본 연구는 기호성이 높으며 여름철 고온에 강한 새로운 tall fescue 품종을 구명하기 위해 초지조성 후 5년째인 1997년 방목기간 동안에 북제주군 한림읍 이시돌 목장에서 홀스타인 육성우(방목개시시 체중 110kg 내외)를 이용하여 구당 250(50mx50m)의 면적에서 2처리(T1 = Fawn tall fescue + orchardgrass + perennial ryegrass + white clover, T2 = Roa tall fescue )

This study was carried out to investigate the reproduction efficiency and disease of Holstein heifer grazed on mixed pasture desighed with association of tall fescue and white clover cultivar (3 treatments = TI : Tall fescue Fawn + White clover Regal + Or

Forty-five holstein calves (average liveweight 150kg) were used to investigate the effect of combination of tall fescue and white clover cultivars on liveweight gain and feed efficiency into animal product in pastures. Daily gains per head for 3 years in

This study was carried out with aim to find out a tall fescue cultivar which is palatable and resistant to hot climate, and a white clover cultivar which is less competitive with other grasses. Pastures with 3 treatments (TI: Fawn, tall fescue + Regal, wh

This study was carried out to obtain good livestock production in comparison with 3 different pasture mixture (Control : TI = Potomac orchardgrass + Bastion perennial ryegrass + Fawn tall fescue + Regal white clover, T2 = Potomac orchardgrass + Bastion pe

Plasma progesterone concentrations were measured by using radjoimmunoassay for early diagnosis of pregnancy in Cheju-native mares. A total of 226 pony mares were examined for pregnancy during breeding and non breeding seasons. Plasma progesterone levels 20~23 days after the onset of oestrus were 4.67+O.67ng /rnl and O.55+O.O4ng /ml for mares becornrning pregnant and not pregnant after the estrus, respectively, and there was a significant differences (p<0.01) between the two groups. Progesterone concentration of pregnant mares gradually increased in 30 days andreached a peak (10.3ng /ml) during the third month of gestation. However, the concentration decresed to the base line (1.llng /rnl) at 7 months and gradually increased again as foaling approached (2.lng /ml). Early diagnosis for pregnancy of Cheju mares by progesterone level at 20~23 days after onset of oestrus was 88% accurate when 4.6ng /ml was used to classify mares as pregnancy and below 1.3ng /rnl was used to determine nonpregnant mares. However, the accuracy of the diagnosis was improved to 96% when a progesterone level of above 2ng /mi was used to classify mares for pregnancy. Diagnosis for pregnancy was 69.6% accurate when mares were classified as pregnancy by horse owners during breeding season. The progesterone levels of pregnant and non-pregnant mares during non-breeding season varied greatly between individual animals, Plasma progesterone levels of pregnant animals ranged from 3.5ng /mi to above 6.2ng /mi whereas similar values were observed in non-pregnant animals. Radioirnrnunoassay technicjues can be applied for the early pregnant diagnosis of Cheju native mares when progesterone levels are measured during the early gestation period (18~23 days after onset of oestrus). However, progesterone concentration of mares in non-breeding season is conisidered unsuitable as a indicator of pregnant diagnosis.

This experiment was carried out to study the determination of survival of vitrified and thawed mammal follicular oocytes by FDA-test. Oocytes were divided into 3 groups according to attachment of cumulus cell. Group A oocytes were tightly surrounded by cumulus cell, group B oocytes were partially surrounded by cumulus cell, and group C oocytes were poorly surrounded by cumulus cell. Vitrification solution developed by our previous study (Kim et al, 1992) which consisted of permeable agent (20 % glycerol + 10 % ethylene glycol) and nonpermeable agent (30 % Ficoll + 10 % sucrose). Oocytes (7~10) loaded into 0.25 ml straw after 10 min equilibration were plunged into liquid nitrogen (- 196) directly. The FDA-score of vitrified and thawed group A oocytes was higher in rat (4.2) than in rabbit (3.9), cow (3.8), mouse (3.4) and porcine (2.4), however that of cumulus cell was higher in rabbit (4.7) than in rat (4.1), cow (2.9), porcine (2.6) and mouse (1.4). The FDA-score of vitrified and thawed group B oocytes were 3.1 (cow), 2.9 (rabbit), 2.9 (mouse), 2.6 (rat) and 2.5 (porcine), respectively. However that of cumulus cell was higher in rabbit (3.7) than in porcine (2.6), rat (2.3), cow (1.7) and mouse (0.3). The FDA-score of vitrified and thawed group C oocytes was higher in mouse (4.1) than in cow (2.9), rabbit (2.6), rat (1.3) and porcine (1.1). As shown in the above results, The survival rates of oocytes were higher in group A than in group B and C except in mouse and cow. These results suggest that the survival of cumulus cell as well as follicular oocytes can be reliably judged by their fluorescence with FDA-test.