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排序方式: 共有135条查询结果,搜索用时 31 毫秒
1.
SUMMARY Twenty-four of 57 calves fed a diet containing 33% cotton seed meal (CSM) died between 7 and 15 weeks of age. Initial deaths were not accompanied by premonitory signs, but after CSM withdrawal most calves developed rough coats, anorexia, weakness, ascites and subcutaneous oedema. Those that died had large volumes of serous fluid in the body cavities, hard livers of ‘nutmeg’ appearance, and pulmonary congestion. Histopathologically the livers showed periacinar necrosis in acute cases and periacinar fibrosis in chronic cases. Lungs from several calves had oedema, haemosiderosis and fibrosis in some pulmonary vessels. Atrophy of myocardial fibres was present in most cases. The concentration of free gossypol in the diet was 100 to 220 mg/kg. Ante-mortem and post-mortem findings supported a diagnosis of gossypol poisoning. The deaths continued for 4 weeks after withdrawal of CSM from the diet. 相似文献
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RO Pinho BS Camilo DMA Lima FAC Villadiego JCM Vergara HH Shiomi RE Cardoso PS Lopes JD Guimarães 《Reproduction in domestic animals》2018,53(2):393-400
The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty‐six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination. 相似文献
3.
Johnson M Mackintosh CG Labes RE Taylor MJ Wharton DA 《New Zealand veterinary journal》2003,51(2):93-98
Aim: To discover whether cross infection between red deer (Cervus elaphus) and cattle is possible with either a bovine isolate of the cattle lungworm, Dictyocaulus viviparus, or with a cervine isolate of the lungworm, Dictyocaulus eckerti which is thought to be maintained primarily in deer. Method: Twelve cattle and 12 red deer were reared parasite-free from birth. At 3-4 months of age, half of each species (n=6) were experimentally infected with D. viviparus and the other half with D. eckerti. The course of infection was monitored for 34 days, after which the animals were slaughtered and the lungs removed to assess levels of infection. Results: Faecal larval counts demonstrated that patent Dictyocaulus infections occurred in all groups. At necropsy, adult worms were found in the lungs in all groups except the cattle that were infected with D. eckerti. The largest numbers of adult worms were found in the red deer infected with D. eckerti. Conclusion: It was demonstrated that both cattle and red deer could be infected with either D. viviparus or D. eckerti. However, D. eckerti larvae that originated from deer established more successfully in deer and D. viviparus larvae that originated from cattle established more successfully in cattle. 相似文献
4.
Qureshi T Labes RE Lambeth M Montgomery H Griffin JF Mackintosh CG 《New Zealand veterinary journal》2000,48(4):99-104
AIMS: To demonstrate the transmission of Mycobacterium bovis infection from experimentally infected ferrets (Mustela furo) to non-infected ferrets in a laboratory setting, using three different isotypes of M. bovis, and to observe ferret behaviour that might be implicated in disease transmission. METHODS: Three female ferrets, each experimentally infected with a unique strain of M. bovis, were housed together with six female and two male non-infected ferrets in an isolation facility. Transmission of infection was monitored clinically, serologically (using an ELISA test), bacteriologically, histologically, and by isotype analysis of M. bovis isolates using spoligotyping to determine whether or not transmission of each strain occurred. Ferret behaviour was observed using a time-lapse video recorder. RESULTS: Transmission of M. bovis infection was confirmed in two male and four female ferrets. Isotype analysis showed that of the experimentally infected females, one did not infect any other ferret, another transmitted M. bovis to one ferret before it died prematurely 49 days post-infection, and the third, which was cannibalised, appears to have transmitted M. bovis to both males and three females. However, two of these latter three females had died before the event of cannibalism took place. One female was infected with two strains. Several behavioural interactions were observed that could have resulted in M. bovis transmission, including den sharing, sniffing of orifices and faeces, cannibalism and aggressive breeding behaviour. CONCLUSIONS: Horizontal transmission of M. bovis infection was demonstrated in ferrets under experimental housing conditions. Routes of transmission may involve cannibalism and factors such as den sharing, playing, fighting, mating, and sniffing of faeces. 相似文献
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We evaluated whether new information could be drawn from additional data collection and unconventional statistical analyses of an on-farm trial. First, we compared a conventional sampling method using a biomass estimate of weed abundance to repeated visual assessment of the percentage ground cover of weeds. The biomass was sampled once after the treatment, whereas the ground cover was repeatedly sampled once before weed control plus several occasions after weed control. Second, we contrasted the outcomes from analysis of variance ( anova ), taking samples from a single point in time with repeated measures (rm) anova and a multivariate method. As the outcomes and conclusions drawn were relatively similar, we conclude that the ground cover estimate of weed abundance was as reliable as the biomass estimate. The rm anova enabled us to follow the temporal trend in response to treatments in the most abundant species, including possible initial differences. Multivariate analysis went even further, by clearly displaying species-wise responses and treatment selectivity. 相似文献
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为研究中国美利奴羊不同甘露(聚)糖结合凝集素(MBL)浓度感染绵羊肺炎支原体(MO)的免疫因子水平变化,本研究选择血清中MBL高、低浓度的绵羊各6只(感染组和对照组各3只),感染组人工感染MO,分别在人工感染前和感染后不同时间,采用荧光定量PCR法检测血液中血清因子及补体表达水平。结果显示,不同MBL浓度的绵羊人工感染后MBL m RNA水平呈下降趋势,MBL高浓度促炎因子IL-2和IFN-γ的m RNA表达水平较高,抗炎因子IL-4的m RNA表达水平在感染后1 d升高,此后开始下降,而IL-4的m RNA水平在14 d后有所升高;MBL低浓度羊感染后其TNF-α的m RNA水平显著升高,随炎症的缓解,逐渐降低;补体C1和C3的m RNA在感染后表现出不同的变化,MO感染可以激活补体途径。本研究结果表明,低血清MBL浓度与绵羊支原体肺炎具有一定的相关性,MBL不同浓度组之间其IL-2、IL-4、TNF-α、IFN-γ、补体C1、C3水平存在差异,低浓度MBL的绵羊更易发生比较严重的炎症反应。 相似文献
10.
C. SABATON L. SIEGLER V. GOURAUD J.L. BAGLINIÈRE & S. MANNÉ 《Fisheries Management and Ecology》1997,4(6):425-438
A mathematical model representing the long-term change in a trout population under different river management scenarios is presented. It describes the structure of a population broken down into age classes based on the Leslie matrix; if the population structure for any given month is known, the model should be able to estimate that of the following month. The passage from one month to the next takes into account various relevant factors: survival rate of individuals in the different age classes; fertility rate of females; linear and weighted growth rates; displacement linked to habitat fluctuations using weighted usable area (WUA) values. The model was applied to two French rivers. Regular monitoring of trout populations on the River Kernec enabled comparison of the response of the model with no displacement, with actual variations in fish stocks on the first river. In addition, the knowledge of WUA chronologies on the River Echez made it possible to carry out initial simulations of the response of a fish population to different river management scenarios at the second site. 相似文献