• Korean Journal of Poultry Science
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• v.16 no.3
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• pp.129-137
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• 1989

This study was conducted to estimate heritabilities and genetic correlations on economic traits in Korean Native Ogol Fowl. The data analysis were the record of 450 pullets produced from 150 dams and 20 sires of Korean Native Ogol Fowl raised at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows ； 1. The average body weights at 8 and 24 weeks,300 and 500 days of age were 514.54, 1490.96, 1753.47 and 2013.31g respectively, The age of first egg was 179.19 days, and the number of egg Produced to 300 and 500 days of age were 80.12 and 162.82 e89s, respectively. The egg weight at first egg, 300 and 500 days of a8e were 40.03 and 49.92 and 55.59g, respectively. 2 The heritability estimates based on the variance of sire, dam and combined components were 0.441-0.661, 0.120-0.490, 0.345-0.465 for body weight； 0.365, 0.207 and 0.282 for age at first egg； 0.354-0.362, 0.204-0.230 and 0.279-0.296 for number of egg production: 0.259-0.464, 0.512-0.633 and 0.386-0.540 for egg weight, respectively. 3. The genetic correlations coefficients of economic traits were as follows: the coefficients between body weight with age at first egg, number of egg Production and egg weight were 0.539-0.617, -0.520-0.157 and 0.180-0.754； between age at first egg with number of egg production and egg weight were -0.717 and 0.552-0.587； between number of egg production and egg weight was -0.383-0.381, respectively.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.851-865
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• 2018

This study investigated the prevalence of Listeria monocytogenes in slaughterhouses, and determined serovars and genotypes, and antibiotic resistance of the isolates obtained from slaughterhouses and humans in Korea. Two hundred ninety samples were collected from feces (n=136), carcasses [n=140 (cattle: n=61, swine: n=79)], and washing water (n=14) in nine slaughterhouses. Eleven human isolates were obtained from hospitals and the Korea Center for Disease Control and Prevention. Listeria monocytogenes was enriched and identified, using polymerase chain reaction (PCR) and 16S rRNA sequencing. Serovars and presence of virulence genes were determined, and genetic correlations among the isolates were evaluated by the restriction digest patterns of AscI. Antibiotic resistance of L. monocytogenes isolates were examined against 12 different antibiotics. Of 290 slaughterhouse samples, 15 (5.17%) carcass samples were L. monocytogenes positive. Most L. monocytogenes isolates possessed all the virulence genes, while polymorphisms in the actA gene were found between carcass and human isolates. Serovars 1/2a (33.3%) and 1/2b (46.7%) were the most frequent in carcass isolates. Genetic correlations among the isolates from carcass and clinical isolates were grouped within serotypes, but there were low geographical correlations. Most L. monocytogenes isolates were antibiotic resistant, and some strains showed resistance to more than four antibiotics. These results indicate that L. monocytogenes are isolated from carcass and human in Korea, and they showed high risk serotypes and antibiotic resistance. Therefore, intensive attentions are necessary to be aware for the risk of L. monocytogenes in Korea.

• Journal of Korean Society of Forest Science
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• v.44 no.1
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• pp.36-42
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• 1979

A study was conducted on the genetic correlations and simple correlations between some characters of the plus trees of Pinus densiflora. The results can be summarized as follows. 1. Simple correlations height growth by age was measured and high correlation(above r=0.9) were observed. Therefore, early selection seems to be possible in the light of the results made up to 8 years old. 2. Genetic correlation between height and root collar diameter was 0.266 and the correlation between height and branch diameter was 0.091 and 0.391 was between root collar diameter and branch diameter.

• Journal of the Korean Data and Information Science Society
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• v.25 no.5
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• pp.1025-1038
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• 2014

Linear mixed model has often been utilized for genetic association analysis with family-based samples. The correlation matrix for family-based samples is constructed with kinship coefficient and assumes that parental phenotypes are independent and the amount of correlations between parent and offspring is same as that of correlations between siblings. However, for instance, there are positive correlations between parental heights, which indicates that the assumption for correlation matrix is often violated. The statistical validity and power are affected by the appropriateness of assumed variance covariance matrix, and in this thesis, we provide the linear mixed model with flexible variance covariance matrix. Our results show that the proposed method is usually more efficient than existing approaches, and its application to genome-wide association study of body mass index illustrates the practical value in real data analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.302-307
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• 2010

The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.433-440
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• 1993

Means and standard errors of 285 Taiwan's local chicken and 429 Single Comb White Leghorn pullets at 35 wk of age were: egg weight (g) $48.3{\pm}0.3$, $54.6{\pm}0.3$, shell index $73.39{\pm}0.26$, $73.20{\pm}0.18$, shell color $15.23{\pm}0.40$, $0.88{\pm}0.27$, shell whiteness $72.61{\pm}0.57$, $90.00{\pm}0.35$, shell strength ($kg/cm^2$) $3.77{\pm}0.07$, $3.35{\pm}0.05$, shell thickness (mm) $0.38{\pm}0.003$, $0.38{\pm}0.002$, Haugh units $85.26{\pm}0.50$, $91.81{\pm}0.38$ and yolk percent (%) $30.17{\pm}0.18$, $27.32{\pm}0.16$ respectively. Theestimated heritabiliities of Taiwan's local chicken based on sire and dam components of variance were as follows: egg weight 0.20, shell index 0.1, shell color 0.87, shell whiteness 0.79, shell strength 0.37, shell thickness 0.14, Haugh units 0.24 and yolk percent 0.16. Genetic correlations based on sire and dam components of variance and covariance were also estimated. Generically, the shell index was positively correlated with egg weight, shell strength and yolk percent, and egg weight was negatively correlated with shell thickness, Haugh unit and yolk percent.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1390-1393
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• 2006

Data spread over 11 years (1986-1996) pertaining to a synthetic population developed by inter se mating of half-breds of Corriedale and Russian Merino with Nali maintained at CCS Haryana Agricultural University, Hisar were utilized for the estimation of genetic parameters for growth traits. The means for birth weight (BWT), weaning weight (WWT), six month body weight (SWT), yearling weight (YWT), preweaning daily gain (PRW) and post weaning daily gain (POW) were 3.35 kg, 10.79 kg, 13.28 kg, 18.96 kg, 82.6 gm and 27.6 gm, respectively. The effects of year and season of birth and sex of lamb were significant for all the traits under study except the effect of season of birth for WWT, SWT and PRW. No definite trend was observed over the years for the averages of body weight and gain. Lambs born during the spring season performed better for BWT, WWT and PRW while the performance of lambs born during autumn was better for the other traits included in the study. The male lambs were heavier than the females for body weight at all stages and gain in weight. The heritability estimates for WWT and PRW were low; for BWT and SWT were moderate and for YWT and POW were high. Birth weight had high heritability and high genetic correlations with subsequent body weights and gains but due to the presence of a maternal effect on BWT and WWT, a sequential selection procedure is recommended for the improvement of growth rate in sheep.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.181-195
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• 1989

The study was conducted to obtain the genetic informations for some useful characters in tobacco breeding. The eight parents and a set of 28 crosses of F1's and F2's were used as materials, and planted on two different cultivated systems, i. e., oriental's and burley systems, during 1986-1988 at taegu Experiment Station, Korea Ginseng & Tobacco Research Institute. The observed characters were six agronomic characters which were plant height, number of leaves per plant, leaf length, leaf width, days to flowering, yield and five chemical components, nicotine, total nitrogen, protein nitrogen, total volatile base and pet, ether extract. The results obtaining are summarized as follows: 1. The higher heritabilities were found for days to flowering yield and nicotine in both generations, but values for number of leaves per plant, leaf length, total nitrogen and protein nitrogen were lower than other characters. 2. Genotypic correlation coefficients among all pairs of characters were slightly higher than the corresponding phenotypic correlations in F1's and F2's on two different cultivated systems. The relationship between leaf length and leaf width was the positive correlation, but that between number of leaves per plant and leaf width was negative. 3. From the genotypic correlations between yield and other characters, a conclusion that the yield was highly correlated with plant height, leaf length, leaf width and days to flowering was given. 4. Quality was positively correlated with number of leaves per plant and nicotine, but negatively with the other agronomic characters and chemical components.

• Journal of Life Science
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• v.8 no.4
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• pp.431-436
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• 1998

These studies were carried out to obtain useful information about the effective selection of vegetable perilla by estimating the genetic relationships between the heritabilities and the genetic correlations of quantitative traits among eight agronomic characters from 91 perilla varieties. The positive correlations were showed among characters such as between leaf weight and leaf size, leaf weight and leaf length, leaf weight and leaf width, leaf weight and plant height, leaf weight and stem diameter, leaf size and leaf length, leaf size and leaf width, leaf size and plant height, leaf size and stem diameter , leaf length and leaf width, leaf length and plant height, leaf length and stem diameter, leaf width and plant height, leaf width and stem diameter, plant height and stem diameter, plant height and the number of internodes per plant, and the number of internodes per plant and the number of leaves per plant. Heritabilities were high as from 0.7311 to 0.9112 among leaf weight, leaf size, leaf length, leaf width, plant height, stem diameter, and the number of internodes per plant.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1080-1084
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• 2002

Carcass characteristics of 241 crossbred pigs (Korean wild boars ${\times}$ Landrace sows) were analyzed to examine variations in fasted body weight (FASTWT), carcass weight (CARCWT), dressing percentage (DP), back fat thickness (BFT) and longissimus muscle weight (LMW), and to estimate genetic and phenotypic parameters using three different slaughter-end points. Covariates in the least squares full sib model were slaughter age, fasted body weight and back fat thickness of the carcass. Coefficient of variation was highest for BFT followed by LMW, CARCWT, FASTWT and DP in magnitude. Regressions of three covariates on traits were all linear. However, slaughter age was not significant as a linear covariate for five traits while FASTWT was significant for CARCWT and LMW and BFT was significant for all remaining traits. Genetic and phenotypic variation was considerably reduced by regressing FASTWT or BFT in the model. Heritability estimates of FASTWT, CARCWT, DP and BFT were 0.68, 0.61, 0.11 and 0.49, respectively, using slaughter age as covariate (model 1). Those of CARCWT, DP, BFT and LMW were 0.15, 0.15, 0.30 and 0.11, respectively, using FASTWT as covariate (model 2). Heritability estimates of the traits using LMW as covariate (model 3) were similar to the estimates from Model 1 except that the estimate of CARCWT was reduced to 0.39. Genetic or phenotypic correlations among FASTWT, CARCWT and BFT were all positive and moderate to high. Those between BFT and LMW were also positive and low to moderate. However, genetic and phenotypic correlations between DP and CARCWT were positive while those between DP and FASTWT were negative. It was suggested from this study that differences in carcass yield traits be determined using slaughter age or back fat thickness as slaughter-end point and carcass quality traits using fasted body weight as slaughter-end point.