• Korean Journal of Veterinary Research
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• v.49 no.2
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• pp.149-155
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• 2009

The objective of this study was to analyze data from the planned national serological monitoring program for Aujeszky's disease (AD) using a simulation model to evaluate probable outcomes expected in the sample derived from the simulated herds at predefined within-herd prevalence and herd prevalence. Additionally, prevalence at animal- and herd-level estimated by the stochastic simulation model based on the distributions of the proportion of infected herds and test-positive animals was compared with those of data from a national serological survey in 2006, in which 106,762 fattening pigs from 5,325 herds were tested for AD using a commercial ELISA kit. A fixed value of 95% was used for test sensitivity, and the specificity was modeled with a minimum, most likely and maximum of 95, 97 and 99%, respectively. The within-herd prevalence and herd prevalence was modeled using Pert and Triang distributions, respectively with a minimum, most likely and maximum point values. In all calculations, population size of 1,000 was used due to lack of representative information. The mean number of infected herds and true test-positives was estimated to be 27 herds (median = 25; 95% percentile 44) and 214 pigs (median = 196; 95% percentile 423), respectively. When testing 20 pigs (mean of 2006 survey) in each herd, there was a 3.3% probability that the potential for false-positive reactions due to less than 100% specificity of the ELISA test would be detected. It was found that the model showed prevalence of 0.21% (99% percentile 0.50%) and 0.5% (99% percentile 0.99%) at animal- and herd-level, respectively. These rates were much similar to data from the 2006 survey (0.62% versus 0.83%). The overall mean herd-level sensitivity of the 2006 survey for fattening pigs was 99.9%, with only a 0.2% probability of failing to detect at least one infected herd.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.363-367
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• 2008

This study was carried out to investigate an epidemiological state of neosporosis in Korean indigenous cattle in Uljin. Bloody samples were collected from 552 female cattle (337 farms), more than 5 years old, in 10 districts of Uljin, Antibody to N caninum were examined by enzyme linked immunosorbent assay (ELISA). Seroprevalence of individual and farm were 7.6% (42/552) and 8.6% (29/337), respectively. Positive rates by districts was variable $(0%{\sim}14,9%)$, and it was seemed to be a tendency that positive farms gathered with in a small zone. In seroprevalence by herd size farms having between 5-9 heads was top (37%), but there was no significant difference among herd size.

• Journal of Veterinary Clinics
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• v.10 no.1
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• pp.65-94
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• 1993

This study examined metabolic profiles of 1349 Holstein cows from 91 commercial herds. Thirteen parameters which are consisted of twelve blood components and body condition score were examined and their mean values. standard deviations and standard limits, which are 80% confidential limits, in each lactational stage were reported. The variations of each parameter affected by season, individual milk yield, adjusted corrected milk yield of herd. and lactation number were also reported. A model of metabolic profile test applicable to this country where the average number of cows in a herd is small as to be fifteen is designed. Metabolic profiles as reflected in each parameter were discussed in relation to adequacy of dietary intake for production, milk production, reproductive performance, and diseases, and the possible measure to improve productivity of dairy cows were proposed. Much of the variation in parameters was due to differences between herds, and less to differences between seasons, differences between individual milk yield, and differences between lactational stages. As the average herd size in this country is small, it is believed that all the cows in a herd must be sampled, and the individual result of each parameter was compared with the standard limit for each lactational stage, and the percentage of cows which are outside the standard limits in a herd was calculated to use as a criteria for evaluation of the herd. Data outside the 99% confidential limits were to be deleted at first, but when the trends of the data outside the 99% confidential limits are same as the trends of the data within 99% confidential limits, the deleted data must be reviewed again, otherwise some important informations would be missed. The mean concentration of blood urea nitrogen in this study was much higher than that was reported in England, U.S.A. and Japan, and it was similar to the upper limits reported in England, U.S.A. and Japan. So it was thought that the concentration of blood urea nitrogen is improper as a criteria for protein intake. The increase of serum total protein cocentration beyond standard limits was due to increase of serum globulin concentration in most of the cows. The correlation coefficient between serum and protein and serum globulin concentration was 0.83. Serum globulin concentration was negatively related to adjusted corrected milk of herd. Serum albumin, calcium and magnessium concentrations were negatively related to adjusted corrected milk of herd, which indicate that high-producing individual or high-producing herd have not taken sufficient protein/amino acids, calcium and magnessium. Packed cell volume was negatively related to adjusted corrected milk of the herd, and the trend was same In each lactational stage. The correlation coefficient between serum and packed cell volume was 0.16 and the correlation was very weak. Blood glucose concentration was lowest in early lactational stage, which indicates negative energy balance in early lactational stage. Blood glucose concentration was negatively related to adjusted corrected milk of herd from peak to late lactational stage, which indicates negative energy balance during the period in high-producing individuals or high-producing herds. Correlation coefficient between serum aspartate aminotransferase activity and serum ${\gamma}$-glutamyltransferase activity was 0.41, and this indicates that serum ${\gamma}$-glutamyltransferase should be included as a parameter of metabolic profile test to evaluate liver function. Body condition score of dairy cows in this country was lower than that of Japan in every lactational stages, and the magnitude of increase in body condition score during middle and late lactational stages was small. Metabolic profile can not be evaluated with solely nutritional intake. When an individual or large percentage of cows in a herd have adnormal values In parameters of metabolic profile test, veterinary clinician and nutritionist should cooperate so as to diagnose diseases and to calculate the e of no운ents simultaneously.

• The Journal of Industrial Distribution & Business
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• v.8 no.6
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• pp.87-95
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• 2017

Purpose - The structural changes of Korean agriculture are complex due to heterogeneous production processes and farms' features. This study analyzed trends of dualism in Korean agriculture over the period 2000-15 based on farm-level data to clarify the specific trends of dualism in terms of farm income, farm-size, and farm operators' age. From the results of this study, we would be able to understand the features of structural changes in Korean agriculture more profoundly. Research design, data, and methodology - We incorporated farm-level data in South Korea: Agricultural census and Farm household economy survey. As measures of inequality, we used size-weighted quantiles, and normalized Gini coefficients as well as mean and conventional quantiles. The size-weighted quantiles are more robust to changes in the number of small farms, but they are more sensitive to changes in the distribution of farm-size. Thus, they would be more useful to identify trends of dualism of Korean agriculture. Results - The results show that the farmland distribution of crop farms became more skewed and dispersed. However, the herd distribution of livestock farms became more concentrated. To be specific, their mean and 1st quantile increases more rapidly than their size-weighted 2nd quantile and size-weighted 3rd quantile. Gini coefficients of livestock farms regarding their herd distribution decreased by 0.1 on average. In the case of income distribution, the results indicate that the polarization regarding farm household/agricultural/non-agricultural income became more severe. However, we also found that the distribution of transfer income became concentrated continuously. The results imply that transfer income including subsidies would decrease farm income polarization. Lastly, during the study periods, Korean farms were aging over time, and age distribution of them more concentrated. Conclusions - The structure of Korean agriculture has been changing, even though the absolute size of it decreased over time. Land (herd) distribution became more dispersed (concentrated). Inequality regarding agricultural income became more severe, and it made farm household income more polarized even though transfer income would decrease income gaps among farms. Lastly, farms continue to age regardless of farm types and this might affect the structural changes in Korean agriculture in the future.

• Korean Journal of Veterinary Service
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• v.33 no.2
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• pp.151-156
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• 2010

This survey was carried out to investigate the seroprevalence of antibodies to Neospora caninum in Korean indigenous cattle that was raised in central area province Gyeongnam, Korea. A total of 719 sera were tested for N. caninum antibodies using ELISA (Herdcheck anti-Neospora, IDEXX Laboratories Inc., Westbrook, Maine USA). Seroprevalence of individual and farm were 29.8%(214/719) and 53.2%(50/94). Regional seropositive rates of the samples were 61%(47/77), 23.3%(7/30), 13.8%(49/355), 37.6%(77/205), 65.4%(34/52) at Changwon, Jinhae, Gimhae, Miryang, Yangsan, respectively. It showed difference at the age and on the herd size of farms. A herd of cattle above the age of 5 was more infective than under 4 years. And in seroprevalence by herd size farms having under 30 heads was top(35.7%). Seropositive 214 herds of N. caninum antibidies were tested for brucellosis by test tube. Positive rate of double infection was 16.4%(35/214).

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.255-262
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• 2023

Caseous lymphadenitis (CLA) is an endemic but not well-studied disease of Korean native goats (KNG) in Korea. Corynebacterium pseudotuberculosis is the causative agent of the contagious and chronic CLA found in goats. This study aimed to validate the potential risk factors associated with CLA and assess its seasonal prevalence to mitigate this disease in KNG. Data were collected through a questionnaire from four high- and four low-prevalence farms randomly selected based on a prior investigation. The monthly assessments of CLA were conducted in a goat abattoir located in Jeonnam Province, Korea, to evaluate its seasonal prevalence. The associated risk factors for CLA in KNG herds imply that herd size, scratching against pillars, pipes, or walls in the herd, and disinfection of goat herds are potential risk factors for CLA (P<0.05). The type of floor and entry of new goats into the herd, which are potential risk factors, affected CLA prevalence in the KNG herd (P<0.2). The prevalence of CLA in KNG was significantly higher in spring (29.34%) than in autumn (14.61%), summer (15.31%), and winter (19.48%) (P<0.05). Based on the risk factor assessment, attention should be to establishing accurate preventive measures by avoiding these identified potential risk factors.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.155-164
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• 1996

The objective of this study was to estimate the investment limit in equipment capital by Capital Recovery Method. The data used was collected from 23 Hanwoo(Korean Native Cattle) farms in 1994. The necessary time for herd size expansion was average 5 years from opening(9.7 heads) to 50 heads, 4 years from 50 to 100heads, 3 years from 100 to 150 heads, and 2 years from 150 to 200 heads, respectively. It took 14 years from opening to 200 heads of herd size. The debts for fattening cattle farms were 15.2million won for the size of 50 heads, 37.1 million won for the size of 100 heads and 89.0 million won for the size 200 heads, respectively. Average rates of debt interest were 5.1 % 7.2 and 10.8, correspendingly. As the hear size increased, debt interest rates also increased due to government funds limit. The investment limits in equipment capital perfarm household were 77.7 million won for 50 heads, 135.1 for 100 heads, and 294.3 for 200 heads for 5,500 won per kg liveweight, 70.7 million won for 50 heads, 122.6 for 100 heads and 269.3 for 200 heads for 5,000 won per kg liveweight, 63.6 million won for 50 heads 110.0 for 100 heads and 244.2 for 200 heads for 4,500 won per kg liveweight.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.53-56
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• 2013

This study was carried out to investigate the seroprevalence of Neospora caninum infection in dairy cattle of northern Gyeonggi province in Korea. A total of 716 dairy cattle from 14 dairy farms were tested for the presence of antibodies against N. caninum using a commercial ELISA test kit. Herd and individual seroprevalences of N. caninum were 92.8% (13/14) and 23.1% (166/716), respectively. The seroprevalence of dairy cattle according to age was the highest at 49~72 months (27.4%), but the difference was not statistically significant (P>0.05). No significant relationship between N. caninum seropositivity with the herd size of the dairy farms was found (P>0.05). The results indicate that N. caninum infection spreads widely in dairy farms of northern Gyeonggi province in Korea.

• Korean Journal of Veterinary Service
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• v.30 no.2
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• pp.197-203
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• 2007

A total of 501 serum samples were selected from blood samples that were submitted to Department of Veterinary Pathology, Kangwon National University from all provinces in Korea from September 2001 to August 2002. Their sera were examined for antibodies to swine influenza virus subtype H1N1 (SlV H1N1) and porcine repro-ductive and respiratory syndrome virus (PRRSV) according to the age of pig, season, and herd size using enzyme-linked immunosorbent assay. The seroprevalence of SIV H1N1, PRRSV, and dual infection were 39.12%, 61.48%, and 25.95%, respectively. The seroprevalence of SIV H1N1 according to herd size was not significant differences (p>0.05). The results showed that the PRRSV infection spread widely in swine herds throughout the country.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.316-320
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• 2000

The present study conducted to evaluate the isolation frequency of Salmonella sap., Escherichia O157:H7 and Listeria monocytogenes in fecal samples collected form 33 dairy cow feedlots in West Gyeong-nam province from tan. 179\ulcorner to Feb. 1999. Salmonella spp. were isolated from 8.7% of fecal samples and 57.5% of dairy cow feedlots participaiting in this study had at least one positive fecal 7ample. The isolation rates of Salmonella spp. in each herd size were 42.9% in ln less than 125 heads, 63.6% in 25% to 50 heads and 75% in more than 50 heads. Of the positive sample, the most common serogroup recovered was Bl(31.5%), followed by C1 and D(22.9%), C2(16.2%), A(4.2%) and E(2.1%), in order. However, E. coli O157:H7 and Listeria monocytogenes were net detected in the fecal samples collected from all feedlots.