• Title/Summary/Keyword: ANIMAL MODEL

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Models Describing Growth Characteristics of Holstein Dairy Cows Raised in Korea

  • Vijayakumar, Mayakrishnan;Choy, Yun-Ho;Kim, Tae-Il;Lim, Dong-Hyun;Park, Seong-Min;Alam, Mahboob;Choi, Hee-Chul;Ki, Kwang-Seok;Lee, Hyun-Jeong
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.3
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    • pp.167-176
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    • 2020
  • The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R2) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

Estimation of Genetic Parameters for Somatic Cell Scores of Holsteins Using Multi-trait Lactation Models in Korea

  • Alam, M.;Cho, C.I.;Choi, T.J.;Park, B.;Choi, J.G.;Choy, Y.H.;Lee, S.S.;Cho, K.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.3
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    • pp.303-310
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    • 2015
  • The study was conducted to analyze the genetic parameters of somatic cell score (SCS) of Holstein cows, which is an important indicator to udder health. Test-day records of somatic cell counts (SCC) of 305-day lactation design from first to fifth lactations were collected on Holsteins in Korea during 2000 to 2012. Records of animals within 18 to 42 months, 30 to 54 months, 42 to 66 months, 54 to 78 months, and 66 to 90 months of age at the first, second, third, fourth and fifth parities were analyzed, respectively. Somatic cell scores were calculated, and adjusted for lactation production stages by Wilmink's function. Lactation averages of SCS ($LSCS_1$ through $LSCS_5$) were derived by further adjustments of each test-day SCS for five age groups in particular lactations. Two datasets were prepared through restrictions on number of sires/herd and dams/herd, progenies/sire, and number of parities/cow to reduce data size and attain better relationships among animals. All LSCS traits were treated as individual trait and, analyzed through multiple-trait sire models and single trait animal models via VCE 6.0 software package. Herd-year was fitted as a random effect. Age at calving was regressed as a fixed covariate. The mean LSCS of five lactations were between 3.507 and 4.322 that corresponded to a SCC range between 71,000 and 125,000 cells/mL; with coefficient of variation from 28.2% to 29.9%. Heritability estimates from sire models were within the range of 0.10 to 0.16 for all LSCS. Heritability was the highest at lactation 2 from both datasets (0.14/0.16) and lowest at lactation 5 (0.11/0.10) using sire model. Heritabilities from single trait animal model analyses were slightly higher than sire models. Genetic correlations between LSCS traits were strong (0.62 to 0.99). Very strong associations (0.96 to 0.99) were present between successive records of later lactations. Phenotypic correlations were relatively weaker (<0.55). All correlations became weaker at distant lactations. The estimated breeding values (EBVs) of LSCS traits were somewhat similar over the years for a particular lactation, but increased with lactation number increment. The lowest EBV in first lactation indicated that selection for SCS (mastitis resistance) might be better with later lactation records. It is expected that results obtained from these multi-trait lactation model analyses, being the first large scale SCS data analysis in Korea, would create a good starting step for application of advanced statistical tools for future genomic studies focusing on selection for mastitis resistance in Holsteins of Korea.

Using zebrafish as an animal model for studying rare neurological disorders: A human genetics perspective

  • Dilan Wellalage Don;Tae-Ik Choi;Tae-Yoon Kim;Kang-Han Lee;Yoonsung Lee;Cheol-Hee Kim
    • Journal of Genetic Medicine
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    • v.21 no.1
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    • pp.6-13
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    • 2024
  • Rare diseases are characterized by a low prevalence, which often means that patients with such diseases are undiagnosed and do not have effective treatment options. Neurodevelopmental and neurological disorders make up around 40% of rare diseases and in the past decade, there has been a surge in the identification of genes linked to these conditions. This has created the need for model organisms to reveal mechanisms and to assess therapeutic methods. Different model animals have been employed, like Caenorhabditis elegans, Drosophila, zebrafish, and mice, to investigate the rare neurological diseases and to identify the causative genes. While the zebrafish has become a popular animal model in the last decade, mainly for studying brain development, understanding neural circuits, and conducting chemical screens, the mouse has been a very well-known model for decades. This review explores the strengths and limitations of using zebrafish as a vertebrate animal model for rare neurological disorders, emphasizing the features that make this animal model promising for the research on these disorders.

A Study on the Skin Characteristics of Qi Deficiency and Blood Deficiency Animal Model (기허(氣虛), 혈허(血虛) 동물모형(動物模型)의 일반(一般) 특성(特性) 및 피부(皮膚) 특성(特性) 연구(硏究))

  • Shin, Yoon-Jin;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.1
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    • pp.76-88
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    • 2009
  • Back ground and Objective : There is a need for objectification and scientific verification of Pattern identification in Oriental medicine. The purpose of this study was to investigate the skin characteristics of Qi deficiency and Blood deficiency animal models. Material and Methods : Sprague-Dawley rats were divided into three groups: normal group, Qi deficiency group and Blood deficiency group. The Qi deficiency animal model was induced through restriction of food (75g/kg/day) for 20 days. Blood deficiency animal model was induced by bleeding from tail vein(0.3 ml/time) 8 times. The normal animal model was kept without any intervention. The general condition was observed by measuring body weight, body temperature, blood pressure, pulse rate, and hematological and biochemical parameters. The skin characteristics were observed by measuring the erythema index(EI), melanin index(Ml), transepidermal water loss(TEWL) and dermal microcirculation. Results : 1. In the Qi deficiency group, body weight was lower than the other groups. In the Qi deficiency group, blood pressure was lower than in the Normal group. There was no difference in body temperature and pulse rate between the three groups. 2. In the Qi deficiency group, blood sugar was lower than in the Blood deficiency group. There was no difference in triacylglycerol between the three groups. In the Qi deficiency group, the WBC count was lower than in the Blood deficiency group. RBC count was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively. In the Qi deficiency group, Hb and Hct were higher than the other groups. 3. EI and MI were decreased in the Qi deficiency group, and EI showed a significant decrease. 4. EI and MI were increased in the Blood deficiency group, and MI showed a significant increase. 5. TEWL was significantly increased in the Qi deficiency group, while it was decreased in the Blood deficiency group, TEWL was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively and all three groups showed significant difference. 6. In the Qi deficiency group, dermal microcirculation was lower than the other groups. Conclusion : The above results show that the erythema index decreases in the Qi deficiency model, and the melanin index increases in the Blood deficiency model. The Qi deficiency animal model shows an increase in transepidermal water loss, while the Blood deficiency animal model shows a decrease. Further studies should develop new models of Pattern Identification that are more specific.

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An Experimental Animal Model of Anomalous Pancreaticobiliary Duct Union (췌담관 합류이상의 실험동물 모델)

  • Han, Seok-Joo;Chang, Hang-Seok;Kim, Jong-Sung;Han, Jin-Soo;Kim, Ho-Geun;Hwang, Eui-Ho
    • Advances in pediatric surgery
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    • v.4 no.2
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    • pp.100-109
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    • 1998
  • The anomalous pancreaticobiliary duct union (APBDU) might cause the formation of choledochal cyst and malignancies of hepatopancreaticobiliary system. The purpose of this study is to make an experimental animal model of APBDU similar to that of human. One to two-month-old Mongrel dogs (n=12) were divided into two groups; the control group (n=2) had a sham operation performed, and in the experimental group (n=10) the end of distal ' common bile duct (CBD) was anastomosed to the side of the dorsal pancreatic duct making APBDD. Serum was obtained for chemical analysis on the 10th postoperative day. The dogs were sacrificed at the 5th week (n=3), the 6th week (n=3), the 7th week (n=2), the 8th week (n=2) and the 6th month (n=2) after the experimental surgery. With sacrifice, operative cholangiogram was taken, and bile juice was obtained for chemistry and bacterial culture. The en-bloc specimens of the hepatopancreaticobiliary system were removed for microscopic examination. Serum and bile juice amylase levels were elevated in the experimental group(n=10), but not in the control group(n=2). Operative cholangiograms of control group revealed no evidence of bile duct dilatation.. On the other hand, the bile duct in the experimental group was markedly dilated without any evidence of stenosis at the anastomosis site (n=10). Histologic examination of the hepatopancreaticobiliary system in the experimental group resembled the findings of choledochal cyst in human. The APBDU of this animal model can produce bile duct dilatation by pancreaticobiliary reflux. We think that this animal model can be potentially promising for the research about the APBDU associated hepatopancreaticobiliary diseases.

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학술자료-2007년 광주 동물보호소 분석을 통한 효과적인 관리방안 제시

  • Myeong, Bo-Yeong
    • Journal of the korean veterinary medical association
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    • v.44 no.6
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    • pp.555-575
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    • 2008
  • The role of animal shelter is important for animal welfare. From this year, the animal shelter have clinic system and veterinarian. So adoption rate increased to 45%, die of illness decresed to 258% in the dog and adoption rate increased to 489%, die of illness decreased to 258% in the cat. The disease and condition of each animal is improved, also belief of adoption is improved too. veterinarian is necessary to animal welfare and systemic, professional model of animal shelter will contribute to animal welfare.

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Prediction of Retail Beef Yield Using Parameters Based on Korean Beef Carcass Grading Standards

  • Choy, Yun-Ho;Choi, Seong-Bok;Jeon, Gi-Jun;Kim, Hyeong-Cheol;Chung, Hak-Jae;Lee, Jong-Moon;Park, Beom-Young;Lee, Sun-Ho
    • Food Science of Animal Resources
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    • v.30 no.6
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    • pp.905-909
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    • 2010
  • Two sets of data on carcass traits and beef cut parameters were used to investigate the relationships between carcass and beef cut measurements, which can be used to make predictions of retail cut percentages. One set had a total of 1,141 measurements of Hanwoo cattle of three different sex origins, which were slaughtered in an abattoir located at the National Institute of Animal Science, RDA, Korea from 1996 to 2008. To develop prediction models for retail cut percentage with higher accuracies than the current model, another set consisting of a total of 13,389 records of carcass and beef cut traits were collected from 30 abattoirs and butcheries in Korea from 2008 to 2009. Bulls yielded heavier and leaner carcasses than steers. High correlation coefficients were estimated between amount of body fat and percent retail cut (-0.82) as well as between back fat thickness (BF) and percent retail cut (-0.62). The amount of retail cut, however, was highly correlated with body weight before slaughter (BW, 0.95) or with cold carcass weight (CWT, 0.94). Relationships between percent retail cut and measurable beef yield traits, BF, loin eye area (LEA) or CWT varied by sex class, which must be considered for development of a prediction model with high accuracy. Models of data for all breeds and sexes fit the effects of breed, sex, and interaction of abattoir by butchers, whereas models of data for each breed and sex fit the effect of interaction of abattoir by butcher only. Due to possible future changes in back fat control, we performed a log transformation of BF. Our new models fit better than the currently used model.