A total of 210 dairy cows of Seongw han area were epidemiologically investigated for mastitis by Milk Quality Test(MQT) method. Milk samples from cows infected with mastitis were also bacteriologically studied.
Seventy four (42.5%) of 174 dairy cows were positive for mastitis and fifty nine (79.7%) among them were infected with subclinical mastitis and fifteen (20.3%) were clinical mastitis.
High infective rate were shown on August (48.7%) and July (45.7%) and it was lowered on Decermber(35.8%).
The incidence rate of subclinical mastitis for herd shown tendency of increase at the barn in which located on lower place (30.7∼43.9%), whereas, the barn in which was on higher place and with bucket type milking system shown tendency of decrease causative organisms.
A. total of 230 strains of etiological agents were isolated from 578 infected duarters which shown MQT score (+) or more. The relevant causative organisms isolated in this study were Staphylococcus aureus (18.3%), Staphylococcus epiderm idis (16.9%), fungi (16.5%), Pseudomonas aeruginosa (15.2%), Escherichia coli (7.8%) and Serratia m arcescens(2.27), respectively.
In oreer to know the morphology and the function of the fat-storing cells (FSC) of the squirrels which were captured at the Pal-Gong mountain near Taegu in December, 1980 (Group A) and May, 1981 (Group B), respectively, the light and electron microscopic observations were conducted on the liver of the squirrels. The results obtained are as follows:
1. Light microscopically, the size of the lipid droplets in the FSC of group A was uniformly larger than those in the cells of group B, and number of the droplets in the FSC of group A was less than those in the cells of group B, The distribution of the FSC of group A was mainly perilobular area while those of group B was centrolobular and midzonal areas. In this point of view, the FSC of the squirrels was similar to those cells of the hamsters.
2. Electron microscopically, general morphology of the sqirrel´s FSC was accorded with those of the other mammals. However, the rouph surfaced endoplasmic reticulum in the FSC of group B was more dilated than those in the cells of group A, and more lipid droplets and pinocytopic vesicles were observed in the FSC of group B than those in the cells of group A.
3. From the above evidences, it could be suggested that the metabolic rates in the FSC of the squirrels collected in the spring were higher than those in the cells of the animals collected in the winter.
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