부산대학교 도서관

1. A survey was conducted on 77 Landrace pigs which were introduced into Haibara County, Shizuoka Prefecture, from overseas in January and February, 1963. As a result, it was found that '30 pigs (39per cent) had stillborn young or given birth to piglets which died immediately after birth, presumably due to Japanese B encephalitis, in the summer and fall of 1963.2. Another survey was carried out on 148 breeding sows which had been mated in Ogasa, Haibara, and Shida. Counties, Shizuoka Prefecture, during a period from March to July, 1963. The rate of successfully grown young among the sows born prior to July, 1962, was 85 per cent among those inoculated against Japanese B encephalitis and 64 per cent among those not inoculated. The same rate among the sows born in and after August, 1962, and Landrace sows imported in January and February, 1963, was 53 per cent among those inoculated and 25 per cent among those not inoculated. These results indicate that the inoculation against the disease was effective.3. Nineteen breeding sows which had suffered from fever during pregnancy showed abnormal parturition, without exception. In the case of fever occurring prior to 90 days of pregnancy, it was not infrequent that the whole fetuses of a litter suffered from still-birth or abortion. In the case of fever occurring after 91 days of pregnancy, some of the fetuses of a litter suffered from stillbirth and not a few piglets succumbed immediately after birth.