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71.
J Gonzalez G Passantino A Esnal N Cuesta JA García Vera L Mechelli A Saez JF García Marín M Tempesta 《Reproduction in domestic animals》2017,52(6):1093-1096
An abortion outbreak occurred in a goat herd of Murciano‐Granadina breed in Almeria Region in Spain where 80 pregnant females aborted. All bacteriological and parasitological examinations resulted negative, whereas virological investigations and real‐time PCR assay showed the presence of Caprine alphaherpesvirus 1 DNA in the pathological specimens from aborted foetuses. Nucleotide sequence analysis revealed that the DNA was highly close related to the Swiss strain E‐CH (99.7%) and a little less extent to the Italian BA.1 strain (99.4%). Histopathological examination revealed multifocal, well‐circumscribed, 50‐ to 200‐μm‐diameter foci of coagulative necrosis in the liver, lungs and kidneys of three foetuses. In the periphery of the necrosis, there were frequently epithelial cells with the chromatin emarginated by large, round, amphophilic intranuclear viral inclusion bodies. The source of the infection in the herd could not clearly find out even some hypothesis were formulated. This seems to be the first report of an abortion outbreak due to Caprine alphaherpesvirus 1 in a goat herd in Spain. 相似文献
72.
73.
Adam Burriss Andrew JF Edmunds Daniel Emery Roger G Hall Olivier Jacob Jürgen Schaetzer 《Pest management science》2018,74(6):1228-1238
The pyridine ring, substituted by a trifluoromethyl substituent has been successfully incorporated into molecules with useful biological properties. During the period 1990 to September 2017, 14 crop protection products bearing a trifluoromethyl pyridine have been commercialized or proposed for an ISO common name, covering fungicides, herbicides, insecticides and nematicides. Chemical processes have been developed to provide trifluoromethyl pyridine intermediates, from non‐fluorinated pyridine starting materials, at scale and with affordable costs of goods. These attractive starting materials were readily adopted by research chemists, and elaborated through simple chemical modifications into new active ingredients. In a second approach, substituted trifluoromethyl pyridine rings have been constructed from acyclic, trifluoromethyl starting materials, which again has served to identify new active ingredients. Molecular matched pair analysis reveals subtle, yet important differences in physicochemical and agronomic properties of trifluoromethyl pyridines compared with the phenyl analogues. This review focuses on the past 27 years, seeking to identify reasons behind the success of such research programmes, and inspire the search for new crop protection chemicals containing the trifluoromethyl pyridine ring. © 2017 Society of Chemical Industry 相似文献
74.
To obviate the destructive interaction of highly reactive metallocene catalysts with classical silica-based supports while retaining the advantage of supported catalysts, a noninteracting polystyrene support was developed. Supported catalysts for the polymerization of alpha-olefins are prepared by treating lightly cross-linked, chloromethylated polystyrene beads consecutively with a secondary amine, an ammonium salt of a weakly coordinating anion, and a neutral dialkylmetallocene. Catalytic sites are distributed homogeneously throughout the support particle, and the polymerization occurs within the bead, in contrast to traditional surface-supported metallocene catalysts. The copolymerization of ethylene and 1-hexene at 40 degreesC affords discrete spherical polyolefin beads with a size (0.3 to 1.4 millimeters) that varies according to the polymerization time. 相似文献
75.
ABSTRACTConsumers perceive pasture-based systems of milk production as natural and therefore better for cow welfare than confinement systems. However both systems are heterogeneous and continually evolving, varying from total confinement to total pasture with many hybrid intermediaries. To compare the welfare of dairy cows in these various systems, we use the three spheres framework, comprising biological functioning, natural behaviour and affective states. Considering biological functioning, pasture-based cows are less at risk of subclinical and clinical mastitis, claw lesions, lameness, metritis, early embryonic mortality, culling and mortality, but at more risk of internal parasitism, malnutrition and delayed onset of oestrous activity postpartum than confined cows. Regarding natural behaviours, pasture-based cows exhibit less agonistic behaviour, better lying behaviour, more normal oestrous behaviours and better synchronicity of behaviours than confined cows. They also have the opportunity to graze, which is one of the main features of the behavioural repertoire of dairy cows, but, they may also experience long periods away from pasture in larger herds, and severe climatic stresses which will become increasingly important as the climate changes. Our current ability to assess the affective state of dairy cows is poor. For example, hunger is an important subjective state that cannot be measured directly. The growing focus on ensuring that animals have lives worth living, means that dairy cows should garner some positive emotions from their lives, and it seems clear that pasture access is essential for this. Clearly measurement of affective state is an important challenge for future dairy cow welfare research. At the extremes of management systems, there can be major differences in animal welfare but in hybrid systems, dairy cows experience elements of both confinement and pasture which may ameliorate the negative effects of each on cow welfare. Ultimately, the optimal system gives cows an element of choice between both environments. Moreover management of the system, whether it is confinement or pastured-based, may be as important as the system of management in ensuring good dairy cow welfare and addressing societal concerns.Abbreviations: BCS: Body condition score; TMR: Total mixed ration 相似文献
76.
Assessing the usefulness of B‐mode and colour Doppler sonography,and measurements of circulating progesterone concentrations for determining ovarian responses in superovulated ewes
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MEF Oliveira IF Ribeiro MGK Rodriguez GS Maciel JF Fonseca FZ Brandão PM Bartlewski 《Reproduction in domestic animals》2018,53(3):742-750
The main goal of this study was to assess the usefulness of two imaging modalities, namely the B‐mode and colour Doppler sonography, and serum progesterone (P4) concentrations for determining the ovarian response in superovulated ewes. Twenty‐four sexually mature Santa Inês ewes underwent the superovulatory treatment consisting of eight injections of porcine FSH (total dose of 200 or 133 or 100 mg; n = 8 ewes/total dose) given at 12‐hr intervals and initiated 48 hr before CIDR ® (Pfizer Inc., Auckland, New Zealand) removal. Six days after natural mating, the ovaries of all donor ewes were visualized and examined with transrectal ultrasonography and then with videolaparoscopy to identify and enumerate corpora lutea (CL ) and luteinized unovulated follicles (LUF s). Jugular blood samples were collected just prior to ovarian examinations. The total number of CL (r = .78 and 0.83, p < .0001) and LUF s (r = .74 and 0.90, p < .0001) enumerated using the B‐mode and colour Doppler ultrasonographic technique, respectively, were correlated with that ascertained by videolaparoscopy. Circulating concentrations of P4 were related directly to the number of healthy CL (r = .73, p = .0002) and inversely to the number of prematurely regressing CL (r = ?.46, p = .03), but the accuracy of predicting the number of short‐lived CL with serum P4 concentrations was very poor. The present results indicate that ultrasonographic imaging and serum P4 measurements on the day of embryo recovery are useful indicators of total/normal CL numbers and both ultrasonographic techniques can be used to quantify LUF s in superovulated ewes. 相似文献
77.
A Córdova JF Pérez B Lleó C García Artiga & S Martín Rillo 《Reproduction in domestic animals》2001,36(3-4):199-202
The aim of this study was to evaluate the straw size effect used for freezing on the in vitro fertilizing capacity. Twenty-one ejaculates from seven fertile boars were frozen under controlled conditions in 0.5 and 5 ml straws. Thawed semen was compared to fresh semen. For fresh and thawed semen in 0.5 and 5 ml straws, the results were: 92.18, 77.38 and 79.04% sperm penetration; 80.68, 66.89 and 69.33% monospermy; 11.51, 10.49 and 9.74% polyspermy; 86.19, 47.14 and 47.02% motility and 75.52, 48.19 and 46.81% normal apical ridge (NAR), respectively. Analysis of variance and test of multiple comparisons showed that under the conditions employed, penetration, monospermy, motility and NAR were significantly reduced by freezing–thawing, but polyspermy was much less affected. The results obtained suggest that frozen boar semen is adequate for in vitro fertilization. In addition freezing in 5 ml straws did not have any detrimental effect on either penetration, monospermy, polyspermy, motility and NAR, in comparison with freezing in 0.5 ml straws. 相似文献
78.
A Répási JF Beckers J Sulon Zs Perényi J Reiczigel O Szenci 《Reproduction in domestic animals》2003,38(6):423-428
Lactating dairy cows with a mature corpus luteum (CL) (diameter of ≥17 mm determined by ultrasonography) and having a follicle with a diameter of 10 mm (n = 49) were randomly assigned to three groups. The first group was treated with a single dose of exogenous prostaglandin (25 mg), while the second group was treated with 35 mg on day 0, and the third group served as control in order to evaluate the effect of rectal manipulation on the CL during ultrasonographic examination. Blood samples were collected daily for analysing progesterone (P4) concentrations. In group 1 the incidence of oestrus and artificial insemination (AI) in 10 days after treatment was 95% (19 of 20). The conception rate was 31.6%, and the average time to oestrus after treatment was 3.7 day. In group 2 the incidence of oestrus and A.I. was 84.2% (16/19). The conception rate was 31.2%, and the average time to oestrus after treatment was 2.8 day. In the untreated group only two cows (2/10) exhibited oestrus during the examined period and none of them became pregnant. There were no significant differences between the two treated groups in terms of reduction in the area of CL and P4 concentrations and of an increase in the area of the dominant follicles. At the same time, the decrease in the percentage changes relative to the area of CL and to the concentrations of P4 were statistically significant in both treated groups. 相似文献
79.
A 0.5-million-year record of millennial-scale climate variability in the north atlantic 总被引:8,自引:0,他引:8
Long, continuous, marine sediment records from the subpolar North Atlantic document the glacial modulation of regional climate instability throughout the past 0.5 million years. Whenever ice sheet size surpasses a critical threshold indicated by the benthic oxygen isotope (delta18O) value of 3.5 per mil during each of the past five glaciation cycles, indicators of iceberg discharge and sea-surface temperature display dramatically larger amplitudes of millennial-scale variability than when ice sheets are small. Sea-surface temperature oscillations of 1 degrees to 2 degreesC increase in size to approximately 4 degrees to 6 degreesC, and catastrophic iceberg discharges begin alternating repeatedly with brief quiescent intervals. The glacial growth associated with this amplification threshold represents a relatively small departure from the modern ice sheet configuration and sea level. Instability characterizes nearly all observed climate states, with the exception of a limited range of baseline conditions that includes the current Holocene interglacial. 相似文献
80.
Deep-Sea coral evidence for rapid change in ventilation of the deep north atlantic 15,400 years Ago 总被引:1,自引:0,他引:1
Coupled radiocarbon and thorium-230 dates from benthic coral species reveal that the ventilation rate of the North Atlantic upper deep water varied greatly during the last deglaciation. Radiocarbon ages in several corals of the same age, 15.41 +/- 0.17 thousand years, and nearly the same depth, 1800 meters, in the western North Atlantic Ocean increased by as much as 670 years during the 30- to 160-year life spans of the samples. Cadmium/calcium ratios in one coral imply that the nutrient content of these deep waters also increased. Our data show that the deep ocean changed on decadal-centennial time scales during rapid changes in the surface ocean and the atmosphere. 相似文献