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 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 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 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 .

This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone () concentration against compared with conception rate were observed in cows and heifers. In inducing estrus administering . to the cows which has corpus luteum in ovaries, ovarian reponses, the changes of progesterone concentration, and conception rate were identified and compared. The results attained from the studies were as follows. Significant decreases of CL in size over time after administration were detected in both cow and heifer groups (p<0.001), but not different between groups in the CL regression rate (p>0.05). In addition, the percentage changes relative to the plasma concentration on day 1 after treatment were decreased to below 1ng/ml. The growth rate of follicle was observed as 31% on day 1 and 42% on day 2 in cows, and 34% on day 1 and 97% on day 2 in heifers, resulting that growth of heifers are faster than that of cows (p<0.05). The conception rate after treatment were 60.5% and 64.2% in cows and heifers, respectively. It also indicated that the conception rate after estrus observation with injection was as high as 66.6% while that with timed-artificial insemination (TAI) regardless of the estrus observation was 56%, which means the pregnancy rate of artificial insemination after estrus observation was higher than that of TAI (p<0.05). In the result of all above, there were significant decreases in CL size and the plasma concentration by days but rapid growth in follicles, which has no differences in cows and heifers. The conception rate was commonly high after estrus observation and more than 50% under TAI.

This study investigated potential relationship between fetal deaths and plasma progesterone concentrations of bitches. Serial ultrasonographic examinations were performed on small-pet 23 dogs from gestation day (GD) 15 through parturition. The dogs were 3 non-pregnant bitches, 9 spontaneous delivery bitches, 6 partial early embryonic death bitches, 2 whole early embryonic death bitches, and 3 aborted bitches. The late pregnancy (GD 51-54) appeared in 2 of the 3 aborted bitches and the hypoluteoidism appeared in 1 of the 3 aborted bitches. The plasma progesterone concentrations of partial early embryonic death bitches (n=6) showed no significant difference when compared with the spontaneous delivery bitches. We observed that plasma progesterone concentrations were dramatic decrease before the onset of embryonic death in whole early embryonic death bitches that plasma progesterone concentrations of aborted bitches at late pregnancy were significantly decreased when compared with those of spontaneous delivery bitches. The plasma progesterone concentrations of the hypoluteoidism bitch were lower than those of spontaneous delivery bitches. At the hypoluteoidism bitch, fetuses were resorbed in early pregnancy and aborted in late pregnancy. On the basis of the results, the diagnosis of partial early embryonic death could not be confirmed without ultrasonographic examination. The partial early embryonic death was considered a spontaneous phenomenon and uncorrelated with plasma progesterone concentration. However, aborted bitches and whole early embryonic death bitches were related to plasma progesterone concentrations and that of bitches gradually decreased before fetal death. These findings suggest that administration of progesterone may be a useful preventing agent against fetal death.

A total 5,946 cows from 24 dairy farms were carried out for the improvement of reproductive performance. Dairy cows in post-parturition 30 day were performed periodic reproductive examination to check for recovery of post-parturition ovary and uterus and for the early diagnosis of reproductive disease. The results obtained from this studies were as follow. The result of 1,126 cows with ovario-uterine disease were 579 slient heat and error of estrus detection (51.4%), 296 ovarian disease (26.3%), 248 uterine disease (22%), mummification and freematin were each 1 head (0.1%), respectively. Hormonal therapeutic effects were follicular cyst 81.5%, luteal cyst 90.7%, endometritis 86.9%, mucometra 90.1%, pyometra 60.9%, respectively. In cows, even if the 1st treatment fails, 2nd, 3rd treatment were performed. Therapeutic effect of 2nd, 3rd were reduced, but the number of cured cows were gradually increased. The cured cows after hormonal treatment were performed service repeatedly and the cumulative conception rate were increased. The cows treated with hormones at first service, the conception rate were follicular cyst 26%, luteal cyst 64.1%, endometritis 38.7%, mucometra 40%, pyometra 20.5%, respectively. The cumulative conception rates were increased by repeated service follicular cyst 57.3%, luteal cyst 84.6%, endometritis 67%, mucometra 75%, pyometra 64.1%, respectively.

To investigate the change of vaginal epithelial cell in estrus-induced Shih-tzu bitch, estrus was induced by PMSG (50 IU/kg, for 10 days) and hCG (1,000 IU, on Day 10) in 12 anestrus Shih-tzu bitches. Day-changes of vaginal epithelial cells during the whole period of hormone treatment were investigated in each experimental bitches. The first day of vulvar bleeding and the first day of male acceptant was on days (), and days after the first PMSG treatment. The duration of proestrus and estrus was days, and days. Characteristic features of vaginal cytology during the estrous cycle were the high proportion of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell and anuclear cell in estrus, and parabasal cell, small and large intermediate cell, and leukocyte in diestrus, respectively. When it was timed from the first day of PMSG administration (Day 0), the cornification index (CI) was the high proportion in proestrus and estrus. The CI peak was maintained above 80% between Day 11~14 (4 days) and CI showed a peak at Day 12. These results indicated that the 12 Shih-tzu bitches showed positive estrus induction by vaginal smear test and observation of clinical estrus sign.

The specimens from 32 aborted fetus and 274 aborted cows were collected in 168 farms of Chonnam province from 2005 to 2008 and were tested the brucellosis. The results obtained are summarized as follows. In the 32 aborted fetus, bovine brucellosis was detected in 12 heads (37.5%), bovine viral diarrhea-mucosal disease was detected in 7 heads (19%), ainovirus infection was detected in 1 head (3.1%), and multi-infection of BVD and brucellosis was not detected, respectively. In the 306 cases of aborted fetus and cows, bovine brucellosis was detected in 44 heads (14%). Status of abortion were confirmed in 63 farms (38%) out of 168 farms from June to August. From the point of raising scale, studies found that 128 farms (76%) out of all raised under 20 heads. The incidence of abortion by brucellosis was mainly showed in 30 heads (68.1%) about 151~250 days of gestation. In the result of the 18 farms survey, the causes of infections were detected movement of infected cattle in 5 farms (28%), unknown cause in 12 farms (67%), and recurrence in 1 farm (5%). The results of this study suggest to take an advantage of the prevention and fundamental research for bovine brucellosis in Chonnam province.