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141.
142.
A diagnosis of dicoumarol toxicity in a herd of Friesian cattle was made following investigation of the deaths of three mature cows and eleven yearling heifers. Affected stock had been fed wrapped, bailed silage containing approximately 90% sweet vernal grass ( Anthoxanthum odoratum ). Sweet vernal grass contains coumarin, which can be converted to dicoumarol, a vitamin K antagonist, through the action of moulds. Most deaths were preceded by lethargy, severe anaemia and subcutaneous and internal haemorrhage. Dicoumarol toxicosis was suspected based on clinical signs, necropsy findings and prolonged prothrombin and activated partial thromboplastin times. Dicoumarol analysis of blood from affected animals and silage confirmed the diagnosis. 相似文献
143.
Correa Mdo A Aguiar AJ Neto FJ Mendes Gda M Steagall PV Lima AF 《American journal of veterinary research》2007,68(9):932-940
OBJECTIVE: To evaluate the effects of 2 remifentanil infusion regimens on cardiovascular function and responses to nociceptive stimulation in propofol-anesthetized cats. ANIMALS: 8 adult cats. PROCEDURES: On 2 occasions, cats received acepromazine followed by propofol (6 mg/kg then 0.3 mg/kg/min, i.v.) and a constant rate infusion (CRI) of remifentanil (0.2 or 0.3 microg/kg/ min, i.v.) for 90 minutes and underwent mechanical ventilation (phase I). After recording physiologic variables, an electrical stimulus (50 V; 50 Hz; 10 milliseconds) was applied to a forelimb to assess motor responses to nociceptive stimulation. After an interval (> or = 10 days), the same cats were anesthetized via administration of acepromazine and a similar infusion regimen of propofol; the remifentanil infusion rate adjustments that were required to inhibit cardiovascular responses to ovariohysterectomy were recorded (phase II). RESULTS: In phase I, heart rate and arterial pressure did not differ between remifentanil-treated groups. From 30 to 90 minutes, cats receiving 0.3 microg of remifentanil/kg/min had no response to noxious stimulation. Purposeful movement was detected more frequently in cats receiving 0.2 microg of remifentanil/kg/min. In phase II, the highest dosage (mean +/- SEM) of remifentanil that prevented cardiovascular responses was 0.23 +/- 0.01 microg/kg/min. For all experiments, mean time from infusion cessation until standing ranged from 115 to 140 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Although the lower infusion rate of remifentanil allowed ovariohysterectomy to be performed, a CRI of 0.3 microg/kg/min was necessary to prevent motor response to electrical stimulation in propofol-anesthetized cats. Recovery from anesthesia was prolonged with this technique. 相似文献
144.
Adjuvant effect of green propolis on humoral immune response of bovines immunized with bovine herpesvirus type 5 总被引:1,自引:0,他引:1
Fischer G Cleff MB Dummer LA Paulino N Paulino AS de Oliveira Vilela C Campos FS Storch T D'Avila Vargas G de Oliveira Hübner S Vidor T 《Veterinary immunology and immunopathology》2007,116(1-2):79-84
Despite recent technological advances in vaccine production, most vaccines depend on the association with adjuvant substances. In this study, propolis, which has been attracting the attention of researchers due to its bioactive properties, was evaluated as an immunological adjuvant. The association of 40mg/dose of an ethanolic extract of green propolis with an inactivated oil vaccine against bovine herpesvirus type 5 (BoHV-5), resulted in a significant increase (P<0.01) in the neutralizing antibody levels, comparing to the bovines that received the same vaccine without propolis. Besides, propolis increased the percentage of animals with high antibody titers (above 32). Phenolic compounds such as artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) and the derivatives of cinnamic acid besides other flavonoid substances were abundant in the propolis extract used, and they could be the main substances with adjuvant action. The effect of the green propolis extract on the humoral immune response can be exploited in the development of new vaccines. 相似文献
145.
J. Alberto Oliveira 《Euphytica》1992,63(3):257-263
Summary A program designed to develop two base populations of perennial ryegrass was initiated in 1985 in Galicia. Multitrait mass selection by a base index was practised in two genetic resources groups of wild Galician populations. Plants selected were intercrossed and the two resulting base populations (F and G) were evaluated in two locations at the spaced plant level and in plot trials with the aim of estimating the genetic parameters and the possibilities for future breeding. The two populations did not show significant differences from commercial cultivars. Production characters had low heritabilities (0.01–0.32) in both locations. Seasonal yields had medium to high family heritabilities (0.36–0.73). For the economic traits chosen, the expected genetic advances were important in both populations for summer and autumn growth in Mabegondo and spring and summer-autumn dry matter yield (1st and 3rd year) in Puebla de Brollón. Expected genetic advance for early spring growth was 0.62 in population F. In the autumn of 1991 equal numbers of plants, selected at each location by combined family and mass selection from each of these populations, were planted in two polycrosses with the aim of improving the genetic basis and adaptation of these populations. 相似文献
146.
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae) 总被引:1,自引:0,他引:1
Patrícia Helena Gallo Pamela Lonardoni Micheletti Kellen Regina Boldrini Claudicéia Risso-Pascotto Maria Suely Pagliarini Cacilda Borges do Valle 《Euphytica》2007,154(1-2):255-260
Microsporogenesis of several Brachiaria species of the Brazilian collection at Embrapa Beef Cattle has been analyzed in detail. This paper reports abnormal cytokinesis
in three accessions of three different species (Brachiaria humidicola, 2n = 4x = 36, Brachiaria decumbens, 2n = 4x = 36, and Brachiaria dura, 2n = 6x = 54). Chromosomes paired in bi-, tri-, and quadrivalents in these accessions, whereas chromosome segregation at meiosis
I was characterized by exclusion of laggards as micronuclei. In a high number of meiocytes, the first sign of cytokinesis
appeared only in metaphase II and did not divide the meiocyte into a dyad. Total absence of cytokinesis was also detected
among meiocytes in the second division. Since in both cases the two metaphase plates were very close, they favored the rejoining
of chromosome sets after anaphase II and formed a restitutional nucleus in telophase II. Second cytokinesis occurred after
telophase II in most meiocytes. Monads, dyads, and triads with n or 2n nuclei were observed among meiotic products. The 2n gametes observed correspond to the first division restitution (FDR). The number of affected cells in each accession was variable,
but the number of microspores with restitutional nucleus, including those scored in tetrads and the released ones, did not
exceed 9%. Although polyploidy is common in the genus Brachiaria, its origin is still unclear. Current results suggest that 2n gametes may have contributed to the evolutionary history of the genus. 相似文献
147.
SUN Qian ZOU Mei-Ling ZHANG Chen-Ji JIANG Si-Rong Eder Jorge de Oliveira ZHANG Sheng-Kui XIA Zhi-Qiang WANG Wen-Quan LI You-Zhi 《作物学报》1962,47(1):42-49
As a typical tropical crop, cassava (Manihot esculenta Crantz) has the characteristics of drought resistance, barren resistance, high biomass and so on. In addition to being used for food and forage, it can also be used for production, processing and starch extraction. Due to highly heterozygous cassava genome, breeding is more difficult. Enriching the genetic diversity of cassava germplasm, comprehensively evaluating its genetic background and traits, and discovering superior alleles that control excellent traits are of great significance for cassava breeding in the future. In order to analyze the genetic diversity, genetic relationship and population structure of cassava germplasm in Brazil, 7946 SNPs and 1997 InDels molecular markers were used. Population structure analysis was performed by ADMIXTURE software, and principal component analysis was performed by GCTA software. Brazilian cassava was divided into nine subgroups, and was roughly consistent with the results of cluster analysis using PHYLIP. Among them, subgroup 1, subgroup 2, subgroup 4, subgroup 6, and subgroup 8 could be clustered together respectively, while the samples of other subgroups could be roughly clustered, and there was a certain cross between the samples. The genetic diversity of cassava germplasm in Brazil (0.274) was higher than the genetic diversity level of cassava germplasm in China and Nigeria. Subgroup 5 of Brazil cassava had a relatively high genetic diversity (0.29). The genetic differentiation of subgroups was low (the genetic differentiation vary from 0.03 to 0.15), but higher than domestic cassava germplasm. The genetic distance between cassava accessions varied from 0.084 to 0.297, with the average of 0.228. The results of this study can provide a basis for subsequent association analysis to identify great alleles and introduction. 相似文献
148.
Summary Apomixis is widely distributed among tropical forage grasses, and has long been merely regarded as an impediment to breeding. Panicum maximum is presented as the first opportunity for Brazilian geneticists to develop and test original breeding schemes adapted to an apomictic species.A large and representative germplasm of P. maximum has been introduced and is currently being evaluated. Basic knowledges on biology and reproduction are also available, which demonstrate an easy manipulation of apomixis and sexuality. Several limiting traits have already been detected during evaluation, which justify breeding attempts. An ideal scheme is given to transfer new qualities to already selected varieties. 相似文献
149.