Effects of feeding rates on growth and production of Nile tilapia, common carp and silver carp polycultured in fertilized ponds     

Ali E Abdelghany  & Mohammed H Ahmad 《Aquaculture Research》2002,33(6):415-423

Abstract In an attempt to identify appropriate feeding rates for multispecies of fish raised in fertilized earthen ponds, the present work was conducted over a 19‐week experimental period to establish the growth performance, production and body composition of Nile tilapia, common carp and silver carp fed 0.0%, 0.5%, 1.0%, 3.0%, 5.0% biomass and to apparent satiation (treatments). Twelve ponds were stocked with a similar number and weight of each fish species. Two ponds were assigned to each of the treatments, and a 25% protein pelleted fish feed was used to feed fish at the specified rate of feeding. At the end of the experiment, growth, weight gain, survival, yield and body composition of fish groups were affected by the treatments. The economic effectiveness also varied among treatments. The most conspicuous attribute of the feeding rates was its lack of influence on growth (g day^?1), weight gain (g per fish), yield (kg ha^?1) or body composition of silver carp. The results of whole‐body proximate analysis indicated that various feeding rates had either an irregular pattern or no effects on the protein and ash gain per 100 g of fish body weight (bw) gain. The most notable exceptions were significant (P < 0.05) increases in body fat and gross energy gains in Nile tilapia, common carp and silver carp accompanied by decreases in percentages of moisture (but not in silver carp) as feeding rate increased. Among the six different feeding levels, feeding to apparent satiation (feed amount was equivalent to 2.67% of fish bw day^?1) appeared to be optimal, as it significantly (P < 0.05) supported the highest fish production, income and net profit compared with all other treatments except for the 3% feeding level, for which the differences in those measurements were comparable.  相似文献   

Genotypic characterization by spoligotyping and VNTR typing of Mycobacterium bovis and Mycobacterium caprae isolates from cattle of Tunisia     

Hela Lamine-Khemiri  Remigio Martínez  Waldo Luis García-Jiménez  Jose Manuel Benítez-Medina  Maria Cortés  Inés Hurtado  Mohammed Salah Abassi  Imed Khazri  Mohammed Benzarti  Javier Hermoso-de-Mendoza 《Tropical animal health and production》2014,46(2):305-311

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Replacing cottonseed meal with ground Prosopis juliflora pods; effect on intake,weight gain and carcass parameters of Afar sheep fed pasture hay basal diet     

Mohammed Yasin  Getachew Animut 《Tropical animal health and production》2014,46(6):1079-1085

The experiment was conducted to determine the supplementary feeding value of ground Prosopis juliflora pod (Pjp) and cottonseed meal (CSM) and their mixtures on feed intake, body weight gain and carcass parameters of Afar sheep fed a basal diet of pasture hay. Twenty-five yearling fat-tailed Afar rams with mean initial live weight 17.24?±?1.76 kg (mean ± SD) were used in a randomized complete block design. Animals were blocked on their initial body weight. The experiment was conducted for 12 weeks and carcass evaluation followed. Treatments were hay alone ad libitum (T ₁) or with 300 g CSM (T ₂), 300 g Pjp (T ₅), 2:1 ratio (T ₃) and 1:2 ratio of CSM : Pjp (T ₄). The CP contents of the hay, CSM and Pjp were 10.5, 44.5 and 16.7 %, respectively. Hay DM intake was higher (P?<?0.05) for non-supplemented and total DM intake was lower in non-supplemented. Average daily weight gain (ADG) was lower (P?<?0.05) for T ₁ compared to all supplemented treatments except T ₅. Hot carcass weight and rib-eye muscle area also followed the same trend like that of ADG. Compared with feeding hay alone, supplementing with CSM or a mixture of CSM and Pjp appeared to be a better feeding strategy, biologically, for yearling Afar rams.  相似文献   

Quality aspect of fish sauce prepared from underutilized fatty Japanese anchovy and rabbit fish     

Kazufumi?OsakoEmail author  Mohammed?Anwar?Hossain  Koichi?Kuwahara  Akira?Okamoto  Atsuko?Yamaguchi  Yukinori?Nozaki 《Fisheries Science》2005,71(6):1347-1355

ABSTRACT:   To explore the potential utility of underutilized fish in the fish sauce industry, fish sauces were prepared from both raw and heat-induced meat of Japanese anchovy Engraulis japonica and rabbit fish Siganus fuscescens using wheat malt, and their quality aspects and sensory properties were assessed. Proximate composition of the fish meat represents protein as the major component (16.0–17.8%), other than moisture. Analyses of free amino acids, peptides including oligopeptides, and organic acids contents in fish sauces revealed suitability of both raw and heat-induced meat of the selected species in commercial fish sauce production. The variations in taste of raw meat fish sauces were species-specific, but the taste of fish sauces from heat-induced meat were similar.  相似文献   

Effect of varying density and water level on the spawning response of African catfish Clarias gariepinus: Implications for seed production     

Gamal O. El Naggar  George John  Mahmoud A. Rezk  Waheed Elwan  Mohammed Yehia 《Aquaculture (Amsterdam, Netherlands)》2006,261(3):904-907

The development of a reliable methodology for spawning of African catfish, Clarias gariepinus without the use of hormone injections would greatly improve the prospects of aquaculture in Africa. Earlier work has shown that it is possible to produce C. gariepinus fingerlings by subjecting the broodfish to a physical stress of reduced water depth and/or increased temperature. The hypothesis that C. gariepinus could be induced to spawn through a combined physical stress of lowered water level and increased stocking density was tested in concrete tanks. Three water levels (25, 50 and 75 cm) and three stocking densities (2, 4 and 6 pairs of broodfish at a 1:1 sex ratio in each hapa) were tested. Water depth in the tanks and brood fish density in the hapas affected spawning success. The percentage of spawning females was significantly higher when broodfish were stocked at 2 and 4 pairs in each hapa at water levels of 25 cm or 50 cm. There was no significant difference in spawning response between the 25 and 50 cm depths while a significant difference was seen between the 75 cm and both 25 and 50 cm depths. The results indicate optimum levels and densities for enhancing spawning success in C. gariepinus.  相似文献   

Developing scoring functions for soil quality to assess land suitability for irrigated wheat in Southern Algeria     

Adil Mihoub  Naima Koull  Samia Helimi  Mohammed Elhafed Kherraze  Sakher Mokhtari  Manuel Pulido Fernández 《Soil Use and Management》2022,38(1):262-276

Efficient land-use management could be optimized through appropriate advice regarding land suitability and achieving a reasonable yield while preserving soil and environmental conditions. The main objective of this study was to determine and define those locations capable of wheat cultivation with irrigation in the municipality of N’goussa (Southern Algeria). Expert opinion (EO) method was used for selecting minimum soil data set (MDS_-EO), where six influencing soil properties (sand, pH, salinity, organic matter, gypsum and lime) and other three key parameters (slope, land use/land cover, and proximity to roads and electricity network) were considered important for irrigated wheat cultivation in the study area. Indicators were weighted according to principal component analysis (PCA) loadings and summed. PCA revealed that the selected nine indicators are appropriate for accounting 73.63% of the total variance. Two maps of land suitability were created here (expressed as a soil quality index within a range from 0 to 1) from multivariate analysis and already known standard scoring functions (SSFs) by using two data sets (pure and scored). The distribution of soil quality index (IQI) showed that above 70% of the land was moderately (MS) to highly suitable (HS) for irrigated wheat. The estimation accuracy of soil quality classes has been evaluated using random forests (RF), having as a dependent variable the final class of land suitability used in each map. It was determined that estimation accuracy could reach 60% (pure data set) and 65% (scored data set) at 0.5 cut-off value for soil quality classes. Final prioritizing according to ranks of sensitivity index (SI) and efficiency ratio (ER) showed that IQI obtained from scored data set is the most suitable approach in soil quality assessment of arid areas. Therefore, it could be applied in southern Algeria for land management, integrated planning and environmental assessments.  相似文献   

Effects of Night Temperature,Spikelet Position and Salicylic Acid on Yield and Yield‐Related Parameters of Rice (Oryza sativa L.) Plants     

A. R. Mohammed  L. Tarpley 《Journal of Agronomy and Crop Science》2011,197(1):40-49

Periodic episodes of heat stress and seasonally high night temperatures (HNT) are predicted to occur more frequently in the current changing weather environment. These events affect aspects of crop growth and development, including oxidative‐stress damage, reducing crop yield and quality. Salicylic acid (SA), a naturally occurring phenolic compound, associated with thermo‐tolerance, prevents oxidative damage by detoxifying superoxide radicals and altering antioxidant capacity in plants. A study was conducted to determine the effects of HNT and SA on multiple rice yield‐determining parameters with special emphasis on effects of HNT and SA at different spikelet positions in the panicle. Plants were grown under ambient night temperature (27 °C) or HNT (32 °C) in the greenhouse. They were subjected to HNT through use of continuously controlled infrared heaters, starting from 2000 h to 0600 h. The HNT did not affect productive tillers, main‐stem panicle length or number of primary branches per panicle; however, reduced yield resulted from significant negative effects on spikelet fertility (SF), grain length and width. The grains located at the base of the panicle showed decreased fertility, length and width. Application of SA increased antioxidant capacity, thereby preventing damage to membranes, hence increasing yield by predominantly affecting SF in rice plants.  相似文献   

Differential Response of Southern US Rice (Oryza sativa L.) Cultivars to Ultraviolet‐B Radiation     

A. R. Mohammed  L. Tarpley 《Journal of Agronomy and Crop Science》2010,196(4):286-295

Elevated ultraviolet‐B (UV‐B; between 290 and 320 nm) radiation, because of depletion of the stratospheric ozone layer, is one of the major environmental factors influencing plant metabolic processes and yield. The southern US rice cultivars contribute greatly towards US rice production, but the effects of elevated UV‐B radiation on these cultivars are not well known. The objective of this study was to determine the effects of elevated UV‐B radiation on leaf photosynthetic rate (P_n), membrane stability, pollen viability, phenolic concentration and yield of eight commercially popular southern US rice cultivars (five inbred cultivars and three hybrids). Plants were grown in a temperature‐controlled greenhouse in Beaumont, TX, USA, and were exposed to UV‐B radiation of 0, 8 or 16 kJ m^?2 day^?1 for 90 days. For most of the cultivars, plants grown under 8 or 16 kJ UV‐B radiation showed significant decreases in P_n, membrane stability, pollen viability, and yield compared with the plants grown under an UV‐B‐free environment, whereas there was a significant increase in leaf phenolic concentration under 16 kJ UV‐B radiation. The hybrid ‘Clearfield XL729’ performed best among the selected southern US rice cultivars under 16 kJ UV‐B radiation.  相似文献   

The cell and molecular basis of mechanical, cold, and inflammatory pain     

Abrahamsen B  Zhao J  Asante CO  Cendan CM  Marsh S  Martinez-Barbera JP  Nassar MA  Dickenson AH  Wood JN 《Science (New York, N.Y.)》2008,321(5889):702-705

Peripheral pain pathways are activated by a range of stimuli. We used diphtheria toxin to kill all mouse postmitotic sensory neurons expressing the sodium channel Nav1.8. Mice showed normal motor activity and low-threshold mechanical and acute noxious heat responses but did not respond to noxious mechanical pressure or cold. They also showed a loss of enhanced pain responses and spontaneous pain behavior upon treatment with inflammatory insults. In contrast, nerve injury led to heightened pain sensitivity to thermal and mechanical stimuli indistinguishable from that seen with normal littermates. Pain behavior correlates well with central input from sensory neurons measured electrophysiologically in vivo. These data demonstrate that Na(v)1.8-expressing neurons are essential for mechanical, cold, and inflammatory pain but not for neuropathic pain or heat sensing.  相似文献   

Analysis of the Offspring Sex Ratio of Chicken by Using Molecular Sexing     

FENG Yan-ping GONG Yan-zhang Nabeel Ahmed Affara PENG Xiu-li YUAN Jin-feng ZHAO Rui-Xia Mohammed Yusuf Osman Jeffer ZHANG Shu-jun 《中国农业科学(英文版)》2006,5(7):545-549

The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.  相似文献