NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
66 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
village cattle congregate in them for grazing day after day, and during the rains derive
some herbage, but during the dry months get nothing. It is a pitiable sight to see
large herds of cattle lying about on the village grazing ground chewing cud and
seeking shelter from the sun.
The second set of causes depending on the nature of the climate have perhaps,
even, a greater influence. In the Madras Presidency the prevailing climate over
the greater part of the area, is one of long dry spells alternating with short wet
ones. The total rainfall is appreciably higher than in temperate regions where
grass lands have reached a high degree of development, but the bulk of the rain
falls within a short period and the dry period that intervenes between two wet
seasons, is so long that the growth of the shorter grasses is hindered, and the
rapidly growing taller grasses mature early and become unpalatable in a short time.
There is an abundance of the coarser grasses during the wet season and a severe
shortage during the dry. The conditions are thus not favourable for the growth of
pastures which require an equable climate with well-distributed rainfall. If culti-
vation of grasses was attempted it would mean frequent irrigations during the dry
season, which would raise the cost of production and make it economically unpro-
ductive to attempt to cultivate pasture.
The two sets of contributory causes are thus interlinked and explain the appa-
rent neglect of one of the greatest assets in the improvement of livestock. There
is a distinct vicious circle in operation, on the one side the efficient cultivation of
tillage lands necessitates good cattle, on the other the pressure of population on the
land, and adverse climatic conditions makes one of the best means of maintaining
working animals—the culture of good grass, producing herbage of high nutritive
value—difficult, if not impossible. Both the contributory sets of causes are impos-
sible to remedy, and the problem of finding roughage thus narrows down to the
better utilisation of available supplies of herbage, from the vast uncultivated wastes
which abound in South India as well as the supplies from the forest regions.
These studies were undertaken with the object of securing data on the follow-
ing aspects of the problem. (i) The seasonal variations in the mineral content of
pasture grass, (ii) the mineral content of various grasses commonly found and (iii)
the influence of manuring on the nutritive value of grasses with a view to improve
quality and quantity of herbage produced and thus increase the visible supplies of
fodder without resorting to actual cultivation of grasses. The first point would
throw light on the quality of herbage at various times of the year, and thus assist
in the better utilisation of the herbage by providing data as to the best time for
harvesting the grass for hay or silage, and also give information as to the quantity
of nutrients an animal is ingesting while grazing. Information on all the points
STUDIES IN SOUTH INDIAN PASTURES
67
is totally lacking for this country, and though there is no acute mineral deficiency
prevalent among cattle, there is a suspicion that in some tracts at least there may
be a shortage of mineral nutrients. A shortage may be more serious than an actual
deficiency, in so for as, by its insidious and long continued action, the results may
react on the species of animal in a more serious manner than a deficiency which
appears as a specific disease.
A shortage may cause the enervation of the
individual resulting in lowered vitality, and lead to the deterioration of the species.
The results of an investigation into the first aspect of the problem, i.e.. the
seasonal variation of the mineral content of natural grass herbage, are reported in
the present communication.
EXPERIMENTAL.
The investigation reported consisted of a study of the mineral matter and
protein of the herbage of four paddocks at the Livestock Research Station at Hosur
during two seasons from July 1929 till December 1930.
The Hosur Livestock Research Station of the Madras Agricultural Department
was prior to the year 1924 a Remount Depot of the Army Department, and consists
of an area of 1,600 acres, the greater part of which is under permanent pasture.
These pastures had been laid down for the greater part by the Army Department
and some of them are as old as 50 to 60 years. The nearest approach to permanent
pastures are found here. The main flora is the Spear grass, Andropogon contortus,
which is almost an indigenous grass to the area, and is of very wide occurrence in
other parts of India. The Livestock Research Station lies at an elevation of 3,000
feet above mean sea level, and is near the south-eastern edge of the Deccan Plateau.
The climate of the locality is a fairly cool and equable one, with a well distri-
buted rainfall, though the tract is frequently subject to famines. The topography
of the country is characterised by its undulations, the tops of the hillocks being
waste lands and the valleys usually well cultivated and receiving their water supply
from large contour tanks which are filled up during the rainy season.
The Spear grass is a very hardy species with a deep rooted habit, and tillers
freely. It is very drought resistant, and given a normal season of frequent light
rainfall keeps green throughout the year and provides grazing for animals. The
principal period of growth is between September and the beginning of December,
when the tract receives the bulk of its rainfall from the North-east monsoon. The
flowering period is about the middle of November. At its best the grass grows
to a height of two feet and is well liked by animals. At the time when it is dead
ripe and seeds have set, the grass is not liked by animals, because of the sharp
barbed seeds it carries and which have given the grass its name. These seeds are
68 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
the one disadvantage of the grass, and the Livestock Station uses a comb drawn
by horses to comb out the seeds before mowing the grass for hay.
The plan of the investigation was to take monthly samples from the four
paddocks selected, over a period of eighteen months. The places where
samples were drawn were marked off by wooden stakes driven into the ground,
and an area covered by a circle of 10 feet radius was separated and not grazed or
mown. The sample was cut by hand from this area, and after thorough mixing on
a cemented floor, shaken free of sand and earth, and all other species other than
the Spear grass picked out. A sample of 100 grams was put into an envelope
and weighed for the determination of the original moisture. The rest of the
sample reduced to about 500 grams by quartering and brought to the Research
Institute at Coimbatore for analysis.
CHARACTER OF THE SEASON.
Table I gives details of rainfall at the Livestock Research Station, Hosur, for
the period during which the investigation was being carried out.
TABLE I.
Month
January . . . .
February . . . .
March . . . . .
April . . . . .
May . . . . .
June . . . . .
July . . . . .
August . . . .
September . . . .
October . . . .
November . . . .
December . . . .
Total
1929
Inches.
0.30
1.30
...
7.54
3.04
1.52
1.31
0.32
7.01
7.05
4.92
1.05
35.36
Days.
1
3
..
7
4
8
4
1
10
8
5
3
54
1930
Inches.
0.50
0.16
0.17
2.20
9.64
2.52
0.96
1.34
2.26
7.70
2.31
2.17
31.93
Days.
1
1
1
2
5
7
4
6
6
13
5
3
54
Mean
Inches.
0.27
0.32
0.48
1.63
4.41
2.15
2.53
4.11
5.68
5.97
3.42
0.91
31.88
NOTE.—A ' rainy day ' is one when rainfall is 0.10" and above.
Mean rainfall for Hosur town 3 miles distant.
The season in the two years can be taken to be normal as judged by the
departure from normal of the rainfall. No other meteorological data could be
obtained owing to the absence of a recording station, in the vicinity of the Research
Station. The rainfall of April 1929 prior to the starting of the sampling and that
of May 1930 during the experimental period are probably the only unusual features.
As usual the North-east monsoon contributed the bulk of the year's rainfall
between September and December, and this period coincides with the period of the
STUDIES IN SOUTH INDIAN PASTURES
69
growth of the grass in normal years. During the eighteen months of the
investigation from July 1929 till December 1930, the seasons can be divided up
into Dry period I, July-August 1929 ; Wet period I, September-November 1929;
Dry period II, December 1929—August 1930; and Wet period II, September
1930—November 1930. Dry period II can strictly be broken into at May 1930;
when an unusually heavy burst of rain occurred in connection with the passage
inland of a cyclonic storm, and when the bulk of the fall of 9.64 inches fell during
48 hours and large losses of moisture occurred by run-off and the residual soil
moisture did not influence the growth of fresh herbage to any great degree.
That month is thus included in the Dry period II. Judged by yields of hay from
adjoining paddocks, the years were fairly normal, the yield for the season 1929 was
500 lbs. hay per acre and that for 1930 was 700 lbs. The year 1930, though it had a
lower rainfall, seems to have been the more favourable for the pasture owing to a
better distribution of the rainfall.
SOIL CONDITIONS.
The Livestock Research Station has a uniformly light red sandy loam soil, of
medium depth which varies in composition and character but slightly. The
topography of the Station would lead one to believe that the soil varies very widely,
because of its undulating nature. Soil profiles as revealed in cuttings for wells and
deep silo pits show a light red soil to a depth of 6-10 feet, underlaid by a
greyish gravelly clay and then by bed rock of gneissic origin. The bed rock is
usually at a considerable depth but outcrops occasionally in the higher parts of
the Station.
Table II gives the composition of the soil in the paddocks from which samples
were drawn.
TABLE II.
Composition of soils of paddocks from which samples were drawn.
—
Lime as CaO
Total Potash
Available Potash
Total Phosphoric acid
....
Available Phosphoric acid
....
Nitrogen
Paddock 3
Per cent.
0.14
0.23
0.024
0.05
0.0016
0.042
Paddock 35
Per cent.
0.28
0.45
0.010
0.05
0.0019
0.072
Paddock 32
Per cent.
0.28
0.31
0.020
0.04
0.0045
0.074
Paddock 38
Per cent.
0.11
0.15
0.013
0.04
0.0086
0.057
F
70 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
Generally the four paddocks were poor in lime and phosphate, Nos. 3 and 38
in nitrogen in addition. The soils had not been manured for two years previous to
the starting of the investigation. The last application, three years previously, had
been cattle manure as a top dressing followed by a grubber to incorporate the
manure in the soil. This method was never found very satisfactory and the cattle
manure is usually left in lumps on the surface to be eaten up by termites or baked
up by the sun during the dry periods. The soils of the four paddocks had been
under grass prior to the occupation of the Station by the Agricultural Department
and no records exist as to when they had been ploughed and laid down to pasture.
For all practical purposes they were permanent pastures. The grass lands were
thus not intensive pastures in any sense but merely well cared for and kept free
from weeds and carried a good growth of Andropogon contortus in an almost pure
culture.
CHEMICAL COMPOSITION OF THE HERBAGE.
Tables III to VI give the mineral composition of the herbage samples drawn
from Paddocks 3, 35, 32 and 38 during the eighteen months of the investigation,
and Table VII the mean values for the four paddocks, represented graphically in
Chart I.
Fig. 1. Seasonal variation in Minerals and Nitrogen.
F 2
STUDIES IN SOUTH INDIAN PASTURES
71
TABLE III.
Sample taken from Paddock No 3, Livestock Research Station, Hosur. (Percentage on dry basis.)
—
1929.
July . . . .
August . . . .
September . . .
October . . . .
November . . . .
December . . . .
1930.
January . . . .
February . . . .
March . . . .
April . . . .
May . . . . .
June . . . .
July . . . .
August . . . .
September
.
.
.
October . . .
November . . .
December . . . .
Original
moisture
61.30
65.61
82.25
73.51
47.88
51.56
50.19
19.46
28.43
55.74
56.97
53.15
39.54
53.76
..
75.01
..
Total ash
31.32
11.92
16.35
11.61
7.29
9.96
10.59
9.12
14.97
12.42
19.16
13.32
11.90
14.57
10.96
9.98
7.32
11.99
Si O 2
27.03
7.92
12.45
8.46
4 30
7.07
7.09
6.36
9.63
8.14
16.11
8.84
7.87
10.70
7.88
6.76
4.11
9.44
Silica free
ash
4.29
4.00
3.90
3.15
2.99
2.89
3.50
2.76
5.34
4.28
3.05
4.48
4.03
3.87
3.08
3.22
3.21
2.55
Calcium as
CaO
0.517
0.718
0.563
0379
0.456
0.459
0.500
0.408
0.378
0.613
0.588
0.631
0.626
0.637
0.491
0.400
0.467
0.666
Phosphate
as P 2 O 5
0.314
0.353
0.336
0.310
0.370
0.382
0.449
0.523
0.185
0.372
0.387
0.484
0.463
0.541
0.284
0.343
0.529
0.521
Potash as
K 2 O
1.108
1.186
0.974
1.324
1.090
1.121
1.202
0.956
0.850
1.258
1.470
1.472
1.400
0.901
1.074
1.290
1.290
1.122
Protein as
nitrogen x
6.25
4.61
4.49
4.17
5.43
8.83
4.50
5.21
3.48
3.12
3.45
5.48
7.49
4.07
2.98
4.82
6.27
8.70
4.81
72 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
TABLE IV.
Sample taken from Paddock No. 35, Livestock Research Station, Hosur. (Percentage on dry basis.)
—
1929.
July . . . .
August . . . .
September . . .
October . . . .
November . . . .
December . . . .
1930.
January . . . .
February . . . .
March . . . .
April . . . .
May . . . .
June . . . .
July . . . .
August . . . .
September . . .
October . . . .
November . . .
December . . . .
Original
moisture
..
66.09
67.43
73.28
69.84
67.60
51.84
35.79
14.06
42.41
53.16
61.43
46.87
45.66
63.85
. .
69.56
..
Total ash
18.18
9.42
10.32
10.29
7.89
7.42
10.40
11.26
11.24
10.84
12.16
11.36
10.58
13.88
10.30
10.86
7.61
12.89
SiO 2
11.75
5.47
6.78
6.39
4.29
4.59
6.71
8.59
9.45
7.00
7.20
7.06
6.98
9.16
6.53
5.86
4.32
5.22
Silica free
ash
6.43
3.95
3.54
3.90
3.60
2.83
3.69
2.67
1.79
3.84
4.96
4.30
3.60
4.72
3.77
5.00
3.29
7.67
Calcium as
CaO
0.990
0.566
0.656
0.552
0.552
0.324
0.459
0.501
0.547
0.673
0.510
0.601
0.666
0.849
0.547
0.490
0.417
0.280
Phosphate
as P 2 O 5
0.392
0.359
0.359
0.535
0.434
0.283
0.437
0.480
0.315
0.407
0.282
0.386
0.391
0.468
0.380
0.517
0.500
0.342
Potash as
K 2 O
1.108
1.360
1.124
2.150
1.377
1.750
1.671
0.879
0.870
1.435
1.297
1.435
1.480
1.374
1.500
1.790
1.619
1.312
Protein as
nitrogen ×
6.25
5.90
5.88
5.01
8.48
8.39
4.97
4.68
3.10
2.94
4.61
7.22
6.15
4.93
5.98
6.50
7.82
8.76
5.95
STUDIES IN SOUTH INDIAN PASTURES
73
TABLE V.
Samples taken from Paddock No. 32, Livestock Research Station, Hosur. (Percentage on dry basis.)
—
1929.
July . . . .
August . . . .
September . . .
October . . . .
November . . .
December . . . .
1930.
January . . . .
February . . . .
March . . . .
April . . . .
May . . . .
June . . . .
July . . . .
August . . . .
September . . .
October . . . .
November . . .
December . . . .
Original
moisture
..
47.58
57.55
77.15
74.29
66.70
49.84
43.47
28.73
28.89
49.77
53.19
54.92
33.17
62.73
..
73.26
..
Total ash
12.49
12.60
13.80
14.30
6.09
10.23
11.69
13.37
14.44
18.66
14.86
13.40
12.81
15.42
11.84
11.17
8.21
12.15
SiO 2
8.34
6.68
9.88
6.69
3.49
7.53
8.71
8.40
11.85
13.49
11.45
9.04
9.44
11.63
8.65
5.27
4.91
9.10
Silica free
ash
4.15
5.92
3.92
7.61
2.69
2.70
2.98
4.97
2.59
5.17
3.41
4.36
3.37
3.79
3.19
5.90
3.30
3.05
Calcium as
CaO
0.990
0.259
0.818
0.672
0.347
0.255
0.236
0.675
0.551
0.916
0.510
0.629
0.541
0.822
0.659
0.400
0.324
0.401
Phosphate
as P 2 O 5
0.520
0.364
0.317
0.526
0.388
0.397
0.355
0.246
0.243
0.552
0.368
0.396
0.588
0.463
0.354
0.388
0.561
0.542
Potash as
K 2 O
1.423
1.042
1.198
2.050
1.040
1.410
1.507
0.701
0.755
1.285
1.358
1.400
1.165
1.000
1.220
1.330
1.250
1.276
Protein as
nitrogen ×
6.25
5.12
4.29
3.96
8.03
8.91
3.23
2.98
3.86
3.18
3.66
6.03
7.10
4.47
3.38
5.11
5.57
8.22
4.44
74 THE INDIAN JOURNAL OP VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
TABLE VI.
Samples taken from Paddock No. 38, Livestock Research Station, Hosur. (Percentage on dry basis.)
—
1929.
July . . . .
August . . . .
September . . . .
October . . . .
November . . .
December . . . .
1930.
January . . . .
February . . . .
March . . . .
April . . . .
May . . . . .
June . . . .
July . . . . .
August . . . . .
September . . .
October . . .
November . . .
December . . . .
Original
moisture
..
61.80
54.41
61.68
72.74
64.25
57.84
38.87
23.93
28.14
47.98
59.58
57.96
47.71
66.16
..
72.76
..
Total ash
11.21
12.81
12.69
11.63
7.73
12.84
8.37
11.63
13.07
12.62
14.95
14.02
11.55
13.46
10.78
10.47
8.91
6.44
SiO 2
7.89
6.82
9.55
8.17
3.69
7.65
5.21
8.97
8.13
8.26
11.92
6.90
7.41
9.68
7.58
7.13
5.60
4.62
Silica free
ash
3.33
5.99
3.14
3.46
4.04
5.19
3.16
2.66
4.94
4.36
3.03
7.12
4.14
3.78
3.20
3.34
3.30
1.82
Calcium as
CaO
0.830
0.832
0.757
0.649
0.509
0.234
0.340
0.593
0.453
0.731
0.684
0.569
0.680
0.752
0.633
0.400
0.290
0.333
Phosphate
as P 2 O 5
0.413
0.267
0.278
0.399
0.477
0.349
0.354
0.235
0.277
0.338
0.241
0.333
0.469
0.584
0.369
0.486
0.520
0.322
Potash as
K 2 O
1.277
0.959
0.568
2.072
1.370
1.320
1.455
0.933
0.920
1.383
1.465
1.644
1.470
1.480
1.854
1.340
1.422
1.216
Protein as
nitrogen ×
6.25
4.17
3.99
3.56
6.57
11.48
3.99
4.20
3.02
3.29
3.52
6.76
6.31
1.78
4.61
6.15
5.91
10.61
4.17
STUDIES IN SOUTH INDIAN PASTURES
75
TABLE VII.
Seasonal variation in minerals. Mean value of four paddocks at Hosur.
(Percentage on dry basis.)
Period
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Month
1929.
July . . .
August . .
September . .
October . .
November . .
December . .
1930.
January . .
February . .
March . .
April . .
May . . .
June . . .
July . . .
August . .
September . .
October . .
November . .
December . .
Calcium
0.623
0.594
0.698
0.563
0.466
0.309
0.380
0.544
0.483
0.733
0.575
0.607
0.628
0.790
0.582
0.402
0.377
0.420
Phosphate
0.416
0.336
0.322
0.412
0.492
0.353
0.393
0.371
0.242
0.415
0.319
0.399
0.477
0.514
0.347
0.431
0.528
0.439
Potash
1.670
1.137
0.966
1.894
1.219
1.450
1.461
0.842
0.849
1.340
1.399
1.512
1.379
1.163
1.162
1.438
1.395
1.281
Protein
4.95
4.61
4.17
7.12
9.40
4.17
4.27
3.36
3.18
3.52
6.37
6.79
3.81
4.23
5.64
6.39
9.07
4.84
Remarks
Heavy rain.
Grass in full flower.
Very dry.
„
„
„
Heavy rain.
Heavy rain.
Grass in full flower.
76 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
The main points which are to be observed in the data presented are :—
(i) There is a well defined seasonal tide in the variation of all the consti-
tuents, and the tide was almost identical during the seasons 1929 and
1930, though the magnitude of the variation was slightly different, pro-
bably because the seasons differed slightly.
(ii) The nitrogen and phosphoric acid content curves had a striking paral-
lelism, almost throughout the experimental period.
(iii) The calcium content varied practically inversely as the phosphoric acid
and nitrogen.
(iv) The potash content had a tide similar to that of nitrogen and phosphoric
acid, but the peak values were not contemporaneous, the two latter
constituents showing a lag of a month.
(v) The nitrogen value had its peak coincident with that of the rainfall curve,
the peak being at the time of the flowering of the grass and the lowest
value at a time of dry weather when there was little or no fresh growth.
The variation in the nitrogen being not due wholly to seasonal factors
but to the stage of growth.
(vi) The pastures investigated showed no definite sign of being deficient in any
of the minerals though a shortage of calcium and phosphate are indicated
at certain seasons.
DISCUSSION OF RESULTS.
The herbage of the pastures under investigation, it must be remembered,
represented a pure culture of Spear grass (Andropogon contortus). There was no
leguminous plant growing along with the grass and hence any variation in the
mineral content represented a change in the chemical composition and was not due
to there being differential amounts of legumes and non-legumes in the herbage.
In temperate regions the growth of leguminous plants affects the composition
of the herbage, and much of the work done on the question of variations in the
mineral content of pastures is strictly not comparable with that under report now.
The results now presented show that even for pure culture grass grown under non-
intensive conditions in a tropical climate, the seasonal variation in the mineral and
nitrogen content of the herbage of grasses is very similar to that recorded in tem-
perate regions.
STUDIES IN SOUTH INDIAN PASTURES
77
Cruickshank [1926] at Aberdeen and Woodman and co-workers [1926] at
Cambridge found that there was a well defined seasonal variation in the mineral
content of herbage of pastures. Cruickshank found that the calcium and phosphate
curves were similar, while Woodman found that the two varied inversely, the
phosphate increased at a time of heavy rainfall and fell during drought, calcium
following a reverse course. Aston [1931] in New Zealand records an increase in
phosphate during periods of rainfall and the converse effect with calcium. Green-
hill and Page [1931] observed that while the calcium content showed no seasonal
trend, the phosphate content showed definite seasonal variation falling during
drought and rising with the incidence of rainfall. Orr and Holm [1931] reporting
on an investigation on the mineral content of pastures in Kenya, state that the
incidence of rainfall has a marked influence on the phosphate, nitrogen and potash
contents, the three constituents rising during times of heavy rainfall. Fergusson
[1931] has observed a similar effect of seasonal conditions on the nitrogen contents
and his results with calcium and phosphoric acid confirm those of other workers.
As Orr [1929] has pointed out there are several factors operating in the varia-
tion of minerals in pastures, one of them is the seasonal factor, the other perhaps
the more important is that of the stage of growth of the grass. At the Livestock
Research Station the period of maximum growth coincides with that of the wettest
part of the year. The peak values for nitrogen and phosphoric acid occur at the
times the grass is at its best and is flowering and also when the rainfall is the
heaviest. That it is the stage of growth which is more important is borne out by
the fact that in May 1931 when the rainfall was very heavy, there was a slight
increase in the nitrogen content which proved to be temporary as it was not sus-
tained during the succeeding month. It was due apparently to there being a
temporary flush of growth stimulated by the heavy rainfall, while during the two
seasons during which the investigation was carried out, the period of peak values
for nitrogen and phosphate were during the month of November when the grass
reached its maximum growth prior to seed formation. The stage of growth of the
grass was apparently of greater moment than the seasonal factor. It would be
interesting to note what would be the effect of a severe drought during the months
of October and November.
INFLUENCE OF SOIL ON THE MINERAL CONTENT OF THE HERBAGE.
The soil on which the grass was grown was, as has been already pointed out
before, poor in calcium and phosphoric acid and two out of the four paddocks were