NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
174
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
TABLE V—(contd.)
Animal
No.
D 5
D 6
Nutrients
CaO
.
.
.
.
MgO
.
.
.
.
K 2 O
.
.
.
.
Na 2 O
.
.
.
.
K 2 O 5
.
.
.
.
Cl 2
.
.
.
.
N
.
.
.
.
CaO . . . .
MgO
.
.
.
.
K 2 O
.
.
.
.
Na 2 O
.
.
.
.
P 2 O 5
.
.
.
.
Cl 2
.
.
.
.
N
.
.
.
.
Intake
Straw
grms.
28.755
18.135
82.789
9.327
7.890
13.157
41.790
24.098
16.006
72.947
7.431
6.715
11.473
36.337
Cake
grms.
2.047
3.167
5.497
1.780
6.420
0.128
15.235
1.773
2.743
4.761
1.542
5.561
0.111
13.196
Water
grms.
0.157
0.089
...
...
...
...
...
0.174
0.099
...
...
...
...
...
Added
mineral
grms.
0.057
0.068
0.163
7.468
...
8.356
...
0.050
0.059
0.141
6.468
...
7.671
...
Total
grms.
31.016
21.459
88.449
18.575
14.310
22.141
57.025
26.095
I8.907
77.849
15.441
12.276
19.255
49.533
In
faeces
grms.
23.488
11.629
12.149
5.177
13.034
13.502
30.725
23.848
11.972
16.670
3.530
11.232
11.614
27.283
Difference
grms.
2.528
9.830
76.300
13.393
1.276
3.639
26.300
2.023
6.777
61.038
12.155
1.044
7.652
22.250
In
urine
grms.
1.075
5.138
73.382
3.058
0.148
2.959
18.658
0.745
3.427
58.273
0.896
0.164
2.990
16.498
Balance
grms.
+ 1.453
+ 4.694
+ 2.918
+ 10.340
+ 1.128
+ 5.680
+ 7.642
+ 1.278
+ 3.350
+2.765
+11.259
+0.880
+4.662
+ 5.752
Loss or
gain in
live.
wieght
lb.
}+0.282
}+0.434
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
177
TABLE VI
Aman straw and green feed
EXPERIMENT F.
(Computed
on the basis of 500-lb. live-weight)
1932
Feed
Aman straw and water-hyacinth
Animal
No.
D 1
D 2
Nutrients
CaO
MgO
K 2 O
Na 2 O
P 2 O 5
Cl 2
N
CaO
MgO
K 2 O
Na 2 O
P 2 O 5
Cl 2
N
Intake
Straw
grms.
6.296
4.553
24.726
5.557
2.181
3.046
7.269
6.100
4.411
23.957
5.384
2.114
2.951
7.044
Green
feed
grms.
58.229
13.176
81.406
2.560
4.970
4.791
14.750
41.609
11.633
71.876
2.261
4.388
4.230
12.727
Added
mineral
grms.
...
...
...
10.606
...
11.639
...
...
...
...
9.872
...
10.880
...
Total
grms.
64.525
17.729
106.132
18.723
7.151
19.526
22.019
47.709
16.044
95.833
17.517
6.502
18.061
19.771
In faeces
grms.
52.770
13.117
14.780
8.080
9.593
11.779
22.529
48.137
11.525
8.830
7.641
8.802
...
19.783
Difference
grms.
11.755
4.612
91.352
10.643
—2.442
7. 747
—0.510
—0.428
4.519
87.003
9.876
—2.300
...
—0.012
In urine
grms.
1.857
4.429
93.888
8.220
0.079
54.200
10.069
2.411
4.130
90.452
12.783
0.084
65.425
9.069
Balance
grms.
+10.398
+ 0.183
—2.536
+ 2.423
—2.521
—46.453
—10.579
—2.839
+ 0.389
—3.449
—2.907
—2.384
...
—9.082
Loss
or
gain in
live.
weight
lb.
—2.281
+ 0.971
178
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
TABLE VI—(contd.)
Feed
Aman straw and Napier grass
Animal
No.
D 4
D 5
Nutrients
CaO
MgO
K 2 O
Na 2 0
P 2 O 5
Cl 2
N
CaO
MgO
K 2 O
Na 2 O
P 2 O 3
Cl 2
N
Intake
Straw
grms.
4.829
3.492
18.969
4.263
1.674
2.336
5.449
4.648
3.361
18.255
4.103
1.611
2.248
5.367
Green
feed
g:ms.
14.778
11.956
153.899
9.520
25.772
18.304
27.666
13.084
10.587
136.265
8.430
22.820
16.207
24.497
Added
mineral
grms.
...
...
...
8.286
...
9.132
...
...
...
...
8.304
...
9.152
...
Total
grms.
19.607
15.448
172.868
22.069
27.446
29.772
33.115
17.732
13.948
154.520
20.837
24.431
27.607
29.864
In faeces
grms.
17.712
9.926
23.107
6.982
26.712
2.100
20.183
16.706
10.718
27.758
5.107
27.884
3.433
21.352
Difference
grms.
1.895
5.522
149.761
15.087
0.734
27.672
12.932
1.026
3.230
126.762
15.730
—3.453
24.174
8.512
In urine
grms.
0.977
4.276
133.453
10.246
0.140
36.607
11.629
1.049
4.481
159.256
7.896
0.139
30.738
13.669
Balance
grms.
+0.918
+1.246
+16.309
+4.841
+0.594
—8.935
+ 1.303
—0.023
—1.251
—32.494
+ 7.834
—3.592
—6.564
—5.157
Loss
or
gain in
live.
weight
lb.
—0.305
—0.857
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
179
Aman Straw and Guinea-grass
D 3
D 6
CaO
MgO
K 2 O
Na 2 O
P 2 O 5
Cl 2
N
CaO
MgO
K 2 O
Na 2 O
P 2 O 5
Cl 2
N
2.982
2.157
11.713
2.632
1.034
1.442
3.444
2.514
1.817
9.872
2.219
0.871
1.216
2.902
56.917
31.155
62.095
24.479
23.151
7.917
54.579
52.421
30.976
61.739
24.339
23.019
7.871
54.266
...
...
...
7.915
...
8.723
...
...
...
...
7.380
...
7.913
...
59.899
33.312
73.808
35.026
24.185
18.082
58.023
54.935
32.793
71.611
33.738
23.890
17.000
57.168
57.100
27.555
11.420
14.863
20.827
1.406
25.580
55.144
23.043
9.699
20.236
21.614
1.182
28.064 1
2.799
7.757
62.388
20.163
3.358
16.676
32.443
—0.209
9.750
61.912
13.502
2.276
15.818
29.104
0.267
6.510
69.391
17.349
0.117
15.597
25.075
1.149
7.973
82.493
15.192
0.173
13.714
27.292
+2.532
+ 1.247
—7.003
+ 2.814
+ 3.241
+ 1.079
+ 7.368
—1.358
+ 1.777
—20.581
—1.690
+2.103
+ 2.104
+ 1.812
—1.108
+ 0.376
E
180 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
Discussion
In the preceding pages, thirty individual data have been arranged and des-
cribed under six heads of Experiments (A to F). They represent investigations
commencing from the stage of deficiency (as for instance Experiments A, B and
C for CaO) and rising to the stage of adequacy (Experiment E). Some have
exhibited instances of heavy ingestion, as for instance P2O5 in Experiment B
and CaO in parts of Experiment F. The combinations were drawn up mainly
in conformity with the nature of the feeds often used in these parts of India.
A study of these data will show that in all combinations except the green
feed groups (Experiment F), rice straw has been the chief source of CaO and
K2O while P 2 O 5 has been mainly derived from the concentrates—cake and kura.
Rice straw has also been the main source of magnesia except in the combination
with rice kura (Experiment B) in which the major part was derived from the
latter—about half to three-fourths of the total. In the case of combinations
with green feeds the greater proportions of CaO, MgO, and K 2 O on one side and
P2O5 on the other, were derived from the green fodders. Guinea-grass and
Hyacinth have been responsible for the heaviest ingestion of CaO, while Napier
accounts for the heaviest ingestion of K 2 O seconded by Hyacinth. Guinea-grass
also accounts for the highest ingestion of soda. It also provided a liberal pro-
tein supply which exceeded some of the cake combinations under Experiments
C and E. Napier grass appears to be poor in CaO (0.4 per cent on dry basis)
and although the fodder was consumed in large amounts, the CaO derived from
it was naturally low.
If the different tables are gone through (I to VI) set up in the different experi-
ments, it may be noted that the results on balances provide an approximate
indication of the mineral requirement. Since lime and phosphate are the main
components, the aspect of their requirements may first be considered.
Lime requirements
As already stated the results provide data from the stage of deficiency to
that of sufficiency; and this is more strikingly noticeable with respect to the
behaviour of CaO. The computations on the basis of 500-lb. live-weight also
provide a more rational comparison. If the intakes of all experiments are
assembled with the symbols of their positive and negative retentions (Table VII)
one can see at a glance that starting from Experiment A up to Experiment D.
the intakes of CaO have gone up from 14 grms. to 23 grms.
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
181
TABLE VII
Intake of Mineral Nutrients
(Computed on the basis of 500-lb. live-weight)
Particulars of Experiments
Aman straw only
Experiment
A
Aman straw and rice Kura
Experiment
B
Animal
No.
D7
D8
D1
D5
D7
D8
D9
D2
D3
D4
D6
Live-weight
during
the experi¬
mental
period
lbs.
343
335
550
530
533
512
612
585
568
570
589
CaO
grms.
14.707—
13.473—
18.024 +
18.227—
15.394—
17.458—
16.795—
14.207—
16.090—
16.231—
15.282—
MgO
grms.
10.636 +
9.743 +
29.516 +
27.387 +
30.104 +
28 . 924—
29 112 +
32.227 +
30.805 +
27.413 +
33.153 +
K 2 O
grms.
57.765—
52.919—
74.950 +
74.688 +
66.384 +
71.868 +
70.599 +
59.876—
65.771—
64.927 +
63.706—
Na 2 O
grms.
23.806 +
22.975 +
16.999 +
17.210 +
15.839—
17.102 +
14.058 +
16.525 +
17.293—
16.845 +
17.041 +
P 2 O 5
grms.
5.098—
4.670—
44.446 +
38.843—
50.169 +
38.906—
45.465 +
58.282 +
51.655 +
42.833—
58.914 +
Cl2
grms.
19.042—
18.730 +
18.909—
19.364—
17.296—
19.218—
19.609—
17.179—
...
19.424 +
17.951.
N
grms.
16.981—
15.557—
33.851 +
32.139 +
33.604 +
31.356—
32.946 +
31.534 +
31.916 +
29.725 +
32.873—
182
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII,
III
TABLE VII—(contd.)
Particulars of Experiments
Aman straw and 1-lb. cake
Experiment
C
Aus straw only
Experiment
D
Aus straw and cake
Experiment
E
Aman straw and
green feed
Experiment
F
Hyacinth group
Napier group .
Guinea group .
Animal
No.
D 1
D 3
D 4
D 7
D1
D 3
D 7
D 2
D 8
D 9
D 4
D 5
D 6
D1
D 2
D 4
D 5
D 3
D 6
Live-weight
the experi-
mental
period
lbs.
500
552
509
484
490
543
474
526
449
603
541
479
553
350
376
448
447
469
517
CaO
grms.
21.302 +
19.994—
21.298—
21.123 +
23.234—
22.925—
20.814 +
26.003 +
29.539 +
23.687 +
28.395 +
31.016 +
26.095 +
64.525 +
47.709—
19.607 +
17.732—
59.899 +
54.935—
MgO
grms.
12.092 +
11.266—
12.040—
12.105—
14.658—
14.462—
13.138 +
17.546 +
19.975 +
15.938 +
19.567 +
21.459 +
18.907 +
17.729 +
15.044 +
15.448 +
13.948—
33.312 +
32.793 +
K 2 O
grms.
87.431 +
82.141 +
87.384 +
86.800 +
73.940 +
73.020 +
66.287 +
82.080 +
93.215 +
74.752 +
89.425 +
88.449 +
77.849 +
106.132—
95.833—
172.868 +
154.520—
73.808—
71.611—
Na 2 O
grms.
17.408 +
16.754—
17.387—
17.372—
14.816 +
14.011 +
14.282 +
15.892 +
18.318 +
14.185 +
16.787 +
18.575 +
15.441 +
18.723 +
17.517—
22.069 +
20.837 +
35.026 +
33.738—
P 2 O 5
grms.
14.041 +
12.908 +
13.890 +
14.278 +
6.391—
6.312—
5.727—
10.728 +
12.313 +
9.631—
12.995 +
14.319 +
12.376 +
7.151—
6.502—
27.446 +
24.431—
24.185 +
23.890 +
Cl 2
grms.
27.028 +
25.961 +
27.047 +
26.829 +
20.857+
19.863 +
19.883 +
21.174 +
24.319 +
18.992 +
21.913 +
22.141 +
19.255 +
19.526—
18.061—
29.772—
27.607 +
18.082 +
17.000 +
N
grms.
44.100 +
41.000 +
43.653 +
44.397 +
34.612 +
33.836—
31.717 +
45.623 +
52.497 +
41.139 +
52.083 +
57.025 +
49.533 +
22.019—
19.771—
33.115 +
29.864—
58.023 +
57.168 +
MINERAL REQUIREMENTS OF CATTLE IN NORTH.EAST INDIA
183
In Experiment A (with 14 grms. intake) all are negative, in Experiment B
(15 to 18 grms. intake) eight, out of nine, are negative, in Experiment C (19 to
21 grms. intake) two, out of four, are negative, in Experiment D (21 to 23 grms.
intake) two, out of three, are negative. In other words up to the stage of 23 grms.
ingestion of CaO, the general tendency has been definitely towards negative
balance. It is only when the ingestion has reached about 24 grms. and upwards
that a definite positive balance has been maintained. It would, therefore, be
a reasonable assumption that under the condition of rice straw feeding the minimum
lime requirement is about 24 grms. per 500-lb. live-weight.
According to Kellner [1915] " the daily consumption of 50 grms. phosphoric
acid and 100 grms. lime per 1,000-kg. live-weight sufficiently meet all require-
ments ". This works out at 22.7 grms. CaO for 500-lb. live-weight.
In the experiments carried out elsewhere, it will be noted that in Diakow's
experiment . [1913] the minimum of 0.115-lb. calcium (equivalent to 79.04
grms. CaO) sufficed " to support a not inconsiderable gain ". On the basis of
500-lb. live-weight this is equivalent to 34.54 grms. CaO.
In Cochrane's experiment,† 0.147-lb. calcium (equivalent to 93.44 grms.
CaO) resulted in gain. In Henneberg's investigations ‡ [1860] upon the main-
tenance of cattle a distinctly smaller amount, viz., 0.09-lb. Ca (equivalent to
57.20 grms. CaO per 1,000-lb. live-weight) proved adequate for maintenance.
This is equivalent to 28.6 grms. CaO per 500-lb. live-weight. Wellmann [1931]
gives the maintenance requirement at 50 to 100 grms. CaO per 1,000-kg. live.
weight, which is equivalent to 11.35 to 22.7 grms. CaO per 500-lb. live-weight.
In India, experiments in these lines were mainly conducted by Warth and
his associates. In one of their experiments [1932] with Bolarum hay and ragi
straw the ingestion of CaO (in the case of no supplement) varied from 34 to 46
grms. for the former and 52 to 56 grms. for the latter. The supply appeared to
be fairly adequate from European standard, but the intake of phosphoric acid
was definitely low and the authors remarked that " lime assimilation fluctuated
according to the amount present in the food " and that some loss of lime " was
associated with and in some way brought about by the loss of phosphoric acid ".
In subsequent trials with jowar hay and rice straw conducted by two of
his associates [Iyer and Krishna Ayyar, 1934], the lime intake varied from 14 to
18 grms. in jowar hay and 22 to 27 grms. in rice straw, yet while the jowar hay
recorded positive balance, two, out of three, under rice straw gave negative results.
The authors have tabulated the two years' averages from which the following is
taken.
* Diakow. Landw. Jahrb. 44, 833.
† Cochrane. Penna. Inst. An. Nutrn. unpublished results.
‡ Henneberg. Beitrag, etc., Heft, 1 (1860) p. 113.
} cited by Armsby.
184 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
Food
Bolarum hay . . . .
Ragi straw
.
.
.
.
Jowar hay
.
.
.
.
Rico straw
.
.
.
.
CaO
Intake
grms.
41.17
57.99
16.02
24.91
Balance
grms.
+0.08
+2.30
+2.62
—2.42
P 2 O 5
Intake
grms.
6.64
12.72
17.70
11.14
Balance
grms.
—3.18
+ 0.05
+ 3.11
+ 0.09
The authors' inference was that " if the ration provides a sufficient excess
of lime there will be some assimilation even if the phosphoric acid content is low "
and further that the "jowar figures show that even when lime is low, assimila-
tion can occur if excess of phosphoric acid is present ". The main question that
arises from it is : Can assimilation be possible if the supply is below the mini-
mum ? To the present authors it appears that minimum supply must neces-
sarily be the first condition, and thereafter the assimilation is more intimately
associated with the kind and quality of the fodder. This point will be apparent
from a study of the behaviour of different fodders ; and if the case of rice straw
(with which this paper is more directly concerned) is taken, it is noted that the
assimilation of lime from it was much poorer ; and that there is a certain definite
stage below which the liability of negative assimilation is very great.
The point of interest is that the minimum amount corresponding to this
stage is much higher than what is generally assumed to be adequate with many
feeds. The figures recommended by Kellner [1915] and Wellmann [1931] have
been already cited. Huffman [1934] prescribes 10 grms. Ca or 14 grms. CaO.
One of the Bangalore workers [Iyer, 1935] found on the basis of another series
of trials with Rhodes grass hay, Aurangabad hay, spear grass hay and jowar
hay that " the actual minimum values found
are 10 grms. phos-
phoric acid and 15 grms. calcium oxide for an animal of 750-lb. live-weight ".
These values are much low as compared to those found under rice straw feeding.
The tests at Dacca were conducted on a comprehensive scale and the results defi-
nitely indicate that rice straw provides certain conditions under which lime assi-
milation does not proceed as satisfactorily as in many other feeds. The tests
at Bangalore, although confined to three only, also point to similar indications
as will be noted from the remark (loc cit) that "for some reasons lime is not very
readily assimilated from rice straw ".
186 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
1928] that the calcium in green food and carefully-won hay is in a more highly
dispersed condition, hence better digested and assimilated than in dry hay.
Their suggestion is based on the positive results obtained by feeding tricalcium
phosphate precipitated on starch. Possibly the lime compound in the rice straw
is in a coarser aggregation and the presence of a larger quantity of potassium salt
accompanied with other factors complicates the matter further.
There might be another factor, viz., deficiency of vitamin as suggested by
Fine [1930], but Godden [1928] remarks that feeding experiments conducted at
the Rowett Institute indicate that, on a properly balanced ration, with the animals
kept under normal conditions in respect of sun light and exercise, there is but
little risk of disease due to deficiency of vitamins. Other investigators such as
Warth [1932] and Theiler, Green and du Toit [1927] also think that in the case of
herbivora the evidences are inconclusive on this point.
The chief facts that emerge out from rice straw feeding are—
(1) that lime assimilation is poor,
(2) that positive balance cannot be attained until the intake is about
24 grms. CaO per 500-lb. live-weight.
(3) that this requirement is higher than the generally prescribed standard,
(4) that rice straw involves a comparatively larger ingestion of potash
on account of which, according to various investigators, lime assi-
milation might be adversely affected.
It need only to be stated here that if 24 grms. CaO per 500-lb. live-weight re-
present the minimum requirement under rice straw feeding, a somewhat higher
amount would be essential in actual practice. Kellner [1915] says that only
one-third to one-half of P 2 O 5 and CaO can be taken from vegetable foods so that
two to three times as much must be given as can be stored in the body. Possibly
the amount if given in pure form, say as calcium carbonate or phosphate, would
be different. According to Hawk [1931], a 50 per cent higher calcium level is
assumed as providing a " margin of safety " in the case of American dietaries
(human). On such basis the requirement under rice straw feeding would be about
36 grms. per 500-lb. The point can only be established after further trial and
it is proposed to take it up according as facilities are available.
Before winding up the discussion on lime requirement, it is necessary to state
that an excess intake over and above the requirement is not only wasteful but
may possibly be injurious. The behaviour of animals under the green feeds
(Experiment F) with regard to Hyacinth and Guinea grass groups are indica-
tions of this. In these the ingestion of lime has been very large, viz., 48 to 64
grms. but in spite of it half the results have recorded negative balance. In the
case of Hyacinth there might be some justification as the feed was rather
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
187
unusual, but the same cannot be stated of Guinea grass. It is more likely that
excess of lime is probably not well tolerated, as it would appear from the investi-
gations of Cox and Imboden [1936] who found in their experiment on reproduc-
tion in rats that excess of phosphorus was better tolerated than excess of lime.
The investigation of Meigs and his co-workers [1926] on lactating cows show
that an excess of calcium might interfere with phosphorus assimilation and that
two parts or more by weight of calcium to one of phosphorus constituted an
excess. They also point out from their work that a long continued loss of calcium
will cause a loss of phosphorus even though the ration may contain plenty of
assimilable phosphorus. The case of D 5 under Napier group in Experiment F
typically represents this condition (vide also discussion under phosphate). They
further obtained results indicating that calcium is very poorly assimilated from
hay which was exposed to rain. This latter point is of much importance to Bengal
and more or less to whole of India where the straw is almost invariably stacked
in the open. Particular care should be bestowed to guard against defective
stacking by which the quality of straw will deteriorate, thereby reacting on the
lime and other mineral content and also on assimilation.
Phosphate requirement
This aspect has been partially dealt with under Experiment E.' If the
various combinations as set forth in Table VII are studied, it will be noted that
the ingestion of P 2 O 5 from them has varied from 4.67 grms. (Experiment A)
to 58.91 grms. (Experiment B). The results may be divided under the follow-
ing :—
(1) those coming under definite deficiency (Experiments A, D, and
Hyacinth group under Experiment F),
(2) those standing on the border line (animals D 2 and D 9 under Experi-
ment E),
(3) those providing adequacy (Experiment C and animals D 8 , D 4 , D 5
and D 6 under Experiment E),
(4) those exceeding the stage of adequacy (Napier and Guinea grass groups
under Experiment E), and
(5) those deviating from normal behaviour (Experiment B).
The results under the deficiency groups of Experiments A and D represent
a condition under which the animals in Bengal are sometimes or often main-
tained. They show in particular that under the Bengal condition of feeding
there is a greater liability of phosphorus deficiency than that of lime. A small
supplement of cake or material rich in assimilable phosphorus can appreciably
improve the condition, and attention should be mainly concentrated towards
impressing this point.
F
188
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
Turning now to the next groups, if the intakes (Table VII) are followed from
the stage where the figures stand on the border line it will be noted that the first
minimum intake coincident with positive balance has been in the case of animal
D 2 which had ingested 10.728 grms. P2O5 (Experiment E) ; and the noteworthy
point is that all ingestions above this quantity (excluding of course the groups
departing from normal behaviour) have been attended with a definite positive
balance.
This particular experiment (Experiment E) represents a condition of ade-
quacy in virtually all nutrients as will be borne out from the results of balances.
There were six animals under it and five of them recorded positive balances in
all nutrients. The sixth one (animal D 9 ) also behaved identically in all other
respects, except in P 2 O 5 in which only it recorded a negative balance. This animal
along with D 2 and D 8 belonged to the ½ lb. linseed-cake group and received
like them about 11.2 grms. P2O5; but while the other two definitely recorded
positive balance this one failed to do so. On closer examination, it was noted
that this animal was the heaviest of the whole lot and weighed 603-lb. When,
therefore, the ingestion was computed on the basis of 500-lb. live-weight, it
worked out at 9.631 grms. P 2 O 5 or less than 10 grms. It will be seen that there
is not a single instance in which an ingestion below this amount has been followed
with a positive balance whereas all ingestions above this amount have been defi-
nitely positive. This amount thus constitutes the limiting factor for proper
assimilation and we are provided with a definite suggestion that the minimum
P2O5 requirement is about 10 grms. per 500-lb. live-weight or 20 grms. per
1,000-lb.
It will be interesting to refer to the findings of other workers. The opinion
of Theiler and Green has been already cited [Theiler and Green, 1932], viz., that
"fatal aphosphorosis will develop" when the phosphorus intake drops to the
vicinity of 20 grms. In the earlier work of Theiler and his co-workers [1927]
they found that with cattle grazing on the veld a daily consumption of about
11.79 grms. of phosphorus was regarded as somewhere about the point at which
osteophagia could develop or disappear in grazing cattle of 1,000-lb. live-weight.
Kellner prescribes 50 grms. per 1,000-kg. live-weight. This works out at 11.35
grms. per 500-lb. Armsby [1917] computed from Lawes and Gilbert's analysis
of the ash of the entire body of farm animals, that during the first year cattle
retain 8.14 grms. phosphorus per day. This figure agrees with Kellner's [1914]
who computed the phosphorus retention of growing calves as 8.3 grms. per
day during the first year. Wellmann [1931] has given the maintenance require-
ment at 25 to 50 grms. per 1,000-kg. or 5.675 grms. to 11.35 grms. per 500-lb.
live-weight. Huffman and his co-workers [1933] found that 5.7 to 9.9 grms.
phosphorus per day was insufficient (under sun-cured alfalfa hay and phosphorus
ration 4:1 to 5:1) but 10 to 12 grms. furnished sufficient phosphorus for