NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
189
maintenance, normal growth, and for the development of the foetus from eighteen
months of age to first calving. They suggest that " at least 17 grms. of phos-
phorus be allowed daily for low milk production and the dry period during the
advanced stage of gestation ". Rose [1912] concluded that the necessary amount
to maintain phosphorus equilibrium in milking cows appeared to be the amount
eliminated in milk plus 20 mg. per kgm. of body-weight. 'Evidently the latter
(26 mgm.) represented the maintenance requirement and is equivalent to 26 grms.
per 1,000-kg. live-weight.
Turning now to the results of Dacca experiments it may be said that when
10 grms. P2O5 per 500-lb. live-weight constitutes the limiting factor under rice
straw feeding, it will be advisable to follow the American practice (as suggested
under lime) and add 50 per cent to it in order to provide a margin of safety. This
works out the minimum requirement at 15 grms. phosphate per 500-lb. live-weight
or 30 grms. per 1,000-lb.
If the amount is to be fed as a mineral supplement it is well to bear in mind
the interesting theory advanced by Meigs et al [1926] viz., that assimilation is
facilitated by feeding calcium and phosphorus alternately. According to them
the absorption of phosphorus from the intestinal tract is hindered by the simul-
taneous presence of calcium compound. They suggest from their metabolic
tests that the phosphorus assimilation by pregnant cows and " probably that of
calcium also " is favoured by adding di-sodium phosphate to the ration and feed-
ing it on alternate days.
Phosphorus ingestion exceeding the stage of adequacy
The experiments bearing on this were in one case limited to four animals
(Napier and Guinea grass groups under Experiment F) and in another (Experi-
ment B under rice kura group) it was governed by other factors for which it does
not strictly fall into this category, and will be dealt with separately. In the former
case the ingestion of P 2 O 5 was from 24 grms. to 27 grms. and was not at any
rate so large as could be considered unusual or excessive. Such ingestion may
be uneconomical but may not necessarily be harmful. On these data little can be
said of the possible effect of a truly excessive ingestion.
There is, however, an interesting side issue which deserves attention. One
of the animals D 5 under Napier feeding recorded a negative balance in spite of
such a large ingestion of P 2 O 5 . Its explanation probably lies in the fact that
Napier grass involved a very heavy (in fact the heaviest) ingestion of potash (155
to 173 grms. K 2 O) while the lime ingestion was only 18 to 20 grms. CaO. The
behaviour of a large ingestion of potash and its adverse effect on lime assimila-
tion has been partially discussed and will also be further discussed under potash.
It has been pointed out that under rice straw feeding (with which a large quantity
F A
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
191
with prepared phytin with basal ration and they found that phytin as a source
of phosphorus was without significant value but equivalent amounts of phos-
phorus given as phosphoric acid " resulted in a pronounced improvement in
calcification " and " Sodium glycerophosphate was still more beneficial ". They,
therefore, express that " phytin proved itself to be a poorly available source of
phosphorus
".
These factors appear to be chiefly responsible for the poor assimilation
and negative phosphate balance in the case of D 5 , D 8 and D 4 in Experiment B
in spite of an ingestion up to the range of 43 grms. P 2 O 5 . Possibly at about
this stage the inorganic portion of P 2 O 5 reached the level of requirement. In
any case the behaviour of rice kura requires to be studied in greater detail and it
is proposed to take it up as soon as possible.
Magnesia
In these experiments the MgO intake has varied from 10 grms. to
33 grms. in the different combinations. The heaviest ingestion has been in
the case of the Guinea grass group under 'Experiment F and the rice kura
group under Experiment B. The rôle played by magnesia is of much less im-
portance as compared to lime and phosphate. According to Green [1935] the
dietary requirements of magnesium are very low and are covered by all ordinary
rations. He expresses doubt whether a magnesium deficiency disease would
ever be found to occur naturally in farm animals. From the results of these
experiments it would appear that the general tendency of positive balance is
manifest from the stage when the intake has been about 15 grms. and upwards.
The results under aman straw and cake (Experiment C) suggests that when
the intake is sufficiently low to record a negative balance it seems to react upon
the economy of soda balance which has been uniformly negative in those very
instances under Experiment C in which MgO was deficient. The soda inges-
tion here was about 17 grms., and with the same quantity of ingestions under Experi
ment B where MgO ingestion was high, seven out of nine have recorded a posi-
tive balance. In experiment E the soda ingestion was similar but MgO was
moderate and here both recorded positive balances. There is thus some tendency
of inter-relation which is chiefly noticeable if MgO ingestion falls below 12 grms.
Amongst the feeds tested rice kura contains the largest quantity of MgO
(about 2.6 per cent on dry matter). It has been found by Mendal and Benedict
[1909], Hart and Steenbock [1913] and Bogert and McKittrick [1922] that exces-
sive intake of Magnesia gives rise to an increased elimination of calcium. Henry
and Morrison [1928] state that those feeds which contain much magnesium in
proportion to calcium, such as wheat bran and middlings, when given in excessive
amount for long periods "are said to cause a weakening of the bones, leading to
such troubles as bran disease or miller's horse ricket". In rice bran there is much
magnesium in proportions to lime and. this might be another aggravating cause
(in addition to those dealt under lime and. phosphorus) to bring such poor result.
192 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
Potash
There is generally an appreciable amount of potassium in all plant
materials commonly used and so normally there is no great likelihood of a
natural shortage. In rice straw potash is present to the amount of 1.6 per
cent to 2 per cent on dry matter and is about 5 to 10 times as much as Na 2 O.
In the experiments under reference the ingestion of K 2 O varied from 53 grms.
to 89 grms. per 500-lb. live-weight in the combinations in which paddy straw
formed the main roughage (Experiments A to E). It will be noted that although
the ingestions of K 2 O were quite large, a very large amount found its way out
specially through the urine so that a positive balance seems to be controlled by
a certain level of ingestion which in these experiments was about 66 grms. per
500-lb. live-weight.
In the experiments conducted by Warth [1926] the feeding was divided into
two groups, viz., rice straw and hay, and the animals were of three live-weights,
viz., 1,000-lb., 750-lb. and 500-lb. The ingestion of potash in his 500-lb. group
animals varied from 63 .4 grms. to 92.5 grms. in the rice straw group, as com-
pared to 25.6 grms. to 31.2 grms. in the hay group. Unfortunately he has not
given the complete balance picture, but as urinary excretion embraces the major
part of potash it gives an indication of the balance specially if it exceeds the intake.
It is seen from his data * that in the case of the paddy straw feeders two out of
three under 750-lb. live-weight and one out of three under 500-lb. have records
in which the urinary excretion of potash has exceeded the intake, .thereby leaving
no doubt of the tendency of a negative balance despite large ingestion. In the
case of hay eaters, however, no such inference is possible as the urinary excre-
tion was lower than the intake.
As the behaviour of straw eaters is one of the main objects of comparison
it will be noted that in spite of limited data there is some parallelism with the
Bengal figures. In the latter the positive balance is maintained when the inges-
tions generally exceeded 66 grms. per 500-lb. live-weight. In Warth's experi-
ments the one recording negative balance under this live-weight had an ingestion
equivalent to 58 grms. and 78 grms. on the basis of 500-lb. computation (the
actual ingestions being 84.2 grms. and 117.9 grms. of intake). Both indicate
that there is a certain level below which positive balance becomes uncertain.
It should be stated, however, that whether in the case of positive or nega-
tive balance the very large excretion is as much an evidence of low economy as
it is an indication of the ingestion, exceeding much about the requirement. Yet
since rice straw forms the main part of roughage there is no way of avoiding the
large ingestion of potash through it.
*Table XVI, page 54 of the Memoris of the Dept. of Agri. in India (Chemical
series), Vol. IX, No. 2.
194 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
As the large potash ingestion under Bengal condition is unavoidable, atten-
tion should be directed towards a better adjustment of other minerals specially
lime and phosphate. It need hardly be stated that the animals in Bengal have
been under a straw feed for generations and for good or evil they have been accus-
tomed to it. Possibly they have acquired some amount of tolerence and
immunity from the deleterious effect, if any, which the larger ingestion might
occasion.
Effect of potash on urination
There is another point which also merits attention. Warth [1926] found
in his experiments that " rice straw induces a marked and persistent diuresis "
and his conclusion is that " the diuresis is intimately related to potash excre-
tion ". Under Bengal conditions, however, this sort of diuresis has not been
noticeable.
TABLE VIII
Food
Aman straw only (Experiment. A) . . .
Aman straw and rice Kura (Experiment B) .
Aman straw—1-lb. linseed cake (Experiment. C) .
Aman straw—1-lb. cake
.
.
.
.
.
.
Aman straw.—2-lb. cake
.
.
.
.
.
.
Aman straw—3-lb. cake
.
.
.
.
.
Aus straw only (Experiment D) . . .
Aus straw—linseed cake (Experiment E) . . .
Hyacinth group (Experiment F) . . .
Hyacinth group with 1-lb. cake . . .
Napier group (Experiment F) . . . .
Guinea grass group (Experiment F) . .
Urine voided
grms.
2658.2
3412.8
2663.2
3492.9
3917.8
4106.9
2585.5
3788.9
3987.3
8802.6
10169.3
6326.6
Water consumed
grms.
8471.0
12853.0
13674.0
14106.8
15640.5
17028.5
11095.0
17191.0
3898.0
7834.0
5234.0
4762.0
In fact, as will be noted from Table VIII, when rice straw was fed alone the
urination was lowest. These data represent actual averages and have not been
converted to any uniform live-weights, but as the animals were more or less similar,
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
195
they give a fairly correct indication of the behaviour of urine excretion under the
different feeds. It should be noted that Hyacinth has the largest percentage
of potash and the ingestion of K 2 O was only next to that of Napier grass but even
here the urination did not show a perceptible rise until it was supplemented with
cake. Similarly, when straw was supplemented with cake, the urination was
higher. Thus, so far as paddy straw is concerned, no marked diuresis could be
ascribed to it under Bengal conditions. Ramiah's work at Coimbatore also points
to same conclusion [Ramiah, 1932]. On the other hand the addition of cake
seems to induce more diuresis.
The only exception has been in the case of Napier group. Here potash
ingestion was heaviest and urination was also the highest. This might be sugges-
tive of a partial association of potash with diuresis but as will be apparent from
the above results there might be other factor or factors. Warth also states that
" while the amount of urine is mainly dependent upon potash there is another
subsidiary factor at work", but according to him "its nature has not been
established yet ".
It remains only to be stated that when potash ingestion is heavy, as typified
in the case of the Hyacinth and Napier groups under Experiment F, the reten-
tion capacity of potash is lowered as is exemplified in the wholesale negative
balances under Hyacinth and one out of two under Napier. Possibly it also
induces a craving for more sodium chloride as is suggested by Bunge's classical
experiment. This part has been further discussed under sodium chloride.
The behaviour of the Guinea grass group is interesting from another stand-
point. This group had a little over 72 to 74 grms. of potash, which would seem
to be sufficient but both the animals have recorded a negative balance. But
here lime ingestion was very high and it cannot be said whether this was res-
ponsible for an adverse effect.
Briefly the results indicate that—
(1) with rice straw feeding the potash requirement is probably about
66 grms. minimum per 500-lb. live-weight. Possibly about 70 to
80 grms. should be enough.
(2) In the case where potash is heavily ingested as in Hyacinth and Napier
groups, it induces an excretion greater than the intake.
(3) Where lime ingestion is very high, as in the case of Guinea grass, the
amount of potash ingested (72 to 74 grms.) did not. record a positive
balance.
(4) Rice straw did not induce diuresis as was noticed by Warth at Banga-
lore.
F
196
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, III
Sodium and chlorine
These two minerals are taken together because sodium chloride is the most
convenient form in which they are supplied to the animal. Sodium chloride
also forms a component part of the body fluid. Sodium salts exert a specific
influence upon the irritability of the nerves and the relaxation of muscles.
Overton [1904] showed that frog muscle immersed in isotonic cane sugar lost
its excitability and that restoration could be brought about by a sodium salt
or in a less degree by a lithium salt but not by salts of potassium. For the
normal contraction of the heart muscle a balance must exist between the calcium
and sodium contents of the blood [Hawk and Bergeim, 1931].
The above facts by themselves would induce a natural demand for common
salt by the animal, and possibly this demand is further increased on account of
the presence of a large amount of potash salts in plant material. This has been
suggested by a highly interesting experiment by Bunge [1873]. He attempted
to attribute the craving which herbivorous animals have for common salt to an
excess of potassium in the diet. According to him when a salt such as potas-
sium citrate gains entrance into the blood stream, a proportion of it reacts with
the sodium chloride forming potassium chloride and sodium citrate. As the
kidney functions in keeping the composition of the blood nearly constant, the
abnormal constituents sodium citrate and excess of potassium salts are eliminated.
In this way a high potassium salt intake may cause increased elimination of
sodium and chlorine.
This is partly indicated in the balance figures of the
Hyacinth and Napier groups under Experiment F in which potash ingestion
was very heavy. One of the sodium figures out of two and both, the chlorine
under Hyacinth are negative, while in the case of Napier one chlorine out of two
has been negative. Sodium figures were, however, positive.
At the same time, it should be stated that experiments on heifers carried
out by Hart, McCollum, Steenbock and Humphry [1911] show the incomplete-
ness of Bunge's theory. These authors have different groups of animals with
rations of different cereals and all the animals had free access to salt. They
found that the sodium chloride consumed had no relation to the amount of potas-
sium in the ration, either as such or when supplemented with potassium salt.
Godden's work in conjunction with Richards and Husband [1928] also shows
similar conclusion. Miller's later investigation on pigs [Miller, 1922] shows that
a sudden increase of potassium salts in the diet caused an immediate increase in
sodium and chlorine excretion during the following twenty-four hours period but
as stated by Bunge, the excretion of sodium and chlorine in Miller's experiment
also decreased when the high potassium intake was continued and Miller says that
" the animal can distribute its sodium and chlorine as required by the different
part of the body during the absorption of large quantities of potash, which may
at other times cause increased sodium and chlorine excretion ".
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
197
Turning now to the other experiment, viz., to those in which rice straw
forms the main roughage, it will be noted that in Experiments A, B, D and
E, sodium has exhibited a general tendency of positive balance. In these the
amount of intake varied from 14 to 23.8 grms. and would seem to be about the
requirement. But although this might generally be so the results under Experi-
ment C suggest that in the event of a deficiency in magnesia the soda balance
is likely to be adversely affected. Here the soda intake was about 17 grms.,
but three out of four have recorded a negative balance and it is these three whose
magnesia balances are also negative. There are also probably other factors—
for instance the lime supply was just on the border line and inclined towards
deficiency as is noticeable from the two negative balances out of four. The
chlorine ingestion was also very high—in fact the highest with the exception of
the Napier group. Leaving these (under Experiment C) the weight of evidence
from the majority of other experiments is in favour of an amount of sodium
equivalent to 16 to 18 grms. Na 2 O per 500-lb. live-weight or 32 to 36 grms. per
1,000-lb. live-weight. The amount would correspond to 30.17 to 33.94 grms.
NaCl per 500-lb. and 60.34 to 61.88 grms. per 1,000-lb. In actual fact about
half the amount is supplied through the feed. This should not mean that the
whole of it should be supplied as NaCl.
With respect to chlorine the ingestion has varied from about 17 to nearly
30 grms. The heaviest ingestion has been in the case of Napier group (Experi-
ment F) closely followed by aman straw and cake under Experiment C. It
cannot be stated whether such an amount as was ingested in these two experi-
ments was really excessive or not. McCollum, Simmonds and Becker [1922]
noticed an inflammatory condition of the eyes resembling xerophthalmia which he
calls salt opthalmias due to excess of chlorine in the food. No such condition was
noted in the present experiment though the Hyacinth animals were distinctly
below condition but in this as already stated there was deficiency of other nutrients
also. In general, it would seem that an ingestion of about 20 grms. of chlorine
should ordinarily meet the necessary requirement for animals of 500-lb. live.
weight. But Experiment B under aman straw and Rice kura, and the Hyacinth
group under Experiment F are exceptions to this. In these two, negative
balances have been the conspicuous feature. In both cases there was some depar-
ture from normal conditions in as much as, in Experiment B, the intake of
calcium (as indicated from the other experiments with rice straw) was very
low and phosphate very high, while in the Hyacinth group calcium and potash
were very high and phosphate and nitrogen low. Leaving these, the require-
ments of chlorine in all ordinary cases under rice straw would appear to be
satisfied as already stated with an amount approximating to 20 grms.
per 500-lb., although in some experiments larger amounts have been ingested.
This would correspond to 32.97 grms. NaCl and about half of it is expected
to be provided through the feed.
MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
199
In this way he has tried to draw a comparison of minerals per 1,000 calories.
Theiler, Green and du Toit [1927] are also inclined to a similar opinion, as they
stressed that it was not the percentage of phosphorus on dry matter which
mattered but the amount in relation to the energy value of pasture. In a more
recent publication Theiler and Green [1932] have also suggested that as a rough
guide " a round figure of 1 per 100 starch equivalent " may be taken as safe for
either P 2 O 5 or CaO throughout the bovine or ovine life. Marek [1924] has
emphasised the importance of " Alkali — Alkalizilat and Eldarkali— Alkalizat ".
Wellmann [1931] working in co-operation with Marek states that the relationship
of the alkaline earths calcium and magnesium and their ratio of phosphoric acid
are important. This relationship (E. A.) is calculated on the basis of 100 grms.
dry matter as follows—
E.A.=(CaO
mg. equiv. + MgO mg. equiv.+. P 2 O 5 mg. equiv.) × 100/Grm. dry matter
Theiler, Green and du Toit [1927] have, however, strongly attacked what
they call the " fallacy of Marck ", and in the course of their discussion have
remarked that the data at present available " are too fragmentary to justify any
generalisation". These diverse views only emphasise the complexity of the
whole subject and any attempt towards interpretation of the results on these
diverse lines can only be made both with caution and reservation.
There is no doubt that the results need scrutiny from all standpoints and in
order to facilitate the same the best course would appear to be to assemble all
the relevant data in the different forms so that they might embody a collection
for future interpretation in the light of more suggestive information which may
accumulate in course of time. Accordingly, the data have been worked out in
the attached Appendices on the basis of different ratios, calorific relations (Orr's),
Marek's E. A. values and so forth. It should, however, be stated that the calories
here have been worked out from actual digestibility values and thus involves no
assumption as was unavoidable in Orr's figures.
Although the interpretation on the basis of these factors is withheld for the
present it should be stated that whatever might be the relation of mineral matter
either with respect to the absolute amount or with respect to their proportions
to each other the nature of the feed is by far the chief determining factor. There
is no doubt that the animal has what may be called a minimum requirement of
minerals but the criterion for this minimum is not always a phase indicated by
the absolute minimum need of the animal or of the presence of this absolute
minimum in the feed but is a condition mostly regulated by the nature of the
feed. In other words, with different feeds this minimum is likely to vary. This
is more strikingly illustrated in the lime requirement under rice straw as the
main roughage. It has already been stated that according to Kellner an amount
of lime equivalent to 22.7 grms. CaO per 500-lb. would "sufficiently meet all