Die Zuverlässigkeit der visuellen Selektion in der ersten Klongeneration von Kartoffeln     

CH. Pfeffer  K. H. Möller  M. Scholz  H. G. Zschüttig 《Potato Research》1988,31(1):17-23

Zusammenfassung Eine Population der ersten Klongeneration mit einem eingefügten Kontrollsortiment wurde an vier Orten ausgepflanzt und durch vier Züchter visuell nach der Methode der negativen Selektion selektiert. Es wurden signifikante Einflüsse der Orte, Jahre und Züchter ermittelt. Die Effizienz kann durch die aktuelle Optimierung der Selektionsgrenzen anhand des Kontrollsortiments erh?ht werden. Ausserdem wird erfolgreich praktiziert, die Populationen aus zwei Knollen je Genotyp zusammenzufügen oder im Rahmen der internationalen Zusammenarbeit der L?nder des Rates für Gegenseitige Wirtschaftshilfe an zwei Orten auszupflanzen.

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Summary A population of first clonal generation material was planted at four sites and selected visually by four breeders using the method of negative selection. Six table cultivars of potato that displayed appropriate levels of the characters under consideration, and six that did not, were planted at random throughout the population as standards. There were significant effects for site, year and breeder. The variance for sites was ca. 2 1/2 times that for the breeders (Tables 1 and 2), with about twice as many positive cultivars selected at site 1 as at site 3 (Table 3). There were also differences in selection results between breeders (Table 4). The uncertainty of visual selection of single plants is obvious from Table 5. Results from two years show a marked effect of year (Table 6). The relative frequencies of wrongly rejected (loss risk — Verlustrisiko) and wrongly selected (ballast risk — Ballastrisiko) standards are shown in Table 7. Only a few negative genotypes (standards) were selected, but there was a considerable loss of positive genotypes. The expected values of the standards and their actual selection results are being used to optimize the selection limits. The exploitation of populations can largely be ensured in bad years or sites, without the use of indicators and individual handling of clones with several tubers, by bulking two tubers per genotype from the first vegetative progeny. This measure may be restricted to highly valuable combinations. The possibility of accidentally selecting identical genotypes can be corrected in later generations simply by electrophoresis of soluble tuber proteins. Growing the population at two sites, best done through the framework of international co-operation, improves the likelihood of optimizing screening.

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Serratospiculosis in a New Zealand Falcon (Falco novaeseelandiae)     

CH Green  BD Gartrell  WAG Charleston 《New Zealand veterinary journal》2013,61(4):198-201

CASE HISTORY: An adult New Zealand falcon was presented with metacarpal fractures in the left wing.

CLINICAL FINDINGS: In addition to the fractures, radiographs revealed an area of opacity in the air sacs. A few days after hospitalisation and initiation of treatment of the fractures, the bird developed signs of respiratory disease; the area of opacity was found to have increased in size and density. Treatment with antibiotics and nebulisation was commenced; the bird initially responded but respiratory signs subsequently worsened and the bird died. At necropsy, air sacculitis and bronchopneumonia were associated with numerous nematodes in the air sacs, which were morphologically consistent with Serratospiculum guttatum.

DIAGNOSIS: Serratospiculosis

CLINICAL RELEVANCE: The discovery of this parasite and the associated disease for the first time in New Zealand indicates that it should be considered in the differential diagnosis of respiratory disease in falcons and possibly other raptors in New Zealand.  相似文献   

Performance,health and behaviour of organic growing-finishing pigs in two different housing systems with or without access to pasture     

J. A. M. Botermans  A.-CH. Olsson  M. Andersson  CH. Bergsten  J. Svendsen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(3-4):158-167

Abstract

The effects of two housing systems (deep litter and straw-flow), with and without access to pasture during the summer period, were studied in an organic growing-finishing pig herd. Performance, health, skin lesions and daytime pig activity were studied in 29 pens of 16 pigs (total of 464 pigs, in 4 batches). Data from 21 pens were used for comparisons of deep litter and straw-flow and data from 16 pens for comparisons of access/no access to pasture. Pigs in the deep litter system had a lower carcass meat percentage (56.6% vs. 57.3%) and more locomotion problems (4.4% vs. 0%) than pigs in the straw-flow system. No difference in daytime pig activity was detected between the two housing systems. Under moderate temperatures, pigs with access to pasture and fed a commercial organic feed inside the building were not more active during daytime behaviour studies (7.30?h–16.30?h) than pigs without access to pasture. However, at 17 weeks of age the pigs with pasture access spent 21% of their time on pasture, less time inside the pig house (20% vs. 33%) and less time on the outside concrete area (4% vs. 12%) than the pigs without pasture. No difference in performance was detected between pigs with and pigs without access to pasture.  相似文献   

Managing anthelmintic resistance: Is it feasible in New Zealand to delay the emergence of resistance to a new anthelmintic class?     

DM Leathwick  BC Hosking  SA Bisset  CH McKay 《New Zealand veterinary journal》2013,61(4):181-192

The recent registration in New Zealand of the first new class of broad-spectrum anthelmintic, for use against nematode parasites of ruminants, in nearly three decades has raised the possibility that parasite management practices could be improved to minimise the emergence of resistance to the new drug. A review of knowledge pertaining to the selection of anthelmintic resistance in nematode parasites of sheep highlights a number of management practices which could be altered to achieve this.

A number of previously common practices such as whole-flock treatment of adult ewes around lambing, and treatment of lambs as they are moved onto pastures with low parasite contamination have been clearly identified as high risk for selecting resistant parasites. Once high-risk practices have been identified steps can be taken to either eliminate their use or mitigate the associated risk. Much of the focus on the management of resistance around the world is on the retention of susceptible genotypes in refugia. While approaches to retaining unselected parasites are likely to vary around the world, empirical studies indicate that the practice is likely to be effective at slowing the development of resistance. The challenge for farmers and advisors will be to strike a balance between retaining sufficient susceptible para-sites to usefully delay the development of resistance while not unduly compromising animal performance and farm profitability. The merits of combining different classes of anthelmintic in order to slow the development of resistance remains somewhat contentious in some countries. However, the attributes of oral anthelmintics are such that they seem likely to meet most, if not all, of the criteria for combinations to be highly effective at slowing the build-up of resistance in nematode parasites.

It is evident that considerable progress has been made in understanding the factors involved in selecting anthelmintic-resistant nematodes since the last broad-spectrum anthelmintic class was released in the early 1980s. Therefore, it should be possible to manage a new class of anthelmintic in such a way as to significantly extend its effective life. The challenge is likely to be in convincing farmers of the merits of adopting such pro-active strategies.  相似文献   

Spray droplet size and carrier volume effect on dicamba and glufosinate efficacy          下载免费PDF全文

Thomas R Butts  Chase A Samples  Lucas X Franca  Darrin M Dodds  Daniel B Reynolds  Jason W Adams  Richard K Zollinger  Kirk A Howatt  Bradley K Fritz  Wesley Clint Hoffmann  Greg R Kruger 《Pest management science》2018,74(9):2020-2029

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A correlation of toxicity of albendazole and oxfendazole with their free metabolites and bound residues     

P. DELATOUR  F. GARNIER  E. BENOIT  CH. LONGIN 《Journal of veterinary pharmacology and therapeutics》1984,7(2):139-145

The possible correlations between embryotoxicity, plasma kinetics of toxic metabolites and covalent binding of metabolites to foetal tissues were studied using two drugs, albendazole and oxfendazole. In the rat, the metabolic inhibitor, SKF-525A, induced changes in embryotoxicity which were well correlated with plasma levels of identified embryotoxic metabolites, but not with the levels of foetal tissue bound drug metabolites.  相似文献   

Notes on the occurrence of tubercular spines in Schistosoma margrebowiei and Schistosoma mattheei     

F J Kruger  V L Hamilton-Attwell  L Tiedt  P S Visser  P H Joubert 《The Onderstepoort journal of veterinary research》1988,55(3):187-189

Scanning electron microscopical (SEM) studies on the tegument of the bovid schistosomes, Schistosoma margrebowiei and Schistosoma mattheei have yielded conflicting results; certain authors observed the tubercles on the tegument of these species to be spined, while others reported that they are spineless. The present study indicates that the protrusion of tubercular spines is subject to phenotypic plasticity regulated by external factors such as the identity of the host species and whether or not the schistosome is paired.  相似文献   

Some parasitic and other natural diseases of the African elephant in the Kruger National Park     

P A Basson  R M McCully  V De Vos  E Young  S P Kruger 《The Onderstepoort journal of veterinary research》1971,38(4):239-254

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Redefinition of the feline urologic syndrome: feline lower urinary tract disease with heterogeneous causes     

C A Osborne  G R Johnston  D J Polzin  J M Kruger  E M Poffenbarger  F W Bell  D A Feeney  S Goyal  T F Fletcher  J A Newman 《Veterinary Clinics of North America: Small Animal Practice》1984,14(3):409-438

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Anthelmintic activity of milbemycin oxime against adult and immature Uncinaria stenocephala in dogs     

WL SHOOP  JR EGERTON  RL SEWARD  CH EARY  HW HAINES  BF MICHAEL 《Australian veterinary journal》1993,70(5):187-188

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