젖소의 비유능력 측정

조윤연 한국낙농육우협회 1984 낙농·육우 Vol.34 No.-

한우의 생시 및 이유시체중의 반복력

조윤연,이진희,박영일 한국축산학회 1969 한국축산학회지 Vol.11 No.2

Repeatabilities of birth and weaning weights of Korean Native Cattle were estimated based on the data from 240 calves raised at the Whasan Branch of the Livestock Experiment Station from 1957 through 1968. The birth weight was adjusted for differences in age of dam, year-season of birth, and sex. The weaning weight was adjusted for differences in age of dam, year-season of birth, sex, inbreeding of calf, and inbreeding of dam. Repeatabilities estimated were 0.23±0.07 for birth weight and 0.23±0.07 for weaning weight at 5 months of age. Phenotypic correlation between the two traits was 0.33±0.07.

분만우의 관리요령

조윤연 한국낙농육우협회 1985 낙농·육우 Vol.48 No.-

젖소의 비유능력 측정

조윤연 한국낙농육우협회 1984 낙농·육우 Vol.33 No.-

한우비육에 관한 연구;한국 빈우의 연령과 비육기간이 비육효과에 미치는 영향

조윤연,육종융,송계원,설동섭,정수영,연시중 한국축산학회 1966 한국축산학회지 Vol.8 No.1

This experiment was conducted to study the effects of age and periods on the fattening of Korean native cattle. Thirty-six herds of non-pregnant cows were alloted into 12 treatments combined with three levels of age (1.5 to 2, 4 to 5 and 8 to 10 years) and four levels of fattening periods (60, 90, 120 and 150 days). The results obtained are summarized as follows; 1. In daily gain a significant difference (p$lt;0.05) was observed among levels of age but there was no significant difference among levels of fattening period. Sixty-day period was the most effective fattening period for the 1.5 to 2 years old cow with its daily gain 0.92 ㎏ and 90-day period was the most effective fattening period for the 4 to 5 and 8 to 10 years old cow with their body gain 0.84 and 0.69 ㎏. 2. Significant (p$lt;0.01) difference in feed efficiency was observed with age and fattening period. In other words older cows required more feeds for 1 ㎏ gain. In This trial age affected highly significantly (p$lt;0.01) the amounts of DCP and TDN required and fattening period was also significantly (p$lt;0.05) affected the only the amount of TDN required for 1 ㎏ gain. 3. There was highly significant (p$lt;0.01) difference in the dressing percentage and marbling degree among fattening period. Dressing percentage was not affected by age, but marbling degree was affected significantly. Longer fattening period showed higher dressing percentage and marbling degree. 4. 1.5 to 2 years old cow fattened for 60 days showed highest net income with 102.22 won daily. Average daily net income of 4 to 5 years old cow with 90 days fattening and 8 to 10 years old cow with 60 days fattening was 49.49 won and 41.15 won. It showed that more net income could he induced with short period of fattening.

근친교배가 한우의 생시 및 이유시체중에 미치는 영향

조윤연,이진희,박영일 한국축산학회 1969 한국축산학회지 Vol.11 No.1

The data from 240 heads of Korean, Native Cattle raised at the Whasan Branch of the Livestock Experiment Station from 1951 through 1968 were analyzed by the least square methods to study the effect on birth and weaning weights of inbreeding of calf, inbreeding of dam, sex of calf, age of dam, and year-season of birth. The inbreeding of calf ranged from zero to 31% and averaged 5.8%. The inbreeding of dam ranged from zero to 31% and averaged 2.0%. The partial regressions were -0.042±0.030 ㎏. of birth weight and -0.292±0.153 ㎏. of weaning weight for each increase of 1% in inbreeding of calf. The partial regressions of birth and weaning weights on inbreeding of darn were 0.005±0.037 and -0.421±0.188 ㎏., respectively. The male calves were heavier than the females by 1.26 ㎏. at birth anal by 5.14 ㎏ at weaning at 5 months of age. The birth and weaning weights of calf from young dam tended to be smaller than the from the mature dam.

Holstein 종 유우의 유량 , 유지량 , 유지율 및 최고유량에 미치는 유전 및 환경적 효과와 상호작용에 관한 연구

상병찬,조윤연,김호중 ( B . C . Sang,Y . Y . Cho,H . J . Kim ) 한국축산학회 1986 한국축산학회지 Vol.28 No.3

This study was conducted to determine the main effects and interactions of year, season, parity, performance of milk production and lactation period on daily average milk yield, fat yield, fat percentage and peak yield with the 2,811 records of Holstein cows at National Animal Breeding Institute from 1970 to 1981. The results obtained in this study are summarized as follows: 1. The daily milk yield, fat yield, fat percentage and peak yield were 14.85±.06㎏, 0.55±.002㎏, 3.59±.008% and 23.96±.11㎏, respectively. 2. The fat yield and fat percentage were no significant among season, but daily milk yield and peak yield were significant (p$lt;0.05) difference in the effects of season. 3. The daily milk yield, fat yield, fat percentage and peak yield were significant (p$lt;0.05) difference among parity, and the daily milk yield, fat yield were superior in the group of 5-9th parity than other parity groups. 4. The daily milk yield, fat yield and peak yield were significant (p$lt;0.05) difference, but daily fat percentage was no significant difference among the effects of performance of milk production. 5. The daily milk yield and fat yield were significant (p$lt;0.05) difference among lactation period, but fat percentage and peak yield were no significant difference. 6. The interaction effects of season by performance of milk production, and parity by performance of milk production were highly significant (p$lt;0.01) difference for the daily yield, fat yield and peak yield, and the interaction effects of parity by lactation period, and performance of milk production by lactation period were significant (p$lt;0.05) difference for the daily milk yield.

도입한 돼지동결정액의 정자활동과 번식능력

지설하,조윤연,임경순,박태진,상병찬,김호중,김인철,노진식 한국축산학회 1984 한국축산학회지 Vol.26 No.8

This experiment was carried out to examine the effects of the imported boar frozen semen on the motility of the spermatozoa and reproductive performance. The fertility and reproductive performance were obtained on the basis of the 48 heads of Landrace, Hampshire, Large Yorkshire and Duroc sows inseminated with 96 tube boar frozen semen at National Animal Breeding Institute from 1983 to 1984. The results obtained are summarized as follows: 1. The average livability and motility of the spermatozoa were 54.3% and 24.8^(+++) after thawed of boar frozen semen, and Landrace was superior with 56.3% and 27.3^(+++), respectively. 2. The average gestation length was 114.3 days, and was shorter with 113.5 days in Hampshire. The conception and parturition rate were 16.7 and 12.5% with pregnancy and parturition of 8 and 6 heads of the 48 sows inseminated with frozen-thawed semen, respectively. And the conception rate was higher with 25.0% in Hampshire, and the parturition rate was superior with 16.7% in Hampshire and Large Yorkshire. 3. Average litter size at birth, 21 days and weaning were 7.7, 6.7 and 6.5 heads and Hampshire was higher with 11.5, 9.5 and 9.5 heads, respectively. 4. Average pig weight at birth, 21 days and weaning were 1.20, 5.45 and 19.25 Kg and Duroc was heavier with 1.39, 6.07 and 21.60 Kg, respectively.

후산정체 (後産停滯) 가 번식효율과 산유량에 미치는 영향

정기화,조윤연,곽대오,박충생 ( K . H . Chung,Y . Y . Cho,D . O . Kwack,C . S . Park ) 한국축산학회 1991 한국축산학회지 Vol.33 No.7

To investigate the influence of retained placenta on the subsequent reproductive performance and milk yield, total 357 heads of Holstein dairy cows raised at N.A.B.I., Choong Nam province were used. The cows not expelled their placenta until 12 hours postparturient were termed as the cow of placenta retention. The days to first service. days open, services per conception, lactation days, peak yield per day. days to peak yield and 305 days ME milk yield were evaluated to determine the subsequent reproductive performances and milk yield, respectively. The mean incidence of retained placenta(RP) was 25.8% in a herd of 357 cows examined. The cows of placenta retention took significantly(P$lt;0.01) longer than normal cows in the days to first service and the days open, by 97.6±8.4 days and 192.6±15.0 days versus 79.3±2.3 days and 142.9+5.5 days respectively, but services per conception and days open more than 300 were not affected by retained placenta. In milk yield, lactation days, peak yield per day and days to peak yield were not affected by retained placenta, but milk yield per lactation was significantly(P$lt;0.05) decreased in RP cows with 5,684± 151.9㎏ versus 6,035±80.0㎏ for normal cows. From these results, there seemed to be negative relationship between incidence of retained placenta and subsequent reproductive performance and/or milk yied.

유우(乳牛)의 산유량(産乳量)과 번식능력(繁殖能力)에 대한 유전적(遺傳的) 모수추정(母數推定)에 관한 연구(硏究)

이학교,조윤연,지설하,오봉국 한국육종학회 1987 한국육종학회 학술발표회 발표요지 Vol.19 No.2