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排序方式: 共有269条查询结果,搜索用时 15 毫秒
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Abd El-Hack M. E. Alagawany M. Chaudhry M. T. Saeed M. Ahmad E. A. M. El-Sayed S. A. A. 《Tropical animal health and production》2020,52(2):525-531
Tropical Animal Health and Production - This study was conducted to evaluate the influence of increased supplementation of zinc oxide (ZnO) on performance, quality of egg, blood chemistry, and... 相似文献
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A field study was conducted in the semiarid region of northern Sudan to investigate the effects of variable irrigation on
the growth, yield, and water use efficiency (WUE) of alfalfa (Medicago sativa L.). Treatments were 65 mm of water applied every 7 days, 80 mm of water applied every 10 days, or 104 mm of water applied
every 13 days. The heavy, infrequent irrigation reduced stem height, stem density, leaf area index (LAI), total biomass production,
and the WUE of alfalfa plants. Maximum yields for six harvests were 15.3, 12.9, and 11.2 ton ha–1 and the WUE values were 0.12, 0.10, and 0.08 ton ha–1 cm–1 for the frequent, less-frequent, and infrequent irrigation regimes, respectively. In all the treatments, alfalfa dry matter
yield was positively correlated with stem height and LAI. The relationship between dry matter yield and total water use was
a linear function (R
2=0.99), regardless of the irrigation treatment. Alfalfa growth, yield, and WUE remained high during the relatively cool months
and declined during the hot period under the three water regimes. It was concluded that alfalfa grown under semiarid conditions
should be watered lightly and frequently to attain high yields and high WUE.
Received: 19 February 1996 相似文献
265.
Farmers are using skimming wells tosupplement their canal deliveries. Toensure sustainable groundwater extraction,proper design and operational guidelinesfor these skimming wells are required. Thestarting point of such guidelines is tolook at farmers' existing groundwaterextraction practices, their extent andassociated problems. For this purpose, afield survey was conducted in the IndusBasin of Pakistan. Participatory ruralappraisal identified several design andoperational problems with farmers' skimmingwells. These include; depth of well,number of strainers, horizontaldistance of strainers, priming, water quality, sand in pumped water,and reduction in well discharge withtime. To investigate these problems,diagnostic analysis was carried out. A testborehole was drilled to get water samplesalong the aquifer depth during drilling.The depth of well was then decided on thebasis of these water quality analyses. Todecide the number of strainers, a pumpingtest was conducted at test borehole toestimate the contribution of individualstrainer and then the numbers wereincreased according to the desireddischarge. Similarly, placing non-returnvalve between blind pipe and strainersolved the priming problem. Operating wellsintermittently rather than continuouslysolved the problems of water quality andreduction in well discharge. The systematicapproach adopted in the study helped thefarmers to rectify the problems. 相似文献
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The interrelationships among bean productivity, prevalence of pathogens in roots, seeds and soil, and root rot disease were described at the pod maturity stage in 13 commercial fields. The soil population and frequency of pathogens isolated from seeds varied by pathogen species and field location. Fusarium solani was the most prevalent fungus isolated from bean seeds and field soil compared to Rhizoctonia solani, Macrophomina phaseolina and F. oxysporum. Principal component analysis revealed that the first component explaining 32% of the total variance was correlated with the root rot index. PC1 was more strongly linked to root and seed infections in comparison with soil populations of pathogens. Based on a correlation between PC2 (accounting for 23% of the total variance) and the number of seeds per bean plant, charcoal, Fusarium and Rhizoctonia root rots were recognized as more important determinants of seed losses to root rot disease. There were correlations among the major pathogens infecting either roots or seeds of beans. These findings provide useful information for future experimental plans to optimize management strategies for bean root rots. 相似文献
268.
Saeed Ataei Richard Burchmore J. Christopher Hodgson Anna Finucane Roger Parton John G. Coote 《Research in veterinary science》2009,87(2):207-210
Pasteurella multocida serotype B:2 is the causative agent of haemorrhagic septicaemia (HS), a fatal disease of cattle and buffaloes. As a step towards the identification of individual antigens that may protect against HS, proteins present in a sonicated cell extract (SCE) and outer-membrane protein (OMP) preparation of a wild-type P. multocida serotype B:2 were investigated by immunoblotting with sera from calves which had been protected against challenge with a virulent strain of P. multocida B:2 by vaccination with a live-attenuated aroA derivative of the challenge strain. Five proteins in SCE, of approximately 50, 37, 30, 26 and 16 kDa, were recognised by the sera. In an OMP preparation, two bands, at 37 and 50 kDa, were recognised as strongly immunogenic. Mass spectrometry analysis of proteins corresponding in size to those detected by immunoblotting identified the 37 kDa band as OmpA, but the band at 50 kDa was not identified with certainty. A major 30 kDa OMP, identified as OmpH, was not strongly immunogenic. 相似文献
269.
Toxic effects of indoxacarb on gill and kidney histopathology and biochemical indicators in common carp (Cyprinus carpio)
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Ali Taheri Mirghaed Melika Ghelichpour Seyed Saeed Mirzargar Hamidreza Joshaghani Hoseinali Ebrahimzadeh Mousavi 《Aquaculture Research》2018,49(4):1616-1627
The aim of this study was to determine the biochemical and histopathological effects of indoxacarb on an economic fish species Cyprinus carpio. The fish were divided into four triplicated groups exposed to either of 0% (control), 5% (0.75 mg/L), 10% (1.5 mg/L) or 20% (3 mg/L) of the pesticide LC50. Blood sampling was performed after 7, 14 and 21 days exposure. There were no changes in blood calcium levels at any times. In the indoxacarb‐treated fish, chloride levels decreased at the first and increased at the second sampling compared to the control. In 3 mg/L treatment, phosphorus increased significantly after 7 days compared to the control. Plasma glucose levels decreased significantly at the 7th and 14th days sampling; however, it increased at the 21st day. After 7 days, creatinine level in 3 mg/L treatment was significantly lower than the control; however, the creatinine levels of indoxacarb treatments were higher than the control at the 21st day. The indoxacarb‐treated fish had higher plasma urea levels compared to the control at the 7th day. At the 21st day, plasma urea level at 3 mg/L was significantly lower than the control treatment. Edema, Lamellar curling, hyperplasia, lamellar fusion and hyperaemia were observed in the indoxacarb‐treated fish gill. Tubular necrosis, hematopoietic necrosis, melanomacrophage aggregates, Bowman's capsule edema, glomerulus degeneration and hyperaemia were observed in the indoxacarb‐treated fish kidney. Generally, sublethal concentrations of indoxacarb cause stress, hydromineral imbalance, metabolism alteration and gill and kidney damages in common carp. 相似文献