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31.
The results of a survey of aspects of the reproductive activity in 449 breeding bitches owned by 198 breeders in England and Wales are reported. Information is provided on the seasonal incidence of oestrus in the total group and in different breeds. Most activity was observed in the February to May period. Oestrous interval data are also reported. Significant differences in the mean length can be shown between breeds though there was no clear correlation between the median length of the oestrous interval for a breed and the mean body weight of that breed. Pregnancy in the bitch was shown to cause a significant increase in the length of the current oestrous interval. Résumé. On rapporte les résultats d'un examen des différents aspects de l'activité de reproduction chez 449 chiennes reproductrices appartenant à 198 éleveurs en Angleterre et au Pays de Galles. On fournit des données sur l'incidence saisonnière de l'?stre pour l'ensemble du groupe et pour des races différentes. On a pu observer la plus grande activité dans la période de février à mai. On rapporte aussi des données sur les intervalles dans les périodes de l'?stre. On a relevé des différences importantes dans la durée moyenne d'après les races, quoiqu'il n'y ait aucune corrélation nette entre la durée moyenne de l'intervalle de l'?stre pour une race donnée et le poids moyen de l'animal de cette race. On remarqua que la grossesse causait une augmentation importante dans la durée de l'intervalle habituel de l'?stre. Zusammenfassung. Die Ergebnisse einer Zusammenstellung über die Fortpflanzungstätigkeit von 449 Zuchthündinnen im Besitz von 198 Züchtern in England und Wales werden berichtet. Informationen über die jahreszeitliche Häufigkeit des Östrus in der Gesamtgruppe und bei den verschiedenen Rassen werden angegeben. Die stärkste Aktivität wurde in der Periode Februar bis Mai beobachtet. Die Östrusintervalldaten werden ebenfalls angegeben. Signifikante Unter-schiede in der mittleren Länge lassen sich zwischen verschiedenen Rassen zeigen, wenn auch keine klare Korrelation zwischen der mittleren Länge des Östrusintervalls bei einer Rase und dem mittleren Körpergewicht dieser Rasse bestand. Wie sich zeigte, verursachte die Trächtigkeit der Hündin eine signifikante Verlängerung des augenblicklichen Östrusintervalls. 相似文献
32.
Follicular wave emergence was synchronized by treating camels with GnRH when a dominant follicle (DF) was present in the ovaries. Animals were scanned twice a day from day 0 (day of GnRH treatment) to day 10, to characterize emergence and deviation of follicles during the development of the follicular wave. Follicle deviation in individual animals was determined by graphical method. Single DFs were found in 16, double DFs in 9 and triple DFs in two camels. The incidence of codominant (double and triple DFs) follicles was 41%. The interval from GnRH treatment to wave emergence, wave emergence to deviation, diameter and growth rate of F1 follicle before or after deviation did not differ between the animals with single and double DFs. The size difference between future DF(s) and the largest subordinate follicle (SF) was apparent from the day of wave emergence in single and double DFs. Overall, interval from GnRH treatment to wave emergence and wave emergence to the beginning of follicle deviation was 70.6 ± 1.4 and 58.6 ± 2.7 h, respectively. Mean size of the DF and largest SF at the beginning of deviation was 7.4 ± 0.2 and 6.3 ± 0.1 mm, respectively. In conclusion, the characteristics of follicle deviation are similar between the animals that developed single or double DFs. 相似文献
33.
An incubation experiment was conducted to investigate the microbial biomass associated Cu in four contrasting soils to which an alkaline stabilised sewage sludge cake was applied. The organisms of sludgeamended and control soils were killed using γ-irradiation technique, and the aqueous and acid-extractable Cu concentrations were determined. Addition of the sludge product increased significantly the concentration of both the aqueous and dilute HOAc-extractable Cu in all the irradiated soils compared to the non-sterilised sludge/soil mixtures, but the increase was more pronounced in the dilute acid-extractable Cu, indicating that the Cu rendered extractable in water and dilute acetic acid by γ-irradiation existed in the both soil liquid and solid phases. The additional increase in extractable Cu following the biocidal treatment is likely to be due to release of Cu from the same fraction of soil microbial biomass. 相似文献
34.
L. S. HÅVARSTEIN C. ENDRESEN B. HJELTNES K. E. CHRISTIE J. GLETTE 《Journal of fish diseases》1990,13(2):101-111
Abstract. Atlantic salmon, Salmo salar L., responded to intraperitoneal injection of formalin killed Vibrio salmonicida or live infectious pancreatic necrosis virus ( ipnv ) by producing specific antibodies. The antibody titre varied significantly within the group tested. Western blot analysis demonstrated that high-titre antisera recognized two major bacterial antigens with molecular weights of 12–15 kD and 22–27 kD. In addition, a few narrow bands with higher molecular weights were observed. An antiserum raised against IPNV recognised two major antigens corresponding to the structural proteins of the virus. E lisa and Western blot analysis showed that the immune serum raised against Vibrio salmonicida reacted slightly with Vibrio anguillarum , whereas no reaction to Yersinia ruckeri or Aeromonas salmonicida was detected. Indirect elisa and an elisa competition assay revealed that the immune serum raised against the N1 serotype was specific for this serotype of ipnv . The results demonstrate that Atlantic salmon has a humoral immune system capable of producing antibodies which discriminate between related bacterial antigens and between different serotypes of a virus. 相似文献
35.
Effects of long-term fertilizer applications on peanut yield and quality and plant and soil heavy metal accumulation 总被引:2,自引:0,他引:2
The status of essential and potentially toxic trace elements in soils and crops can be affected by long-term fertilization practices. This study aimed to investigate changes in peanut (Arachis hypogaea L.) yield and kernel quality, and changes in copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in soil and peanut kernels after 16 years of continuous cropping with different fertilization treatments. Five fertilization treatments were applied at a red soil site in Southeast China:chemical fertilizer (F) containing nitrogen, phosphorus, and potassium, F + trace elements (FT), pig manure (M), M + effective microorganisms (MB), and MB + trace elements (MBT). Properties of soil and pig manure, heavy metal contents in soil and peanut kernels, and the compositions of amino and fatty acids in kernels were determined. Application of pig manure significantly increased peanut biomass, kernel yield, and crude protein and total amino acid contents in kernels, but led to higher amounts of Cu, Zn, and Cd in soil and higher amounts of Zn and Cd in peanut kernels compared with that of chemical fertilizer. There should be greater concern about potential kernel Cd and Zn contaminations resulting from long-term application of pig manure contaminated with potentially toxic metals as an organic fertilizer. 相似文献
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In order to limit the number and impact of exotic pest invasions, leading-edge technologies must be embraced and embedded within integrated national and international biosecurity systems. Outlined here are recent advances in the detection of exotic pests, and prospects for the early recognition of disease. Applications of new tools are described, using our understanding of the genomes of pathogens and vectors. In addition, the role of mathematical and simulation models to aid both biosecurity planning, and decision making in the face of an epidemic, are discussed, and recent attempts to unify epidemiology and evolutionary dynamics are outlined. Given the importance of emerging diseases and zoonoses, the need to align human and veterinary surveillance within fully integrated systems is underlined. 相似文献
40.
红三叶草丛枝菌根对有机磷的吸收 总被引:3,自引:1,他引:3
The capacities of two arbuscular mycorrhizal (AM) fungi, Glomus mosseae and Glomus versderme, tomineralize added organic P were studied in a sterilized calcareous soil. Mycorrhizal (inoculated with either of the AM fungi) and non-mycorrhizal red clover (Trghlium pmtense L.) plants were grown for eight weeksin pots with upper root, central hyphal and lower soil compartments. The hyphal and soil compartmentsreceived either organic P (as Na-phytate) or inorganic P (as KH2PO4) at tbe rate of 50 mg P kg-1. No P wasadded to the root compartments. Control pots received no added P. Yields were higher in mycorrhizal than innon-mycorrhizal clover. Mycorrhizal inoculation doubled shoot P concentration and more than doubled total P uptake of plaflts in P-amended soil, irrespective of the form of applied P. The mycorrhizal contributionto inorganic P uptake was 80% or 76% in plants inoculated with G. mosseae or G. verefforme, respectively. Corresponding values were 74% and 82% when Na-phytate was applied. In the root compartments of the mycorrhizal treatments, the proportion of root length infected, hyphal length density and phosphatase activity were all higher when organic P was applied than when inorganic P was added. 相似文献