ABSTRACTS
Studies on bovine mastitis—VIII. The control of chronic Streptococcus mastitis.
MINETT, F. C., STABLEFORTH, A. W., and EDWARDS, S.J. J. Comp. Path.
and Ther. 46, 131-138 (1933).
Previous papers in this series of publications have treated of the bacteriology of Streptococcus
mastitis and of the diagnosis of the prevalent chronic form of this disease. The organisms have been
grouped as I, II and III of Mastitis Streptococci, the group I being far more responsible for the out-
break of the chronic Streptococcus mastitis and, important from the economic point of view.
Observations covering a period of five years were made in a practically self-contained herd consisting
of 53 heifers, dry and milch cows. In the first year of observations, 10 cows were affected with chronic
Streptococcus mastitis. During the first two years, preventive measures were adopted and the infected
cows were milked last and subsequently kept on separate premises. This led to the formation of a
group of cows, which for three years and six months remained free from Streptococci responsible for the
chronic and contagious form of Mastitis. Of the ten originally infected cows which remained on the
farm for varying periods up to five years, five were under observation for the longest time and they
appeared to have made a complete recovery.
The authors conclude that this is the first time that it has been shown by frequent tests of milk
that a herd of cows was maintained free from infection, and they prove that chronic Streptococcus
mastitis is a contagious disease preventable by the hygienic measure described above.
The Technique used in the examination of milk samples is described in this article. [ B. S.]
Russian methods of artificial insemination multiply sires' value. LANDAUER, W.
J. Hered, 24, 87-92, (1933).
The author describes the following methods used in Russia for artificial insemination, and gives
photographs of instruments and breeding rack used in this connection. In Russia the need of artificial
insemination arose chiefly on account of the great distances in rural districts which frequently made it
impossible to use valuable breeding animals to best advantage, and the author thinks it probable that
artificial insemination will, in future, play an important part in the breeding programme of stock -
owners.
I. The Sponge Method of Ivanov was extensively used in the past, but on account of certain
fundamental defects it has been discontinued.
II. The Sperm-Collector Method.—Russian experience has shown that this method of getting the
sperm with Sperm collector is the most successful one and it has been adopted in Russia for all occasions
where large number of ewes are to be inseminated. About 10 times as much sperm can be obtained
with the sperm collector and the motility and length of life is also much greater as with the sponge
method. In 1931 several hundred thousand sheep, about 187,000 cows, and also horses and donkeys
were successfully inseminated by the method. The sperm collector, after being passed into alcohol
(65 per cent.) for ten minutes, is, for a short while, put into alkaline physiological salt solution. It is
then introduced into the vagina with the help of a pair of pincers. After the ewe has been served, the
sperm collector is removed and sperm stored in a glass container. With the aid of a syringe and vaginal
speculum, a quantity from 0.2 to 0.4 c.c. of sperm is introduced into the uterus of an ewe. All the
manipulations of obtaining the sperm and inseminating the ewes are to be carried out in a room with a
temperature between 15-25° C.
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