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51.
Summary The addition of a seaweed concentrate to tissue culture medium improved the quality of potato plantlets. Season, cultivar
and explant type affected the most beneficial concentration applied. Concentrations higher or lower than the optimum were
less beneficial or adverse to plantlet quality. Terminal buds were more sensitive to non-optimum seaweed application than
axillary buds. Decreased water loss from plantlets was one of the potential benefits of seaweed concentrate in vitro, thus
improving establishment after transplanting. 相似文献
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Engelhardt B 《Science (New York, N.Y.)》2011,334(6063):1652-1653
53.
Keel bone condition in laying hens: a histological evaluation of macroscopically assessed keel bones
Scholz B Rönchen S Hamann H Hewicker-Trautwein M Distl O 《Berliner und Münchener tier?rztliche Wochenschrift》2008,121(3-4):89-94
The objective of the present study was to conduct a corresponding histological analysis of 162 macroscopically assessed keel bones (1: severe, 2: moderate, 3: slight, 4: no deformity). Four layer lines were used and hens were kept in furnished cages, small group systems (both allowing more activities due to the provision of perches) and an aviary system, which fully conformed to the EU standards. Investigations were carried out in the 3rd, 6th, 9th and 12th laying month of two experimental trials. In 97.9% of grade 4 keel bones, no histological deviations were found, whereas in keel bones manifesting deformities of grade 1 and 2, the predominant histological observation was the incidence of fracture callus material (FCM) and new bone in the form of woven bone. FCM was also detected in 50.9% of grade 3 keel bones, whereas in 40.7%, only s-shaped deviations of keel bones were found, which were related to extended pressure loading while perching activities rather than short-duration trauma. Histological analysis showed that keel bones of grade 1 and 2 were mainly attributed to traumatic origin and therefore associated with pain experience in layers. Grade 3 keel bones manifested either FCM as a result of trauma or adaptational deformities without any evidence of a preceding fracture in response to mechanical pressure loading and were most likely not associated with pain. Therefore, histological analysis was found to be a mandatory tool when evaluating grade 3 keel bones with respect to layers'welfare. Furthermore, this analysis corroborates the findings that in aviary systems deformities of keel bones are predominantly caused by painful fractures. 相似文献
54.
Anna Lineva Robert Kirchner Ellen Kienzle Josef Kamphues Britta Dobenecker 《Journal of animal physiology and animal nutrition》2019,103(1):317-323
Excess phosphorus (P) as seen in cat foods can have a negative effect on health (Dobenecker, Webel, Reese, & Kienzle, 2017 ; Pastoor, Klooster, Mathot, & Beynen, 1995 ). P surpluses may affect the environment, and economics in food producing animals, whereas marginal supply may impair performance and health. P can only be absorbed if it is soluble. Solubility of feed P in water and weak acid solution—as a precondition for absorption—was investigated in feed for dogs, cats, pigs and poultry. Different P containing mineral compounds (Ca(H2PO4)2, CaHPO4?2H2O, Ca4Na(PO4)3, KH2PO4, K4P2O7, NaH2PO4, Na5P3O10 (29 samples), as well as eight different ingredients such as wheat or meat, 64 compound feeds for pig and poultry, eight complete dry and 13 complete moist dog foods, 25 complete moist cat foods and 29 experimental diets were analysed for P solubility. Finely ground feeds were soaked in water or hydrochloric acid (0.4%) for 1 and 90 min. The samples were centrifuged and the supernatant was analysed for P (photometric vanadate molybdate method after wet ashing). The solubility of P from inorganic sources reflected the solubility of the main compound of the feed grade material. “organic” ingredients, such as fish meal or meat, showed a lower P solubility than inorganic sources. Most ingredients from animal origin (exception fish meal) had a higher P solubility than those from plant origin. When inorganic and “organic” P sources were mixed, the P solubility of the mixture reflected the P solubility and percentages of its compounds. In chicken, turkey and pig compound feed the percentage of acid soluble P increased with increasing P content. Pet moist food showed high percentages of water‐soluble P. The results show that the method is suitable to obtain data on water and acid solubility of P in feed and ingredients. 相似文献
55.
Milena Thöle Britta Schuhmann Saskia Köstlinger Helge Linzmann Michael Fehr Kerstin Müller 《Journal of Exotic Pet Medicine》2018,27(3):43-49
Two sexually intact adult male chinchillas were presented with a swelling in the perineal region. Radiographically both masses had a soft tissue opacity. Ultrasonography confirmed the tentative diagnosis of perineal hernia. In the first case the ultrasonographic examination revealed a fluid-filled structure inside the swelling, which was determined to be the urinary bladder. In the second case the hernia sac was filled with homogeneous tissue, belived to be fat. Subsequently, unilateral perineal herniorrhaphies including an internal obturator muscle flap transposition technique were performed. Both chinchillas recovered well with subsequent uneventful healing of the surgical sites. No long-term complications or recurrences of the perineal hernias were reported. This clinical report shows that perineal hernias occur in chinchillas and can be surgically treated with success. 相似文献
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Hazard identification of contaminated sites—ranking potential toxicity of organic sediment extracts in crustacean and fish 总被引：1，自引：0，他引：1
Jenny Karlsson Henrik Sundberg Gun Åkerman Kerstin Grunder Britta Eklund Magnus Breitholtz 《Journal of Soils and Sediments》2008,8(4):263-274
Background, aim, and scope It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment.
To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated
with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites
that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been
based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current
study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment
extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between
compounds with different polarities.
Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure
(i.e., ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar
compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts
were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow
trout embryos were exposed using nano-injection technique.
Results and discussion Clear concentration–response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related
pattern. Interestingly, our results indicate that some of the locations contained toxic semi-polar compounds, which are normally
not considered in risk assessment of sediment since they are focused on compounds isolated in the hexane fraction.
Conclusions The ranking of the five sediments followed the expected pattern of potential toxicity in both organisms, i.e., sediments with
known pollution history caused major effects while reference sediments caused minor effects in the two test systems. Silica
gel turned out to be an excellent carrier for exposure of N. spinipes to very hydrophobic and otherwise non-bioavailable sediment extracts.
Recommendations and perspectives Since both test systems demonstrated that a substantial part of the potential toxicity was caused by semi-polar compounds
in the acetone fractions, this study enlightens our poor understanding of which compounds are causing adverse effects in environmental
samples. Therefore, by investigating potential toxicity (i.e., hazard identification) as a first screening step in prioritizing
processes, these implications could be avoided. For proper sediment risk assessment, we however recommend whole sediment toxicity
tests to be used for selected sites at following tiers. 相似文献
59.
Kokako (Callaeas cinerea wilsoni) population recovery on the North Island of New Zealand depends primarily on control of key introduced mammal pests, especially ship rats (Rattus rattus) and brushtail possums (Trichosurus vulpecula). Recovery can still occur if pest control is pulsed (x years ‘on’; y years ‘off’) because kokako sub-adults and adults are generally long-lived, although chick production is high only during ‘on’ years. Pulsing effort means that conservation resources can be extended to other sites or problems during ‘off’ years; that toxin input at any one site is reduced; and that project staff do not burn out by repeatedly working at a site. Mathematical modelling supports empirical evidence that pests need not be controlled every year in order to maintain or greatly increase kokako populations. It predicts that the total number of years during which there is pest control is the main factor determining population size. Three years of pest control in each 10 should be sufficient to at least maintain a population with 20 females when mean parameters apply, but pulsed control should still be effective with very pessimistic parameters. In the safest strategies, control should occur in minimum pulses of 2-3 years to avoid single poor years when few breeding attempts are made. Very small populations should first be increased to at least 20 females by translocation or continuous pest control. This will greatly reduce the probability of chance extinction, and increase the efficiency of subsequent pest control. The model will apply best to closed kokako populations below carrying capacity, in which pests are controlled over the entire block. Empirical data on the effects of habitat carrying capacity on kokako dispersal, and on the importance of stoats as predators of adult females are required to further strengthen the model. 相似文献
60.
Britta Eklund Maria Elfström Irene Gallego Bengt-Erik Bengtsson Magnus Breitholtz 《Journal of Soils and Sediments》2010,10(1):127-141