종두우의 육종가 추정 모형에 따른 정확도의 비교에 관한 연구 1 . 종두우의 평가 모형에 따른 정확도의 비교

양영목(Y . M . Yang),이광전(K . J . Lee) 한국축산학회 1991 한국축산학회지 Vol.33 No.9

This study was undertaken to estimate true and approximate reliabilities in BLUP-models with and without maternal grandsires(MGS). A total of 2,121 records(milk and fat yields) sired by 76 sires(14 MGSS) was used for calculating reliabilities on the breeding values of dairy sires. The results obtained are as follows. 1. Effective number of daughters per sire varied from 7.14 to 174.58. 2. Without considering MGS, reliabilities ranged from 0.295 to 0.863, and from 0.276 to 0.855 in milk and fat yields, respectively. 3. Considering MGS, MGS-model reduced the predicted error variance(PEV) by more than 9.5% and reliabilities ranged from 0.342 to 0.872 and from 0.322 to 0.86.3 in milk and fat yields, respectively. This result indicates that we should pay more attention to the reliability estimates. 4. Approximate reliabilities are always overestimated over the true estimates. 5. When true estimate was more than 0.55, the deviation between approximate and true estimates decreased. These results indicate that approximate method is useful as a reliability estimation.

염색체 이상에 관한 세포 유전학적 연구 (4) - 염색체 전좌 -

이연근(Y . K . Lee),이광전(K . J . Lee),이동희(D . H . Lee),양영목(Y . M . Yang),손진기(J . K . Son) 한국축산학회 1994 한국축산학회지 Vol.36 No.1

The early suppression of lethal gene maximizes the effect of domestical improvements applying cytogenetical analysis on the chromosome of dairy cattle, which demonstrated the chromosomal aberration. Fourteen females and three males of dairy cattle tested for the experiment. The chromosomal analysis cultivated blood from the jugluar vein or coccygeal vein of experimental cattle. The results obtained in the experiments show following: The diploid(2n=60) of female cattle has the 29 pairs of acrocentric autosome or telocentric, and the two large submetacentric XX chromosome. As staining the G-handing. one of them shoved chromosomal aberration. We have found the 1/29 translocation relating to calving, rearing and production efficiency.

Thoroughbred 경주마의 경주능력에 대한 환경요인의 효과 및 유전분산 (遺傳分散) 추정

박경도,이광전,양영목,최윤석,김재남,김연순 ( K . D . Park,K . J . Lee,Y . M . Yang,Y . S . Choi,J . N . Kim,Y . S . Kim ) 한국축산학회 1992 한국축산학회지 Vol.34 No.1

This study was undertaken using a total of 2,577 racing records of horses from September, 1989 to July, 1990 that collected at the K. H. A. A. (Korean Horse Affairs Association) to investigate effects of environmental factors and to estimate genetic variance for racing performance. Results obtained from this study were as follows. Horse`s age, racing number, track condition and racing season showed significant effects on racing time, and winner`s racing time was not appropriate environmental factor for mean racing time in Korea. Racing performance was the best when horse`s age was 3-4yr, racing number was l situated inside, moisture content was more than 16% in track and racing seasons were spring and winter. Estimates of σ²_e by Maximum Likelihood were smaller than those by Minimum Variance Quadratic Unbiased Estimation (MIVQUE). Adjustment for winner`s racing time reduced estimates of σ²_s, σ²_h, and σ²_e, especially, estimates of σ²_h, which were reduced by an average of about 1000% and estimates of repeatabilities were lower than those of heritabilities. Estimates of heritabilities and repeatabilities by nationality ranged from .13±.17 to .30±.20 and from .36±.07 to .52±.14, respectively. Pooled estimates of heritabilities and repeatabilities were .19±.13 and .42± .06 respectively.

혈록관계와 (血綠關係) 유전적 군이 포함된 혼합모형에 의한 젖소 종모우의 육종가 추정

이광전(K . J . Lee),양영목(Y . M . Yang),양희성(H . S . Yang) 한국축산학회 1989 한국축산학회지 Vol.31 No.11

This study was undertaken to estimate dairy sires` breeding value by BLUP procedures with additive relationship and genetic group. The data used consisted of calving during the years 1976 to 1987 on Holstein cows in 29 dairy farms of Kyung-Kee, Chung-Nam, Kyung-Nam, Kyung-Buk, and Kang-Won Provinces. In total there were 1129 records and 43 sires. All records were standardized to 305-days, 2x milking and mature-equivalent by USDA-DHIA correction factors. The results obtained were as follows. 1. The variance components of sire, herd-year-season* sire, and error for milk yield by Henderson Method III were 121300.80445, 126877.24500, and 1575221.08369, respectively. The heritability for milk yield was 0.26. 2. The BLUE values of H.Y.S. ranged widely from 815.437㎏ to 6240.884㎏, the herd number 29 was the highest rank. 3. The breeding value of sires ranged widely from-529.401㎏ to +4459.008㎏. 4. The sires of registered number 1479300, 1625389 and 10395 were the highest rank of the genetic group Ⅰ, Ⅱ and Ⅲ respectively. 5. The sires of registered number 1625389, 1597697 and 320576 were the first, the second, and the third rank in all, respectively.

개체모형의 유전적 군에 관한 연구

이광전(K . J . Lee),최윤석(Y . S . Choi),설동섭(D . S . Seol),손진기(J . K . Son),양영목(Y . M . Yang) 한국축산학회 1992 한국축산학회지 Vol.34 No.5

1933 milk records and their pedigrees in 48 herds calving from 1985 to 1991 were used to study the methods for genetic grouping in the animal model. The first method (Method 1) was based on sex of parent and birth date and sex of the animal with unknown parent. The second method(Method 2) was based on sex of parent and birth date. There were little differences in iteration time between Method 1 and Method 2. Considering the numbers of iteration to meet convergence, Method 1 was more efficient than Method 2 in data ((reduced data). But for data 2(full data), Method 2 had fewer numbers of iteration to meet convergence compared to Method 1. PTA correlations between Method 1 and Method 2 were relatively low(0.72). When permanent environmental effect was not considered in the animal model, correlations between Method 1 and Method 2 were the lowest for PTA and their ranks (0.56, 0.68). Method 1 seemed to be superior to Method 2 considering PTA correlations between intermediate iterations and last iteration. It was suggested that Method 1 is more desirable for genetic grouping of the animal model in the point of low PTA correlations between Method 1 and Method 2, as well as little differences in iteration time and iteration number. It shows that the additive genetic effect for milk yield has been continuously increased since 1976, considering animal model`s PTA based on Method 1 for genetic grouping.

개체모형을 이용한 경주마의 능력지수 개발에 관한 연구

이광전(K . J . Lee),박경도(K . D . Park),양영목(Y . M . Yang),최윤석(Y . S . Choi),안준천(J . C . An),신미영(M . Y . Sin) 한국축산학회 1992 한국축산학회지 Vol.34 No.4

A total of 6,338 racing times of 690 horses was used for this study. Data were repeated racing times of horses that raced at least three times at the 1000m race for a year, 1991 and collected from the Korean Racing Association (K.R.A.). Results obtained were as follows. 1. Investigated percentages of the total variance accounted for by contemporary group, month, day and race were 7.73%, 8.45% and 29.55%, respectively. Ratios ²σ_e/²σ_a and ²σ_e/²σ_p were 3.486 and 10.457, respectively. 2. Animal model used repeated racing times. Estimated breeding values of the horses ranged from -2.44 to +2.65. The regression coefficient and r² of the breeding value on birth-year were 0.04 and 0.001, respectively. Breeding value and permanent environmental effect did not have significant variation among the birth years. 3. The trait that has the highest correlation with estimated breeding values for repeated racing times was the average time. The correlation coefficient between the two traits and estimate of heritability for the average time were 0.86 and 0.41, respectively. 4. Performance index obtained by the multiple regression procedure of the estimated breeding values for the repeated racing times on the other traits was as follows. I = -47.6564 - 0.0193X₁ + 0.6405X₂ + 0.0972X₃ - 0.0047X₄ (r²=0.76) (X₁=best time, X₂=average time, X₃=poorest time, X₄=% races placed 1-2).

젖소군의 유량생산 수준별 유전능력 평가에 관한 연구

이광전(K . J . Lee),박경도(K . D . Park),양영목(Y . M . Yang),최윤석(Y . S . Choi),이연근(Y . K . Lee),조광현(K . H . Jo) 한국축산학회 1993 한국축산학회지 Vol.35 No.6

The results obtained from a total to 1993 milk records ranging 1985 to 1991 were as follows. 1. Milk yields and standard deviations of three production levels on the basis of ME milk yield of all cows freshening in the same herd-year were 7,284.68㎏∼9,333.28㎏and 1,370.30∼1,686.56, respectively, and therefore showed the heterogeneity among three production levels of milk. 2. When milk records were transformed to logarithms, average milk yields, standard deviations, and coefficients of variation for production levels were stable. 3. In case of transforming to logarithms, residual variance component of low group increased markedly and this result indicated that the ranks of genetic evaluations for bull-sires and bull-dams could be reversed. 4. REML estimates of heritability for low, medium, and high groups were 0.189, 0.234, 0.254, respectively, and multiple traits evaluation was necessary. 5. Proportions of sires selected from groups by herd-year production levels corresponding to top 5% based on PTAM were 18.2%, 36.4%, 45.5%, for low, medium, and high groups. 6. In case of log transformation, proportions of sires selected from groups corresponding to top 5% of PTAM were 38.9%, 61.1%, 0.0% for low, medium, and high groups, respectively. On the other hand, proportions of elite cows corresponding to top 1% were 45.5%, 54.54%, 0.0% for low, medium, and high groups. 7. Genetic correlations and rank correlations of PTAMs among low, medium, and high groups showed large values. These high correlations indicated that heterogeneity among dairy herds in Korea was due to environmental causes. 8. Without accounting for heterogeneity of milk yields among dairy herds in Korea, the direct application of evaluation models developed by advanced countries could bring the possibility of misranking genetically superior bulls and cows.

가축의 유전적 개량을 위한 지시형질의 이용에 관한 연구 - 젖소를 중심으로 -

이광전(K . J . Lee),정길생(K . S . Jung),한상기(S . K . Han),박홍양(H . Y . Park),양영목(Y . M . Yang),박경도(K . D . Park),박동준(D . J . Park) 한국축산학회 1991 한국축산학회지 Vol.33 No.11

This study was carried out with bull calves of high and low breeding value for milk yield, using a pedigree index. At the same time, plasma concentrations of several traits were investigated in order to find out the potential use of indicator traits for the genetic improvement. Results obtained from this study are as follows. 1. Total protein contents of plasma showed significant differences between genetic groups during feeding(P$lt; 0.05), while albumin contents were significantly different during refeeding (P$lt;0.01). Phenotypic correlation between pedigree index and total protein was -0.2111 and this result indicates that further research ias needed for the potential use of indicator traits. 2. Cholesterol concentraions of plasma showed significant differences between genetic groups only during the feeding period, and the content of bull calves with high breeding value was higher than that of lower bull calves. 3. Mean concentrations of glucose were not significantly different between genetic groups of three treatments, while fasting caused a reduction in glucose concentration which increased upon refeeding. 4. Correlation between pedigree index and blood urea nitrogen was -0.0478 and no potential use of indicator traits was found. 5. Concentrations of triglyceride with the high breeding group were lower than those of the low yielding group, and the reversal trend was observed upon refeeding. 6. Phenotypic correlation between total protein and globulin was 0.69. while genetic correlation between cholesterol and triglyceride showed the highest value of 0.97. 7. Heritability and intraclass correlation of cholesterol were estimated as 0.224 and 0.229, respectively. Coheritability of blood urea nitrogen was calculated as -0.03. There was no indication of the potential use of indicator traits.

젖소군의 유량생산 수준별 유전적 모수 추정에 관한 연구

이광전(K . J . Lee),박경도(K . D . Park),강민구(M . G . Kang),최윤석(Y . S . Choi),양영목(Y . M . Yang),손진기(J . G . Son),강민식(M . S . Kang) 한국축산학회 1993 한국축산학회지 Vol.35 No.6