Linear and non-linear regressions were used to derive the calibration function for the measurement of roxithromycin plasma concentration. Their results were compared with weighted least squares regression by usual weight factors. In this paper the performance of a non-linear calibration equation with the capacity to account empirically for the curvature, y = ax∨b + c (b not equal to 1) is compared with the commonly used linear equation, y = ax + b, as well as the quadratic equation, y = ax²+ bx + c. In the calibration curve (range of 0.01 to 10 ㎍/mL) of roxithromycin, both heteroscedasticity and nonlinearity were present therefore linear least squares regression methods could result in large errors in the determination of roxithromycin concentration. By the non-linear and weighted least squares regression, the accuracy of the analytical method was improved at the lower end of the calibration curve. This study suggests that the non-linear calibration equation should be considered when a curve is required to be fitted to low dose calibration data which exhibit slight curvature.

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.

A 5-year-old female Cocker spaniel dog (body weight 7.0 kg) was presented with primary complaints of exercise intolerance and loud precordial thrill which was noticed since she was a puppy. Physical examination revealed a grade Ⅴ/Ⅵ continuous murmur over the maximal point of the left basal area, bounding femoral pulse, but no differential cyanosis. Tall R waves were detected in electrocardiogram, suggesting left ventricular enlargement. Diagnostic imaging studies showed enlarged left ventricle, bulged descending aorta (dAo), markedly dilated right pulmonary artery, and continuous shunt flow between the dAo and main pulmonary artery. Based on these findings, the dog was diagnosed as left to right shunted patent ductus arteriosus (PDA). The patent ductus arteriosus was treated by lodging a PDA duct occluder via the transvenous approach. Clinical signs were markedly improved after the ductal occlusion, the shunt flow was mildly persistent. The case presented is the first case of PDA occluded by the PDA duct occluder via the transvenous approach in a small breed of dog. Although the residual shunt flow was mildly persisted, the dog was clinically normal without detectable murmurs.

A 2-year-old lineolated parakeet (Bolborhynchus lineola) was presented with abdominal distention and respiratory distress for two months. The bird was poorly fleshed and the liver was enlarged on coelomic palpation. Plain and contrast radiographic examinations exhibited hepatomegaly and distended intestinal loop, which compromised the air sacs. Multifocal yperechogenecity was observed in the liver on ultrasonography. Postmortem gross examination revealed hepatomegaly with numerous pinpoint tan foci in the hepatic parenchyma and distended small intestine filled with adult ascarids. Microscopically, granulomatous hepatitis and enteritis infected by intrahistiocytic acid-fast bacilli were evident. Polymerase chain reaction indicated that the acid-fast bacilli were Mycobacterium avium subsp. avium.

A trematode species belonging to the genus Prosthogonimus (family: Prosthogonimidae) was collected in August, 2004 from the bursa of Fabricius of a single Little Grebe, Tachybaptus ruficollis, caught in Chuncheon, Korea. Five specimens were collected in total and fluke morphology was examined under using a light microscope. The average parasite size was 5.6 × 3.2 mm (length × width; based on 4 specimens). The genital pore was located on the anterior right margin of the oral sucker. The cirrus sac was strongly sinuous and extended beyond the intestinal bifurcation to the ventral sucker. The prepharynx was extremely short and the pharynx was small. The vitellaria consisted of 6 follicle bunches and extended from the ventral sucker to the posterior of the testes. Finally, the uterus filled the body cavity posterior to the testes. In addition, there were no heavy slings occurred anterior to the testes. Based on these morphological characteristics, the parasites were identified as P. cuneatus. The discovery of P. cuneatus within a Little Grebe constitutes a new host identification and a new geographical record. This is the first reported case of Prosthogonimus infection within wild birds in Korea.

The large amount of tissue culture medium (TCM), which contains some of the active secretory components of Korean wild ginseng (KWG; Panax ginseng) such as saponins, is usually discarded after harvest of KWG. The present study was aimed to investigate the efficacy of oral administration of the TCM-KWG on growth performance and diseases resistance in broiler chickens. A day old broiler chickens randomized in 6 groups (n=60/groups) were administered orally with 0, 2, 4, 8, 16 and 32 mL/L TCM-KWG through drinking water for 5 weeks and examined the change of weight gain, feed intake and blood components. Also, five weeks old broiler chickens (n=15/groups) were challenged orally with Salmonella (S.) gallinarum and investigated the mortality in broiler chickens. An average weight gain and feed intake significantly didn't change in TCM-KWG administration groups as compared to control group. The concentration of calcium (Ca), phosphate (Pi) and potassium (K) in serum were increase by TCM-KWG administration in broiler chickens. We also found that oral administration of TCM-KWG through drinking water significantly reduced the mortality in broiler chickens experimentally infected with virulent S. gallinarum. The results of this study indicated that TCM-KWG administration may elevate the resistance on disease and improved the skeleton formation and body homeostasis of chickens, and TCM-KWG can be used as a cost-effective and environmentally alternative additives to control of the disease and growth.

This study investigated the potential effects of amitraz on the pre- and postnatal development, behavior, and reproductive performance of offspring of parent rats given amitraz during pre-mating, gestation, and lactation. The test chemical was administered via the drinking water containing 0, 40, 120, and 360 ppm to male rats from 2 weeks before mating to the end of 14-day mating period and to females from 2 weeks before mating, throughout mating, gestation and lactation up to weaning. Based on fluid consumption, the male rats received an average of 0, 5.7 ± 1.33, 13.2 ± 2.08, and 35.8 ± 3.42 mg/kg/day amitraz, and the female rats received an average of 0, 8.7 ± 4.42, 20.1 ± 9.60, and 47.6 ± 22.38 mg/kg/day amitraz, respectively. At 360 ppm, an increase in the incidence of abnormal clinical signs, a suppression in the body weight gain, a decrease in the food consumption and litter size, an increase in the post-implantation loss, and a decrease in the seminal vesicle weight were observed in the parent animals. In addition, a suppression in the body weight gain, a decrease in the grip strength, a delay in the negative geotaxis, an increase in the pre- and post-implantation loss, and a decrease in the number of live embryos were observed in the offspring. At 120 ppm, suppressed body weight gain and reduced food consumption were observed in the parent rats. Suppressed body weight gain and decreased grip strength were also observed in the offspring. There were no signs of either reproductive or developmental toxicity at 40 ppm. Under these experimental conditions, the no-observed-adverse-effect level of amitraz for parent rats and their offspring was estimated to be 40 ppm in rats.

To determine the prevalence of Escherichia (E.) coli O157 : H7 from pigs after the Hazard Analysis and Critical Control Point (HACCP) system has been applied to Korean swine farm since 2006, 291 fecal samples were tested between May and December in 2008. Four E. coli O157:non-H7 (1.4%) were isolated from 4 different non-HACCP-accredited farms and they didn't have virulent genes which can cause illness for human. Also, Clostridium (C.) perfringens, Salmonella spp. and E. coli enterotoxins were tested using multiplex PCR. The positive rate for these pathogens of non-HACCP-accredited farms was higher than that of HACCP-accredited farms, and especially in case of C. perfringens, E. coli enterotoxins LT and STa, it was statistically significant (p less than 0.05). Thus, the early implementation of the HACCP program is expected to greatly contribute to the safety of livestock products as well as food hygiene.

The present study was undertaken to establish reference values for the composition blood lymphocyte populations and compare forty three Hanwoo neonatal calves (KC) with twenty one Holstein calves (HC) by blood cell count and immunophynotying. The percentages of CD2+, CD4+, CD8+, CD26+, ACT2+, MHC class, MHC class Ⅱ and WC1+ T cells, B cells were determined by flow cytometry. The number of lymphocyte and monocyte in HC were higher than those of KC. However, the number of neutrophils was higher in HC than KC. The proportions of CD2+, CD4+, CD8+, MHC class, and WC1+ lymphocytes remained relatively stable during the study period, while there was a moderate increase in the relative percentage of CD26+, ACT2+, MHC class Ⅱ and B cell from birth to approximately 3 weeks of age. Marked differences in the relative proportions of the lymphocyte subpopulations were noted between the individual calves. The present study shows that the T-cell subpopulations are present in peripheral blood of KC at levels comparable with HC, while the MHC class Ⅱ and B cell population of KC increases significantly with age. The absolute number of WBC in KC was due to the decrease of absolute number of neutrophil rather than the increase of lymphocyte. The results indicated that KC have significantly higher number of neutrophils, and proportion of MHC class Ⅱ and B cell than HC.

Fifty young calves, about five to six months old purchased from nation-wide were investigated with the prevelance of neutralizing antibody (Ab) of infectious bovine rhinotracheitis virus (IBRV), parainfluenza 3 virus (PI₃V), bovine viral diarrhea virus (BVDV) and bovine respiratory syncytial virus (BRSV). The positive detection ratio of neutralizing Ab against IBRV was only 3% and two of positive samples showed low antibody titer (below 2). Ab against BRSV showed 48% of positive ratio and among 24 positive samples, antibody titer of 23 samples were below 3. But in the case of BVDV, 68% of samples were positive and 23 samples appeared to possess high antibody titer, above 4 and the antibody titer of five samples were above 8. The highest positive result came from PI₃V. The positive ratio in the samples investigated in this study was 72%, but the antibody titer of positive samples were generally below 3 (77.8% in positive samples).