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981.
982.
983.
984.
A 15 year-old Thoroughbred mare was examined for lethargy, fever, and inappetence of 1-day duration. A hard-bodied tick was removed from the horse. A complete blood count (CBC) demonstrated leukopenia with lymphopenia and thrombocytopenia. Morulae were visualized in circulating granulocytes. A polymerase chain reaction (PCR) confirmed the identity of these organisms as Anaplasma phagocytophilum. The horse was treated symptomatically for fever and inappetence with flunixin meglumine (1.1 mg/kg [0.5 mg/lb]) and oral electrolyte paste. Oxytetracycline (6.6 mg/kg [3 mg/lb] intravenously every 24 hours) treatment was begun as soon as a definitive diagnosis was determined. The mare responded to treatment, but she was switched to oral doxycycline (10 mg/kg [4.5 mg/lb] every 12 hours) after 5 days because of perivascular swelling at the injection site. Complete resolution of clinical signs was seen. There was no evidence of recurrence 1 year later. No additional horses at the farm were affected. The horse in this report presented for lethargy, inappetence, and fever, with limited other abnormalities. This represents a classical presentation of a mild to moderate case of anaplasmosis, which had not previously been reported in Virginia. The disease may be more widespread than has been previously reported, and it should warrant inclusion on a complete differential diagnosis list in a case of fever of unknown origin.  相似文献   
985.
The in vitro antimicrobial sensitivity of 14 mycoplasma and 13 ureaplasma strains isolated from the genital tracts of bulls was examined. It was found that at relatively low concentrations, tetracycline, declomycin and tylosin were lethal to both types of organisms. Lincospectin, berenil, streptomycin and erythromycin were lethal to mycoplasmas but were only inhibitory to the ureaplasma strains at the same concentrations. Polymyxin B and novobiocin were ineffective at the levels tested.  相似文献   
986.
Ralstonia solanacearum is a phytopathogenic bacterium that colonizes the xylem vessels of host plants leading to a lethal wilt disease. Although several studies have investigated the virulence of R. solanacearum on adult host plants, infection studies of this pathogen on the seedling stages of hosts are less common. In a preliminary observation, inoculation of R. solanacearum F1C1 on 6‐ to 7‐day‐old tomato seedlings by a simple leaf‐clip strategy resulted in a lethal pathogenic condition in seedlings that eventually killed these seedlings within a week post‐inoculation. This prompted testing of the effect of this inoculation technique in seedlings from different cultivars of tomato and similar results were obtained. Colonization and spread of the bacteria throughout the infected seedlings was demonstrated using gus‐tagged R. solanacearum F1C1. The same method of inoculating tomato seedlings was used with R. solanacearum GMI1000 and independent mutants of R. solanacearum GMI1000, deficient in the virulence genes hrpB, hrpG, phcA and gspD. Wildtype R. solanacearum GMI1000 was found to be virulent on tomato seedlings, whereas the mutants were found to be non‐virulent. This leaf‐clip technique, for inoculation of tomato seedlings, has the potential to be a valuable approach, saving time, space, labour and costs.  相似文献   
987.
988.
During the investigation of factors affecting fruit size in strawberry, the physical characteristics of the fruiting structure were examined as a possible cause of size limitation in fruit. The greatest total weight of fruit which can be sustained at any one time on an inflorescence appeared to be related to the dimensions of the main peduncle. At this limit the fruit yield may be no more than half the potential fruit yield of the inflorescence, indicating that unless ripe berries are removed development of immature berries may be restricted or stopped.This implies that under conventional management high yields will require frequent picking to achieve full potential. Once-over cropping, as in mechanical harvesting, may entail accepting yields one half or less of those now being obtained by conventional hand picking.It is suggested that if evaporative losses from ripe berries can be reduced, as by cloching, tunnelling, windbreaks, or plant breeding for less permeable cell walls, increased yields might be expected.  相似文献   
989.
Glyphosate was recently evaluated for its potential to interact with the estrogen, androgen and thyroid (EAT) hormone pathways, including steroidogenesis, under the United States Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP), then by Germany, the rapporteur Member State who led the European Annex 1 renewal for glyphosate, and then by the European Food Protection Agency (EFSA) also as part of the Annex 1 renewal for glyphosate. Under the EDSP, 11 Tier 1 assays were run following the USEPA's validated 890‐series test guidelines and included five in vitro and six in vivo assays to evaluate the EAT pathways. Steroidogenesis was evaluated as part of the estrogen and androgen pathways. An up‐to‐date critical review has been conducted that considered results from the EDSP Tier 1 battery, guideline regulatory studies and an in‐depth analysis of the literature studies that informed an endocrine assessment. A strength of this evaluation was that it included data across multiple levels of biological organization, and mammalian and nonmammalian test systems. There was strong agreement across the in vitro and in vivo Tier 1 battery, guideline studies and relevant literature studies, demonstrating that glyphosate does not interact with EAT pathways including steroidogenesis. Based on an analysis of the comprehensive toxicology database for glyphosate and the literature, this review has concluded that glyphosate does not have endocrine‐disrupting properties through estrogen, androgen, thyroid and steroidogenic modes of action. © 2020 Society of Chemical Industry  相似文献   
990.
MILK UREA CONCENTRATIONS IN DAIRY CATTLE: There has been increased use of milk urea concentration as an indicator of dietary protein intake and protein metabolism in dairy cattle over recent years. The value of milk urea content data in predicting dietary composition, particularly for pasture-fed cattle, has not been well described. PROTEIN METABOLISM AND UREA SYNTHESIS: Many factors influence the degradation of dietary proteins in the rumen, post-ruminal protein metabolism and urea synthesis in cattle. Strong positive correlations between nitrogenous fertiliser use and the crude protein content of pastures were identified by use of meta-analysis. Similar strong positive correlations were noted between dietary protein intake, rumen ammonia and plasma urea concentrations. The costs of urea synthesis include energy losses, and importantly, the loss of endogenous amino acids, which are deaminated in the synthesis of urea. MILK UREA AS AN INDICATOR OF PROTEIN METABOLISM: Urea concentrations in blood, plasma and milk are strongly correlated. Milk is an adequate indicator of blood and plasma urea content, but non-nutritional factors may significantly influence milk urea concentrations. Recommendations for dietary protein management based on milk urea concentrations must be undertaken with care.  相似文献   
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