The dynamic state of sero-positive cattle (SPC) to bovine leukemia virus (BLV) was studied by the immunodiffusion test with BLV gp-antigen. A total of 2, 192 serum samples were collected from 814 cattle of 10 herds in 6 districts of Iwate Prefecture 2 to 8 successive times from 1977 to 1980. SPC were detected from 6 herds. SPC increased in number and positive rate in herds A-b and B-a during the observation period. Although a temporary decrease in positive rate was demonstrated in herds A-a and B-b due to a partial removal of SPC, a probable increase in positive rate was suggested if the removed animals were left as they were. In herd D-a, cleaning of BLV was successful by segregation of SPC from the herd after the first survey. Antibody against BLV was supposed to be maternal in one of 3 SPC in herd C-a. In the other two SPC it was to be acquired from vertical and horizontal infection respectively. The 4 herds without SPC were maintained to be clean during the observation period of 8 to 11 months. The positive transition rate of antibodies aginst BLV was significantly higher in the postgrazing season than in the pregrazing season. A frequent positive transition of antibodies against BLV, as well as a high prevalence of enzootic bovine leukosis, was noted among cattle in highly contaminated herds. Discussion was made on an eradication program of the malady.
Auricular dermatitis with crust and ulcer occurred on a hog farm. It affected about 600 of 900 pigs 70-90 days old. A crust and ulcer formation appeared in the upper or lower part of the auricle and extended gradually on the whole auricle. Some pigs died. Staphylococcus epidermidis and Streptococcus mitior were isolated from lesions. In an inoculation experiment, S. epidermidis caused only a transient crust formation, but S. mitior induced purulent dermatitis. The disease may have been induced by association with the infection of these organisms and stress (overcrowding, climatic condition, et al.).
Changes of serum a-fetoprotein (AFP), GOT and GPT levels after carbon tetrachloride (CC14) administration were studied in young dogs, in which the ability to produce AFP still remained, and adult dogs, in which this ability was reduced. The serum AFP level increased after a single dose of CC14 in both young and adult dogs. The maximum level of AFP was about seven times as high as the initial level in the adult dogs and about two times in the young dogs. The increase of serum transaminase activity was higher in the young than in the adult dogs. The increased serum AFP level following CC14 administration returned to the initial level in about 35 days in the young and in more than 45 days in the adult dogs. In both increase and recovery of serum AFP level following CC14 treatment, a lag of some days was observed, as compared with those of serum transaminase activity. The extent of increase was smaller in serum AFP level than in serum transaminase activity following CC14 treatment. The increase in AFP production following CC14 administration in dogs might be due to activation of a mechanism which was different from that existing in embryonic life.
A 28-month-old Holstein heifer was affected with aortic insufficiency associated with ventricular septal defect. She manifested tachycardia with a systolic and diastolic cardiac murmur, marked carotid pulsation at the base of the neck, prominent palpable cardiac impulse over the left thoracic wall, tachypnea on exercise, and abnormal ECG pattern suggesting cardiac hypertrophy. Necropsy revealed a ventricular septal defect (1.5 cm in diameter) at the base of the aortic valve. The right aortic cusp, deformed and thickened, had prolapsed into the ventricular septal defect, causing aortic insufficiency. Two other aortic cusps were also thickened and distorted.
A holstein and a Japanese Black cow were conceived for the first time by one artificial insemination with frozen semen of the respective breeds. They were delivered of twins judged to be dizygotic. The Holstein twins were male and born at 271 and 296 days of gestation, respectively. The Japanese Black twins were male and female and born at 286 and 475 days of gestation, respectively. The male was small and weak, weighing about 20 kg. The female was normal in size. She was not a freemartin, but was fertile and bred normally.