수수의 飼料價値에 關한 育種的 硏究 Ⅱ. 수수의 糖類 및 全窒素含量의 變異幅에 關하여

K.C. HONG(洪基昶),H.C. KWON(權赫之),C.S. KIM(金徹洙) 한국육종학회 1977 한국육종학회지 Vol.9 No.1

To find the magnitude of variation of total non-structural carbohydrate(TNC) and total nitrogen content and 25 other characters that measured from 105 Sorghum cultivars, and their interrelationships, this experiment was carried out from 1. April to 1. December 1976 at the experimental Farm of the College of Agriculture, Korea University, that located Wa-bu myon, Yang-ju county, Kyong-ki province, Korea under the financial support from Ministery of Science and Technology of Korea. Completely randomized design was employed and replicated three times. Considerable variation was observed from all measured characters, including both TNC and total nitrogen contents. Breeding for both characters seemed to be of fair economic return. High correlation was found between TNC and its components, and one of them would be used as a representative of this character to make screening process for TNC easy. Except NO₃-N there was no significant correlation between total nitrogen and its components. This seemed to indicated the much more complicated physiological and genetical control of biosynthetic pathway of nitrogen than that of TNC. Parallel increase of total nitrogen and NO₃-N content would be possible and this requires cautions in selecting breeding material for nitrogen. With dry matter, considerably high correlation was found with stem weight, leaf weight and leaf sheath weight. Among them, stem weight showed the highest correlation with dry matter, indicating this is the main component of dry matter. To breed high quality and yield forage sorghum, much consideration is needed for this.

종돈의 능력검정에 관한 연구 1 . 비육돈의 비육종료시 체중에 따른 산육능력의 비교

홍기창(K . C . Hong),윤덕영(D . Y . Yoon),박홍양(H . Y . Park) 한국축산학회 1989 한국축산학회지 Vol.31 No.6

This study was carried out in order to test the fattening performance and the change of body composition of pigs by slaughter weights. Sixty heads of three-way crossbred pigs were used for this purpose. Those pigs were slaughtered at live weight of 90, 100 and 110㎏, respectively. The results were summarized as follows: 1. In order to improve the feed requirement and backfat thickness in fattening pigs reared to 110㎏, the fattening performance of breeding pigs must be more improved. 2. As the slaughter weight increased, the carcass lengths were increased in both sexes. In the viewpoint of anatomy this shows the possibility of more attachment of muscles. 3. The percentages of dressing and lean cut were increased at 110㎏ slaughter weight and the proportion of ham was significantly increased than any other valuable parts. 4. But the quality of carcass was relatively lower than that of the developed countries. Therefore, it is desirable to select breeding pigs more intensively based on carcass quality. 5. Gross income per head was the highest at 110㎏ slaughter weight. But considering the turnover rate 90㎏ slaughter weight is acceptable under the present pork pricing system. 6. In order to increase pork export, the present system of grading and pricing should be reorganized. 7. Considering above-mentioned findings the present performance test of breeding pigs at 90㎏ should be changed to 110㎏ as soon as possible.

종돈의 육종가 추정에 있어서 사료섭취량의 고려

홍기창 ( K . C . Hong ) 한국축산학회 1988 한국축산학회지 Vol.30 No.7

Daily feed intake decreased by 4, 8 and 1%o in the breeds German Landrace, Belgian Landrace and Pietrain from 1972-75 to 1979-82, respectively. This situation suggests to pay more attention to feed intake in breeding value estimation and selection. Decreased feed intake is due to the unfavourable genetic correlations of -0, 50, 0.50 and 0.40 resp. between feed intake and lean meat content, meat-to-fat ratio and backfat thickness. Direct inclusion of feed intake in the breeding value is difficult, since the economic weight of this trait is questionable. In the present study, effects of using the restricted selection index for feed intake on the expected genetic gains in other traits are investigated. Restriction of feed intake decreases the expected genetic gain in lean meat content to about 53%, whereas that in the daily gain increases to about 130% the various breeding value variants studied. As far as total genetic gain is concerned, restriction of feed intake affects this only little. Because there is no economic weight for feed intake, the restriction of feed intake in the selection index can be considered until the development of reliable measuring methods for the traits lean tissue growth rate (LTGR) and lean tissue feed conversion (LTFC).

모돈의 생산성 향상에 관한 연구 1 . 모돈의 생산성 향상을 위한 조기이유에 관한 연구

홍기창(K . C . Hong),전진태(J . T . Jeon) 한국축산학회 1991 한국축산학회지 Vol.33 No.4

74 piglets from 8 sows were weaned at either 3 or 4 weeks of age to examine growth and various aspects of reproductive performance in the weaned pigs and the sows. The number of the live young born was not significantly different between the group weaned at 3 weeks (11.33±0.67) and the group weaned at 4 weeks (10.67±0.33). No significance of the difference was found between the two groups in the number of litter at weaning (9.33±0.33 vs 9.33±0.88) and in farrowing interval (146.67±2.33 days vs 152.33±0.33 days) (p$lt;0.05) indicating that early weaning may not influence the reproductive performance of sows. There were no significant differences in the average body weight at 21(6.21±0.13㎏ vs 6.23±0.16㎏) and 28 days(7.63±0.14㎏ vs 7.90±0.18㎏) between the 3 weeks and 4 weeks group (p$lt;0.05). Average daily gain 3 (56 days to 154 days) (0.62±0.10㎏ vs 0.58±0.02㎏) and the days to 90 ㎏ in body weight(169.05±1.13 days vs 167.33±0.63 days) were also similar in the both groups. These results suggest that early weaning may be employed without any great loss in both sow and litter.

모돈의 생산성 향상에 관한 연구 2 . 자돈의 성장형질에 대한 포유자돈 합방의 효과

홍기창(K . C . Hong),전진태(J . T . Jeon),윤덕영(D . Y . Yoon),박홍양(H . Y . Park) 한국축산학회 1991 한국축산학회지 Vol.33 No.8

We examined the effects of litters mixing during pre-weaning period on the growth trait of piglets, and the possible way of selection for the mothering ability of sow on the behavioral basis of piglet using 6 sews and their 53 piglets. A significant difference(p$lt;0.01) was found in the weight at 8-week of age, being 21.95 ㎏ in experimental vs 19.53 ㎏ in control group. This tendency continued until the time of marketing, gaining an additional 3 kg per piglet. The body weight gain of piglet during 4 weeks(from 4 to 8 weeks age) was also significantly higher(p$lt;0.01), being 14.13 ㎏ in experimental us 11.99 ㎏ in control group. Futhermore. it was found that the behavior of piglets toward the better ow could be used as an indication for the better mothering ability of sow, The results suggest that mixing the litter: during pre-weaning period would give beneficial effects on the growth, and provide an alternative way of selection for the sow with better mothering ability.

돼지에 있어 적육생산을 위한 선발에 따른 사료섭취량의 변화

홍기창 ( K . C . Hong ) 한국축산학회 1988 한국축산학회지 Vol.30 No.7

Data from three German test stations of the period 1972 to 1982 (n=65630) were analysed to study the development of daily feed intake and of other important traits in the pig and to calculate heritabilily estimates and genetic correlation. During the period, all pigs in German test stations were fed ad libitum in groups of two female full-sibs on a diet of identical composition as regards feed components and energy concentration. For estimating the genetic parameters the periods 1972-1975 and 1979-1982 were analysed seperately for the breeds German Landrace (DL), Belgian Landrace (LB) and Pietrain (PI). Daily feed intake decreases in the three breeds from first to second period. In the LB and DL breeds feed intake decreases by 8% and 4%, respectively. In the PI breed feed intake decreases only by 1%, but average daily feed intake is 8% below that of LB and 15% below that of DL. The other traits feed conversion and meat-to-fat ratio change by 5% to 25% in desired direction. For the genetic analysis all traits are defined as the deviation from a contemporary mean within station. For the contemporary mean the period is 60 days for DL and 90 days for LB and PI pigs. All heritability estimates are based on half-sib analysis. For DL heritability of daily feed intake is .5 in both periods. For LB and PI estimates are unreliable due to the small number of pigs available in the first period, while in the second period the heritability for feed intake is also .5. Genetic correlation between feed intake and some other importance traits are also based on half-sib analysis. There is a very high genetic correlation of .8 between feed intake and weight gain during fattening period in all three beeds, while there is no genetic correlation between feed intake and feed conversion. Genetic correlations between feed intake and backfat thickness and feed intake and meat-to-fat ratio are unfavourable. The correlation between feed intake and backfat thickness is.5 for all breeds, but between feed intake and meat-to-fat ratio it is .5, .6 and .8 for DL, LB and PI, respectively. In German pig breeding backfat thickness and meat-to-fat ratio have higher weights in the breeding value than weight gain and feed conversion, respectively. The decrease in feed intake may be explained by unfavourable correlations between the former two traits and feed intake. To avoid a further decrease in feed intake it has been suggested to include this trait in selection of pigs in the future.

돼지 계통조성에 있어서 기초군 형성에 관여하는 요인과 유전적 모수의 추정

전진태(J . T . Jeon),홍기창(K . C . Hong) 한국축산학회 1989 한국축산학회지 Vol.31 No.6

This study was carried out to estimate the genetic parameters and the factors having effect on the selection of foundation stock in linebreeding of pig. Between November 1987 and September 1988, data used for this study were a total 145 performance-tested records of pig in Landrace. The results obtained were summarized as follows: 1. The average values of average daily gain(ADG), days to 90kg and backfat at 90kg were 0.79±0.01kg, 159.09±1.81 and 18.64±0.30mm, respectively. 2. The heritability estimates of ADG, days to 90kg and backfat at 90kg were 0.73, 0.72 and 0.36, respectively. The estimates of genetic correlation between ADG and days to 90kg, ADG and backfat at 90kg, backfat at 90kg and days to 90kg were -0.625, 0.482, and -0.635, respectively. 3. It is expected that the on-test age, off-test age and test period of farm test in linebreeding should be fixed on a certain age and period. 4. If boars were 10 heads and sows were 50 heads in closed population, the inbreeding coefficient(F) was estimated 10.50% after 13 generation. 5. The ratios of selection intensity to generation interval were estimated 0.127 and 0.128 in 1st and 2nd parity, hence, 1st parity, 12 month, seems to be appropriate for the generation interval in linebreeding.

allyl Trenbolone 에 의한 미경산돈의 발정 동기화 유기

이상호(S . H . Lee),홍기창(K . C . Hong),전진태(J . T . Jeon) 한국축산학회 1992 한국축산학회지 Vol.34 No.5

Estrous synchronization was induced using a synthetic progesterone derivative, allyl trenbolone (Regumate porcine), in sexually mature gilts. Gilts were divided into a control group and 2 treatment groups (6-7 gilt per group) fed 20 ㎎ allyl trenbolone in feed/gilt daily for 18 consecutive days (Regumate). Gilts in one of the treatment groups received 2,000 IU PMS and 1,500 IU hCG after the cessation of Regumate (Regumate + PMS + hCG). Estrus was effectively synchronized with apparently no adverse effect in 86% of the treated gilts within 7 days after treatment. The intervals from the cessation of treatment to estrus were 6.1 days with Regumate and 5.1 days with Regumate+PMS+hCG groups, respectively. The average number of ovulated follicles in the gilts of Regumate group was similar to that in control group, and could be increased variably by the additional injections of PMS and hCG. The results suggest that Regumate is effective in inducing estrus synchronization in sexually mature gilts. The additional use of PMS and hCG with Regumate may be useful for the relatively narrow synchronization of estrus and superovulation in gilts.

6개국의 돼지능력검정형태에 관한 비교 연구

차영만(Y . M . Cha),홍기창(K . C . Hong),전진태(J . T . Jeon) 한국축산학회 1991 한국축산학회지 Vol.33 No.4

This study was primarily carried out to obtain a basic information in the internal (domestic) test method by comparing the current circumstance of internal test with that of foreign test. Data from Korea, England, Denmark, U.S.A. and West Germany were analysed. The results are summarized as follows; 1. It appears that the change of current test type from individual performance test to sib or progeny test is required for estimation of carcass performance. 2. Although no significant difference was found in terms of listed condition for the pig to be tested among 6 conturies, future consideration should be taken in reproductive performance such as the number of teats, and prevention of diseases. 3. The alteration in the type of pig test may be an initial step for the changes of test items due to its close link to test items. However one should purse an objective estimation for the performance of lean meat production. 4. It is suggested that the effect of stepwise change of the nutrition level during the test period should be examined for the estimation in the performance of the lean meat production. 5. Since higher proportion of lean meat may be required of the introduction of the carcass classification and pork export, there should be reconsideration about the current off-test weight ($lt;90㎏).

닭의 인공수정에 있어서 적정주입 정액량에 관한 연구

이재근,송해범,정선부,홍기창 ( J . K . Lee,H . B . Song,S . B . Jung,K . C . Hong ) 한국축산학회 1980 한국축산학회지 Vol.22 No.2

This experiment was carried out to determine the optimum amount of semen (sperm number) to use per injection in artificial insemination of hens. the experimental birds used were 240 hens of White Plymouth Rock inbred line and 20 cocks of Australorp pure line at 7 months of age. The four treatments compared were: 0.005 ㎖ or 16 to 18 million sperm per insemination (T1), 0.01 ㎖ or 32 to 36 million sperm (T2), 0.02㎖ or 64 to 72 million sperm (T3), and 0.03 ㎖ or 96 to 108 million sperm (T4). thirty birds were allotted per treatment within a replication, and there were two replications in the experiment. Ringer`s Solution were used for diluent of semen(1:3), and semen was inseminated within 30 minutes after collection. The hens were inseminated 4 times with the intervals of 4 days. The results obtained are summarized as follows. 1. The fertility for four days after the second insemination was 46.4% for the T1, 72.9% for T2, 73.3% for the T3 and 86.3% for the T4. The fertility of the T1 was significantly lower than the others, but the differences among T2, T3 and T4 were not significant. These results agree with the previous report (1978). 2. The fertility for 4 days after the 3rd insemination was 71.0% for the T1, 73.4% for the T2, 73.3% for the T3 and 77.1% for the T4, and t he fertility after the 4th insemination was 70.4% for the T1, 65.7% for the T2, 69.2% for the T3 and 79.3% for the T4. None of the differences among the treatments were statistically significant in each ease. It was concluded that the insemination of 0,005㎖ (16 to 18 million sperm per insemination) can attain the same level of fertility as the insemination of 0.01 ㎖ to 0.03㎖ after the 3rd or 4th insemination. 3. In view of the results obtained in this study, the least optimum dose of semen in the case of 4 days interval was estimated to be within the range from 0,005㎖ to 0.023㎖