３种微生态制剂对养殖水体水质影响的比较研究     

王笃彩  闫斌伦  李士虎 《水生态学杂志》2011,32(1):66-70

对3种微生态制剂改善河蟹养殖池水质的效果进行分析比较。实验组各池中分别加入超浓缩光合细菌(PSB)、"西菲利"活菌生物净水剂、活菌净水剂以及3种微生态制剂组成的混合制剂。观察氨态氮、亚硝态氮、硫化氢、溶解氧、化学耗氧量、pH及异养菌总数等水质指标。结果表明:3种微生态制剂均能改善水质,抑制异养菌的过度增长,但对水质指标的改善各有侧重,混合制剂优于单一制剂。  相似文献   

Proximate Chemical Composition of Whiting (Merlangius merlangus euxinus Nordmann, 1840) Roe     

Demet Kocatepe  Hülya Turan  Yalçin Kaya  Rabiya Erden  Fulya Erdoğdu 《Journal Of Aquatic Food Product Technology》2013,22(4):362-368

This research investigated the proximate chemical composition of whiting roe from October to April. The highest water content (83.99%) was found in March, while the lowest (72.40%) was found in December. The highest protein (14.54%) and lipid contents (9.71%) were found in December, while the lowest protein content (7.35%) was found in January and the lowest lipid content (0.38%) in April. Crude ash content of whiting roe changed from 0.86 to 1.49%. The highest (154 kcal/100 g) and lowest energy values (64 kcal/100 g) were determined in December and April, respectively. Whiting roe can be used as a source of valuable nutrients for human nutrition.  相似文献   

Breeding strategies with poplars in Europe     

Eric Teissier du Cros 《Forest Ecology and Management》1984,8(1):23-39

Poplar breeding in Europe is in a more advanced state than breeding programmes of other species. In Europe, poplars are part of the scenery and are integrated in the economy. Traditionally poplar stands are established in lowland areas. But an increasing interest in their use moved them to upland sites. Poplar uses are multiple: lumber, industrial wood, wind-breaks and landscape plantations, etc. Selection characteristics are classified in different groups: vegetative propagation ability, vigour, adaptation to sites and climate, resistance to diseases and insect pests, wood quality, and coppicing ability. Strategies have improved with time. The most efficient strategies for the long term involve constitution of base populations, selection of parents for intra- and interspecific hybridizations, selection within the progenies, and vegetative propagation. Short term strategies are also applied simultaneously. Advanced breeding techniques with poplars include: haploidy, polyploidy, reduction of incompatibility barriers and genetic engineering.  相似文献   

T cell-mediated immunity to Cowdria ruminantium in mice: the protective role of Lyt-2+ T cells     

J L Du Plessis  P Berche  L Van Gas 《The Onderstepoort journal of veterinary research》1991,58(3):171-179

The inability of athymic nude mice to make a drug-aided recovery from infection with either the Kümm or the Welgevonden stocks of Cowdria ruminantium and their inability to mount an immune response, suggest that immunity in heartwater is cell-mediated. The adoptive transfer of immunity with the spleen cells of mice immune to the Welgevonden stock is supportive evidence. Immune spleen cells depleted of Lyt-2+ T cells are unable to confer resistance to challenge to recipient mice, whereas the depletion of L3T4+ T cells had no effect on the protection conferred by immune spleen cells. This is conclusive evidence that immunity in heartwater is largely cell-mediated. Immune serum, C. ruminantium and complement incubated in the presence of mouse peritoneal macrophages, inhibits the infectivity of the heartwater agent, but not in the absence of macrophages. The decreased resistance to challenge of immune mice treated with gloxazone adds further support to the concept that in heartwater persistence of C. ruminantium in the host is associated with immunity.  相似文献   

Boar sperm production: Use in artificial insemination — A review     

F. du Mesnil de Buisson  M. Paquignon  M. Courot 《Livestock Production Science》1978,5(3):293-302

The production of spermatozoa increases with boar age from puberty to adulthood. Increasing collection frequency to more than once or twice a week increases the quantity of spermatozoa recovered per boar. Possible improvement of quality by collecting more often remains open to discussion. Sperm production is mainly a result of testis size, which varies with individuals and families. Selection on female ovulation rate leads to more rapid testis growth of males in the families selected. There is a correlation between pregnancy rate obtained after insemination with a given board, small size (direct boar effect) and embryonic survival rate at 25 days. Keeping boars at a high temperature lowers the quantity of spermatozoa recovered, pregnancy rate and embryonic survival in the sows inseminated. Fresh sperm may be stored for 2 days without decreasing its fertilizing ability (dose of 3 × 10⁹ spz. per AI). It may be efficiently used on day 3 of storage (double dose). The preparation and use of deep-frozen sperm is simple. Efficacious use is highly correlated with a good knowledge of sow oestrus. The number of sows which can be inseminated with one deep-frozen ejaculate is limited to 8–10 due to the number of motile spermatozoa after thawing.  相似文献   

Heartwater in Angora goats. II. A pathological study of artificially infected, treated and untreated goats     

L Prozesky  J L Du Plessis 《The Onderstepoort journal of veterinary research》1985,52(1):13-19

Pathological lesions in untreated Angora goats infected with the Ball3 strain of Cowdria ruminantium corresponded with those previously reported. A severe nephrosis was the most prominent pathological lesion in the animals treated after the 1st day of the febrile reaction. Renal ischaemia appears to be central to the pathogenesis of the kidney lesions.  相似文献   

Heartwater. The development and life cycle of Cowdria ruminantium in the vertebrate host, ticks and cultured endothelial cells   总被引：2，自引：0，他引：2  

L Prozesky  J L Du Plessis 《The Onderstepoort journal of veterinary research》1987,54(3):193-196

Various aspects of the development and life cycle of Cowdria ruminantium are discussed. C. ruminantium is transmitted transstadially by certain Amblyomma species. Apparently organisms initially develop in the gut epithelial cells of ticks and subsequent stages of C. ruminantium invade and develop in the salivary gland acini cells of the vector. Stages at which transmission to the final host are attained appear to be coordinated with the feeding cycle of the ticks and the vertebrate host is infected via salivary glands of the tick. In the vertebrate host, ticks and cultured endothelial cells, different morphological forms of C. ruminantium (electron-dense and reticulated forms) are found. Organisms enter cells through a process resembling phagocytosis and reticulated forms of the organisms appear to be the main vegetative stage. In the vertebrate host, organisms proliferate in vascular endothelial cells, neutrophils, macrophages and reticulo-endothelial cells.  相似文献   

A retrospective case series of computer-controlled total intravenous anaesthesia in dogs presented for neurosurgery     

Joubert KE  Keller N  Du Plessis CJ 《Journal of the South African Veterinary Association》2004,75(2):85-89

This article describes the anaesthetic management and use of total intravenous anaesthesia (TIVA) for neurosurgery in 4 dogs. Propofol in conjunction with morphine was used for the maintenance of anaesthesia. Anaesthesia was induced with either thiopentone or propofol. The program Stelpump (a target-controlled infusion program) was run on a laptop and connected to a syringe driver via an RS 232 cable. The program was found to be reliable and safe for the administration of TIVA in dogs. Invasive monitoring was required in order to monitor cardiovascular changes during surgery. Ventilation was controlled to maintain the end-tidal carbon dioxide below 40 mm Hg. The anaesthesia was characterised by haemodynamic stability. The haemodynamic stability was probably the result of the choice of TIVA and balanced anaesthesia. Intracranial pressure and oedema was controlled with dexamethasone, mannitol and ventilatory management either in combination or alone. Three dogs survived to hospital discharge and 1 dog was euthanased 2 weeks later due to tumour metastasis. The development and characterisation of the anaesthetic effects of TIVA needs to be elucidated in order to provide clinicians with rational guidelines for the appropriate use of TIVA in veterinary medicine.  相似文献   

Colostrum-derived antibodies to Cowdria ruminantium in the serum of calves and lambs     

J L Du Plessis 《The Onderstepoort journal of veterinary research》1984,51(4):275-276

Antibodies to Cowdria ruminantium were detected in the serum of calves born from artificially immunized heifers, by means of the indirect fluorescent antibody test, only for as long as 4 weeks after birth. Lambs born from artificially immunized ewes, however, were still serologically positive at 8-12 weeks of age. Much higher antibody titres were recorded in the sera of ewes and their lambs than in that of heifers and their calves.  相似文献   

A comparative study between mature ostriches (Struthio camelus) and adult cockerels with regard to the true and apparent digestibilities of amino acids     

S. C. Cilliers  J. P. Hayes  A. Chwalibog  J. J. du Preez  J. Sales 《British poultry science》1997,38(3):311-313

1. A study was conducted to compare apparent and true digestibility of amino acids in a high protein experimental diet between young ostriches (7 months of age) and cockerels.

2. A mean value for true digestibility of amino acids (TAAD) of 0.837 ± 0.0073 (range 0.780 to 0.862) was derived for ostriches, compared with a mean value of 0.795 ± 0.0258 (range 0.723 to 0.825) for cockerels.

3. True retention of dietary protein was 0.646 ±0.0114 and 0.609 ±0.0643 for ostriches and cockerels respectively.

4. Results in the present study produced evidence that the method for determining metabolisable energy values of ingredients for ostriches is also suitable for measuring the digestibility of amino acids.

5. It was concluded that accurate diet formulation for ostriches requires the assessment of amino acid digestibilities for individual ingredients, because values derived from poultry would underestimate digestibilities for ostriches.  相似文献