This study was conducted in order to observe the changes in cellular association of seminiferous tubules from 4 to 22 weeks of age and to obtain the cycle and relative duration of seminiferous epithelia from 24 weeks of age in male ducks. Fifety-five male ducks were used in the experiment and divided into 11 groups, consisting of 5 male ducks each, with 2 weeks intervals from 4 to 24 weeks of age. The body and tests weight showed most rapid increase during 4 to 6 weeks and 18 to 22 weeks of age, respectively. The seminiferous tubules were abruptly enlarged in diameter of tubules during 18 to 22 weeks of age. Gonocytes were seen from 4 to 6 weeks of age, however they were not observed as from 8 weeks of age. Both type Ap spermatogonia and type Ad spermatogonia occurred from 8 to 12 weeks of age, while spermatocytes and spermatids were beginning to appear at 16 weeks and 18 weeks of age, respectively. Spermatozoa were first observed at 20 weeks of age. Full spermatogenic activity was completed at the age of 20 weeks. Average paired weight of the testes in male ducks was 78g at 24 weeks of age and its ratio spermatogenic activity was completed at the age of 20 weeks. Average diameter of seminiferous epithelium at 22 weeks of age was 232 micro m, and average numbers of Sertoli cell, spermatogonia, spermatocyte, spermatids and spermatozoa in the cross section of seminiferous epithelium were 15.30, 59.08, 41.78, 71.11 and 165.30, respectively. Spermatogonia and spermatids were classified into 2 and 4 types, respectively. The cycle of the seminiferous epithelium could be divided into 5 stages at 24 weeks of age. The relative frequencies of stages from I to V were 13.5 %, 25.0 %, 22.3 %, 20.6 % and 18.7 %, respectively. Thus, establishment of spermatogenesis in male ducks were beginning to appear at 20 weeks of age

This work was carried out to get some informations about blood types and their researches, involved blood stock and genetic identification. Horses examined were total 55 heads of sire, mare and their progeny in Korean Horse affairs Association. Albumin and phenotypes of 26 mare were examined. The appearance of phenotype AA, BB, AB, was 1, 18, 7 respectively. The gene frequency of albumin A was 0.17 and albumin B was 0.76. The appearance of phenotype AA, BB, Ab in 29 progeny was 1, 16, 12 respectively. The gene frequency of albumin A was 0.24 and albumin B was 0.76. The gene frequency of gene A was higher than their parents. Identification of the relationship between parents and their progeny was also examined. 4 of type AB between AA and BB, 4 of type BB between BB and BB, 13 of type AB between BB and AB were borned. In third case, all of progeny was type AB. This results suggest positive relationship between them

This experiment was carried out to investigate the hematogical and blood chemical values in dairy cattle during the dry and lactating period. Blood was collected from six healthy dairy cattle in Kyongnam province. Leucocytes count, hemoglobin concentrations and the percentage of packed cell volume were lowest at the early lactation period. Leucocytes count was not affected during dry to lactating period. The differential count of eosinophilic leucocytes was low at the late lactation period, while the basophilic leucocytes was high at the dry period. Inorganic phosphorus value was below under normal leve. Creatinine value was from 1 to 2mg/100ml of serum. Positive reaction to CRP was shown in normal dairy cattle. The values of AST and ALT were higher during the dry than lactating period. r-GTP and total cholesterol tend to be decreased during the lactating period. CPK value was not affected for dry and lactating period

A new sudden death in rabbits appeared in China and Korea in 1984 and 1985, respectively, and was recognized to be an acute infectious disease caused by a virus. The disease was reported as a "new viral disease", and thereafter, a tentative name of "viral hemorrhagic disease", "hemorrhagic pneumonia" or "viral hemorrhagic pneumonia" has been described in the case reports. But authors had called the viral disease "rabbit viral hepatitis" due to picornavirus infection, because the principal lesion of the disease was an acute hepatitis. The purpose of this report is to describe the electron microscopic findings on the livers in experimentally infected rabbits. All the livers of the affected rabbits were shown to have degenerative changes of a type that is characteristic of acute hepatitis. In the liver cells, there were dilation of rER and mitochondria, vacuole formation of various sizes, and appearances of many virus-like particles in the vicinity of rER, granular bodies and crystalline arrays of viral particles in the cytoplasm with necrotic changes of the nucleus. Clusters of virus-like particles and viral crystals appeared in the cytoplasm of sinusoid endothelial cells and Kupffer's cells with morphological changes of organelles. Also viral crystals were demonstrated in the cytoplasm of macrophages among the liver cells. On the whole, the liver cells had many virus-like particles and a few crystalline arrays of viral particles. Therefore, this implies that the liver cells are the main site of the viral replication in inducing the viremia. It was concluded that the liver was the primary target organ of this viral disease, and the pathological and the ultrastructural evidence suggest that the virus may belong to genus enterovirus

This investigation was conducted on 249 Jindo dogs aging from 2 to 12 months to determine body type and external appearance of the dogs. The withers height of male dogs growed rapidly during the period between 2 months and 7 months of age, and was 22.94cm and 49.77cm, respectively. Afterward the growth rate slowed down up to 12 months, 53.33cm. The growth rate of female was similar to male, and the withers height was 22.91cm, 46.81cm, 48.70cm at 2, 6 and 12 months of age. For male and female the body length was 27.21, 27.23cm at 2 months, 51.40cm, 51.62cm at 6 months, 58.33, 52.15cm at 12 months, respectively. Growth rate of the body length was very rapid from 2 to 6 months of age, but afterwards the growth rate was slow and somewhat retarded. For male and female, the withers height to body length ratio was 100 : 109.4 and 100 : 107.1 in 12 months old group. Cross over between the sexes in growth rate occurred between 5.3 to 6.5 months of age for wither height, between 6.0 to 7.2 months for body length, respectively. The average chest girths of male and female were 31.46, 30.46cm at 2 months, 54.92, 52.20cm at 7 months, 60.25, 57.90cm at 12 months, respectively. The growth rate of chest girth was rapid between 2 to 7 months of age and gradual between 7 to 12 months. The average skull lengths of male and female were 11.76, 11.32cm at 2 months, 21.83, 19.60cm at 12 months, respectively. The average head widths of male and female were 8.37, 7.94cm at 2 months, 15.47, 12.46cm at 12 months. Erected type of ear was completed from oblique type at 6 months in male and 7 months in female. On our detailed examinations, we concluded that Jindo dogs completed their growth at 6 to 7 months of age

To study the effects of ibaraki virus on preimplantation mouse embryos collected from prepubertal ICR and BALB/cByJ mice (30-40 days old) by superovulation, zona pellucida-intact (ZPI) or free (ZPF) embryos (n=774) of 4- to 8-cell and morulae were exposed to 10** (5.8) TCID50 of the viurs up to 96 hours. The embryos were examined morphologically by observing the degeneration and hatching rates, and virologically and immunologically by determining the presence of infection with the virus, in addition, the effect of washing the embryos to remove virus possibly attached to was also investigated. The ZPI 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rate than those not exposed, for 96, and for 72 to 96 hours, respectively (p0.01). The ZPF 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rates than those not exposed, throughout the whole culture hours in vitro (p0.01). The ZPI 4- to 8-cell embryos and morulae not exposed to the virus showed considerably higher rates of hatched blastocyst than those exposed (p0.01). The virus infection rates of the ZPF 4- to 8-cell embryos and morulae were significantly higher than those of the ZPI embryos according to cell culture system. The viral antigen was detected exclusively on the zona pellucida of ZPF embryos by the immunofluorescent assay. In the ZPI embryos exposed to ibaraki virus, the virus was detected in the two times-washing groups, but not in the ten times-washing groups. The results indicated that zona pellucida of murine embryos would provide an effective protection and that ten times-washing of the ZPI embryos previously exposed to the virus was effective to remove virus from the embryos

The present study was carried out to investigate the effects of nitrate (KNO3) on the thyroid glands in rabbits which were administrated KNO3 of 1g/kg/day for 6 weeks. Growth rate, and serum levels for T4, T3 and TSH were observed every week. The histological changes and the weights of the thyroid glands were observed in 6 weeks. The mean growth rates of experiments were decreased significantly in the 1st week, but were increased a little from the 5th to 6th week compared with those of controls. The serum levels for T4 of the experimental group manifested significantly decreased values than those of control through the experimental term consistently and the serum levels for T3 were greatly decreased in the 3rd and 4th weeks. TSH contents of the serum were not changed through the experimental term. The mean weight of the thyroid gland in the experiment was decreased significantly after 6 weeks compared with that of cotrol. In the experimental group, the color of colloid in the thyroid follicles revealed deeper eosinophilic and the heights of the follicular epithelial cells were taller than those of controls. The colloid in the thyroid follicles revealed depletion. As summarized above, the observations suggest that nitrate can be an antithyroid substance in rabbits and it leads the thyroid glands to hypofunctional state

In order to observe the pathological changes of kidney in rabbits infected with the viral haemorrhagic disease, the kidney tissues from the 91 rabbits infected with the viral haemorrhagic disease were examined by light and electron microscopy. On light microscopic observation, the kidney lesions were identified as haemorrhagic glomerular necrosis (33.0 %), membranous glomerulonephritis (20.9 %), thrombotic glomerulopathy (19.8 %) membranoproliferative glomerulonephritis (8.8 %), mesangial proliferative glomerulonephritis (8.8 %) ischemic acute tubular necrosis (7.7 %), and acute serous glomerulitis (6.6 %). On electron microscopic observation, cytoplasmic degeneration of mesangial cells, and irregular thickening of basement membranes with electron dense granular materials were observed. In podocytes swelling of mitochondria, dilatation of endoplasmic reticulum and extensive fusion of foot processes were also observed. Nonenveloped round icosahedral picornaviral particles with a diameter of 28-33nm were detected in the cytoplasm of degenerative endothelial cells, polymorphonuclear leucocytes, and monocytes

In vitro antifungal susceptibility test was carried out on 53 strains of Candida spp. isolated from milk of dairy cows with subclinical mastitis and teat cups of milking machines. Nystatin, clotrimazole, miconazole, econazole, 5-fluorocytosine, cycloheximide, haloprogin and griseofulvin were tested by the agar dilution method. The 84.8 % to 98.2 % of Candida strains were inhibited by clotrimazole, econazole and miconazole at = 20.32 micro g/ml)

To develop more specific and sensitive diagnostic methods for infectious bovine rhinotracheitis, 7-C-2 monoclonal antibody specific to polypeptides of infectious bovine rhinotracheitis virus (IBRV) was applied in indirect immunofluorescence antibody assay (IFA), indirect immunoperoxidase assay (IPA) and radial immunodiffusion enzyme assay (RIDEA). It was found that IBRV infected in MDBK cells could be detected as early as 8 hours post infection by IFA, and that IFA was more rapid and specific to identify IBRV antigen than IPA. The diagnostic efficacy of RIDEA and SN test was studied with 88 bovine sera. It was evident that RIDEA could eliminate the false positive reaction encountered in serum neutralization (SN)test, being more rapid and sensitive than the latter. Highly significant correlation coefficiency (r= 0.76, p0.01) was evaluated between the titers of sera and the diameters of RIDEA. Tracheal membranes and sera collected from 96 slaughtered cattle with lesions in respiratory organs were examined to detect IBRV antigen and antibody by IFA, RIDEA and SN test. It was presented that positive rates were 32.3 % in IFA, 20.8 % in RIDEA and 21.9 % in SN test, and that coincidence rate between RIDEA and SN test were 100 % in positive sera and 98.7 % in negative sera. In conclusion, it was assumed that application of monoclonal antibody could improve the diagnostic efficacy of IBR by enhancing sensitivity and specificity of IPA, IFA and RIDEA