NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
254
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, III
the dung gives little indication of any connection. An animal of good appearance
will show large number of ova, whereas an emaciated creature will show few.
The above information, though meagre, all goes to support Mr. Parr's conclu-
sions that mineral deficiency and parasitical infestation explain in great measure
the poor cattle of these tracts of country with heavy rainfall. Research on both
matters is needed but to my mind the parasities need tackling first, as estimation of
the results of lack of mineral supplies would always be confused by the presence of
parasities.
The local professional graziers have some very shrewd ideas on prevention and
treatment. I have seen copper coins put into very acid dahi with the result that
after a few hours the dahi turns a bluish colour ; this coloured dahi is then fed to
the cattle. And they firmly believe in the use of leaves of certain trees. Their
temporary shelters are frequently moved to new ground, a benefit which the cattle
of settled cultivator are denied and consequently they suffer. To maintain the
supply of any decent local bullocks at all, the continuance of large grazing reserves
seems essential, as under confined conditions these parasities have things all their
own way. Luckily, Assam has such reserves up till the present though they are
threatened.
I remain,
Yours truly,
R. C. WOODFORD,
Live-stock and Dairy Expert, Assam.
[ Note by Mr. G. D. Bhalerao, Helminthologist, Imperial Institute of Veterinary
Research, Muktesar, on the note by the Live Stock and Dairy Expert, Assam,
regarding parasitic gastritis amongst cattle produced by Mecistocirrus digitatus :—
1. Conditions favourable for the development of the parasite.—I am in entire
agreement with the Live-stock and Dairy Expert, Assam in considering that his
province offers an ideal environment for the development and rapid propagation of
the stomach worms of cattle. I have remarked in a previous note that the
conditions prevailing in the hills (at Muktesar) are not so favourable for the rapid
multiplication and extensive distribution of the parasite. The extremes of climate
are detrimental to their growth and to spread of the infection. Humid climate with
the land abundantly irrigated with water are the optimum conditions for the
development of the larvae and their more extensive geographical distribution.
CORRESPONDENCE
255
2. Life-history.—The phase of the life-history important from the standpoint
of infection has been already worked out by me. The eggs when they are passed
out with the faeces of the host have in them usually 16 or 32 segments of the
developing embryo. Eighteen to twentyfour hours after deposition, the embryos
are formed in the eggs. Eighteen to twentyfour hours after the formation of
embryos the larvae of the first stage are hatched out of the eggs. The larvae of the
first stage are active, but are not, capable of very great translocation.
After four days the larvae of the first stage become ensheathed and less active.
They continue in this ensheathed condition for about six days when the larvae of
the second stage emerge from them. These are again active, and after three to
four days of an active life the larvae of the second stage become ensheathed. The
ensheathed larvae are gradually transformed into the larvae of the third stage, the
infective larvae. The infective larvae do not come out of their sheaths outside the
host, but await an opportunity of being swallowed by the definitive host. The
development of the larvae in the cattle has not yet been worked out, since no
further opportunity has occurred for doing this at Muktesar, but this is not of great
importance from the standpoint of the transmission of the infection.
3. The mode of infection.—No doubt one of the modes of infection, as has been
suggested by the Live-stock and Dairy Expert, Assam, is through the food of the
cattle, the grass. The ensheathed larvae deposit themselves on the blades of grass
and when the latter are eaten by cattle, infection takes place. But this method of
infection is, in my opinion, probably of secondary importance. The larvae, as has
been said previously, not having been endowed with much power of translocation,
cannot voluntarily undertake a journey even to a distance of a few inches. The
only means by which the larvae can be distributed in the grass are by the actual
deposition of dung containing ova, the arrest of the larvae in the young grass
blades during inundations, and through the agency of the cattle themselves when
they walk along the ground breaking up the infected dung.
Another agency through which, in my opinion, the major portion of the
infection takes place is the drinking water. In a place like Assam which enjoys a
heavy rainfall the ground on which the infected faeces is deposited is often
inundated by rain water which accumulates in ponds and puddles and other larger
shallow collections. Most of the larvae, including those that are deposited on the
grass, would be carried along with the rain water and be stored up in such
reservoirs, which are the main stay of drinking water for most of the cattle
population in the province. In this way it is probable that the main source of
infection is the drinking water and not the food.
I deem it worth recording here that from an examination of all the worms
that were once recovered from a heavy infection of a dairy cow at Muktesar, from
256 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, III
the parasites that I have examined from Assam, and from two minor local
collections, I am forced to conclude that there is a very great repeated infection in
the case of this parasite. If in a case of heavy infection all the parasites are
carefully examined it will be noticed that they are not all at the same stage of
development and maturity. The majority of them are found to be immature
adults and comparatively few have reached sexual maturity. The number of
fertilised females is still less. On the contrary, in the case of hill bulls, where the
infection is, as a rule, very light, almost all the worms are at the same stage of
maturity. The inevitable conclusion is that in the plains repeated infection of the
same animals takes place. At Muktesar, where the larvae experience adverse
conditions, the chances for reinfection are reduced to a minimum.
4. Prophylaxis.—The prophylactic measure that the Live-stock and Dairy
Expert, Assam, has been already taking, namely restricting the cattle as much as
possible while grazing and removing the dung soon after deposition to pits surrounded
by trenches containing a vermicidal solution, is an excellent one. Another measure
that I would like to suggest is that the water reservoirs for the cattle should be
stone and lime built and their supply should be replenished from time to time from
deep streams to which cattle have very little access. In view of the infection, as
I have suggested above, taking place mainly through the drinking water this
precaution is of extreme importance.
5. Treatment. — The Live-stock and Dairy Expert, Assam, has tried copper
sulphate solution, but he reports that this has not been very successful. Copper
sulphate, combined with arsenic, is undoubtedly a very good anthelmintic for
stomach worms in sheep, and some success has been obtained with it in cattle at
Muktesar, but it is true that it is by no means altogether efficient in these animals.
Recently Maurice C. Hall (August 1930), in a paper read before the
International Veterinary Congress, London, recommended very strongly the following
anthelmintic mixture for the stomach worms of cattle, viz., a 1 per cent. solution
of copper sulphate and 40 per cent. solution of nicotine sulphate—3.8 litres of
the former and 1 oz. of the latter. The dose for adults is one quart and this
prescription might certainly be given a trial.
6. Other points raised by the Live-stock and Dairy Expert, Assam.—In one place
it is remarked that the faeces of some calves show less ova because they "have
acquired a certain amount of resistance." The only reason that can be attributed
for the scanty infection among the calves is the lack of opportunities for being
repeatedly infected. They being primarily confined to stables, the possibility of
their being infected with contaminated grass and water is reduced to a minimum.
This conclusion is also in keeping with the observations of the Live-stock and
CORRESPONDENCE
257
Dairy Export, Assam, himself, who says in another place that " The result of this
confinement is generally an improvement in condition."
Another point raised by the Live-stock and Dairy Expert, Assam, and which
appears to be inexplicable to him is "An animal of good appearance will show
larger numbers of ova, whereas an emaciated creature will show few." It has
already been remarked above, while discussing the question of repeated reinfection,
that in any infected case the number of fertilised females may not be large, and
in that case the ova passed in the faeces will be few, although the actual number
of parasites infecting the animal, including a large number of immature ones, may
be very large. The animals in better condition may harbour a much less number
of parasites, but the proportion of gravid females in them may be much more than
in the previously mentioned cases. The number of ova in the faeces is always
governed by and proportional to the gravid females inhabiting the alimentary
canal of the host.
[ The above letter from the Live-stock and Dairy Expert, Assam, and note
thereon by the Helminthologist, Imperial Institute of Veterinary Research,
Muktesar, are of very great interest to all concerned with the breeding and roaring
of cattle in humid areas, throughout India.
The parasite particularly incriminated in this instance—Mecistocirrus digitatus—
is widely distributed in such areas, and there appears to be little doubt that repeated
worm infestation is largely responsible for the marked deterioration which is known
to take place among cattle reared in such areas. (A. O.)]
MGIPC-S3-III-1-21—17-9-31—1,000.
ORIGINAL ARTICLES
SILAGE INVESTIGATIONS AT BANGALORE.
II. QUALITY AND YIELD OF SILAGE IN RELATION TO FILLING
CONDITIONS.
BY
T. S. KRISHNAN, B.A.,
Animal Nutrition Section, Imperial Department of Agriculture, Bangalore.
(Received for publication on 9th May 1931.)
OBJECT.
In a previous paper (" Silage Investigations at Bangalore ", Memoirs of the
Department of Agriculture in India, Chemical Series, Volume X, No. 10) the results
of a study of the ensilage of Jowar (Sorghum vulgare) were reported. There, the
ensilage was done only under one set of conditions. In the present experiment
an attempt has been made to determine the effect of (a) rate of filling and (b)
addition of water on the resulting silage, with the same material.
METHOD OF EXPERIMENT.
The following scheme was adopted. Ensiling was done in pits of rectangular
shape, 12 feet long, 6 feet wide and 8 feet deep, the increased depth being employ-
ed to diminish the exposed surface, while ensuring a greater capacity. The Jowar
was harvested when in prime condition for ensilage, and was chaffed to bits of
about an inch in length. The chaffed material was employed for filling the pits.
Generally, the harvesting of the crop was done in the forenoons and the chaffing
and filling in the afternoons. Portions of the thoroughly mixed, chaffed Jowar,
being filled in the pits, were enclosed in loosely woven tared gunny bags, and the
weight of the green sample determined. The bags were buried in the pits at
suitable depths. During the filling of the bags, separate samples were taken for
immediate analysis.
Pits were filled according to the following scheme :—
Pit No. 1. Slow filling with watering.
Pit No. 2. Slow filling without watering.
Pit No. 3. Rapid filling with watering.
Pit No. 4. Rapid filling without watering.
( 259 )
B
260 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [I, IV.
In each pit four bags were buried, two at a height of 3 feet from the bottom,
and the other two at 6 feet from the bottom and vertically over those lower down.
They were arranged to lie along the length of the pit centrally, and at 3 feet from
the ends. One bag in each layer had a clinical thermometer, enclosed in an iron
tube, to register the maximum temperature attained. Only these bags were
employed for the complete analysis. The others were used only for the determina-
tion of the loss of dry matter on ensilage.
Filling of the Silos.
Table I gives the details of the filling of the silos. The conditions of ensilage,
duration of filling of the pits, numbers and details of the location of the experi-
mental bags, as well as of the weather during the operations, will be found
therein.
At the close of each day's operation, during filling, the material in the pit was
thoroughly trampled down by half a dozen men. The pits were always filled to a
height of a foot above ground level before closing up. They were closed and press-
ure applied by earth being piled on to a height of two feet above ground level,
in all cases, with slopes on all sides to allow any rain water to drain away.
Opening of the Silos.
The pits were opened in serial order, and as the bags turned up during the
consumption of the silage, they were removed, weighed, sampled and an aliquot
taken for analysis. Details of the settling as well as of the depth of spoilt silage
at the top are given in Table II.
TABLE II.
Statement of settling and spoiling during ensilage.
Pit No.
1
2
3
4
Conditions of ensilage
Slow filling with water-
ing.
Slow filling without water-
ing.
Rapid filling with water-
ing.
Rapid filling without
watering.
Total height
filled
9'
9'
9'
9'
Depth of
settling
1' 6"
1' 9"
3' 0"
4' 0"
Thickness of
spoilt layer
at the top
0' 3"
0' 4"
0' 6"
1' 6"
Depth of resi-
dual good
silage
7' 3"
6' 11"
5' 6"
3' 6"
SILAGE INVESTIGATIONS AT BANGALORE
261
In all the pits considerable settling has taken place, the effect being most
marked in Nos. 3 and 4—the rapidly filled ones—and even here, No. 4 shows a
greater shrinkage than No. 3. The large shrinkage in these two pits is no doubt
due to the want of pressure, as they were filled in a few hours and therefore could
not be consolidated to the required extent. But the fact that watering helped
consolidation greatly is shown by the lower shrinkage in No. 3, than in No. 4.
This is repeated in the case of Nos. 1 and 2 respectively. But, as these were filled
only slowly, the operation extending over a week, the bottom layers had already
settled down well, and the main subsidence probably took place only in the top
third of the material.
In all the pits there was a layer of rotten, mouldy silage, at the top and sides
which had to be rejected. The thickness of the top layer varied, as will be seen
from Table II. The depth of spoilt material at the sides was small, being about
2" in all cases. Evidently Nos. 3 and 4 contained more air due to the insufficient
packing, which collected at the top when the mass settled down, and hence a
greater loss was noticed. This is reduced by slow filling as is seen from the loss in
pits 1 and 2.
The very extensive spoiling noted in No. 4 pit needs a special word of explana-
tion. This pit was not watered, and a dry silage was aimed at. But, as will be
shown later (Table VII—Loss of dry matter), the moisture content of the silage of
this pit was very high. There is no doubt that this pit was flooded by rain which
fell two days after filling. It does not represent what it was intended to, but is
of interest as a flooded pit, and the data obtained from it must be considered in
this light. The entry of the large bulk of water in the rapidly fermenting material
at the top, containing a large amount of air as well, has accentuated the loss
enormously, with the result that the depth of spoilt material constitutes a very
large proportion, roughly a third, of the entire contents of the silo.
Quality of the Silage produced.
It is of interest to note that the types of silage formed in all the pits were
much alike. They may be defined as " Brown " silage of a slightly " Acid " nature.
The products in pits 1 and 2 were distinctly less acid, and those in Nos. 1 and 3
had a slightly more pleasant odour than the rest. The product of pit No. 4, though
acid, had not the good aroma of the others, thus showing the effects of the leach-
ing down of the spoilt material from the top layers.
As a general conclusion, watering gives the silage a better aroma, and slow
filling, a lower acidity.
B 2
262 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [I, IV.
Note on Temperature Record.
In the present experiment only the maximum temperatures attained in the
bags were recorded. These are given below in Table III.
TABLE III.
Record of maximum temperatures attained in the various pits.
Pit No. . . . .
Conditions of filling
Maximum
temperature
attained in bags put in
at 3' from the bottom.
Maximum
temperature
attained in bags put in
at 6' from the bottom.
1
Slow filling
with watering
42.1 °C
40.5°C
2
Slow filling
without water-
ing
42.1°C
47.0°C
3
Rapid filling
with watering
36.0°C
47.8°C
4
Rapid filling
without water-
ing
. .
38.9°C
Even here, the reading of the one in pit 3, 36°C, is not above suspicion, as it
denotes scarcely any rise of temperature, while the other one in the same pit regis-
tered a considerably higher temperature, viz., 47.8°C. The range of tempera-
tures recorded agrees well with the detailed study made in the previous experiment
at Bangalore (Loc cit). The temperature record was in the region appropriate to
the production of " Brown Silage " with a slightly " Acid " character. It is quite
likely that in the pits which were watered a greater quantity of heat was produced
but the large bulk of water added, having also to be raised to that temperature,
prevented the recording of an otherwise higher temperature.
Method of Analysis.
The determination of the dry matter in the green Jowar, as well as in the
silage, and the corrections for the volatile substances, were carried out exactly as
described in the earlier publication. The preparation of the alcoholic extract was
carried out according to Woodman (Journal of Agricultural Science, XV, 343) as
modified by Foreman (Biochemical Journal, XXII, 208) and the analysis of the
same according to Woodman (above). The rest of the processes were identical
with those quoted in the previous paper.
SILAGE INVESTIGATIONS AT BANGALORE
263
DISCUSSION OF RESULTS.
A. Changes in Moisture, Dry matter and Organic matter.
Tables IV to VII contain some of the information gained from the bags in
pits 1 to 4 respectively.
Pit No. 1.—The fresh weight of silage is considerably more than the green weight
of Jowar ensiled, evidently due to the addition of water. The loss of dry matter
due to ensilage is fairly uniform (Table IV), the average being 5.71 per cent. and
10.07 per cent. on the corrected and uncorrected basis respectively. The uncor-
rected figure is given to emphasise the degree of error introduced if due allowance
is not made for the loss of volatile ingredients. As will be seen, this error is fully
equal to the loss of dry matter on the corrected basis. The loss of organic matter
naturally follows closely the loss of dry matter. In this case the average loss is
5.3 per cent. (Table XII), which is slightly lower than the dry matter loss.
Pit No. 2.—Here there is very little change in the fresh weight as the result
of ensilage (Table V) owing probably to the fact that watering was not done. The
same cause accounts for the extremely dry quality of the resultant silage. But
there is a distinct lowering, slight though it be, in the percentage dry matter as the
result of ensilage. This is probably due to the absorption of the water resulting
from the oxidation of the material during fermentation and bacterial action. The
loss of dry matter agrees well with that noted in No. 1 pit above, being 6.51 per
cent. and 8.26 per cent. on the corrected and uncorrected basis respectively. The
loss of organic matter in this pit is 7.4 per cent. (Table XIII), which is slightly
more than that of the loss of dry matter.
Pit No. 3.—This has also produced a wet silage like No. 1, due to watering,
having a much lower percentage dry matter in the silage than in the green Jowar.
The loss of dry matter here is considerably more than in any other pit. This can
only be due to rapid filling, causing the retention in the mass of material of a very
considerable quantity of air which stimulated the rapid oxidative changes and
bacterial action at the expense of the organic matter. Watering would certainly
help, but that it is not the main cause is seen from the fact, that No. 1 pit which
was also watered shows, comparatively, only a very low loss. The losses of dry
matter on the corrected and uncorrected basis work out on an average to 13.59
per cent. and 18.73 per cent. respectively (Table VI), being roughly double the
loss noticed in the other pits. The organic matter, at whose expense this exten-
sive bacterial action takes place, naturally shows a very high loss, viz., 16.3 per
cent. (Table XIV). Here also this loss is more than that of the dry matter.
Pit No. 4.—As has already been stated before, this pit was unfortunately
spoilt owing to the soaking in of a very large amount of water, a wet silage being