A total of 301 Thoroughbred mares were investigated the characteristics of breeding in the local areas in Jeju during the period from February 2000 to July 2001. The pregnancy rate and foaling rate in 143 mares were 93.0%, 72.0%, respectively, and mean gestational length was 339.3 days in 2000. The pregnancy rate in 158 mares was 86.7% in 2001. Mature follicles were ovulated in right(46.0%), left(45.2%), and bilateral(7.8%) ovary. The incidence of multiple pregnancies in 158 mares between 15 days and 45 days after mating were 89.3%(single), 10.1%(twin), and 0.6%(triple). The incidence of EED was 13.3%.

To establish a prediction table of parturition day real-time B-mode ultrasonographic examinations were performed in 12 pregnant Shih-tzu bitches. Measurement of inner chorionic cavity diameter and fetal head diameter was performed from 15 days of gestation to parturition. These were converted retrospectively based on the day of parturition (Day 0). The data of inner chorionic cavity diameter obtained from Day -44 to Day -25 and fetal head diameter obtained from Day -25 to Day -1 were used to compile a prediction table of parturition day.

The aim of the present study was to test the efficiency of estrous induction in the premature, metestrous and anestrous bitches. The estrus was induced with prostaglandin F2 alpha, estradiol-17 beta, pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) in the treatment A, and with PMSG and HCG in the treatment B. Day 0 was the first day of estrone injection in the treatment A and the day of PMSG injection in the treatment B. Twenty three of the twenty six bitches laparotomized under general anesthesia between 11 and 18 days after onset of behavioral estrus, whereas three bitches were not laparotomized and remained until parturition. Ovarian responses were evaluated with the total number of corpora lutea or ovulation sites. The uterine horns were flushed with phosphate-buffered saline added heat treated canine serum (10 %), the flushing media was collected into watch glass and the ova were examined under stereomicroscope. Standing estrus was observed on the day 17.7 +- 1.5 after injection of estrone in the treatment A, but ovarian responses were not detectable. Standing estrus was observed on the day 12.2 +- 0.2 after injection of PMSG in the treatment B and 14 of 17 bitches showed ovarian responses. Ova were recovered in 9 of the 14 bitches. Ovarian responses were observed in one of the three premature bitches, two of the three metestrous bitches and all of the 11 anestrous bitches. The average number of the ova collected from 9 bitchs were 12.2 +- 1.4. Three bitches in the treatment B exhibited behavioural estrus and all of them were mated with fertile male dog, resulting the pregnancy in only one bitch. The pregnant bitch gave the birth of two pups