NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
ABSTRACTS
Excretion of Streptococcus pyogenes in the milk of naturally infected cows.
BENDIXEN, H. C. and MINETT, F. C. (1938). (Journal of Hygiene Camb. 38,
374-383.)
THE authors record observations on two cows known to be responsible for out-
breaks of tonsilitis or scarlet fever due to excretion of Str. pyogenes in the milk. In
the case of one cow (M. 36), no marked clinical manifestations of mastitis were noticed,
but the milk from the affected quarter (L. F.) was altered and Streptococci in almost
pure cultures were recovered from the milk for a period of about thirteen months
including a dry period of three months. The other quarters remained unaffected.
Experimental infection into the teat canal of another cow with culture from the
L. F. quarter set up clinical mastitis. The animal was subsequently killed and
histo-pathological examination of the affected tissue revealed chronic inflammation.
The second cow had a previous history of injury to the R. F. teat resulting in
clinical mastitis of both the fore-quarters. Haemolytic streptococci which proved
fatal to mice, were isolated from milk samples of affected
quarters, in this case the
duration of excretion of Str. pyogenes was not more than six weeks.
The importance of injuries to the teats in the spread of mastitis is emphasized.
(J. A. I.).
Studies on the microbiology of the caecum of the horse. F. BAKER,
and R. MARTIN (1939). (Zeutralblatt Bakteriologie, Parasitenkunde und Infektion¬
krankheiten, Bd. 99 pp. 400-424.)
THE authors in this article have paid particular attention to the features which
attend the disintegration of cell-wall substances. Changes taking place in slitu were
observed by direct microscopical examination of the caecal material fixed in 10 per cent
formalin. Along with this polariscopic and microchemical methods were employed
by means of which it has been possible for them to establish, with considerable amount of
precision, not only the nature and extent of disintegration taking place, but also the
characteristics of the micro-organisms by which it is effected. Prevalence of iodophile
microflora and fauna and the significance of this feature have been discussed in relation
to the synthesis and degradation of carbohydrates in the caecum. The authors claim
that in the caecum of the horse, the presence of functional activity of protozoa is far
more prominent than in either the guinea-pig or the rabbit.
It has been demonstrated that the cyto clastic process is brought about by the action
of iodophile mirco-organisms exercised in situ. The processes involved in the disinteg-
ration of the components of cellulose and hemicellulose, as evidenced by polariscopic
method and microchemical and staining reactions, are described in some detail. Two
phases in the destruction of the optically birefringent polysaccharides have been noticed.
In the first phase of reaction, the colour reactions with chlorzinciodine and staining with
335
M
ORIGINAL ARTICLES.
THE POSSIBILITIES OF CATTLE FLY SPRAYS IN INDIA*
BY
S. K. SEN, M.Sc., F.R.E.S.
Imperial Veterinary Research Institute, Mukteswar
(Received for publication on 21 August 1939)
(With two text-figures)
INTRODUCTION
THE use of repellent sprays for protecting cattle from attacks of flies
constitutes, at the present time, an integral part of dairy practice in the pro-
gressive countries of the world, although opinion would appear to be still
divided as to whether the protection thus afforded results in an actual increase
in the yield of milk. It is even held by some workers [Freeborn, Regan and
Folger, 1925] that, by reason of certain untoward physiological effects pro-
duced by them, the application of commercial fly sprays with a base of pet-
roleum causes a reduction—which may be as high as 10 per cent—in the yield
of milk and that such reduction may be greater than what would normally
occur if the animals were left exposed to the attacks of flies. The factors
which determine the production of milk, however, are so variable that it is
only on the basis of a large number of controlled observations that its precise
relationship with fly infestation can be assessed with any degree of certainty,
the two most important of these factors being obviously the stage of lactation
and the character of the ration provided for the animals. It is almost need-
less to say that the possibility of ensuring a uniformity in these factors is con-
siderably greater in a single large herd consisting mainly of cattle of one breed
than in a number of small herds comprising, for the most part, animals of a
heterogeneous and, as one not infrequently notices in India, even nondescript
character. An occasion for carrying out a short series of observations of this
kind arose during October 1936, when the present writer was called upon to
enquire into the possibility of protecting the milch cattle of the Government
Cattle Farm, Manjhra (Lakhimpur-Kheri, U. P.) from infestation of flies.
The enquiry also provided an opportunity for examining the possibility of
finding out a spray which, while being inexpensive, would be free from the
property of producing burning or scurfing of the skin, for both these desiderata
assume a position of paramount importance in a tropical country like India.
Curiously, the question of cattle fly sprays has hitherto been almost
exclusively viewed with reference to milk production, although their use would
be no less justified as a measure of preventing these animals from contracting
such diseases as are known or suspected to be transmitted through the agency
of flies or from the less utilitarian point of view of sparing them the annoyance
and irritation caused by these pests. To provide a graphic account of the
* Paper read at the Indian Science Congress held at Lahore, January 1939.
( 339 )
340
The Possibilities of Cattle Fly Sprays in India
extent to which cattle are liable to be terrorized by attacks of flies, the writer
cannot do better than reproduce the following passage from a letter addressed
by one of the authorities in charge of the farm referred to above : ' The cows
are worried both by day and night by flies. You saw how they always stood
huddled together so as to give one another as much protection as possible.
They graze in the same way even during the night. They are constantly
jostling one another and only a few leading the herd get any decent grazing.
One of the two newly purchased bulls from Ferozepur simply refuses to stay
with his herd at all on account of fly trouble and wants to spend the whole
day under cover.'
The experiments that are to be described presently were carried out
during September-October in two consecutive years, when the two prevalent
species of biting flies on the farm were Lyperosia exigua and Musca crassirostris.
The former, in particular, was a source of great annoyance by reason of the
determined manner in which it attacked its hosts, which included calves as
young as one month old. Curiously, Stomoxys calcitrans which, as in most
other countries, is a ubiquitous pest of cattle in India, was conspicuously
absent at the time.
There were about 340 head of cattle on the farm, including 40 milch cows
and the majority of these were of the Sahiwal breed.
MATERIAL AND METHODS
In the trials carried out during the first year, only two sprays were tested
for their repellent action against the two species of flies mentioned above.
These were :—
(a) Graybill's formula (Jensen's modification) as given below :—
Hard soap
Water .
Petroleum
.
.
.
.
.
.
Powdered naphthalene
.
.
.
.
.
.
.
.
.
.
.
.
1 lb.
1 gal.
4 gal.
4 oz.
Dilute to one part emulsion to three parts water.
(b) ' Keep Green '.—This is a proprietary preparation issued by Messrs
F. S. Kerr & Co., Vulcan House, Ballard Estate, Bombay, and is stated to be
a mixture of 'Pyrocide 20 ' (a concentrated extract of pyrethrum flowers) and
a soap spreader. For actual use, the product is diluted with water at 1 : 15.
In the beginning, the preparations were sprayed on the bodies of the
animals with a ' Flit' sprayer, but, this having been found ineffective, they
were smeared with cotton wool. In spite, however, of this drastic method of
application, the preparations failed to exert any marked repellent effect on
the flies. The results obtained with ' Keep Green ' were communicated to
Messrs F. S. Kerr & Co. and in reply they suggested the use of ' Pyrocide 20 '
in combination with pine oil and gas oil (infra), a combination which had
been previously used as a mosquitocide with what would appear to be a con-
siderable amount of success by Sinton and Wats [1935].
S. K.
SEN
343
The repellents tested during the following year, including the one just
mentioned, comprised:—
(a) Fish oil . . .
Oil of tar . . .
Oil of pennyroyal . . .
Kerosine . . .
(b) Petrol . . .
Pyrethrum . . .
Pine oil . . .
(c) High speed Diesel oil*
Pine oil . . .
Pyrocide 20 . . .
.
.
.
.
.
.
.
.
.
.
.
.
1 gal.
2 oz.
2 oz.
½ pint.
(Formula of Bishopp, 1931)
.
.
.
.
.
.
.
.
.
300 c. c.
¾ oz.
75 c.c.
(Formula of Pearson, 1935)
.
.
.
.
.
.
.
.
92 gal.
3 gal.
5 gal.
(Formula recommended by Messrs F. S. Kerr & Co., ante)
The initial experiments were directed to determining the relative efficiency
of the three sprays mentioned above. For this purpose, eight cows were
tethered in a suitable place and their normal fly susceptibility determined by
taking the daily average counts of flies present on their body at fixed hours
for three consecutive days; for, as pointed out by Pearson, Wilson and Richard-
son [1933], ' close observations of a relatively few cows of known fly suscepti-
bility give more consistent and dependable results than less accurate observa-
tions on a large number of cows.' Six of these cows were used for testing the
repellent action of the sprays (two for each spray) and the remaining two were
left as controls. The results of fly counts showed that the spray containing
' Pyrocide 20 ' as one of its ingredients was the most effective of the three,
its repellent action being noticeable not only on L. exigua and M. Crassirostris
but also on non-biting flies. A series of trials were therefore carried out to
test the effect of this spray upon the yield of milk in the case of five Sahiwal
cows, an equal number of cows of the same breed being kept as controls. The
five animals were sprayed daily at 6 A.M. for 21 consecutive days with effect
from 2 October 1937, the amount of fluid used per spray being two oz.
(60 c. c.). The spray was applied by means of a ' Flit' sprayer, care being
taken that the fluid did not get into the eyes or to the udder, for in the latter
event it was likely to impart odour to the milk. The animals were allowed to
graze in the normal manner, and on the termination of the experiments both
the sprayed and unsprayed animals were given a wash with soap. None of
the sprayed animals showed any evidence of burning or scurfing during the
whole of the observation period of 42 days.
OBSERVATIONS ON THE EFFECT OF SPRAY ON MILK PRODUCTION
For a correct appraisal of the effect of the sprays, it was considered desir-
able to collate the records of milk yield in the case of the ten experimental
animals, not only for the period during which the spraying operations were
*This was recommended for use as a substitute for gas oil, for the latter was not
available at the time.
344
The Possibilities of Cattle Fly Sprays in India
carried out, but also during the three weeks both preceding and following
these operations. An examination of some of these records (as graphically
represented in Figs. 1 and 2*) shows that a very noticeable increase in the
yield of milk occurred in the case of four sprayed cows (Fig. 1) and that this
yield was sufficiently consistent to warrant the conclusion that it was due to
the effect of the spray. As for the actual amount of increase in the yield,
this was worked out at a daily average of 1.6 lb., the average for the individual
cows ranging from 0.6 to 3.1 lb. as shown in Table I below :—
TABLE I
Milk records, in lb., of five Sahiwal cows sprayed with fly repellent
Serial
No.
1
2
3
4
5
Brand
No.
6
239
241
217
237
Average
of daily
yield
during
3 weeks
preceding
use of
spray
(11
November
to 1
October
1937)
13.7†
5.9
7.0
10.0
6.9
Average
of daily
yield
during
3 weeks
of the use
of the
spray
(2
October
to
22
October
1937)
16.8
7.3
7.6
12.0
8.0
Total for 5 cows :—
Decrease
from or
increase
over the
record
of the
preceding
3 weeks
+ 3.1
+ 1.4
+ 0.6
+ 2.0
+ 1.1
+ 8.2
Average
of daily
yield
during
3 weeks
following
use of
spray
(23
October
to 12
November
1937)
16.1
7.1
7.6
11.6
7.5
Decrease
from or
increase
over the
record
of the
proceding
3 weeks
—0.7
—0.2
Nil
—0.4
—0.5
—1.8
Remarks
† Average of 15 days
(18 September to
1 October). Calved
on 18
February
1937.
Calved on 21 Feb-
ruary 1937.
Calved on 26 Feb-
ruary 1937.
Calved on 7 Sep-
tember 1937.
Calved on 6 Feb-
ruary 1937.
It may be presumed that the effect of the spray would have been more
marked if it had been applied earlier in the season when biting flies were more
numerous. It is worthy of note that the average of daily yield during the three
* For reasons explained later, the milk records of one of the control cows had to be
excluded from consideration. The milk records of only four sprayed and four control
cows are therefore represented in the text-figures.
FIG.
FIG. 1.Milk records of four sprayed cows
on alternate days
(341—42)
B
FIG. 2. Milk records of four control (unsprayed) cows
on alternate days
(345—346)
S. K.
SEN
347
weeks following the use of the spray was still appreciably higher than that
during the period preceding its use, so that it would seem that the effect of the
spray persisted for this length of time after it had been discontinued. In
regard to the controls, one of them (Cow No. 218) showed a sudden and
somewhat abnormal increase in yield after calving on the 24th of September
1937, and if this animal be excluded from consideration, then the level of the
milk yield in the case of the controls remained stationary for all practical
purposes (Fig. 2). As a matter of fact, the average of daily yield in the
case of these four animals, during the period of spraying operations, was
actually worked out at —0.2 lb., as shown in Table II, a figure which was
in striking contrast with what was recorded for the sprayed animals.
TABLE II
Milk records, in lb., of five Sahiwal cows kept as ' controls '
Serial
No.
1
2
3
4
5
Brand
No.
154
188
248
211
218
Average
of daily
yield
during
3 weeks
preceding
use of
spray
(11
September
to 1
October
1937)
13.7
8.0
7.7
11.6
8.2
Average
of daily
yield
during
3 weeks
of the use
of the
spray
(2
October
to 22
October
1937)
12.6
8.3
8.0
11.3
14.0
Decrease
from or
increase
over the
record
of the
preceding
3 weeks
—1.1
+ 0.3
+ 0.3
—0.3
—0.8
+5.8
Average
of daily
yield
during
3 weeks
following
use of
spray
(23
October
to 12
November
1937)
12.4
8.0
7.9
10.9
15.4
Decrease
from or
increase
over the
record
of the
preceding
3 weeks
—0.2
—0.3
—0.1
—0.4
—1.0
+ 1.4
Remarks
Calved on 5 March
1937.
Calved on 1 Sep-
tember 1937.
Calved on 20 April
1937.
Calved on 1 Feb-
ruary 1937.
Calved on 24 Sep-
tember 1937. This
animal has
been
excluded from consi-
deration .
348
The Possibilities of Cattle Fly Sprays in India
As for the cost of the spray, this was calculated at slightly less than six
pies (exclusive of freight) per spray of 60 c. c. It is, however, very probable
that a much smaller quantity would prove equally effective, because the re-
sults of similar trials carried out by Freeborn and Regan [1932], in U.S.A.,
appeared to them to point to the conclusion that, in order to obtain an average
repellent efficiency of 80 per cent over a period of 21 hours with petroleum
oils containing pyrethrum, pine oil or both, it was necessary to apply
'approximately 250 c. c. of spray per 1,000 lb. of cow ' and, furthermore,
according to the same workers, 20 c. c. of a very light spray is a complete
coverage for a cow weighing 1,000 lb. On the basis of these calculations, 30
c. c. of the ' Pyrocide 20 ' spray should be a good coverage for cows of
Sahiwal breed and at the same time give a fairly high repellent efficiency for
a period of ten hours (7 A.M. to 5 P.M.). The cost, however, would obviously
require to be further reduced if the use of cattle fly sprays is to find a ready
place in dairy practice in India.
SUMMARY AND CONCLUSIONS
The two factors which impose a limitation on the value of repellent sprays
in combating cattle flies in India are their liability to cause burning of the
skin and their high cost compared with the benefit they may be expected to
accrue from their use in the case of cows of low milk yield. The paper dis-
cusses the possibility of overcoming these difficulties in the light of the results
of a series of fly repellency tests carried out in one of the Government cattle
farms in the United Provinces. In the course of these tests, it was observed
that a spray consisting of high speed Diesel oil, ' Pyrocide 20 ' (a concen-
trated extract of pyrethrum flowers) and pine oil, when applied on Sahiwal
cows for 21 consecutive days, during October, did not produce any burning
or scurfing of the skin, although the spray proved to be very effective against
Musca crassirostris and Lyperosia exigua, which were at the time the two
prevalent species of biting flies on the farm. About 60 c. c. of the fluid was
used for each spray and the cost of this quantity was slightly less than six
pies. In view, however, of the results recorded in this field by workers in
other countries, it is probable that a much smaller dose would prove equally
effective. The use of the spray was also found to result in an appreciable
increase in the yield of milk.
REFERENCES
Bishopp, F. C. (1931). U. S. Dept. Agric. Farmers' Bull. 1097, 17
Freeborn, S. B., & Regan, W. M. (1932). J. Econ. Ent. 25, 167-74
––––––––––––––––––––&
Folger, A. H. (1925). J. Econ. Ent. 18, 79-90
(Cited by Melvin, Roy in J. Econ. Ent. 25, 1154-64 ; 1932)
Pearson, A. M. (1935). Bull. Del. Agric. Expt. Sta. 196, 63 (Abstr. in Rev.
App. Ent., B, 24, 304-5 ; 1936)
––––––––,Wilson,
J. L., & Richardson, C. H. (1933). J. Econ. Ent. 26, 269-74
Sinton, J. A., & Wats, R. C. (1935). Rec. Malar. Surv. Ind. 5,275-306
AROMA IN DAHI.
I. ISOLATION OF A NEW STRAIN OF STR. DIACETYL AROMATICUS
FROM INDIAN DAHI
II. PRODUCTION OF AROMA IN MILK CULTURES INOCULATED WITH
THE NEW STRAIN OF STR. DIACETYL AROMATICUS
BY
R. KARNAD, M.Sc.
(Department of Biochemistry, Indian Institute of Science, Bangalore)
(Received for publication on 28th March 1939)
(With Plate XXVI and one text-figure)
INTRODUCTION
DURING recent years, more and more attention is being paid to the aroma-
producing micro-organisms of butter, in view of the important part they
play in the development of the flavour, which is the chief factor determining
the market value of butter.
Recent researches [Hammer, 1920; Knudsen, 1931; Kluyver, 1933;
Ruehe, 1937; Storch, 1919; Van Beynum, 1937 ; Vas and Csiszar, 1936] in
the bacteriology of ' starters' used for butter-making have shown that good
starters contain, in addition to Sc. lactis, or of a closely related species named
by Orla-Jensen Sc. cremoris, one or more streptococci which enhance the
aroma of butter through formation of volatile acids.
The aroma bacteria were discovered almost simultaneously by the Dutch
investigators, Boekhout and Ott de Vries [1917] in Holland, by Hammer and
Bailey [1919] in America, and by Storch [1919] in Denmark. According to
Hammer, the outstanding character of the aroma bacteria is the formation
of volatile acids and other aromatic products by fermenting the citric acid
of milk. He has characterized the ' associated organisms' into two groups
Sc. citrovorus and Sc. paracitrovorus [Hammer, 1923]. Orla-Jensen and Spur
[1926] found certain capsule forming bacteria having an important influence
on the formation of butter aroma. Their ability to ferment citric acid is of
minor importance. They produce l-lactic acid from lactose in presence of
yeast extract, and belong to the β-cocci. While Boekhout, Ott de Vries and
Hammer make a sharp contrast between the ' aroma bacteria' and ' lactic
acid bacteria', Orla-Jensen and Knudsen and Sorensen [1929] conclude that
the aroma bacteria also belong to the group of lactic acid bacteria.
( 349 )
350
Aroma in Dahi
Recent work has shown that diacetyl, CH 3 . CO.—CO. CH 3 , a compound
derived from acetyl-methyl-carbinol, CH 3 . CO. CHOH. CH 3 , by oxidation,
is of great importance from the standpoint of the aroma of butter [Davies,
1934 ; 1936].
Schmalfuss detected diacetyl in a milk culture of rod-shaped lactic acid
organism. Schmalfuss and Barthmeyer [1928] concluded that diacetyl is an
assimilation product of the organism. The quantity of diacetyl in the butter
appeared to be correlated with the intensity of the aroma. Margarine to
which diacetyl had been added developed the aroma of butter.
Van Niel, Kluyver and Derx [1929] showed that in a series of butter
samples that had been given definite scores on aroma, a rather close correla-
tion existed between the aroma and the presence of acetyl-methyl-carbinol.
In fine butter, from 0.0002 to 0.0004 per cent of diacetyl was found, and when
this substance was added to butter poor in odour, an unmistakable aroma
appeared. They arrived at the important conclusion that diacetyl was either
responsible for the aroma of butter or that it was the principal component of
the aroma material.
Hammer [1931] reported that butter cultures having a satisfactory
flavour and aroma always contained considerable acetyl-methyl-carbinol and
some of them contained diacetyl, while cultures lacking in flavour and aroma
contained little or no acetyl-methyl-carbinol or diacetyl. It appeared that
these substances were largely formed through the action of the streptococci
on citric acid ; and the acidity of the milk greatly influenced the acetyl-methyl-
carbinol and diacetyl formation.
None of the citric acid-fermenting streptococci studied by Michaelian
[1932] produced diacetyl in milk while a few of them produced it when various
acids were added. The addition of citric acid resulted in a greater produc-
tion of diacetyl than that of other acids, so that citric acid appeared to be
the source of diacetyl.
The chemistry of the formation of acetyl-methyl-carbinol in cultures is
not quite understood. While some investigators consider that carbohydrates
are the chief sources, Michaelian, Farmer and Hammer [1933] showed that
citric acid is the main source. Though it has been observed that acetaldehyde
is an intermediate product in the fermentation of both carbohydrates and
citric acid by the aroma bacteria, further information on the subject is
lacking.
This brief review brings into prominence the rôle of diacetyl in determin-
ing the aroma of butter. Very little work has been done in India on the pro-
duction of flavouring compounds in Indian dairy products. A systematic
study was therefore undertaken and the results obtained are incorporated in
this paper.
Ind. Jour. Vety. Sci. Anim. Husb., Vol. IX, Part IV ]
PLATE XXVI
FIG. 1. Fresh culture of 'Str. diacetyl aromaticus' (growth in milk)
FIG. 2. 'Str. diacetyl aromaticus' growth in yeast extract with 2 per cent dixtrose-
and 2 per cent Calcium carbonate