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1.
1. The effect of supplementing grower diets with bicarbonate or chloride on haematological variables, pulmonary hypertension syndrome and ascites in broilers exposed to cold temperature was investigated. 2. High concentrations of dietary chloride had no effect on the pH of the venous blood but a low chloride/high bicarbonate diet significantly increased blood pH. There was no consistent effect of dietary chloride or bicarbonate concentrations on growth performance, although in 1 experiment birds given a low chloride/high bicarbonate diet consumed less food and gained less weight than controls. 3. Birds fed on high-chloride diets tended to have a higher incidence of ascites and pulmonary hypertension than controls. Birds fed on low-chloride and high-bicarbonate diets had significantly lower pulmonary hypertension and lower heart weights, which may have indicated a decrease in pulmonary and systemic blood pressure. 4. We conclude that increasing dietary bicarbonate and reducing dietary chloride has potential as a low cost and effective method to reduce the pulmonary hypertension which leads to ascites in broiler chickens.  相似文献   
2.
Two potyvirus isolates, one from germplasm of yard-long bean (Vigna unguiculata ssp.sesquipedalis) introduced into the Netherlands, and another one from soybean plants (Glycine max) in Indonesia, were compared with two virus isolates of blackeye cowpea mosaic virus (BICMV) from the USA and a Moroccan isolate of cowpea aphid-borne mosaic virus (CAMV). It is proposed that all five isolates be now considered BICMV on the basis of host ranges, symptoms and serology. From our results, and a reassessment of the literature it is suggested to drop the name CAMV in favour of BICMV.Samenvatting Twee potyvirussen, de een in Nederland ingevoerd met genenmateriaal vanVigna unguiculata ssp.sesquipedalis en de ander uit planten van sojaboon (Glycine max) in Indonesië, werden vergeleken met twee isolaten van blackeye cowpea mosiac virus (BICMV) en een Marokkaans isolaat van cowpea aphid-borne mosaic virus (CAMV). Op grond van waardplantenreeksen, symptomen en serologie stellen de auteurs voor om alle vijf isolaten te beschouwen als BICMV. Gebaseerd op de verkregen resultaten en een kritische beschouwing van de literatuur wordt de aanbeveling gedaan om de naam CAMV te laten vallen ten gunste van BICMV.  相似文献   
3.
A total of 52 faba-bean (Vicia faba L.) fields, located in the main growing areas in Morocco were surveyed for viruses. From 240 samples with symptoms suggestive of virus infection, the following viruses were detected using electron microscopy, serology, and biological indexing: Alfalfa mosaic virus (AMV), bean yellow mosaic virus (BYMV), broad bean mottle virus (BBMV), broad bean stain virus (BBSV), broad bean true mosaic virus (BBTMV), pea earlybrowning virus (PEBV), pea enation mosaic virus (PEMV), pea seed-borne mosaic virus (PSbMV), and a complex of luteoviruses including bean leafroll virus (BLRV). This is the first report of the occurrence of BBTMV, PEMV, PSbMV, and the luteoviruses (including BLRV) of faba bean in Morcco. The luteoviruses and BBMV were found to be the most prevalent. They were detected in 56 and 50%, respectively, of the surveyed fields; while AMV, BBSV, and PEBV were found in single fields only. The remaining viruses were less prevalent, and were detected in a range of 4 to 15% of the fields surveyed. The incidences per field of the prevalent viruses varied and ranged from 1 to 33% for BBMV and up to 20% in the case of luteoviruses. BBMV was found confined to the central and northern parts of the country, BBTMV and PEMV mainly occurred in the central area, while the luteoviruses and BYMV were spread over the faba-bean growing regions of the country.  相似文献   
4.
In a balance trial with 10 pigs (mean body mass 50 kg) the influence of a bacterial protein supplement (Alcaligenes eutrophus) on N-metabolism was investigated. The bacteria were included into the diet at levels of 7 and 14% at the expense of extracted soyabean meal. Thus bacterial "pure protein" (bacterial non-nucleic acid N X X 6.25) amounted to 30 and 60% of the protein of the ration. Consuming 2 kg of feed dry matter per day the animals of the control group (I) and the experimental groups (II and III) ingested 48 g, 52 g and 55 g of total N respectively. The difference in N-intake is explained by the additional nucleic acid-N, amounting to 19,8% of total bacterial N. Daily weight gain (on average 1054 g) and feed conversion efficiency (feed ingested/weight gain; on average 1,9) were relatively improved at the highest dietary level of bacterial cell mass. Faecal N-excretion was increased significantly, whereas renal N-excretion remained unchanged. Mean apparent N-digestibility was 87,4% showing no significant difference between the experimental groups. N-balance values were noticibly increased following the intake of the bacterial protein supplement. The excretion of urinary urea-N was slightly reduced whereas 4-6 times as much allantoin-N was excreted when bacteria were fed. It is calculated that about 80% of the bacterial purines are renally excreted as allantoin and uric acid.  相似文献   
5.
A damaging virus isolated in the Netherlands from lettuce was studied and compared with a virus isolated from dandelion orginating from Czechoslovakia. It was found to biologically resemble dandelion yellow mosaic virus incompletely described from dandelion and lettuce in Great Britain (Kassanis, 1944, 1947) and from dandelion in Germany (Hein, 1963). Mechanical transmission was greatly improved by buffer solution and transmission byMyzus persicae seemed to be in the non-persistent manner. Longevity in vitro of the virus hardly exceeded one day. Thermal inactivation was between 60 and 65 °C and the dilution end-point was between 10 000 and 100 000. It was still infectious in leaf material dried and stored over CaCl2 at 4 °C for 6 1/2 years. The virus was isolated and purified with difficulty and was found to consist of one type of spherical particle of ca 30 nm diameter, with a sedimentation coefficient of 159 S, a buoyant density of 1.42 g.cm?3 and an A260/A280 ratio of 1.67. An antiserum was prepared with a titre of 256 in the agar double-diffusion test. The virus could be identified in crude extracts from lettuce andChenopodium amaranticolor by enzyme-linked immunosorbent assay (ELISA), but not by agar double diffusion. It could only be visualized in crude sap in the electron microscope after trapping of virus particles on antiserum-coated grids. The virus cannot yet be assigned to any known virus group. It is of potential economic importance to lettuce because of its occurrence in widely differing regions in Europe, its aggressiveness and virulence on 22 out of 23 lettuce cultivars tested (and on endive) and its pathogenicity toLactuca genotypes which are resistant to lettuce mosaic virus and other important pathogens of lettuce. ‘Laibacher Eis’ was the only cultivar showing some tolerance.  相似文献   
6.
Most of 43 viruses could easily be detected directly in 53 out of 66 leaf samples dried and stored over CaCl2 for varying periods of time up to 20 1/2 years. Detection usually was with PTA pH 6.5, but alfalfa mosaic, cucumber mosaic and tomato aspermy viruses required PTA pH 3.0 to 4.0. Bean common mosaic, cowpea aphid-borne mosaic and cowpea mosaic viruses were also easily observed in newly dehydrated samples obtained for diagnosis from Morocco and Tanzania.Broad bean wilt virus, cowpea mosaic virus and cucumber mosaic virus were detected with agar gel-diffusion tests in dry leaf material ground in buffer. This serological assay demonstrated a high concentration of cucumber mosaic virus in leaf material dried over CaCl2 20 years ago. This paper further coroborates the value of the CaCl2 method of dehydration and storage of plant viruses in leaf material.Samenvatting Zeer uiteenlopende plantevirussen kunnen goed worden bewaard in bladmateriaal van geïnfecteerde planten dat is gedroogd en bewaard boven CaCl2. Bij rechtstreekse elektronenmicroscopische toetsing van 66 monsters met verschillende isolaten van 43 virussen konden in 53 monsters gemakkelijk virusdeeltjes worden waargenomen (Tabel 1 en Fig. 1 en 2). Meestal lukte dit met fosforwolfraamzuur pH 6,5 dat doorgaans voor in ruw plantesap voorkomende virussen wordt gebruikt. Bij luzernemozaïekvirus en komkommermozaïek virus gelukte dit alleen maar bij lagere pH (3,0 en 4,0). Ook het tomate-aspermievirus was dan veel gemakkelijker aantoombaar. Methylaminewolfraamzuur gaf geen beter resultaat.Draden van bonerolmozaïekvirus en van cowpea aphid-borne mosaic virus en bolletjes van cowpea mosaic virus waren snel waarneembaar in elektronenmicroscopische preparaten gemaakt van bladmateriaal van recent uit Marokko en Tanzania ontvangen monsters.Cowpea mosaic virus, tuinboneverwelkingsvirus en komkommermozaïekvirus konden eveneens gemakkelijk en snel serologisch worden aangetoond in met bufferoplossing vermalen droog blad van respectievelijk cowpea, erwt en tabak. Het laatstgenoemde, reeds 20 1/2 jaar geleden gedroogde bladmateriaal, bleek in vergelijking met pas geïnoculeerd vers blad van komkommer enChenopodium quinoa zelfs zeer veel serologisch actief virusmateriaal te bevatten (Fig. 3).De beschreven waarnemingen bevestigen nogmaals de waarde van de toegepaste methode van virusbewaring en tonen aan dat het mogelijk is vele virussen te herkennen in van elders ontvangen gedroogde bladmonsters, zonder het risico te lopen van virusontsnapping, zoals altijd aanwezig bij werk met toetsplanten in de kas.Guestworker from Istituto Sperimentale per la Patologia Vegetale, Rome, Italy, participating in the investigations from September 21 to December 21, 1977.  相似文献   
7.
This study describes the age-related variation in boar taint compounds, skatole and androstenone, and testosterone, oestradiol-17 beta (E17 beta), oestrone sulphate (ES), dehydroepiandrosterone sulphate (DHEAS), triiodothyronine (T(3)) and insulin-like growth factor-1 (IGF-1) in six boars. Three pairs of littermates of crossbred entire male pigs (from three Yorkshire x Duroc dams and one Hampshire sire) were included. Blood samples were taken at the age of 9-15 weeks and thereafter at weekly intervals from the age of 20-32 weeks. Plasma concentrations of skatole, androstenone, testosterone, E17 beta, ES, DHEAS, T(3) and IGF-1 were measured. We found that skatole levels in boars increased at the age around puberty after an increase in the levels of testicular steroids. Levels of skatole were not associated with the levels of sex steroids, T(3) and IGF-1. However, the increased level of testicular steroids is probably the underlying factor needed for high skatole levels to occur although the specific mechanism leading to increased skatole levels remains unknown.  相似文献   
8.
9.
A 2-month-old, intact male Merino sheep was presented for acute inappetence and pyrexia. Contrast-enhanced abdominal computed tomography identified reticulorumenal intramural gas with suspected ruminal ulceration, arborizing portal venous gas, and mild peritoneal fluid. The lamb was treated medically for presumptive ulcerative reticulorumenitis and non-septic peritonitis. Over 10 days, the lamb initially showed mild improvement before clinical deterioration and was ultimately euthanized. Definitive diagnosis of necrotizing, ulcerative reticulorumenitis was made via necropsy with histopathology. An underlying cause was not determined.Key clinical message:Contrast-enhanced computed tomography was effective in identifying gastric emphysema and portal venous gas associated with reticuloruminal ulceration.  相似文献   
10.
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