t(1/2) = 23-35 days). This demonstrates the variability between different micro-organisms in their susceptibility to desiccation. Under anaerobic conditions generated in anaerobic jars, atrazine degraded much more rapidly than isoproturon in materials taken from three soil profiles (0-250 cm depth). It is suggested that some specific micro-organisms are able to survive and degrade herbicide under severe conditions of desiccation.  相似文献   

Effects of temperature and level of feeding during rearing on carcass and reproductive traits in pigs     

M.H. Fahmy 《Livestock Production Science》1975,2(3):247-259

A total of 315 crossbred females (gilts) ranging in weight from 14 to 68 kg was split between pole-type and a closed piggery (cold and moderate environments, respectively One third of the pigs in each piggery was fed a growing ration ad libitum, the remaining pigs were restrictively fed 80% of the amount consumed by the first group. Data on ultrasonic backfat probe, estimated market index, and age were taken on the pigs at 90 kg live weight. Results indicated that the effect of environmental temperature was very small on backfat thickness and carcass index, but was significant on age. The pigs fed ad libitum had 10.2% thicker backfat, were 4 points inferior in index, but were 13 days younger at 90 kg (P < 0.01) than those restrictively fed. When the gilts exhibited their first oestrus after 90 kg live weight, half of the pigs restrictively fed were flushed by feeding them ad libitum for one oestrus cycle. All gilts were bred at the second oestrus. The gilts raised in a cold environment were 4 kg lighter, farrowed litters 0.2 larger and 0.5 kg heavier than those raised in the moderate environment. Gilts restrictively fed, then flushed gained 3 kg on flushing and farrowed litters averaging 10.7 pigs, 0.2 and 0.8 pigs larger than those of the gilts fed ad libitum and not flushed respectively. Significant differences between crosses were observed in all the traits studied except gestation length and litter size. There was little effect on the different traits of the initial weight at which the gilts were exposed to the treatment.  相似文献   

Effect of low‐ or high‐CP diet with cold‐pressed oil supplementation on growth,immunity and antioxidant indices of growing quail     

Laila A. Mohamed  Mohamed M. El‐Hindawy  Mahmoud Alagawany  Ayman S. Salah  Sabry A. A. El‐Sayed 《Journal of animal physiology and animal nutrition》2019,103(5):1380-1387

This study was to investigate the effect of dietary protein levels and supplementation with two cold‐pressed oils on the performance, immunity and antioxidant indices of growing Japanese quails. A 3 × 4 factorial experiment, using 3 dietary crude protein (CP) levels (22%, 24% and 26%) and 4 supplemental herbal oils levels: control without additives, 250 mg marjoram (Mar), 250 mg thyme (Thy) and 125 mg Mar + 125 mg Thy per kg diet. A total of 720 unsexed, 7‐day‐old quail chicks were randomly distributed into twelve treatment groups (4 replicates per group of 15 chicks in each). The live body weight (LBW) on 42 days and body weight gain (BWG) from 7 to 42 days were significantly improved (p < 0.01 and 0.05) in chicks fed 24% or 26% CP compared with those of the 22% CP group. The groups fed diets supplemented with Mar or in combination with Thy oil exhibited significantly better LBW, BWG and feed conversion ratio (FCR) than the control at all periods except BWG from 21 to 42 days and FCR from 7 to 21 days were not significant. Feed intake was gradually decreased with increasing dietary CP level or adding herbal oils during the periods 21–42 and 7–42 days of age. Plasma triglycerides, cholesterol, total lipids and malondialdehyde were decreased by cold‐pressed oils supplementation, but the activity of reduced glutathione and superoxide dismutase was increased (p < 0.01) compared with the control. In conclusion, quails fed a diet containing 24% or 26% CP or diets supplemented with Mar or Thy oils or both exhibited improvement in the performance, lipid profile, immunity and antioxidant capacity without any detrimental impacts on the other studied parameters.  相似文献   

Modelling the potential benefits of different strategies to control infection with Trypanosoma evansi in camels in Somaliland     

Abdirahman Salah  Ian Robertson  Abdullahi Sheikh Mohamed 《Tropical animal health and production》2016,48(1):199-205

  相似文献   

Metabolism of 2,2-dimethyl-2,3-dihydrobenzofuranyl-7 N-dimethoxyphosphinothioyl-N-methylcarbamate in the house fly,rat, and mouse     

R.I. Krieger  P.W. Lee  M.A.H. Fahmy  M. Chen  T.R. Fukuto 《Pesticide biochemistry and physiology》1976,6(1):1-9

The metabolism of a selectively toxic derivative of carbofuran, 2,2-dimethyl-2,3-dihydrobenzofuranyl-7 N-dimethoxyphosphinothioyl N-methylcarbamate (PSC), was examined in the house fly, rat, and mouse. In house flies, PSC is metabolized mainly to carbofuran and related oxidation products containing the intact N-methylcarbamyl ester moiety. Degradation to phenolic products was the principal route of metabolism in rodents. The results indicate that the selective toxicity of PSC between insects and mammals is attributable to differing pathways of metabolism.  相似文献   

Mode of action of sulfenylated carbamates: Rapid conversion of N,N′-thiodicarbamates to parent carbamate measured by neurophysiological bioassay     

C. Collins  J.M. Kennedy  M.A.H. Fahmy  T. Miller 《Pesticide biochemistry and physiology》1980,13(2):158-163

Four N,N′-thiodicarbamate derivatives of carbofuran induced uncoupled convulsions with similar latencies following topical application to the cuticle of tethered S_NAIDM house flies, despite considerable differences in their lipophilic properties. There was a small but statistically significant delay in the latency to response to the derivatives compared to carbofuran, but when perfused directly on the exposed thoracic ganglia to assess intrinsic activity, carbofuran acted up to 4.4 times faster than the derivative. It is suggested that the NS bond of the derivatives is cleaved soon after application to the house fly cuticle and carbofuran is released from each derivative in sufficient quantities to accumulate toxic concentrations in the central nervous system at similar rates.  相似文献   

Modulatory effect of vitamins A, C and E mixtures against tefluthrin pesticide genotoxicity in rats     

S.H. Salah  H.S. Abdou 《Pesticide biochemistry and physiology》2010,98(2):191-241

The present experiments to be reported were declared the effect of mixtures from the three antioxidant vitamins (A, C and E) on some hematologic parameters, liver and testes nucleic acid system, blood immune-system, chromosomal aberration and sperm-shape of tefluthrin (LD₅₀) intoxicated rats. A total of 90 male albino rats were used divided into six groups (15 rats each).Oral ingestion of technical tefluthrin significantly decreased the count of RBCs, Hb content and stimulated plasma LDH activity, also reduced the levels of blood immuno globulins (IgG, IgA and IgM). Under the effects of tefluthrin liver and tests nucleic acids (RNA and DNA) contents were decreased and the activities of nucleases (RNAase and DNAase) were also inhibited relative to these values of normal healthy control group.Chromosomal aberrations and sperm-shape abnormalities were significantly increased after ingestion of tefluthrin, compared to the control group. Mitotic index (MI) and sperm count was decreased significantly due to the potential cytotoxicity of tefluthrin.Treatment of intoxicated rats with antioxidant vitamins (A, C and E) mixtures reduced the harmful influences of tefluthrin. Blood IgG, IgA and IgM levels, RBCs count and Hb content were improved relative to normal healthy animal group.The frequency of chromosome aberrations in bone marrow cells of intoxicated rats treated with vitamins as well as the frequency of sperm abnormalities were decreased and readjusted near to that of the healthy control animals, also MI and sperm counts were increased significantly near to the control group after vitamins ingestion as treatments.It is interesting to note that, the ingestion of vitamins mixtures readjusted and normalized the hematologic parameters around those of normal healthy control. In case of liver and nucleic acids system, the disturbed effects of the pesticide induction of RNA and DNA contents as well as RNAase and DNAase activities were alleviated by the treatments with the present antioxidative vitamins mixtures, in which the nucleic acids contents and nucleases activities of liver and testes of tefluthrin intoxicated rats were ameliorated and normalized compared with those of normal control.  相似文献   

Growth performance, feed utilization, and body composition of Nile tilapia (Oreochromis niloticus L.) fed with differently heated soybean-meal-based diets     

Mohamed Salah Azaza  Wassim Kammoun  Abdelwaheb Abdelmouleh  Mohamed Mejdeddine Kraϊem 《Aquaculture International》2009,17(6):507-521

This study was undertaken in order to determine the effect of feeding heat-treated, defatted soybean meal (SBM) on growth, feed utilization, and body composition of Nile tilapia (Oreochromis niloticus). A control diet (SBM₀) of 378 g kg⁻¹ crude protein with 18.4 kJ g⁻¹ gross energy was formulated, and three diets identical to the basal diet were autoclaved for 10, 20, or 30 min. The autoclaved diets were named SBM₁₀, SBM₂₀, and SBM₃₀, respectively. Each diet treatment was applied to triplicate groups of 30 fish (2.45 ± 0.03 g) per tank (120 l). The fish were hand fed to satiation four times daily for 45 days. At the end of the feeding trial the fish fed with the SBM₃₀ diet had significantly (P < 0.05) higher weight gain and protein efficiency ratio than those fed with the other diets. No feed-related mortality was observed during the whole experimental period. Heating SBM for 30 min reduced trypsin inhibitor activity (TIA) and increased apparent protein digestibility (APD), and indicated significant differences (P < 0.05) among various treatments. No significant differences were found in carcass moisture, lipid, and ash of fish fed with different experimental diets. An increase in the body protein content of fish fed with diet SBM₃₀ was significantly (P < 0.05) higher than in all other experimental groups. The results of this study seem to indicate that autoclaving the SBM for 30 min improved its nutritional value in practical feeds for Nile tilapia fingerlings.  相似文献