خيارات البحث
النتائج 21 - 30 من 449
Intramammary antibiotic withdrawal periods for dairy goats compared to those for dairy cattle النص الكامل
2008
I.M. Petzer | E.F. Donkin | E. Du Preez | J. Karzis | T.J. Van der Schans | J.C. Watermeyer | R. Van Reenen
This study investigated the withdrawal periods (WP) of two intramammary antibiotics Cloxamast LC (Intervet SA) and Spectrazol Milking Cow (Schering-Plough Animal Health) in dairy goats and compared them to those recommended for use in cattle. The WP for Cloxamast LC, measured by the Thermo Resistant Inhibitory Substances (TRIS) test, was 60 h in composite samples, 56 h in udder half samples, and the dye was visible for up to 56 h. The WP was significantly shorter than the 72 h recommended WP for use in cattle. It was however significantly longer when the 24 h safety margin (48 h) was subtracted from the recommended WP for cattle. For Spectrazol Milking Cow the antibiotics could be detected by the TRIS test for 61 h in composite samples and 59 h in udder half samples. This did not differ significantly from the recommended 60 h WP for cattle. However, it was significantly longer than that recommended for use in cattle without the 24 h safety margin. There was no significant difference in WP between infected and non-infected udder halves, while there was a weak positive correlation between WP and stage of lactation (R2 = 0.253). There was a moderate positive correlation (R2 = 0.583) between the TRIS test and the presence of dye in milk in udder half samples and between WP in both udder half and composite milk samples (R2 = 0.456). Weak to moderate positive correlations were present between milk yield and the WP in both udder half (R2 = 0.414) and composite (R2 = 0.262) milk samples. Significant differences (P < 0.001) were also observed between the milk yield of udder halves with and without palpable udder damage and between samples that tested TRIS positive and negative on both composite (P = 0.008) and udder half samples (P < 0.001). There was no significant difference between the milk yield of samples with or without dye. There was a significant difference in milk yield between infected and non-infected udder halves (P = 0.054) and a weak negative correlation between milk yield and stage of lactation (R2 = -0.379).
اظهر المزيد [+] اقل [-]Can osteophagia provide giraffes with phosphorus and calcium? النص الكامل
2008
I.P. Bredin | J.D. Skinner | G. Mitchell
The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.
اظهر المزيد [+] اقل [-]Expression of galectin-3 in the testis and epididymis of mouse
2008
Kim, W.J. (Cheju National University, Jeju, Republic of Korea) | Kim, H.L. (Cheju National University, Jeju, Republic of Korea) | Joo, H.G. (Cheju National University, Jeju, Republic of Korea) | Shin, T.K. (Cheju National University, Jeju, Republic of Korea) | Lee, Y.D. (Korean Racing Authority, Jangsoo, Republic of Korea) | Kim, S.J. (Kyungpook National University, Daegu, Republic of Korea), E-mail: kjoon00@knu.ac.kr
The testis and epididymis are important organs of the male reproductive system; the function is to produce, mature, transport, and store sperm. It is important to understand the localization and expression of specific proteins based for the studies of its physiological processes. In the study, we investigated the expression and distribution of galectin-3, one beta-galactoside-binding proteins, in the testis and epididymis of mouse using western blot and immunohistochemistry. Western blot analysis revealed that the expression of galectin-3, 29 kDa protein, was low in the testis. In the epididymis, high expression was detected in the body and tail part, but moderate expression in the head part. By immunohistochemical analysis, we found that positive localization of galectin-3 was detected in some myoid cells and Leydig cells in the testis, but few in the seminiferous tubules. In the epididymis, galectin-3 was intensely expressed in the epithelium of epididymis, especially in the epithelium of both body and tail epididymis. Collectively, these results suggest that galcetin-3 is constitutively expressed in the testis and epididymis of mouse with varying intensity, and the role of galectin-3 in the male reproductive organ may be involved in the specific function of its structures.
اظهر المزيد [+] اقل [-]Determination of eugenol in Eugenia caryophyllata by high-performance liquid chromatography with photodiode array detection and method validation
2008
Yun, H.J. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Yun, S.M. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Lee, M.H. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea), E-mail: leemh@nvrqs.go.kr | Son, S.W. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea)
A method for the quantification of eugenol in the medicinal herb Clove was developed and validated. For preparation of sample solutions clove was dried at 60℃ for 2h and ground by mixer and extracted with 95% ethanol for shaking extraction. The elutes were analyzed by HPLC system included a reversed phase column, a isocratic mobile phase of 60% methanol and PDA detector set at 280 nm. Calibration graphs were linear with very good correlation coefficients(r² greater then 0.9999) from 0.0125~1 ㎍/ml. The limit of detection per sample injection (20 ㎕) was 0.81 ng/㎕ and limit of quantification was 2.47 ng/㎕. The method showed good intra-day precision (%RSD 0.08~0.27%) and inter-day precision (%RSD 0.32~1.19%).
اظهر المزيد [+] اقل [-]Evaluation of antitumor, hepatoprotective and antimutagenic potentials of Phellinus gilvus
2008
Kang, E.H. (Kyungpook National University, Daegu, Republic of Korea) | Kim, K.S. (Kyungpook National University, Daegu, Republic of Korea) | Park, S.C. (Kyungpook National University, Daegu, Republic of Korea), E-mail: parksch@knu.ac.kr
This study was carried out to evaluate the antitumor, hepatoprotective and antimutagenic activities on hot water extract of Phellinus gilvus (PGE). Growth of tumor in mice that were orally given 0.25, 0.5, 1.0, 2.0 gㆍkg-¹ dose of PGE was inhibited in a dose-dependant manner (p less than 0.05). The hepatoprotective effect of PGE in the carbon tetrachloride (CCl₄)-intoxicated rats was studied. In CCl₄+PGE groups, PGE was orally administered with 100 mg/kg/day dose 7 days before the treatment of CCl₄. The serum activity of aspartate aminotransferase and alanine aminotransferase in CCl₄+PGE group were decreased at a rate of 59.6% and 54.1% compared with those in CCl₄ group, respectively (p less than 0.05). Also, total cholesterol and triglyceride in CCl₄+PGE group were significantly decreased at a rate of 90% and 73.6% compared with those in CCl₄ group (p less than 0.05). In the Ames test, we confirmed PGE doesn't have any activity as a mutant, and PGE showed inhibitory effect against mutagenesis induced by 2-amino fluride and sodium azide in Salmonella typhimurium TA98, TA100 and TA 1535 in a dose-dependent manner. From the above results, we may suggest that PGE might have useful as a material for functional food and/or animal pharmaceutics.
اظهر المزيد [+] اقل [-]Determination of amitraz by high-performance liquid chromatography with photodiode array detection and method validation
2008
Yun, H.J. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Yun, S.M. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Lee, M.H. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea), E-mail: leemh@nvrqs.go.kr | Son, S.W. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea)
In veterinary medicine amitraz has been used as an insecticide to eliminates mites, lice, and ticks in dogs, cats, goats, swine and cattle. The objective of present study was to developed an analytical method using one-step extraction and determination of the amitraz in veterinary drugs by liquid chromatography (LC). The amitraz was analyzed by LC equipped with Waters XTerra RP18 (4.8×250 mm; 5 ㎛; Waters, USA) analytical column, using 75% acetonitrile (acetonitrile/D.W; 75/25) at 1.0 ml/min. The UV-VIS detection of amitraz was made at 290 nm. Calibration graphs were linear with very good correlation coefficients (r² greater than 0.9999) from 80~120 ㎍/ml. The limit of detection was 0.09 ㎍/ml and limit of quantification was 0.27 ㎍/ml. The method showed good intra-day precision (CV 0.05~0.09%) and inter-day precision (CV 0.06~0.18%).
اظهر المزيد [+] اقل [-]Analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans to assure safety of imported meat
2008
Kim, M.K. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea), E-mail: kimmk@nvrqs.go.kr | Kim, D.G. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Kim, S.Y. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Choi, S.W. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Kwon, J.W. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Yun, S.J. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Song, S.O. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Chung, G.S. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea)
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are ubiquitous and can contaminate the food chain. A study monitoring PCD/Fs in imported meat was conducted at the National Veterinary Research and Quarantine Service (NVRQS, Republic of Korea) in order to maintain food safety from the bioaccumulative PCDD/Fs. Seventeen PCDD/Fs with toxic equivalency factors (TEFs) established by World Health Organization (WHO, 1998) were analyzed in imported beef, pork, and chicken by high resolution gas chromatography/mass spectrometry (HR-GC/MS). Results of the monitoring for the last 5 years are presented. The levels of PCDD/Fs were similar to other studies except two unusually high concentrations in pork and beef. Excessive levels greater than the Korean provisional maximum residue limit of PCDD/Fs were found in a sample of pork imported from Chile and a sample of beef imported from U.S, and those products were rejected and returned. These was no obvious trend or differences with respect to time or origin of meat in this study.
اظهر المزيد [+] اقل [-]Prevalence of bovine tuberculosis in dairy cattle in Korea from 1961 to 2004
2008
Yoon, H.C. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Chung, B.H. (Konkuk University, Seoul, Republic of Korea) | Yoon, C.S. (Konkuk University, Seoul, Republic of Korea) | Lee, J.H. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Moon, O.K. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Park, S.Y. (Konkuk University, Seoul, Republic of Korea) | Lee, W.C. (Konkuk University, Seoul, Republic of Korea) | Kim, T.J. (Konkuk University, Seoul, Republic of Korea), E-mail: tjkim@konkuk.ac.kr
The trend in the prevalence of bovine tuberculosis (BTB) in Korean dairy cattle was investigated in relation to test programs used between 1961 and 2004, during which a total of 8,961,061 dairy cows were tested and 10,248 confirmed to have BTB. The annual prevalence increased in the late 1960s, then decreased during the 1970s and 1980s, and started to increase again from the late 1990s. It seemed that the prevalence varies according to the different test program used. The prevalence of BTB was higher when the tests were performed with heat-concentrated synthetic medium (HCSM) or purified protein derivative (PPD) tuberculin alone compared to that when using combined HCSM and PPD tuberculin testing.
اظهر المزيد [+] اقل [-]Infection patterns of porcine reproductive and respiratory syndrome virus by serological analysis on a farm level
2008
Park, C.K. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea), E-mail: parkck@nvrqs.go.kr | Yoon, H.C. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Lee, C.H. (Kyungpook National University, Daegu, Republic of Korea) | Jung, B.Y. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Lee, K.K. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Kim, H.S. (Chungnam National University, Daejeon, Republic of Korea)
Porcine reproductive and respiratory syndrome (PRRS) is the most economically important viral infectious disease in pig populations worldwide. This study was conducted to better understand the epidemic and dynamics of PRRS virus (PRRSV) on each farm and to evaluate the risk of PRRSV infection in Korea. Interviews with pig farmers were carried out to obtain PRRS vaccination programmes in 60 pig farms throughout Korea. Blood samples were also collected from the 59 pig farms to investigate outbreak patterns of each farm. Vaccination against PRRS was performed in 16.7% farms for breeding pigs and 8.3% of farm for nursery pigs. According to the seroepidemiological analysis, 56 (94.9%) out of 59 farms were considered to be affected by PRRSV infection. The results revealed that 68.9% of sows tested were seroconverted and interestingly, gilt herds had the highest seropositive rate (73%), suggesting that gilts may play a key role in PRRSV transmission in sow herds. Among the PRRS-affected piglet herds, 33 (55.9%), 14 (23.7%) and 6 (10.2%) farms were initially infected with PRRSV during the weaning, suckling and nursery period, respectively. It seems likely, therefore, that PRRSV infection predominantly occurs around the weaning period in piglet herds. Based on antibody seroprevalence levels in both sow and piglet groups, we were able to classify patterns of PRRSV infection per farm unit into 4 categories; category 1 (stable sow groups and non-infected piglet groups), category 2 (unstable sow groups and non-infected piglet groups), category 3 (stable sow groups and infected piglet groups), and category 4 (unstable sow groups and infected piglet groups). Our data suggested that 43 (72.9%) farms were analysed to belong to category 4, which is considered to be at high-risk for PRRS outbreak. Taken together, our information from this study will provide insight into the establishment of an effective control strategy for PRRS on the field.
اظهر المزيد [+] اقل [-]Antimicrobial resistance of Staphylococcus aureus isolated from domestic and imported raw meat in Korea
2008
Heo, H.J. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Ku, B.K. (National Veterinary Research and Quarantine Service, Anyang, Republic of Korea) | Bae, D.H. (Kyungpook National University, Daegu, Republic of Korea) | Park, C.K. (Kyungpook National University, Daegu, Republic of Korea) | Lee, Y.J. (Kyungpook National University, Daegu, Republic of Korea), E-mail: youngju@knu.ac.kr
The rapid evolution of antibiotic resistance in Staphylococcus (S.) aureus is of considerable concern. Methicillin-resistant S. aureus (MRSA) strains are especially one of the greatest public concerns since the treatment of infections is more difficult when encountering resistance. In this study, we conducted a nationwide survey on the antimicrobial resistance of S. aureus isolated from raw meat samples collected from 16 countries, including Korea, and investigated the prevalence of MRSA as a possible source of human infection. Of 1,984 meat samples, S. aureus was isolated from 218 (11.0%) samples consisting of 23 (12.1%) from domestic meat and 195 (10.9%) from imported meat. The isolated rates of poultry meat, pork and beef were 12.8%, 7.0% and 10.0%, respectively. With regard to imported meat, the incidence varied from 4.8% to 16.6% from 13 countries, with the exception of Austria and Poland. In a resistance test to 20 antimicrobial agents, one hundred and eighty-four isolates (84.4%) were resistant to one or more antimicrobial agents tested. Especially, 17 (7.8%), 124 (56.9%) and 28 (12.8%) isolates showed a resistance to 3, 2 and 1 drugs, respectively. One isolate originating from domestic beef was resistant to 7 drugs. Another isolate originating from imported poultry meat showed resistance to oxacillin and methicillin by the disk diffusion test and minimal inhibition concentration method, but showed negative for detection of the mecA gene.
اظهر المزيد [+] اقل [-]