To help the interpretation of causes of death, it is critical that the background incidence of factors contributing to death be recorded and archived. Information was gathered from the control groups of 19 rat carcinogenicity studies. All cases of death occurring within the 2-year period were reviewed. Out of 1124 males and 1084 females, 720 male (64.1%) and 689 female (63.6%) decedents were recorded. There was no difference in the probability of survival between two sexes. Analysis of factors contributing to death revealed that 400 males (48.7%) had neoplastic changes, 189 males (23.0%) had non-neoplastic lesions, and 232 males (28.3%) died from unknown causes.

The etiologic agents of mucormycosis are several nonpathogenic fungi of the order Mucorales and are ubiquitous. A total of 82 chickens were infected with the disease and developed anorexia, diarrhea, malnutrition, dyspnea, and paralysis in a chicken farm, Sokcho, Kwangwon. At necropsy there were multiple nodular lesions and hemorrhages in livers, spleens, kidneys, gastro intestinal track, and respiratory system. On histopathological examination it was found that the nodular lesions were consisted of granulomatous inflammation accompanying characteristic hyphae (4-24 micro wide) of the fungi

The effects of the serum total protein and immunoglobulin levels of the colostrum-conferred Korean native calves at 2 days of age on the disease incidence during the suckling period were studied. Serum total protein, total immunoglobulin, IgG, and IgM levels of 6 Korean native calves died from septicemia were lower than those of calves survived (p0.05). Korean native calves having low serum total protein and immunoglobulins were affected with diarrhea earlier in life, when compared with calves having high serum levels (P0.05). Korea native calves having low serum total protein were affected with bronchopneumonia earlier in life, when compared with calves having high serum levels (P0.05). Korean native calves having low serum neutralizing antibody titers to bovine viral diarrhea virus had high incidence rate of BVD, when compared with calves having having high serum neutralizing antibody titers (P0.05)