Fecal material from cattle, which was confirmed to be infected with Johne's disease by clinical and pathological symptoms, was decontaminated with 4% NaOH and inoculated into the Lowenstein-Jensen media supplemented with 1% of heat-killed Mycobacterium bovis. After 2-4 week-incubation at 37 deg C, typical acid-fast mycobacteria was isolated. The requirements of mycobactin for growth and the other biochemical properties, isolated mycobacteria was identified as Mycobacterium paratuberculosis

As a fundamental study to increase the reproductive efficiency in cattle, highly motile sperm were separated and collected from raw semen, extended semen and frozen semen by different methods using various concentrations of bovine serum albumin or Tyrode's solution. Various characteristics and light microscopic and electron microscopic morphology of sperm separated by different methods were compared

In the evaluation of anthelmintic efficacy by fecal egg counts for cattle naturally infected with helminths, the reasonable technique of fecal egg counts and the reliable guidelines were determined. Modified technique of Harashigeru and Kim's sedimental tube was the most reasonable in fluke egg counts. Universal egg counting technique was preciser than McMaster egg counting technique and was lower in coefficient variation. Fecal egg counts of pretreatment should be carried out twice and mean of the egg should be calculated

To investigate the sensitivity of repeat tuberculin test with bovine PPD, seibert's fraction A(SFA) and avian PPD tuberculins in visible and non-visible lesion reactor cattle to HCSM tuberculin. The comparative test, under the condition of this experiment, was entirely unsatisfactory to differentiate between visible and non-visible lesion cases, the high frequency distribution of the skin fold thickness greater than 10mm to SFA tuberculin appeared in visible lesion cases, whereas the skin reaction 1 less than 4mm to the SFA tuberculin appeared in NVL cases