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961.
Addition of copper sulphate (about 200 mg per kg) to conventional diets produced a small, though variable, growth response and improved food conversion in broilers maintained under commercial conditions. In some experiments interactions were found between sex or coccidiostat and copper in the diet. Broilers fed on diets containing greater concentrations of copper (between 400 and 600 mg per kg) exhibited reduced growth rate and food intake. The gizzard linings of birds receiving diets containing 600 mg CuSO4 per kg showed extensive damage. This damage was attributable to a massive increase in the shedding of the gizzard glandular cells into the koilin layer and to disruption and cessation of koilin production. Similar though less severe gizzard changes occurred in birds which received 400 mg per kg and there was a slight increase in cellular desquamation in some of the birds receiving 200 mg per kg. High concentrations of copper were found in the gizzard lining and caecal contents of birds receiving supplementary copper and there was a progressive increase in the concentration of copper in the litter on which such birds had been reared. 相似文献
962.
963.
964.
Maria C.S.?NunesEmail author Maria J.?Vasconcelos José M.C.?Pereira Nairanjana?Dasgupta Richard J.?Alldredge Francisco C.?Rego 《Landscape Ecology》2005,20(6):661-673
The purpose of this study is to investigate if, or under what conditions, fires select given land cover types for burning.
If fires burn unselectively then the land cover composition (the proportional area of various land cover types) of individual
fires should approximate the land cover composition available in their neighborhood. In this study we test this hypothesis
by performing statistical analyses of a data set consisting of paired vectors with the proportions of land cover types present
in burned areas and in their respective surroundings. The statistical methods employed (a permutation technique and the Cmax statistic) are commonly used in resource selection studies where data is subject to a unit-sum constraint. The results of
the analysis of 506 fires that burned in Portugal in 1991 indicate that fires are selective, with small fires exhibiting stronger
land cover preferences than large fires. According to the results of a multiple comparison analysis performed for small fires,
there is a marked preference for shrubland followed by other forest cover types, while agriculture is clearly avoided. A similar
analysis is performed to test if fire selectivity is related to the ecological region where it occurs. The results obtained
in this study contribute to the discussion on the relative importance of fuels as a drivers of fire spread. 相似文献
965.
Forzán MJ McClure JT 《The Canadian veterinary journal. La revue veterinaire canadienne》2005,46(4):342-344
Necropsy of a 3-day-old Holstein heifer revealed proximal megacolon and distal colorectal hypoplasia. Histologically, the hypoplastic distal colon and rectum lacked submucosal and myenteric ganglia. Clinical history, physical examination, and pathologic findings were consistent with intestinal aganglionosis, a congenital anomaly well documented in humans and foals but not previously reported in cattle. 相似文献
966.
Ex vivo whole blood stimulation with endotoxin has proved to be a useful method for quantitative evaluations of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) response ability in humans. In the present study, a dose- and time-response study was carried out in order to develop an ex vivo whole blood stimulation assay for the quantification of TNF-alpha production in pigs. The TNF-alpha response was enhanced with increasing endotoxin stimulation dose. The maximum TNF-alpha response occurred after 2-8 h of stimulation. Subsequently, the assay was used to evaluate the TNF-alpha response in pigs (n=32) in relation to weaning. The TNF-alpha response was 332 pg ml(-1) (+/-59 pg) plasma 2 days before weaning and 127 pg ml(-1) (+/-23 pg) plasma 2 days after weaning, which was a significant reduction (p<0.001). Total and differential counts of leucocytes were the same before and after weaning. Thus the lower TNF-alpha response may be due to reduced monocyte responsiveness to the endotoxin, rather than caused by a reduction in monocyte numbers. The reduced TNF-alpha response in piglets after weaning may be a factor of importance to the increased disease susceptibility seen in piglets in this period. 相似文献
967.
Abstract In dogs, dermatophytosis should be considered in any case of alopecic, papular or pustular lesion. The aim of this study was to develop an enzyme-linked immunosorbant assay (ELISA) as an aid in the diagnosis of canine dermatophytosis. The antigen used was a whole fungal extract obtained from an isolate of Microsporum canis cultured on a liquid medium from the parasitized hair of a cat with patches of alopecia. To assess the ELISA performances, sera from 18 dogs with dermatophytosis caused by M. canis (group A, n = 18), 20 dogs with skin diseases other than dermatophytosis and 22 healthy dogs (group B, n = 42) were tested. Four further animals were tested: three with dermatophytosis caused by M. gypseum and one by T. mentagrophytes. A significant difference (P < 0.01, Wilcoxon's test, w = 364) was found between IgG-specific levels of sera of recently M. canis-infected dogs (infection < 15 days) and controls (although three dogs had negative titres at this stage). A highly significant difference (P < 0.001, w = 462) was noted between controls and dogs with infection of longer duration (> 30 days). All dogs had positive titres at this stage. A highly significant correlation (P < 0.001, Spearman's test, rho = 0.86) between duration of infection and IgG concentration was noted. The test has good sensitivity (83.3%) and high specificity (95.2%) but some dogs retained positive titres after elimination of infection. The sensitivity is higher than that of direct microscopic hair examination and similar to that of fungal culture with DTM (dermatophyte test medium). 相似文献
968.
Zoonotic aspects of Mycobacterium bovis and Mycobacterium avium-intracellulare complex (MAC) 总被引:4,自引:0,他引:4
Pathogens that are transmitted between the environment, wildlife, livestock and humans represent major challenges for the protection of human and domestic animal health, the economic sustainability of agriculture, and the conservation of wildlife. Among such pathogens, the genus Mycobacterium is well represented by M. bovis, the etiological agent of bovine tuberculosis, M. avium ssp. paratuberculosis (Map) the etiological agent of Johne disease, M. avium ssp. avium (Maa) and in a few common cases by other emergent environmental mycobacteria. Epidemiologic surveys performed in Europe, North America and New Zealand have demonstrated the existence and importance of environmental and wildlife reservoirs of mycobacterial infections that limit the attempts of disease control programmes. The aim of this review is to examine the zoonotic aspects of mycobacteria transmitted from the environment and wildlife. This work is focused on the species of two main groups of mycobacteria classified as important pathogens for humans and animals: first, M. bovis, the causative agent of bovine tuberculosis, which belongs to the M. tuberculosis complex and has a broad host range including wildlife, captive wildlife, domestic livestock, non-human primates and humans; the second group examined, is the M. avium-intracellulare complex (MAC) which includes M. avium ssp. avium causing major health problems in AIDS patients and M. avium ssp. paratuberculosis the etiological agent of Johne disease in cattle and identified in patients with Crohn disease. MAC agents, in addition to a broad host range, are environmental mycobacteria found in numerous biotopes including the soil, water, aerosols, protozoa, deep litter and fresh tropical vegetation. This review examines the possible reservoirs of these pathogens in the environment and in wildlife, their role as sources of infection in humans and animals and their health impact on humans. The possibilities of control and management programmes for these mycobacterial infections are examined with regards to the importance of their natural reservoirs. 相似文献
969.
Annette Herz Sherif A. Hassan Esmat Hegazi Feeby N. Nasr Ali A. Youssef W. E. Khafagi Essam Agamy Mohieddine Ksantini Taieb Jardak Basilis E. Mazomenos Maria A. Konstantopoulou Laura Torres Fátima Gonçalves Albino Bento José A. Pereira 《Gesunde Pflanzen》2005,57(5):117-128
Zusammenfassung Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit künstlicher Bewässerung und hohem Einsatz von Düngern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelmässigen Insektizideinsatz bekämpft. Das von der EU geförderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongestützten Überwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur Förderung natürlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zusätzlich wurden Module für eine optimale Anwendung biotechnischer und biologischer Methoden bezüglich der Phänologie der Schadinsekten und möglicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren Ländern Europas und Nordafrikas erlaubte den Entwurf möglicher Lösungsansätze für verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke für eine zukünftige praktische Umsetzung werden in dieser Veröffentlichung beschrieben. 相似文献
970.
Scortichini M Rossi MP Loreti S Bosco A Fiori M Jackson RW Stead DE Aspin A Marchesi U Zini M Janse JD 《Phytopathology》2005,95(11):1316-1324
ABSTRACT Thirty-eight bacterial strains isolated from hazelnut (Corylus avellana) cv. Tonda Gentile delle Langhe showing a twig dieback in Piedmont and Sardinia, Italy, were studied by a polyphasic approach. All strains were assessed by fatty acids analysis and repetitive sequence-based polymerase chain reaction (PCR) fingerprinting using BOX and ERIC primer sets. Representative strains also were assessed by sequencing the 16S rDNA and hrpL genes, determining the presence of the syrB gene, testing their biochemical and nutritional characteristics, and determining their pathogenicity to hazelnut and other plants species or plant organs. Moreover, they were compared with reference strains of other phytopathogenic pseudomonads. The strains from hazelnut belong to Pseudomonas syringae (sensu latu), LOPAT group Ia. Both fatty acids and repetitive-sequence-based PCR clearly discriminate such strains from other Pseudomonas spp., including P. avellanae and other P. syringae pathovars as well as P. syringae pv. syringae strains from hazelnut. Also, the sequencing of 16S rDNA and hrpL genes differentiated them from P. avellanae and from P. syringae pv. syringae. They did not possess the syrB gene. Some nutritional tests also differentiated them from related P. syringae pathovars. Upon artificial inoculation, these strains incited severe twig diebacks only on hazelnut. Our results justify the creation of a new pathovar because the strains from hazelnut constitute a homogeneous group and a discrete phenon. The name of P. syringae pv. coryli is proposed and criteria for routine identification are presented. 相似文献