NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
STUDIES ON THE DETERMINATION OF DIGESTIBILITY COEFFICIENTS :
93
TABLE III—contd.
1
Ether
Extract.
Crude
fibre.
Nitrogen
free Ex-
tract.
Basis
of
calcula-
tion
2
1 & 2 lb. .
1 & 3 lb. .
2 & 3 1b. .
Mean
Graphical
Method.
Multiple
Regression
Equation.
Old
me-
thod—
1 lb. cake
2 lb.cake
3 lb. cake
1 & 2 lb. .
1 & 3 lb. .
2 & 3 lb. .
Mean
Graphical
Method.
Mu1tiple
Regression
Equation.
Old
me-
thod—
1 lb. cake
2 lb. cake
3 lb. cake
1 & 2 1b. .
1 & 3 lb. .
2 & 3 1b. .
Mean
Graphical
Method.
Mu1tiple
Regression
Equation.
Old
me-
thod—
1 lb. cake
2 lb. cake
3 lb. cake
No.
of
observa-
tion
3
6
6
6
18
18
18
6
6
6
6
6
6
18
18
18
6
6
6
6
6
6
18
18
18
6
6
6
Paddy straw
Mean
Digesti-
bility
4
0.42380
0.42933
0.38307
0.41206
0.43164
0.43790
0.48598
0.53243
0.59379
0.62755
0.61833
0.57620
0.60736
0.61650
0.61894
0.60692
0.58331
0.58251
0.48125
0.46583
0.40493
0.45067
0.46172
0.46352
0.45295
0.42152
0.42695
Standard
deviation
Actual
5
0.1622
0.1077
0.2561
0.1868
0.0554
0.0495
0.1033
0.0768
0.0738
0.0363
0.1588
0.1084
on
mean
6
38.27
25.09
66.86
45.33
8.83
8.01
17.93
12.65
15.33
7.79
39.22
24.05
Linseed cake.
Mean
Digestibi-
bility
7
0.96495
0.96070
0.98392
0.96985
0.96356
0.95600
0.89000
(H. & M.)
0.04150
0.11485
0.66140
0.27258
0.27290
0.07709
0.57000
(H. & M.)
0.44235
0.63245
0.87090
0.64887
0.67298
0.61345
0.78000
Standard
deviation
Actual
8
0.1307
0.0587
0.1212
0.1353
0.058
0.5596
0.296
0.056
0.6188
0.1466
0.6430
0.5407
on
mean
9
13.54
6.11
12.32
13.95
254.94
487.24
195.95
387.41
139.89
23.18
73.83
83.37
94
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VI, I
DISCUSSION
Before these figures are scrutinised, it is necessary to bear in mind the ad-
mittedly inexact nature of the chemical method of analysis used for their estima-
tion. We have, at present, little knowledge regarding the fate of the food materials
and their respective components during the course of their digestive processes in
the alimentary canal of the herbivora. What is under existing convention assum-
ed as digested is really the difference between the feed and what is obtained as
undigested residue in the faeces. This does not take into account the secondary
transformations taking place during digestion, nor such fractions or parts of feed,
which although evacuated may still be capable of digestion. There is then the
fact that faeces also contain excretory waste products from the body in addition
to the undigested residues of the food, and as Armsby [1910] has remarked " the
presence of so-called metabolic products in the faeces may give rise to serious
errors in the determination of digestibility of some ingredients in the food, notably
fat and protein."
In another place, Armsby [1903] has remarked that in " extreme cases, absurd
results are sometimes obtained such as negative digestibility or a digestibility
greater than 100 per cent". He [1910] has further expressed an apprehension
of " the possibility of conversion of members of one group of nutrients into those
of others." In fact, the recent investigations of Woodman and Stewart [1932]
on the mechanism of cellulose digestion (by fermentation), show that in the case
of oil cake the ether extract fraction seems to undergo such transformations as to
assume an insoluble nature thereby showing an apparent increase in fibre. While
this refers to bacterial fermentation, the present authors feel that the possibility of
some changes of like nature in the animal system are not unlikely, thus giving an
apparent increase of the fibre content of faeces and correspondingly lowering or
giving a negative value of the fraction representing digestion. At any rate, the
process is full of complexities and they find ample illustration in the figures set
forth in Table III. With respect to paddy straw the standard deviations for
the digestibilities of dry matter, organic matter, crude fibre and to some extent
Nitrogen-free Extract are comparatively small, ranging between 8 to 19 %. The
corresponding standard deviations of the same components under cake are how-
ever much higher, being 19.3 to 38.2% for dry matter and 22.5 to 40.97% for
organic matter, whereas it has been unusually high in the case of crude fibre,
the climax being over 487% in one set (Table III, column 9).
Again the standard deviations for crude protein and ether extract under
cake have been quite low, ranging from 5.38 to 8.75% in the former and 6.11 to
13.95% in the latter, whereas the same for paddy straw have been very high
particularly with respect to crude protein where in one set it has worked out at
533.65% (Table III, column 6).
96
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VI, I
MINIMUM NUMBER OF TESTES NECESSARY FOR RELIABLE VALUES
This naturally leads to the question as to what should be the minimum number
of replications to warrant a certain specified standard of statistical accuracy.
For this purpose we can use the well known formulae :—
E 2 = σ 2 / n, where
σ=Population value of the percentage standard deviation of the observed sample
(for which the sample value is substituted in this case),
E=intended percentage error on mean, and
n=required number of replications for attaining the specified standard of accuracy.
Now, having regard to the many practical difficulties in the way of extensive
replications, it cannot, very often, be a practical proposition in digestion experi
ments to aim at an error of very low denomination.
A moderately low error, say, from 5 to 15% may be considered to be quite
reasonable as meeting the ordinary requirement; and with that idea in view, the
values have been worked out under three sets of errors, viz., 5%, 10% and 15%.
These are now set forth in the following table :—
TABLE IV
Dry matter
Organic mat
ter.
Crude pro
tein.
Ether Ex
tract.
Crude fibre
Nitrogen
free extract.
Basis of
calculation
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
1 and 2 lb. . .
1 and 3 lb. . .
2 and 3 lb. . .
Paddy straw
Standard
deviation
in % on
mean
11.950
8.515
17.231
11.679
8.260
19.055
77.663
32.155
533.645
38.273
25.086
66.855
8.828
8.005
17.928
15.335
7.793
39.217
Number of replications
necessary for an
accuracy of
5%
6
3
12
6
3
15
241
42
...
59
26
170
4
3
13
10
3
62
10%
4
...
...
2
...
4
61
11
...
15
7
45
...
...
4
3
...
16
15%
...
...
...
...
...
2
27
5
7
3
20
...
...
...
...
...
7
Linseed cake
Standard
deviation
in % on
mean
53.460
19.300
32.989
51.813
22.499
38.212
5.381
5.589
8.748
13.545
6.110
12.318
254.94
487.24
195.95
139.887
23.179
73.832
Number of replications
necessary for an
accuracy of
5%
115
15
44
108
21
59
2
2
4
8
2
7
?
?
?
?
20
...
10%
29
4
11
27
6
15
...
...
... ...
2
...
2
?
?
?
?
6
...
15%
13
2
5
12
3
7
...
...
...
...
...
...
?
?
?
?
3
...
STUDIES ON THE DETERMINATION OF DIGESTIBILITY COEFFICIENTS
:
97
A study of these figures will show that the comparatively low standard devia-
tion under the calculation basis of 1 lb. and 3 lb. combinations (a reference to
which has already been made) have been correspondingly reflected in
a lower number of required replications. For a better comparison they are
reproduced in the following table :—
TABLE V
(1 lb. and 3 lb. basis of calculation.)
Dry matter
....
Organic matter
....
Crude protein
....
Ether Extract
....
Crude
fibre
....
Nitrogen-free extract...
Paddy straw
Standard
deviation
in % on
mean
8.515
8.260
32.155
25.086
8.005
7.790
Number of replications
necessary for an
accuracy of
5%
3
3
42
26
3
3
10%
...
...
11
7
...
...
15%
...
...
5
3
...
...
Standard
deviation
in % on
mean
19.300
22.499
5.589
6.110
487.24
23.179
Linseed cake
Number of replications
necessary for an
accuracy; of
5%
15
21
2
2
?
22
10%
4
6
...
...
?
6
15%
2
3
...
...
?
3
As already stated, these results have been worked out from a rather limited
number of requisite types of data. Nevertheless, they serve as actual illustrations
of the possible order of uniformity or otherwise and the trend and possibility of the
reduction in errors by means of a reasonable number of replications. We note
here that with respect to four only of six components of paddy straw, viz., dry
matter, organic matter, crude fibre and nitrogen-free extract, not more than
three replications would be necessary to keep the error within 5%. But crude
protein and ether extract appear to be liable to greater fluctuations, in consequence
of which even an error of 10% seems to be beset with practical difficulties, as
even then it would require as many as 11 replications (7 for ether extract and
11 for crude protein). In fact in these two cases it may ordinarily be a more feasi-
ble course to be satisfied with an error as high as 15%, for it is only then that the
replications can be kept within the moderate limit of 3 to 5.
In the case of linseed cake, crude protein and ether extract are the only
two components whose errors are concomitant with low replications. For the
values with 1 and 3 lb. basis of calculation even a replication of 2 is enough to
keep the error within 5%, but in respect of other components the position is
different. As many as 4 to 6 replications would be necessary in the case of dry
matter, organic matter and nitrogen-free extract to keep the error within 10%,
whereas, even this is not sufficient with respect to crude fibre,
98
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VI,
It should be borne in mind, as has been mentioned already that with respect
to crude fibre of linseed cake, and crude protein and to some extent ether extract
of paddy straw, there are other factors eluding experimental control. Leaving
these exceptional cases, it may be broadly stated that if we set a limit of, say,
10% error, the maximum replication should be about six. If it is 15 % the repli-
cation should be 3 for all, except with respect to crude protein of paddy straw,
where with three replications the error will work out at a figure exceeding 25%.
One will often have to be satisfied with such a large error when other considerations
will require us to limit the number of replications to 3.
It is necessary to state here that apart from the limited available data with
which the validity of the formulae has been tested, these figures are from an
experiment conducted on three different planes of nutrition. It has been assumed
as a first approximation that the digestibilities at these different planes were the
same and constant. It is not known how far the preponderance of one food-
stuff reacts on those of the other. Possibly a number of tests on the same plane
of nutrition might provide data for testing the validity of the formulae on one
side and the extent of difference in digestibility under the different planes of
nutrition. For the present such figures are not available but if circumstances
permit they will be tried. In the meantime, the results so far obtained are placed
before other workers so that, if possible, they may also give a trial to the procedure.
The results dealt with are with reference to two feeds on the basis of formulae
3 and 4. It has not been possible to try the formulae 8, 9 and 10 with respect
to three feeds as the requisite data were not yet available but theoretically their
validity rests on identical principles.
SUMMARY AND CONCLUSIONS
1. In view of contingencies where the amount of food material may not be
sufficient for an extensive test, the admitted necessity of shorter method has
led to two lines of approach, viz., (i) method of computation and (ii) the minimum
number of tests necessary for a certain specified standard of statistical accuracy.
2. The method of computation has led to the working out of the formulae :-
x = D 1 C 2 —D 2 C 1 / R 1 C 2 —R 2 C 1
y = D 2 R 1 —D 1 R 2 / R 1 C 2 —R 2 C 1
where x and y are the digestibilities (unitary basis) of two feeds R and C and D,
their total amount actually digested. The calculations are based on two diges-
tion tests indicated by suffixes in the above formulae. Similarly, if there are
three feeds the calculation can be made with the data from three trials as set
forth in formulae 8, 9 and 10 (vide text).
STUDIES ON THE DETERMINATION OF DIGESTIBILITY COEFFICIENTS:
99
3. The minimum number of tests necessary for a desired standard of accuracy
has been derived from the formulae E 2 = σ 2 / n where
σ=% standard deviation found
E=% standard deviation aimed
n=number of replications.
4. The limited number of requisite data did not permit of a more extensive
trial of the formulae, and even here it has been confined to a test on two feeds
as no data with three feeds were available. The results have, however, been highly
encouraging and it is found that, with respect to paddy straw and cake (two feeds),
a fair order of accuracy is possible with a replication of 3 to 5, except in the case
of crude protein and ether extract under paddy straw and crude fibre under linseed
cake.
5. The method of computation enables us to set a direct evaluation of indivi
dual digestibilities and thus obviates the necessity of conducting separate trials
with single feeds followed by combined feeds.
ACKNOWLEDGMENTS
The first acknowledgment is due to the Imperial Council of Agricultural
Research for providing the grant for the work.
The authors are indebted to Mr. K. McLean, Director of Agriculture, Bengal,
for encouragement, to Mr. F. J. Gossip, Livestock Expert, Bengal, for stall
facilities and practical help, to Mr. G. B. Pal, Officiating Agricultural Chemist for
helpful criticism.
The authors also beg to acknowledge their indebtedness to Mr. Abdul Hye,
Assistant Chemist, for many suggestions and help and to Mr. Syed Ali for the
major part of the computation.
Finally, the authors acknowledge with pleasure the ungrudging help and
suggestions received on the statistical side from Prof. P. C. Mahalanobis and
his colleague, Mr. S. Bose of the Indian Statistical Institute, Calcutta.
REFERENCES
Armsby, H. P. (1930). The Nutrition of Farm Animals.
—(1910).
The Principles of Animal Nutrition.
Carbery, M., Chatterji, I. and Hye, A. (1934). A New Method of Experimentation
and Computation for Directly Obtaining he Digestibility Coefficients of Indivi
dual Feed Nutrients in a Mixed Ration. Ind. Jour. Vet. Sci. and Ani. Husb.,
44, 295.340.
Fisher, R. A. (1925). Statistical Methods for Research Workers.
Woodman, H. E. and Stewart, J. (1932).
Jour. Agri. Sci. 22, 3, 527-547.
A SEVERE AND WIDESPREAD OUTBREAK OF RINDER-
PEST AT THE GOVERNMENT CATTLE FARM, HISSAR,
AND ITS CONTROL BY THE GOAT-VIRUS-ALONE
METHOD
BY
S. M. SARWAR, M.R.C.V.S.,
Veterinary Investigation Officer, Punjab
AND
B. N. HANDA, B.Sc, M.R.C.V.S.,
Assistant Superintendent, Stock, Government Cattle Farm, Hissar.
(Received for publication on 3rd August 1935)
INTRODUCTION
In the heart of Hissar district, with an area of some sixty-three square miles,
is situated the Government Cattle Farm, Hissar, where for many years cattle of
the finest Indian breed have been reared by the Punjab Government. The Bir
or grass-lands of this farm are of very wide extent and cover an area of about
21,000 acres. The number of livestock on this farm amounts to several thousand
heads.
The farm stock is distributed in different places, at a distance of several
miles from one another. The distribution is given below :—
1. Home Farm. All the stock requiring special care and supervision, such
as dairy cows, standard cows, special cows and weak and debilitated animals.
2. Sally Farm. The general herd of cows along with their bulls and young
progeny.
3. Thaska Farm. The white herd of cows along with their bulls and young
progeny.
4. Kherwan Farm. The heifers from their weaning age till their maturity
which is 3 years.
5. Chowni Farm.—The male stock till they mature into bulls when they are
issued to the districts for distribution at the age of 2½ years.
6. Bobran Farm.—The grey herd is located here in the rainy season and
throughout the summer months until the cold weather starts.
( 100 )
SEVERE AND WIDESPREAD OUTBREAK OF RINDERPEST
101
Fig. I shows the distribution of the livestock at different places, and. the
roads connecting them.
HOUSING ARRANGEMENT OF CATTLE OF THE GOVERNMENT CATTLE FARM, HISS
Strength of the stock.—The following will give some idea of the strength of the
stock on the farm which were counted on the 25th February, 1935 :—
Cows ...........
Male produce ........
Female produce .........
Herd Bulls .........
Supernumerary bulls ........
Castrated produce ...........
Bullocks
............
Total .......
2,792
1,684
1,730
54
11
49
464
6,784
102
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VI, I
HISTORY OF THE OUTBREAK
A heifer was brought for treatment from Kherwan to the Farm Veterinary
Hospital, situated in the Home Farm, on the 27th June, 1934. This animal mani-
fested marked depression and dullness. The ears were drooping and the back
arched. The muzzle was dry and the skin lustreless. Rumination was absent
and the respiration accelerated. The next day tears were running profusely from
the eyes. There was only a slight elevation of the body temperature. The bowels
were constipated.
Two or three days after, small protuberances and vesicles developed on the
neck, before and behind the shoulders, along the vertibral column and in the
flank. In the mouth, especially on the mucous membranes of the lips, gums,
and under the tongue some irregular erosions were seen but there was nothing
characteristic about them.
The next day the animal died and on making a post mortem examination,
the disease was confirmed as Rinderpest.
In the meantime, the disease at Kherwan flared up and a few more animals
began to manifest symptoms. But the entire smyptom-complex was only excep-
tionally present in a single animal. In the Kherwan herd in some animals the
functional disturbances of the respiratory organs or those of the digestive were
more in the fore-ground, while in others a simultaneous affection of all organs was
present in varying intensity. In most cases the illness was of a very short duration
and the body temperature showed a slight elevation.
In the great majority of these severe cases, the disease lasted on an average
from four to seven days.
The disease was brought under control at Kherwan by the serum-alone method
but within a fortnight or so it broke out in the Home Farm stock and also spread
to cows and calves at Bobran. The source of infection was definitely traced to
the villages which are situated in the close vicinity of the farm and use farm roads
as means of communication. The total loss, so far, was 80 and the situation
appeared to be very grave on account of the high susceptibility of the farm
stock.
Edwards [1925], in his paper on ' Some recent advances in the protection
of cattle and other animals against disease ', states as follows :—
" The theory of the ' waves ' of intensity in rinderpest would seem capable
of explanation in a similar manner. After the onset of a ' wave ' of rinderpest
the disease spreads with increasing intensity until the virus eventually finds that
the amount of susceptible ' soil' remaining, upon which it can become readily
implanted, becomes more and more rare. The virus itself thus loses to a consider-
able degree its properties of penetrating in the animal body, and it is not until
there is available in abundance a new susceptible ' soil' represented by the cattle
SEVERE AND WIDESPREAD OUTBREAK OF RINDERPEST
103
progeny that have grown up in the interval that the' virus ' finds a medium at
hand for its ready propagation and, concomitantly, progressive exaltation of its
disease-producing properties."
This explanation of Edwards applied in a remarkable degree to the suscep-
tibility of the farm stock which had remained free from this disease for a number
of years.
According to Haupt it requires from 5 to 6 weeks before the disease affects all
animals of a herd consisting of 15 to 20 animals. Consequently rinderpest did
not spread very rapidly in large herds of the farm in the outbreak under report.
CONTROL OF THE OUTBREAK
Kerr and Menon [1934] report that goat blood virus alone and goat tissue
vaccine alone was used successfully on an extended scale in face of the disease
in Bengal, and similar conditions being the experience in this province, it was
decided to control the outbreak by means of goat virus alone vaccination.
To commence with, it was decided to immunise the female produce at Kher-
wan which were then free from infection. These inoculations at Kherwan were
meant to serve a dual purpose ; firstly to immunise the animals which were becom-
ing once more susceptible on account of the passing off of the serum effects and,
secondly, to study the nature of the reactions to be expected in the main herd.
Consequently 1,151 heifers and 33 bullocks were inoculated with the goat virus.
It was then decided to tackle the main infected herd where goat tissue vaccine
was brought into use. Any animal exhibiting the slightest signs of ill-health
was excluded from the vaccine inoculations and segregated for observation. In
all, the following number of incontact animals were vaccinated :—
Bobran—
Cows and calves ........
Bulls ......
Bullocks ........
Sully—
Cows .......
Calves .......
Bullocks .......
Thaska—
Bullocks .......
Home Farm—
Cows and heifer. .....
Bullocks .......
Mundianwala—
Bullocks .......
Stable—
Bullocks .......
Total
1,750
28
10
267
142
66
62
250
164
109
69
2,817
104.
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VI, I
REACTIONS IN THE CASE OF BLOOD VIRUS
In some animals typical rinderpest reactions, following the injection of virus,
were seen. In others graded reactions of the same type were witnessed, which
in most cases consisted of fever only. All the animals subjected to goat virus
were examined twice daily and, if found to be suffering from severe reaction,
treatment was taken up immediately. In highly susceptible animals, there
was a sharp rise in temperature, usually not later than the fifth day after inocula-
tion, which persisted for 3 days and towards the end of this period the appearance
of vesicles occured in the mouth.
The percentage of reactors, in this case, was found to be 75. The degree of
febrile reaction was also studied and it was found that in case of blood virus, the
reaction was more pronounced, the temperature ranging between 103 5° to 106°.
These animals also showed a well-marked depression. Six heifers showed excep-
tionally severe reactions and had to be fed on succulent diet for a few days, but
none needed any special medical attention.
REACTION IN THE CASE OF GOAT TISSUE VACCINE
In the case of goat tissue vaccine, the temperature did not rise beyond 104º,
the majority of animals showing 103° to 103.5°. The percentage of reactors was
only 50. There was hardly any depression in these animals.
TEMPERATURE RECORDING
The temperature recording was carried out in the following manner. Out
of each batch of animals inoculated during the course of a day, 20 animals were
selected at random and their temperature was recorded on the 4th, 5th, and 6th
day after the inoculations. In this way, 40 blood inoculated and 80 goat tissue
vaccinated animals were brought under observation.
VACCINTION OF UNAFFECTED SEGREGATED ANIMALS
The male stock at Chowni was temporarily excluded from these inoculations
as there appeared to be no immediate danger of the disease spreading to that area.
On account of its natural segregated situation, there was every possibility of the
place remaining free for at least a number of days, and so every attention was
paid in this period to incontact vaccinated animals.
After the completion of work with the general herd the vaccine inoculation
of the male produce was then undertaken. 1,173 male calves and 26 bullocks
were vaccinated.
During the course of these inoculations a case of rinderpest occurred amongst
the lot of bull calves that were still uninoculated. The incontact animals were
immediately isolated and vaccinated with goat virus vaccine. Out of these in-
contacts, 6 more calves developed Rinderpest. Evidently these animals were in