This study was carried out to determine the effects of beta-carotene on the control of mastitis in dairy cows during the dry period. The relationship between the levels of plasma beta-carotene and the status of udder health in Holstein dairy cows were investigated. Blood samples were collected from 117 cows to compare the levels of plasma beta-carotene in lactating cows. The levels of plasma beta-carotene were 1.82 micro gram/ml in healthy cows(n=65) and 1.12 micro gram/ml in mastitic cows(n=52), respectively(p0.01). In the experiment to compare the level of plasma beta-caroten in the cows at different stages of lactation, the plasma beta-carotene levels were 1.73 micro gram/ml in lactating cows(n

This survey was carried out to investigate the seroprevalence of antibodies to Neospora (N.) caninum in dairy cattle raised in Kangwon province in Korea. A total of 349 sera collected from dairy cattle were tested for N. caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Ninety six (27.5%) dairy cattle were positive by IFAT. Seroprevalence of cows was 28.9% (91/315) and seroprevalence of boars was 14.7% (5/34). The seroprevalences of cows were increased according to the ages from 19.6% in cows less than 2 year-old to 50.0% in cows more than 7 year-old. Among the seroprevalences of cattle according to the raised areas, five counties or cities, Wheongsung was 34.6% (27/78), Wonju was 29.3% (46/157), Hongcheon was 28.9% (13/45), Chuncheon was 15.0% (3/20) and Cheolwon was 13.3% (2/15). It was proved that dairy cattle raised in Kangwon provinces exposed extensively and seriously to N. caninum.

The objective of this study was to investigate the calf death and analyse the causes of the mortality by based on medical records and autopsy findings during 10 years in a large dairy farm. Total of 1,361 calf born and 146 calf dead during the invested period. Mortality rate was 10.7% and showed the big difference by year-specific mortality from 2.8% (4 calves) to 19.2% (28 calves). The highest rate of mortality was 1 week age (18.5%, 27 calves) and followed by 2 week age (11.6%, 17 calves) and mortality of more old calf tended to be reduced. The death less than 4 weeks and 8 weeks of age of the entire mortality accounted for 41.1% (60/146 calves) and 70.0% (102/146 calves), respectively. Causes of calf death were digestive diseases (53.4%), respiratory diseases (17.1%), musculoskeletal disease (8.2%), and systemic disease (8.2%) in order. Specific causes of calf death was highest in enteritis (43.2%), followed by pneumonia (14.4%), sepsis (8.2%) and fractures (3.4%). Seasonally, most of calf death happened in winter (48.6%) and then fall (21.2%). This results showed that enteritis and pneumonia are the main reason of calf death but other reasons were involved in calf death on the based on autopsy finding. On going research relating factors of calf mortality is needed.

The proteins of the bovine erythrocyte membrane were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate, and their relations to the slow sedimentation rate of bovine erythrocytes were investigated by treating the erythrocytes with trypsin. The erythrocyte sedimentation rates of bovine erythrocytes from Holstein and Korean native cattle were very slow compared with the human one (1/7 as slow as the human one) as reported previously. However, when human and Holstein erythrocytes were treated with trypsin (0.2 and 0.5 mg/ml) for 1 hour at 37deg C, their sedimentation rates were markedly accelerated while the sedimentation rate of Korean native cattle's erythrocytes were not affected. Although the general protein profiles of the bovine erythrocyte membranes were almost similar to that of human, bovine erythrocyte membranes showed one additional protein band called band Q in this study, which migrated electrophoretically to the mid-position between band 2 and band 3 in human erythrocyte membranes. Treatment of Holstein and human erythrocytes with trypsin caused a decrease or disappearance of the band Q from the erythrocyte membrane. Although the band Q in Korean native cattle's erythrocyte membrane was decreased by trypsin treatment of the erythrocytes, the magnitude of the decrement was not so pronounced as in the case of human and Holstein erythrocytes. The glycoprotein profiles of the bovine erythrocyte membranes revealed by periodic acid-Schiff stain showed a marked difference from that of human. The PAS-1 (glycophorin) and PAS-2 (sialoglycoprotein) present in human erythrocyte membrane were almost absent from the bovine erythrocyte membranes. Instead, the bovine erythrocyte membranes showed a strong PAS-positive band near the origin of the electrophorograms, which is named as PAS-B in this study