웅성특이 염기서열을 이용한 소의 초기 수정란의 성감별에 관한 연구

오봉국,황규춘,이원유,이병천,황우석,한재용 ( B . K . Ohh,K . C . Hwang,W . Y . Lee,B . C . Lee,W . S . Hwang,J . Y . Han ) 한국축산학회 1996 한국축산학회지 Vol.38 No.1

한우의 체중 및 체척치에 대한 환경효과와 연도별 개량추세

오봉국,이득환,이문연 ( B . K . Ohh,D . H . Lee,M . H . Lee ) 한국축산학회 1990 한국축산학회지 Vol.32 No.7

This study was conducted to find out the changes of estradiol-17α and progesterone levels in the plasma of Cheju mares from the occurrenoe of their puberty and during estrus cycle with 9 heads of Cheju ponies. The estradiol-17α and progesterone in the plasma samples were assayed by radioimmunoassay methods. The results are as follow; 1. The estradiol-17α levels showed 45.4∼93.6 pg/ml during 6-10 months of puberty, however it reaehed at peak of 162.6±73.77pg/ml at 13months with onset of estrus. 2. The progesterone levels during puberty of fillies reached peak levels of 8.28±4.52ng/ml at 14months and 0.01∼0.36ng/ml during 6-10 months of puberty. 3. The estradiol-17β and progesterone levels decreased to 75.1±27.26pg/ml and 1.96±2.25ng/ml respectively during 16months of puberty in the non-breeding season. 4. The estradiol-17β levels during the estrus cycles showed a peak level of 107-145pg/ml at 1-7 days after the onset of estrus and decreased 66.1-91.9pg/ml at I1-17 days. 5. The progesterone levels during the estrus cycle showed less than Ing/ml at 1-7 days after the onset of estrus and a peak level of 7.5-7.7ng/ml at 11-15 days.

産卵鷄種의 主要經濟形質에 대한 結合能力 推定에 관한 硏究

OHH B.K(吳鳳國),J.S. YEO(呂政秀),J.K. LEE(李正九),M.Y. LEE(李文演) 한국육종학회 1980 한국육종학회지 Vol.12 No.3

This study was carried out to estimate combining abilities for economic traits in layer chickens. The data used in this study were the record of 10 single crosses produced by half diallel cross of 5 lines of Single Comb White Leghorns, such as A, B, C, K and S lines. Total 720 progenies of the crosses were reared at the Poultry Breeding Farm, College of Agriculture, Seoul National University from Feb. 1979 to August, 1980. Combining abilities were estimated by Griffing’s mathematical model for the traits; age at the first egg, total egg number, egg weight and body weight. The results abtained from the studies were summarized as follows; in estimate of combining ability, an age at first egg of BS cross was largely due to significiantly higher general combining ability (G.C.A) effect of B and S strains than C and K strains in G.C.A. effect, and to specific combining ability (S.C.A) effect of B and S strains. AB and BS crosses showed the highest egg production. AB cross performance was result from high G.C.A. effect of A and B strains.BS cross performance was result from high G.C.A. effect of B and high S.C.A. effect of BS cross. Specific combining ability effect in egg weight was not statiscally significant, but S strain showed high G.C.A. effect. A and B strains in body weight showed significantly low G.C.A. effect. From the above results, BS cross in an age at first egg, AB and BS crosses in egg production, S strain in egg weight and AB cross in body weight were superior to other strains or crosses.

혼합모형식에서 Pseudo - REML 방법을 이용한 유우의 비유형질에 대한 분산성분 및 유전모수 추정

이득환(D . H . Lee),오봉국(B . K . Ohh),신영수(Y . S . Sin),이학교(H . K . Lee) 한국축산학회 1991 한국축산학회지 Vol.33 No.3

Variance components and genetic parameters for first lactation were estimated using Schaeffer`s Pseudo-REML method in mixed model equation(MME). Variance components were estimated with the data of 596 First lactation records which had been gathered at the National Animal Breeding Institute from 1970 to 1988. Analyzed traits were 305-day milk yield, fat yield and fat percentage. Iteration numbers for estimation were 42, 29, and 31 at milk yield, fat yield and fat percentage in convergence criteria of 1 × 10^-5, respectively. Heritabilities estimated from sire variance components in mixed model equation were 0.333, 0.245, and 0.178 for milk yield, fat yield and fat percentage, respectively. Estimates of genetic correlation were 0.782 between milk yield and fat yield. -0.596 between milk yield and fat percentage. and 0.086 between fat yield and fat percentage.

한우의 체중 및 체형에 대한 유전모수 추정에 관한 연구

오봉국(B . K . Ohh),이득환(D . H . Lee),양영훈(Y . H . Yang) 한국축산학회 1990 한국축산학회지 Vol.32 No.6

This study was conducted to estimate heritabilities and genetic correlations on body weight and body measurements obtained from 4193 records of cows after 500 days of age in Korean native cattle(hanwoo). Results obtained were summarized as follows ; 1. Heritabilities and standard errors of body weight, chest width and chest girth were 0.35±0.084, 0.20± 0.053 and 0.24±0.062 respectively, and the estimates were higher values than those of other traits(wither height, rump height etc.). 2. Genetic correlation coefficient was estimated 0.96 between body weight and chest girth, 0.94 between body weight and rump width, 0.97 between wither height and rump height and 0.94 between body length and rump width. 3. For improving hanwoo as beef cattle, improvement for rump width as standing for developing latter part might be concurrent improvement for body length and body weight.

유우의 산유능력에 관여하는 형질들의 유전력 , 유전상관 및 상관반응 추정에 관한 연구

손시환,오봉국,이정구,조윤연,오대균 ( S . W . Sohn,B . K . Ohh,J . K . Lee,Y . Y . Cho,D . K . Ohh ) 한국축산학회 1983 한국축산학회지 Vol.25 No.1

The objects of this study were to estimate the heritabilities, phenotypic and genetic correlations among productive traits and to find optimum selection method based on genetic parameters for each trait in dairy cattle. The data used in this study were obtained from the Holstein Friesian cows of The National Livestock Breeding Station. There were 1429 records from 354 cows, representing 44 sires. The data collected from 1969 through 1981. The traits studied were Milk Yield, Fat Yield, Fat Percentage, Peak Yield and Peak Lactation Period. The results obtained in this study were summarized as follows; 1. In the average performance of productive traits, milk yield was 4820.32 ± 1152.05 ㎏, fat yield 170.29 ± 41.62 ㎏, fat percentage 3.54 ± 0.33 %, peak yield 24.31 ± 5.75 ㎏ and peak lactation period 44.12 ± 27.39 day. As compared with average foreign report, above average performances showed low trend except peak lactation period. 2. The heritability estimates from sire component were 0.211 for milk yield, 0.249 for fat yield, 0.520 for fat percentage, 0.236 for peak yield, 0.199 for peak lactation period. As a result, these traits are not high heritable characters except for fat percentage. 3. The genetic correlation coefficient of milk yield with fat yield was 0.841, milk Meld with fat percentage -0.098 and fat yield with fat percentage 0.458. Relationship of milk yield was measured to be 0.518 with peak yield, 0.744 with peak lactation period. Expected genetic change in productive traits based on a phenotypic selection differential was also studied. Therefore, direct selection may be more effective than indirect selection.

한국 유우집단에 있어서 산유능력에 영향을 미치는 환경요인에 대한 분석

이정구,오봉국 ( J . K . Lee,B . K . Ohh ) 한국축산학회 1986 한국축산학회지 Vol.28 No.9

This study was carried out to investigate the importance and relative magnitude of environmental factors for 305-day mills yield by using seven different fixed models constructed with the combination of fixed sets of effects such as herd, year, month, parity, herd × month interaction, arid linear and quadratic regressions for age at calving. Data used for this study included a total of 4,485 sets of 305day lactation records of Holstein cows from six dairy farms participating in the registration project of the Korean Animal Improvement Association from 1969 through 1984. The results obtained from this study are summarized as follows: 1. Use of the fixed model 2 including herd, year, month, and linear and quadratic regressions for age at calving was more appropriate than use of any other model to analyze the importance of environmental factors for 305-day milk yield based on total records. 2. In the analyses of records for each lactation set, use of the fixed model 1 including herd, year, month, and linear regression for age at calving was appropriate for first or second lactation records, whereas use; of the fixed model 5 that quadratic regression for age at calving is added to the fixed model 4 was more appropriate for third and later lactation records. These results indicated that the relative importance of quadratic effects of age at calving was increased at third and later lactations. However, the herd × month interaction effects were not significant for any lactation records. 3. The variance component estimates expressed as percent of the total variance for actual milk yield based on total records under fixed models were: 14-16% for herd, 4-5% for year, 1-2% for month of calving, and less than 1% for herd × month interaction. And the relative sizes of each variance component estimates for each lactation records of milk were similar to those based on total lactation records.

종모우모형에서 직접법과 반복법의 해의 비교

양영훈,오봉국,이득환 ( Y . H . Yang,B . K . Ohh,D . H . Lee ) 한국축산학회 1990 한국축산학회지 Vol.32 No.11

For the evaluation of breeding values of animals, A trial to get solutions from the Iterative(SUR: Successive underrelaxation method) and the G-inverse was carried out using a sire model with 76 levels of 7 independent factors in this study. The results showed no differences between the solutions from directive(G-inverse) method and that from iterative method. For the four(0.1, 0.2, 0.3, 0.35) different relaxation factors(W) to speed up the convergence to the final solution, even though the number of rounds of interaction was affected, there were no differences in the final solutions. The numbers of rounds of iteration t get final solutions from a restriction({ b₁^n+1 - b₁} $lt;0.0001) under for the 0.1, 0.2, 0.3 and 035 relaxation factors were 1729. 928, 649 and 563 rounds respectively. It is the good iteration parameter(w) whether the convergence is speeded up or not. Since Iterative method is very simple to be programized and needs relatively small computer memory, it could be useful for solving large and complex equations in animal evaluation.

국내 홀스타인종 유우의 유량에 대한 연령보정계수 ( 年齡補正係數 ) 추정

이정구,오봉국 ( J . K . Lee,B . K . Ohh ) 한국축산학회 1985 한국축산학회지 Vol.27 No.2

Age-correction factors were developed on 4,538 complete lactation records from registered Holstein cows in the Animal Improvement Association of Korea from 1969 to 1983. These factors were computed by use of the gross comparision method for separate two seasons and overall season because yields of lactations initiated in season 1 (December through June) were about 6% larger than amounts produced by cows calving in season 2 (July through November). The new factors were smoothed across ages to eliminate minor fluctuation in yield that result from small number of records available in some age-month groups. It was concluded that the younger cows would lead to have 1 to 3 percentage of biased production records and that the older cows would have 5 to 7 percentage of biased production records if USDA age adjustment factors were used to the Korean field data.

한우의 체중과 주요체형측정치에 대한 모우의 산차 및 세대효과

이문연,오봉국,송찬원,이기복 ( M . Y . Lee,B . K . Ohh,C . W . Song,K . B . Lee ) 한국축산학회 1985 한국축산학회지 Vol.27 No.11

This study was carried out to investigate the effects of the parity of dam and generation on body weights and body measurements such as chest girth, rump width, rump height, thuds width, withers height and body length of Korean Native Beef Cattle(HANWOO) at birth, 3, 6, 12, 18, 24 and 32 months of age. The data used for this study consisted of 2145 heads of registered female HANWOO which were collected in the 8 provinces from 1979 through 1985 by KAIA and NLCF. In general, the parity effects of dam were the important for the sire evaluation on the body weight; and body measurements. These effects were high at the 3-6th parity and were decreased after the 6th parity. However, the parity effects of dam on body weight in 32 months slightly increased by increasing of parity. This was considered due to some selection effects. The effects of the generation including the environmental and genetic factors were slightly high in generations advanced. This was considered as the important indicators of the improvement in feeding management and the changes of the genetic specification in the population evaluated compared with the base population.