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

돼지 성조절에 관한 연구

이용빈,오봉국,서국성,오성종,임경순 ( Yong B . Lee,Bong K . Ohh,Guk S . Suh,Sung J . Oh,Kyong S . Im ) 한국축산학회 1979 한국축산학회지 Vol.21 No.1

This study was conducted to investigate the sex ratio between the natural born pigs and B-body test sperm, which the data were obtained from a total of 1.242 pigs born at Swine Farm, Jeil Sugar Co. And it was attempted the sedimentary and galvanic separation. of X-and Y-bearing spermatozoa with 4 boar semens at College of Agriculture, Seoul National University. The results obtained were as follows; 1. The natural sex ratio of pigs born was about 50%, and B-body test sperm was a-so about 50%. It was, therefore, statistically non-significant differences of the sex ratio between the natural born pigs and B-body test sperm. 2. The B-body test sperm obtained from Fractionated semen was similar to B-body sperm of control 3. Spermatozoa of swine were separated into different fractions by sedimentation. B-body rest sperm to anode was 53.70%, and the B-body from bottom was 33.43%. 4. The swine semen could separate X- and Y-bearing sperm by galvanization without interfering the sperm liability. In galvanization of sperm, the percentage of the B-body sperm induced to anode was 60.4%, while the sperm to cathode was 28.15%. This experiments with seminal galvanization and sedimentation for the separation of X- and Y-bearing sperm have been exclusively conducted with swine. Since the data presented in this report were still unstable, more detail research would, so far, be needed.

산란종계의 난중에 대한 유전적 모수추정에 관한 연구

최연호,오봉국 ( Y . H . Choi,B . K . Ohh ) 한국축산학회 1983 한국축산학회지 Vol.25 No.6

This study was carried out to present the informations for the optimum age of selection based on partial records to improve egg weight in layers. The data used in this study were the records on 787 White Leghorn hens from two different strains, A and K, which were raised at College of Agriculture, Seoul National University since 1976. The traits analysed in this study were mean egg weights in each period divided into 4 week intervals from first egg and annual mean egg weight in lines A and K. Heritability estimates for mean egg weight in each period from sire component and dam component were; different in appearance in two lines. In line A, the fact that heritability estimates from sire component was higher than those from dam component except for EW 22 suggested the importance of the sex-linkage effect on the inheritance of the traits studied. But the result of line K was shown to be reverse. The heritability estimate for EW 30 that is mean egg weight from 29 weeks to 32 weeks of age was higher than any other periods in line A. In the genetic correlation between. annual mean egg weight and mean egg weights in each period, the coefficient of EW 34 was 0.999 for line A and 0.900 for line K. The figures were highest among all genetic correlation coefficients. Results obtained above suggested that it might be possible to select hens at the period of 33-36 weeks of age to improve egg weight based on early part of the record.

한우의 이상염색체 분포에 관한 연구

여정수(J . S . Yeo),정일정(I . C . Cheong),정경진(K . J . Chung),정선부(S . B . Chung),정연후(Y . H . Jung),이기복(K . B . Lee),설동섭(D . S . Sul),오봉국(B . K . Ohh) 한국축산학회 1990 한국축산학회지 Vol.32 No.9

Through chromosomal analysis of 109 heads of the Korean Native Cattles, this research was observed results as follows; 1. Six heads(5.5%) were cosisted of two kinds of mosaic chromosomal spreads( I : monosomy, normal and trisomy II: monosony and normal) and these mosaicsms were variated at #29 chromosome. 2. One head was showed supernumery chromosome suggested B-chromosome. 3. 1/29 Robertsonian translocation was not found in the Korean Native Cattles.

제한급사에 의한 산란계의 합리적인 육성방법에 관한 연구

오봉국,박상문 ( B . K . Ohh,S . M . Park ) 한국축산학회 1973 한국축산학회지 Vol.15 No.4

The effect of feed restriction during the rearing period on the reproductive performence of a total of 300 pullets from colonial layer line was examined. The rearing treatments, which from at 8 weeks to 21 weeks of age, were A-control (ab lib), B-20% restricted, C-40% restricted and D-low energy ration (ab lib). Feed consumption was checked twice weekly in each control group and the amount of feed for the restricted groups changed accordingly. All groups were full fed during laying period after 21 weeks of age. The birds remained in grower cage until 21 weeks of age whereupon they were again re-randomised within a treatment on transfer to a layer cage shed with three replications each of 25 birds in a completely randomised design. The results obtained were as follows; 1) Mortality was not significantly affected by the rearing treatment in either the rearing phase or laying phase of the experiment. 2) In the body weight at 21 weeks of age, the full fed birds (control) weighted 1.43㎏ while 20% restricted birds averaged 1.24㎏, 40% restricted averaged 1.03㎏ and low energy ration (full fed) averaged 1.27㎏. These differences in the body weight disappeared by the time the birds were 31 weeks of age. 3) Restricting the feed intake from 8 to 21 weeks of age resulted in an overall feed saving of 20 to 40% during rearing period, however there were no differences between treatments in total feed consumption during experimental period(8-72 weeks). 4) In feed conversion, the kilograms feed required to produce a kilograms of eggs were less for the restricted groups. The restricted feeding groups (20% and 40%) were saved feed about 10 to 15% of feed requirement to produce eggs. 5) Feed restricted groups delayed sexual maturity as measured by age at 50% production, by 10 to 26 days depending upon the severity of restriction. 6) Average hen day egg production up to the end of the experiment 72 weeks of age) was 59% for the control, and 60∼62% for the restricted groups. Average hen housed egg production per bird up to the end of the experiment was 194 eggs for control, and 212 for 20% restricted, 209 for 40% restricted and 203 for low energy ration. 7) The egg size was significantly increased in restricted groups relative to control. The difference between restricted groups and control was highly significant for extra large, large and medium egg size. 8) In the economic analysis, relative profit was about 10 to 13% higher fur the restricted groups, compared to the birds on the full fed group.

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.

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.

염색체의 배수성 증가에 의한 닭의 신품종 개발 2 . 다배수성 개체의 생산

여정수(J . S . Yeo),정선부(S . B . Chung),오봉국(B . K . Ohh),정경진(K . J . Chung) 한국축산학회 1990 한국축산학회지 Vol.32 No.10

For the induction of polyploid chicken. 660 birds were supressed by tri-ethylene melamine(0.25mg/2kg B.W) and 330 fertilized eggs from chicken of 24 hours laying cycle were incubated. Only 65 chickens Acre hatched in observation of many dead eggs and pips caused to unbalanced genetic structure. At 10-12 weeks of age chromosomal structures of 55 chickens were analysed in blood culture and 4 of them were identified as polyploid (3A+ZZW). Characteristics of polyploid chickens were heavier weight 21% and 88% than normal male and female at 30 weeks of age, sterility of female and weak legs. Through analysis of chromosomal structure of G-and C-banding polyploid chicken were observed the three pairs of chromosomes without specific genetical disorders.

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.

한우의 월령별 (月齡別) 체척치와 (體尺値) 체중의 회귀에 (回歸) 관한 연구

오봉국(B . K . Ohh),양영훈(Y . H . Yang) 한국축산학회 1989 한국축산학회지 Vol.31 No.12

This study was carried out to investigate the relationship between body weight and body measurements on Korean Native Beef Cattle(HAN-WOO) at birth, 6, 12, 18, and over 30 months of age through stepwise regression analysis. The determinant coefficients of final steps at birth, 6, 12, 18 and over 30 months of age were 0.58, 0.7 8, 0.93, 0.94 and 0.75 respectively. The relationship between body weight and chest girth was very close correlative, compared with the other body measurements. Through every months of age, chest girth. body length, shank circum, hipbone width, chest width and thurl width were included in the final models and had close contribution to the body weight. From the standpoint of prediction of body weight with body measurements, it is at 12∼18 months of age that can be predicted body weght with relative precision.