• Journal of Embryo Transfer
• /
• v.27 no.3
• /
• pp.141-147
• /
• 2012

This study was operated to establish induction using ultrasonography by estimating the relation of follicle size and estrus manifestation. Clinical estrus symptoms were observed 97.4% in cows and 87.5% in heifers when overall 55 cows were induced to estrus in a single dose of $PGF_{2{\alpha}}$ after verifying CL through ultrasonography, which means estrus hours among those 52 cows showing the clinical estrus symptoms were estimated 2.39 days on cows and for 2.37 days on heifers which showed no differences (p>0.05). The estrus manifestation hours according to the follicle size in cows didn't have any significance each other (p>0.05), though estrus hours was 54 hours (the shortest) with follicle size bigger than 10 mm and were made up within 69 hours. The estrus manifestation hours according to the follicle size in heifers didn't have any significance each other (p>0.05) and took around 42 hours (the shortest) with follicle size of 5mm (the smallest) and were made up within 66 hours. Follicles after $PGF_{2{\alpha}}$ injection were ovulated and assigned to many phases as follows; Group 1 (growing phase) - continuously growing into ovulation, Group 2 (growing and static phase) - delaying in growth after the growth of follicles, Group 3 (static and growing phase) - growing after growth delay, Group 4 (regressing and new growing phase) - the follicle is closed and a new follicle grows. In addition, the process of follicle development and estrus hours had no significance each other (p>0.05), though estrus manifestation hours in Group 1 and 2 was relatively short, and in Group 3 and 4 for a relatively long time. In the result of all above, the estrus manifestation hours after $PGF_{2{\alpha}}$ injection has no differences accoring to the follicle size in cows and heifers. Therefore, High pregnancy rate is obtained when practicing artificial insemination within 3 days in estrus or TAI in 72 to 80 hours after adminitrating $PGF_{2{\alpha}}$.

• Korean Journal of Animal Reproduction
• /
• v.21 no.4
• /
• pp.411-421
• /
• 1997

A survey was carried out to investigate the symptoms and occurance of reproductive disorder in Hanwoo(Korean native cattle). Data of the reproductive disorder of 561 heads from 28 farm households have been collected from Dec. '95 to Nov. '96 and analyzed calving no, nutritional body condition and housing forms. The results obtained are summarized as follows: 1. The incidence of reproductive disorder was 20.1% and the major common symptoms were repeat breeding(39.8%), anestrous(31.0%), nymphomania(10.6%) and subestrous(8.9%). 2. The incidence of reproductive disorder according to the calving no., that of heifer, calved one to two calving no. and over three calving no. were 20.6%, 13.9% and 34.5%, respectively. 3. Reproductive disorder incidence according to the nutritional body condition was 18.3%, 14.6% and 48.7% at body condition score(BCS) less than 2.0, 2.5 to 3.0 and over than 3.5, respectively. At BCS over 3.0, the symptoms of common reproductive disorder were repeat breeding(17.6%), anestrous(12.2%), nymphomania(10.8%) and subestrous(2.7%). 4. The incidence of reproductive disorder according to the housing form 15.8% and 34.6% for group feeding in open house and individual stanchion feeding in stall, respectively. In group feeding, reproductive disorder incidence of cows raised in space of more than 9.9$m^2$ per head was 14.1%, while that of cows raised less than 9.9$m^2$ per head was 18.2%. And incidence of repeat breeding, aneestrous and subestrous was more frequent in individual stanchion feeding than group feeding.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.2
• /
• pp.194-199
• /
• 2007

Effects of recombinant bovine somatotropin (bST) on plasma hormonal concentration, embryo quality, and pregnancy rate were examined during the superovulation and synchronization treatment in donor and recipient cows. Hanwoos (Korean native beef cattle) were treated with controlled internal drug release (CIDR) combined with bST (CIDR+bST) or without bST (CIDR) as donor cows. The embryos recovered from donors were transferred into Holstein recipient heifers treated with bST (CIDR+bST) or without bST (CIDR) for synchronization. The correlation between IGF-I and P4 showed a positive pattern in the CIDR+bST group (r=0.44, p<0.01), but a negative pattern was shown in the CIDR group (r = -0.59, p<0.02) at day 7 of estrous cycles. Although the number of recovered, transferable, and degenerated embryos was not different, quantities of grade 1 (excellent) embryos in CIDR+bST group were significantly higher than those of the CIDR group (p<0.01). The pregnancy rate was higher in the CIDR+bST recipient group compared to CIDR group (p<0.05), when the embryos were recovered from the donors treated with CIDR. However, the pregnancy was maintained highly in both recipient groups, when the embryos were produced by CIDR+bST treated donors. It can be concluded that bST administration combined with CIDR is an effective method for superovulation and synchronization treatment to stabilize plasma hormonal levels, to obtain excellent quality of embryos, and to get higher pregnancy rate.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.1
• /
• pp.31-35
• /
• 2007

The main purpose of this study was to improve the efficiency and quality of in vitro embryo production in Korean Native Cows (KNC). We examined the effects of ovarian morphologies (Experiment 1) and the culture vessel (Experiment 2) on in vitro maturation (IVM). We measured the subsequent development rates and cell numbers of blastocysts. In Experiment 1, the ovaries of KNC were divided into six groups, based on follicle and corpus luteum (CL) morphology. The development rates to the 2- and 8-cell stages were similar among the six groups. The development rates to blastocyst stages were significantly higher in the group without a CL or follicle (WOCL/F) than in the groups with follicular cysts (FCs), regressive CLs (RCLs) or cystic CLs (CCLs) (p<0.05). The cell number of the inner cell mass (ICM) of blastocysts in the FCs and RCLs groups, and the number of cells in the trophectoderm (TE) in the WOCL/F group, FCs, growing CLs (GCLs) and RCLs were significantly higher than in other groups (p<0.05). The total cell number (TCN) in the WOCL/F, FC and RCL groups was also significantly higher than in other groups (p<0.05). The ICM cell number/TCN ratio was significantly higher in the FC and RCL groups than in the GCL and DF groups (p<0.05). In Experiment 2, oocyte IVM was carried out in culture dishes, in 0.25- or 0.5-ml straws used for freezing sperm. The development rate to the 2-cell stage was significantly higher in the 0.5-ml straw group than in the 0.25-ml straw group. The development rates to the blastocyst stage were similar in the dish and the two straw groups. There were no differences in the cell numbers of ICM, TE or TCN or ICM cell number/TCN ratios between groups.

• Korean Journal of Animal Reproduction
• /
• v.22 no.4
• /
• pp.367-373
• /
• 1998

A survey was carried out to investigate the effect of the herd size on the reproductive traits of Hanwoo(Korean native cows). Data on the reproductive traits of 670 Korean native cows were collected from January, 1996 to December, 1997 and analyzed by the herd size. The results obtained were summarized as follows: 1. The average ages at first breeding were 437.9, 425.5 and 452.9 days in herd size 1 (less than 20 heads), 2 (21∼50 heads) and 3 (more than 51 heads), respectively (the over all average was 443.0 days). However, there was no significant difference between herd sizes (p＞0.05). 2. The average ages at first conception were 452.8, 438.4 and 467.1 days in herd size 1, 2 and 3, respectively (the over all average was 460.0 days). However, there was no significant difference between herd sizes (p＞0.05). 3. The average ages at first calving were 741.2, 730.2 and 755.9 days in herd size 1, 2 and 3, respectively (the over all average was 746.6 days). However, there was no significant difference between herd sizes (p＞0.05). 4. The average days to first estrus after calving was 70.1 days and it was shortest in herd size 3 (64.8 days) and longest in herd size 1(82.1 days). 5. The average numbers of services per conception were 1.54, 1.61 and 1.48 in herd size 1, 2, and 3, respectively (the over all average was 1.53). However, there was no significant difference between herd sizes (p＞0.05). 6. The average days to first conception after calving were 115.6, 99.1 and 80.6 days in herd size 1, 2 and 3, respectively (the over all average was 91.2 days). There was a trend that it was shorter as the herd size increased(p＜0.05). 7. The average length of calving interval was 375.3 days and it was shortest in herd size 3 (367. 4 days) and longest in herd size 1 (389.5 days).

• Journal of Embryo Transfer
• /
• v.27 no.1
• /
• pp.15-20
• /
• 2012

The objective of this study was to investigate the relationship between body weight, body condition score (BCS), blood urea nitrogen (BUN), glucose, cholesterol and number of transferable embryos for the purpose of improving reproductive performance in Hanwoo donors. Seventy five cows, at random stages of the estrous cycle, received a CIDR together with injection of 1mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment begann. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU = 1 ml) administered twice daily in constant doses over 4 days. On the 3rd administration of FSH, CIDR was withdrawn and 25 mg $PGF_2{\alpha}$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received $100{\mu}g$ GnRH at the time of 1st insemination. Embryos were recovered 7 days after the 1st insemination. In conclusion, cows with body weight < 400, 400~450 and > 450kg had number of transferable embryos of $4.2{\pm}1.7$, $6.1{\pm}2.7$ and $4.8{\pm}2.6$, cows with BCS <2.25, 2.25~2.75 and ${\geq}2.75$ had number of transferable embryos of $4.6{\pm}1.6$, $5.7{\pm}2.4$ and $5.1{\pm}2.7$ respectively. These data indicate that a body weight and BCS for superovulation of CIDR-treated Korean native cows does not affect the embryo yield.

• Korean Journal of Veterinary Research
• /
• v.53 no.4
• /
• pp.269-271
• /
• 2013

Here, we report the poisoning case of 10 cows. Several distinct clinical signs such as convulsion, excessive salivation, circling, lateral recumbency, and death were observed. Necropsy and histopathological examination did not reveal any significant abnormal findings. Moreover, no bacteria or viruses were detected in tissue, blood, and feeding food. However, endosulfan was detected from the stomach contents and microbials. Our results strongly suggest that death of cows may be closely associated with endosulfan poisoning.

• Korean Journal of Veterinary Research
• /
• v.27 no.1
• /
• pp.137-140
• /
• 1987

Information on certain reproductive traits were obtained from field material. The data for this study were taken from 1,111 breeding records of 273 cows and 193 heifers at Koheung, Chonnam, during the period 1979 to 1984. The cattle were bred by artificial insemination; only one or two cattle were reared by one farmer. The heifers were first bred at 551.75 days after they were born; they were pregnant at 569.06 days after birth. The average estrous cycle length was 21 days; the average number of inseminations per conception was 1.56. The non-return rate for first inseminations for cows and heifers was 62.5% and 59.6%, respectively. The gestation length was 285.79 days. Of 1,111 viable calved born 582 were male, giving a sex ratio of 100:110. The average length between calving and first insemination was 88.9 days; average calving interval was 397.69 days.

• Korean Journal of Veterinary Research
• /
• v.14 no.1
• /
• pp.1-7
• /
• 1974

Little work has been done on the changes in the blood picture occurring at different ages in cattle. In our country Kim (1963) and Jeong (1965) recorded the blood picture of mature Korean native cattle and, recently, Mun et al. (1974) has recorded the blood picture of Holstein cows. And a comprehensive survey of the blood picture of Korean native cattle has not been made. The object of the present investigation was to make good this deficiency, and to suggest standards for the blood picture of Korean native cattle at frequent intervals from birth to maturity. The cattle were kept under average farming conditions in this country. Observations were made at the following ages: at birth; 1, 2 and 4 days; 1, 2 and 4 weeks; 2,4,6 and 9 months; 1, 2 and 3 years of age. Blood samples were drawn from the jugular vein. Erythrocyte enumerations, concentration of hemoglobin in blood and hematocrit values were made in usual manner. Erythrocyte counts increased from $8{\times}10^6/mm^3$ during the first week to a level of $10{\times}10^6/mm^3$ at 2 months of age, showing steady state untill 6 months of age; it then fell to adult level ($8{\times}10^6/mm^3$) at 9 months of age. Concentration of hemoglobin in blood and hematocrit values were closely related to the changes of erythrocyte counts. The values increased from 10 g/100 ml and 31~35 ml/100 ml during the early life to 11 g/100 ml and 38 ml/100 ml at 2 months of age, showing steady state untill 6 months of age; these then fell to adult level (10 g/100 ml and 31~34 ml/100 ml) at 9 months of age for concentration of hemoglobin in blood and hematocrit values, respectively. Mean corpuscular volume and mean corpuscular hemoglobin showed a common pattern. The values were $42{\sim}43{\mu}m^3$ and 12.4 pg during the early life and fell a little to 6~9 months of age; these then increased to reach adult levels of $43{\mu}m^3$ and 12.6 pg for mean corpuscular volume and mean corpuscular hemoglobin, respectively. Mean corpuscular hemoglobin concentration was little affected with age.

• Korean Journal of Veterinary Research
• /
• v.43 no.3
• /
• pp.349-359
• /
• 2003

Corpus luteum (CL) is the primary productive organ of progesterone in pregnant cows. Progesterone levels in bovine plasma depend on the volume, weight and shape of the CL. Progesterone productions during the late stages of gestation occur both in the CL and placenta, and placentas producted more progesterone than CL on progesterone prcduction. Because division of progesterone production of these two organs is impoxxible, the CL function can not be determined by plasma progesterone levels following gestation stages. This study was carried out to evaluate histological findings on the CL spurium and CL verum, and also on the CL following the pregnant stages by histological and immunohistochemical and electron microscopical methods and then we expect to assume the functions of CL by histological findings. 1. Proliferations of luteal cells occur by day 120 of gestation, vessel hyperplasia occur by day 90 of gestation, and the walls and lumens of vessels developed by day 120 of pregnancy. 2. Sizes of CL cells increased to maximum around day 200 of gestation and similarly maintained by day 240. So these findings indicated that the function of Cl is most active around day 200 of gestation. 3. On parturation day, the number and size of luteal cells were maintained but stain intensity of the luteal cells and vessels are declined or disappeared, and fibrosis of luteal cells increased, and the vessel lumens are emptied. These findings indicate that CL is inactive. 4. In immunohistochemical findings, proliferative positive cells by PCNA antibody appeared more in number during early stages of gestation but appeared less following course of pregnant stages and not nearly appeared on day 120 of gestation. Apoptotic positive cells by TUNEL methods not nearly appeared on the early pregnant stages and a few appeared at late pregnant stages. So developments of CL proceed until day 120 of gestation and regression of CL was occurred by transform of luteal cells into fibrocytes than by luteal cell apoptosis. 5. In electron microscopical findings, the size of luteal cells increased more in CL verum than in CL spurium. During gestation stages, the size of luteal cells increased, mitochondria in the luteal cell cytoplasms densely and abundantly developed and also swelled mitochondria increased. The interspace of luteal cells are also dilated, transformation of luteal cells into fibrocytes are more number. The lumens and walls of peripheral capillaries of large luteal cells more broadened and thickened, and transformation of large and small luteal cells to fibrocytes are increased. The above findings suggest that function of pregnant CL more developed by day 120 of gestation and are most active around day 200 of gestation and similarly maintained by day 240 and are promptly regressed on paturation day.