Les matières azotées et les acides organiques de quelques plantes fourra-gères destinées à l'alimentation des ruminants

Résumé Le taux d'azote des Raygrass, Fléole, Dactyle, Fétuque, Trèfle, Luzerne, décroît beaucoup au cours du développement, mais le taux de lysine, par rapport à (N×100/16), est relativement constant, de l'ordre de 7%; le taux de cystine est variable, compris entre 0,7 et 0,3% et plus faible chez le trèfle (0,3 à 0,2); la méthionine est au taux de 1,8 à 2% chez les graminées; 1 à 1,3 chez les légumineuses.L'azote protéique est toujours plus élevé (69 à 80%) % de l'N total dans les feuilles que dans les tiges (40 à 67%) ou les racines (16% chez les betteraves). Les aminoacides libres (luzerne, raygrass, choux, betteraves) comprennent partout alanine, sérine, valine, acide aminobutyrique; asparagine, acide aspartique, sont abondants chez Luzerne et Raygrass; glutamine et acide glutamique chez Choux et Betteraves. — Les acides malique (le plus important), malonique (à taux élevé dans feuilles et tiges agées), citrique, quinique, ont été dosés chez la luzerne, les acides malique, citrique, quinique, chez le Raygrass.

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Summary The content in nitrogen of Rye-grass, timothygrass, Cocksfoot, fescuegrass, clover, lucerne, decreases during the development, but the content in lysine, in relation to (N×100/16), is relatively constant, near 7%; the rate of cystine is variable, comprised between 0,7 and 0,3%, weaker in clover (0,3 to 0,2); methionine is at the rate of 1,8 to 2% in gramineous plants; 1 to 1,3 in leguminous plants.Protein nitrogen is always higher (69 to 80%) in leaves than in stems (40–67%) or in roots (16% in beets). Free aminoacids (lucerne, rye-grass, cabbages, beets) everywhere include alanine, serine, valine aminobutyric acid; asparagine, aspartic acid are abundant in lucerne and rye-grass; glutamine and glutamic acid (the most important), malonic (high rate in well developped leaves and stems), citric, quinic acids have been determined in lucerne, malic, citric and quinic acid in rye-grass.

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Zusammenfassung Der Stickstoffgehalt folgender Gräser: Raygrass, Lieschgrass, Knauelgrass, Schafgrass, Klee, Lucerne, nimmt während des Wachstums stark ab, der Lysin-Gehalt, im Vergleich zum Protein-Gehalt (N×100/16) bleibt ungefähr konstant, mit Werten 7%; der Cystin-Gehalt schwankt zwischen 0,7 und 0,3% und ist noch niedriger beim Klee (0,3 bis 0,2%); Methionin 1,8 bis 2% bei den Gräsern, 1 bis 1,3% bei den Leguminosen.Der Eiweiss-Stickstoff liegt immer höher in den Blättern (69–80%) als in den Stengeln, (40–67%) und in den Wurzeln (16% bei der Rübe). Die freien Aminosäuren (Luzerne, Raygrass, Kohl, Rübe) sind überall: Alanin, Serin, Valin, -Aminobuttersäure; Asparagin und Asparaginsäure wurden in grösserer Menge bei Luzerne und Raygrass gefunden; Glutamin und Glutaminsäure, sind bei Kohl und Rübe zu finden. Äpfelsäure, (die wichtigste Säure), Malonsäure (ziemlich hoher Gehalt in den gut ausgebildeten Blättern und Stengeln), Zitronensäure und Chinasäure wurden bei der Luzerne bestimmt; Äpfelsäure, Zitronensäure, Chinasäure, wurden beim Raygrass ermittelt.

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Avec la collaboration technique de MmeJ. Boudon et de MllesR. Chabrier, V. Goujon, E. Penot.     

Isolation of Feline Herpesvirus 1 from the Trigeminal Ganglia of Acutely and Chronically Infected Cats

Feline herpesvirus 1 (FHV-1) is one of the most common viral infections of domestic cats worldwide, estimated to cause 50% of all respiratory infections in this species. Feline herpesvirus 1 is also an important ocular pathogen of cats, causing conjunctivitis, epithelial and stromal keratitis, symblepharon formation, keratocon-junctivitis sicca, and corneal sequestration. Despite the importance of this viral disease, major questions remain unanswered concerning the pathogenesis of its most important manifestation, the recrudescent infection. Although the taxonomic classification of FHV-1 as an alpha herpesvirus implies the ability of FHV-1 to establish neural latency, attempts at recovering the virus from the trigeminal ganglia of latently infected cats have typically yielded negative results. This failure has stimulated speculation that neural tissue is not an important site for latent FHV-1. However, in the most successful of such studies, FHV-1 was isolated from the trigeminal ganglia of 3 of 17 cats using an explant technique. In the present study, we describe the successful isolation of FHV-1 from the trigeminal ganglia of cats using a similar tissue culture method.     

Experimental reproduction of enteritis in bobwhite quail (Colinus virginianus) with Cryptosporidium and reovirus

Five-day-old bobwhite quails were inoculated with reovirus and Cryptosporidium previously isolated from the intestinal contents of young, commercially raised bobwhite quails experiencing severe enteritis. Quails inoculated with reovirus alone did not develop clinically apparent disease, infection was localized principally in the intestinal tract, and no lesions were detected. Quails inoculated with Cryptosporidium, alone or with reovirus, developed severe enteritis with high mortality and marked growth depression. Cryptosporidia caused blunting of intestinal villi and provoked a mononuclear cell response in the lamina propria. The severity of intestinal lesions correlated with numbers of parasites. An apparent synergistic effect in dually infected quails was indicated by enhanced Cryptosporidium oocyst shedding, greater numbers of cryptosporidia in the intestinal tracts, and systemic reovirus infection. In addition, multifocal liver necrosis was detected in dually infected quails but was absent in quails infected with only reovirus or Cryptosporidium. The results suggest that Cryptosporidium promoted systemic spread of reovirus, and reovirus intensified Cryptosporidium infection, but no significant synergistic effect on mortality or weight gain was detected. The most important agent in the naturally occurring acute enteritis of bobwhite quails was Cryptosporidium.     

Mild infectious laryngotracheitis in broilers in the southeast

During 2001, a mild infectious laryngotracheitis virus (ILTV) infection occurred in broiler flocks in the southeastern United States. Clinical signs included mild tracheitis, swollen sinuses, and conjunctivitis, with no increased mortality and minimal serologic response. Infrequent intranuclear inclusion bodies with or without syncytial cell formation were observed in eyelid, trachea, and larynx and in the chorioallantoic membrane of infected embryos. Immunohistochemistry and a nested infectious laryngotracheitis polymerase chain reaction (ILT PCR) were utilized to confirm the presence of ILTV nucleic acid in fixed tissues. In addition, 2-wk-old specific-pathogen-free (SPF) birds inoculated with field material exhibited the mild signs observed in broilers in the field. Tracheal swabs and tissues taken from these SPF birds were also positive by nested ILT PCR. Restriction fragment length polymorphism analysis of ILT PCR products indicated that ILT virus associated with mild respiratory disease in the southeast is related to the chicken embryo origin vaccine type strains.     

Crystal structure of the rabies virus nucleoprotein-RNA complex

Negative-strand RNA viruses condense their genome into a helical nucleoprotein-RNA complex, the nucleocapsid, which is packed into virions and serves as a template for the RNA-dependent RNA polymerase complex. The crystal structure of a recombinant rabies virus nucleoprotein-RNA complex, organized in an undecameric ring, has been determined at 3.5 angstrom resolution. Polymerization of the nucleoprotein is achieved by domain exchange between protomers, with flexible hinges allowing nucleocapsid formation. The two core domains of the nucleoprotein clamp around the RNA at their interface and shield it from the environment. RNA sequestering by nucleoproteins is likely a common mechanism used by negative-strand RNA viruses to protect their genomes from the innate immune response directed against viral RNA in human host cells at certain stages of an infectious cycle.     

Comparison of four staining methods for detection of mast cells in equine bronchoalveolar lavage fluid

Mast cells normally are present in equine bronchoalveolar lavage fluid (BALF), but usually represent <2% of all cells in healthy horses. An increased percentage of mast cells has been associated with airway hyperactivity and inflammatory airway diseases, but marked differences are reported between studies in normal and diseased horses. Because an abnormal mast cell count may be of clinical relevance, we compared the ability of a fast Romanowsky method to stain mast cell granules with that of 3 metachromatic stains: automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains. The BALF cells from 24 horses were studied. A differential cell count was performed blindly on 400 cells. The percentages of mast cells obtained were analyzed by means of repeated-measures analysis of variance and Fischer's PLSD test. The Bland and Altman method was used to assess agreement among stains. The mean percentage of mast cells in BALF was significantly lower with the fast Romanowsky than with the automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains. With the fast Romanowsky stain, the metachromatic granules of mast cells were not stained, and their identification was based on morphologic criteria. Toluidine blue staining allowed detection of the highest mean percentage of mast cells, but was inadequate for performing a differential cell count on other cell types. In conclusion, fast Romanosky stain may be inadequate for detection of mast cells in equine BALF, whereas automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains provide metachromatic staining of mast cell granules.     

Ecdysteroid receptor docking suggests that dibenzoylhydrazine-based insecticides are devoid of any deleterious effect on the parasitic wasp Psyttalia concolor (Hym. Braconidae)

BACKGROUND: The moulting accelerating compounds (MACs) or ecdysteroid agonists represent a selective group of insecticides acting upon binding to the ecdysteroid receptor (EcR) and leading to lethal premature moulting in larval stages and aborted reproduction in adults. Psyttalia concolor Szèpl. is a useful parasitic wasp attacking important tephritid pests such as the medfly and olive fruit fly. RESULTS: Contact and oral exposure in the laboratory of female parasitic wasps to the dibenzoylhydrazine‐based methoxyfenozide, tebufenozide and RH‐5849 did not provoke negative effects. No mortality and no reduction in beneficial capacity were observed. The ligand‐binding domain (LBD) of the EcR of P. concolor was sequenced, and a homology protein model was constructed which confirmed a cavity structure with 12 α‐helices, harbouring the natural insect moulting hormone 20‐hydroxyecdysone. However, a steric clash occurred for the MAC insecticides owing to a restricted extent of the ligand‐binding cavity of the PcLBD‐EcR, while they did dock well in that of susceptible insects. CONCLUSIONS: The insect toxicity assays demonstrated that MACs are selective for P. concolor. The modelling/docking experiments are indications that these insecticides do not bind with the LBD‐EcR of P. concolor and support the theory that they show no biological effects in the parasitic wasp. These data may help in explaining the compatible use of MACs together with parasitic wasps in IPM programmes. Copyright © 2012 Society of Chemical Industry     

Alien chromosome transmission and somatic elimination in monosomic addition lines of Gossypium australe F. Muell in G. hirsutum L.

The efficiency of using monosomic alien addition lines (MAALs) to introgress agronomical traits of interest carried by wild diploid Gossypium species into the main cultivated cotton species G. hirsutum depends on the opportunities of confronting the alien chromosome with the recipient background genome at each generation and on the occurrence of translocations and homoeologous recombinations. The selfed-progeny of five MAALs of G. australe in G. hirsutum was screened with SSR markers to determine the transmission frequency of the alien chromosome and monitor its integrity. Three MAALs revealed a transmission frequency significantly lower than the expected ratio and one MAAL presented an exclusive transmission of the additional chromosome. In these four MAAL the alien chromosome was transmitted almost unaltered. With the fifth MAAL the alien chromosome was normally transmitted but was altered in half of the plants carrying it. In one MAAL, normally carrying brown fiber, the emergence of some plants carrying white and brown fiber revealed the somatic elimination of the additional chromosome. The loss of this chromosome seems to be triggered by its deletion.