Уточнить поиск
Результаты 101-110 из 572
Acute and subacute toxicity of trichlorfon in guppies (Poecilia reticulata)
2009
Heo, G.J., Chungbuk National University, Cheongju, Republic of Korea | Shin, G.W., Chonbuk National University, Jeonju, Republic of Korea
The aim of the present study was to determine the acute and subacute potential of trichlorfon in guppies (Poecilia reticulata). We first defined the 24h median tolerance limit (TLm∧24h) of the fish to trichlorfon. Guppies were then treated with TLm∧24h and 1/10 TLm∧24h trichlorfon concentrations to evaluate of any histological alterations occurred. The TLm∧24h value of trichlorfon was 11 ppm. This concentration resulted in acute toxicity to the gills and kidneys with edema, hyperplasia of the gill lamellae, and vacuolated degeneration and necrosis of renal tubular cells. In the case of subacute toxicity using a 10-fold dilution of the TLm∧24h value (1.1 ppm), no behavioral changes, external lesions or histopathological changes were observed. Therefore, safe concentration of trichlorfon might be 1.1 ppm in guppy for controlling parasitic infections.
Показать больше [+] Меньше [-]Investigation on an epidemic of tuberculosis in dairy cattle farms In Jeongeup, Korea
2009
Yoon, H.C., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Moon, O.K., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Kim, Y.J., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Cho, B.J., Jeongeup Branch, Jeonbuk Institute of Livestock and Veterinary Research, Jeongeup, Republic of Korea | Lee, S.D., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Lee, J.W., Jeongeup Branch, Jeonbuk Institute of Livestock and Veterinary Research, Jeongeup, Republic of Korea | Lee, S.J., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea
The present study describes an investigation on an epidemic of Tuberculosis (TB) which has been occurred among dairy cattle farms in Jeongeup, Jeollabuk-do since 2007. The investigation was performed in three ways as follows: 1. Collecting information about bovine TB outbreaks using investigation reports, an on-the-spot and tracing-back investigations; 2. Analyzing the outbreak pattern; 3. Establishing hypothesis and performing statistical analysis on potential risk factors. In the early 2000s, TB outbreaks were sporadically reported in beef cattle, and only a small number (1~2) of reactors was confirmed in each of outbreak farms. The number of TB outbreaks has been suddenly increased from 2007, mainly in dairy cattle farms. And these outbreaks were temporarily clustered during the period, from March 2007 to April 2009 (relative risk, RR=13.7, p less than 0.001). And two spatial clusters of which radiuses were 0.3 km (RR=6.9, p less than 0.001) and 0.9 km (RR=3.6, p less than 0.01). The analysis to find risk factors was performed on 99 dairy farms (21 outbreaks), which are located in the most seriously affected village during 2007-2009. Middleman (odds ratio, OR=47.4, p less than 0.05) and raw milk collecting system (OR=6.9, p less than 0.05) were recognized as with the highest association. Considering the fact that all the outbreak farms except one had their own manure composting tank, it might be that the manure containing pathogen was leaked from tank and transmitted to other farms by fomites such as middleman or raw milk collecting system.
Показать больше [+] Меньше [-]Diaphragmatic hernia in a Jeju horse (crossbred) broodmare
2009
Yang, J.H., Equine Hospital of Busan Race Park, Korea Racing Authority, Busan, Republic of Korea | Koh, Y.N., Jeju Animal Theme Park, Jeju, Republic of Korea | Hwang, K.K., Jeju National University, Jeju, Republic of Korea | Lim, Y.K., Jeju National University, Jeju, Republic of Korea
Diaphragmatic hernias, whether congenital or acquired (traumatic), are rarely observed in the horse. Acquired diaphragmatic hernias typically occur secondary to trauma or an increase in intra-abdominal pressure due to falling, heavy exercise, or parturition. Diaphragmatic herniorrhaphy is difficult to perform in adult horses and the horses with symptomatic diaphragmatic hernias usually die. A 10-year old, 340 kg, Jeju horse (crossbred) broodmare with sudden onset of gait disorder and a moderate emaciation was examined. Findings on physical examination included conjunctivitis, dehydration, shallow breathing, dyspnea, weaken heart beat, lack of auscultatable sounds from the gastrointestinal tract, and anorexia. Rectal temperature was 38.4℃ and respiratory rates were moderately increased. There were slight signs of acute colic. The broodmare died one day after non-specific treatment of fluids, nutriment, antibiotics and non-steroidal anti-inflammatory drug. The cause of death was strangulation of the small intestine through a diaphragmatic hernia. The rent was about 2 cm in diameter and located in the central right part of diaphragm. Around 60 cm of small intestine was protruded into thoracic cavity through the rent. The cause of the hernia could not be ascertained. The broodmare had been pastured with many other horses, and the groom had not noticed any aggressive behavior among them. It was, however, speculated that trauma by stallion's attack may have been the cause of the diaphragmatic hernia, because the new horse may be the object of behaviors ranging from mild threats to seriously aggressive kicking, squealing, rearing, and biting.
Показать больше [+] Меньше [-]Evaluation of the control of pathogen load by an anti-Salmonella bacterium in a herd of cattle with persistent Salmonella infection
2009
Patton, Toni G. | Sharma, Vijay K. | Carlson, Steve A.
To determine whether an anti-Salmonella bacterium is involved in control of pathogen load in persistently infected cattle herds. 24 Holstein calves experimentally infected and 39 Holstein cows naturally infected with Salmonella spp. An Escherichia coli (designated as P8E5) that possessed anti-Salmonella activity was isolated from Salmonella-negative bovine feces obtained from a herd with endemic Salmonella infection. In vitro analysis involved enumerating Salmonella enterica serovar Typhimurium coincubated with E coli P8E5. In vivo analysis involved coadministration of Salmonella spp and E coli P8E5 or an E coli control strain to neonatal Holstein calves. Fecal samples were collected on multiple days after inoculation, and quantitative PCR assay was performed by use of Salmonella-specific primers. E coli P8E5 reduced viability of Salmonella spp in vitro. Shedding of Salmonella organisms was diminished in calves administered E coli P8E5, whereas the control strain of E coli had no effect on shedding of Salmonella organisms. In this study, an E coli strain was identified that possessed bacteriocin-like activity and was able to decrease viability of Salmonella organisms in vitro and in vivo. Therefore, it is possible that this organism could be representative of native microbiota that dampen Salmonella spp in persistently infected cattle herds.
Показать больше [+] Меньше [-]The comparative prevalence of five ixodid tick species infesting cattle and goats in Maputo Province, Mozambique
2009
C. De Matos | C. Sitoe | L. Neves | J.O. Nothling | I.G. Horak
This study compares the prevalence of ixodid tick species on cattle and goats in Maputo Province. Adult ticks as well as the nymphs of three species, and only the adults of two species were collected from sets of five cattle at 21 localities throughout the province and compared with those collected from similar sets of goats at the same places. Amblyomma hebraeum adults and / or nymphs were present on cattle and on goats at all 21 localities, and 90 cattle and 22 goats were infested with adult ticks. Rhipicephalus (Boophilus) microplus adults and / or nymphs were collected from cattle at 20 and from goats at 15 localities, and 92 cattle and 34 goats were infested [Chi-square test (×2), P < 0.001]. The total length of several maturing female R. (Boophilus) microplus collected from cattle and goats exceeded 5 mm, indicating that they successfully engorge on both host species. Rhipicephalus appendiculatus adults and / or nymphs were present on cattle at 15 and on goats at 13 localities, but 28 cattle and only one goat were infested with adult ticks (×2, P < 0.001). Adult Rhipicephalus evertsi evertsi were recovered from cattle at 20 and from goats at 17 localities, and 74 cattle and 69 goats were infested. Adult Rhipicephalus simus were collected from cattle at 18 and from goats at 11 localities (Fisher's exact test, P = 0.04), and 60 cattle and 14 goats were infested (×2, P < 0.001). These findings underscore the advisability of including goats in acaricide application programmes designed for the control of tick-borne diseases in cattle at the same locality.
Показать больше [+] Меньше [-]A brief history of botulism in South Africa : historical overview : Onderstepoort and veterinary research in Africa
2009
C.M. Cameron
When looking back into the history of botulism and contemplating the final understanding of the syndrome and the ultimate solutions, there are four facets that stand out clearly. The first is that much of the solution was guided by astute observations, curious travellers, committed veterinarians and particularly farmers themselves who were able to relate the occurrence of the condition to climatic and grazing conditions. Secondly, there was the identification of the osteophagia and pica syndrome which led to the feeding of bone-meal as a successful mitigating measure as well as the establishment that botulism was not due to a plant poisoning. Thirdly, the solution of the problem depended on the integration of experience and knowledge from diverse disciplines such as soil science, animal behaviour and husbandry, nutrition, botany and ultimately advanced bacteriology and the science of immunology. Finally it required the technical advancement to produce toxoids in large quantities and formulate effective aluminium hydroxide precipitated and oil emulsion vaccines.
Показать больше [+] Меньше [-]Currently important animal disease management issues in sub-Saharan Africa : policy and trade issues
2009
G.R. Thomson
The present international approach to management of transboundary animal diseases (TADs) is based on the assumption that most can be eradicated ; consequently, that is the usual objective adopted by international organizations concerned with animal health. However, for sub-Saharan Africa and southern Africa more particularly, eradication of most TADs is impossible for the foreseeable future for a variety of technical, financial and logistical reasons. Compounding this, the present basis for access to international markets for products derived from animals requires that the area of origin (country or zone) is free from trade-influencing TADs. The ongoing development of transfrontier conservation areas (TFCAs), extending across huge areas of southern Africa, therefore presents a development conundrum because it makes creation of geographic areas free from TADs more difficult and brings development based on wildlife conservation on the one hand and that based on livestock production on the other into sharp conflict. Sub-Saharan Africa is consequently confronted by a complex problem that contributes significantly to retarded rural development which, in turn, impedes poverty alleviation. In southern Africa specifically, foot-and-mouth disease (FMD) presents the greatest problem in relation to access to international markets for animal products. However, it is argued that this problem could be overcome by a combination between (1) implementation of a commodity-based approach to trade in products derived from animals and (2) amendment of the international standards for FMD specifically (i.e. the FMD chapter in the Terrestrial Animal Health Code of the World Organisation for Animal Health [OIE]) so that occurrence of SAT serotype viruses in free-living African buffalo need not necessarily mean exclusion of areas where buffalo occur from international markets for animal products. This would overcome a presently intractable constraint to market access for southern African countries and enable conservation and livestock production to be more effectively integrated, to the benefit of both.
Показать больше [+] Меньше [-]Some anatomical studies on the arterial supply and venous drainage of the tail of the buffalo "Bos Bubalis L."
2009
M. R. A. Gad | Z. A. Adam | M. G. Tawfiek
Twenty tails of buffaloes were used in this study from apparently healthy adult animals. They are dissected to reveal their arteries and veins. Fourteen photographs illustrated the results in the study. The study revealed that the arterial supply of the tail comes from the median caudal, superficial caudal, deep caudal, dorsolateral caudal arteries and the tail is drained by five caudal veins; median caudal, two ventrolateral caudal and two lateral caudal veins.
Показать больше [+] Меньше [-]African horsesickness : transboundary diseases
2009
B.J. Erasmus
African horsesickness (AHS) played a major role in the history and development of southern Africa, both in times of peace and of war. Frequent epidemics of AHS resulted in major transportation impediments. The viral (filterable) nature of the aetiological agent was proven in 1900 by Sir John M'Fadyean in London, making it one of the first animal diseases for which this had been demonstrated. Similarly, the cultivation of AHS virus in the brain of mice and its subsequent attenuation were also amongst the first such feats for animal viruses. Interestingly, both milestones followed the initial work of Max Theiler (son of Sir Arnold) with yellow fever virus.
Показать больше [+] Меньше [-]Trends in the control of theileriosis in sub-Saharan Africa : tick-borne diseases
2009
D. McKeever
The declining efficacy of acaricide treatment as a means of reducing the prevalence of Theileria parva infections in sub-Saharan Africa has intensified efforts to achieve control through immunization of susceptible cattle. The infection and treatment method of immunization has enjoyed a resurgence with the availability of more effective cold chain facilities, although concerns remain regarding the possibility of vaccine strains spreading in local tick populations. In addition, an in-depth understanding of protective mechanisms deployed by immune cattle and the antigens targeted by them has led to substantial progress in the development of candidate subunit vaccines against both sporozoite and schizont stages of the parasite. The likely success of these vaccines, as well as infection and treatment immunization, will ultimately depend on the extent to which they disturb the endemic status of the parasite. These issues are discussed in the light of recent information on the genotypic diversity of T. parva in the field and the extent to which this is compromised by the immune response.
Показать больше [+] Меньше [-]