110
Fluorine Intoxication of Cattle in India
METABOLISM STUDIES
Metabolism trials were conducted in both sets of animals after eight months of ex-
perimental feeding. The results are given in Tables I and II.
DISCUSSION
It will be seen from Table I that when fluorine is administered in small doses the
balance of both calcium and phosphorus improves. This supports recent findings that
fluorine in small quantities helps in the prevention of caries. High fluorine intake, how-
ever, brings about a definitely negative balance of calcium and the phosphorus balance,
already negative, becomes more pronounced. The increased negative balance of phospho-
rus is mainly due to the highly increased elimination of this mineral in urine. A simul-
taneous greater excretion of nitrogen through the kidneys may be taken to signify ex-
tensive muscular degeneration. This breakdown of the soft tissues is also apparent
from the great loss in body weight of the animals of the high fluorine group. A simi-
lar loss of phosphorus by dairy cattle on fluorine administration was found by Du Toit,
et al. [1937] who considered that fluorine produced symptoms of osteomalacia by induc-
ing a condition of phosphorus shortage. This hypothesis cannot, however, be substan.
tiated in view of our finding that the animals in the fluorine alone group of the
second trial were actually in positive phosphorus balance when symptoms of fluorosis
were clearly observable. This is further confirmed from the blood anylysis [Majumdar
et al. 1943] of the experimental animals, where no lowering of blood inorganic phospho-
rus, characteristic of aphosphorosis, could be recorded. In the absence of nitrogen balance
data, the possibility of negative phosphorus balance in the animals of Du Toit et al. [1937]
being due to the breakdown of soft tissues cannot be ruled out.
There seems, however, to be some apparent connection between the level of feed
phosphorus and the production of fluorotic symptoms. These symptoms were precipitated
in animals kept on a low phosporus diet (first trial) ; but were delayed when adequate
phosphorus was supplied (second trial). The effect of the level of intake of phosphorus
was very clearly exhibited by the animals of the calcium group in the first set of ex-
periments. Here so long as the supplement of calcium phosphate was given, the ani-
mals remained in good condition. The supplement helped to maintain the ration adequate
in phosphorus. When calcium phosphate was replaced by calcium carbonate, the animals
started losing weight and their condition thereafter rapidly deteriorated. These experi-
ments apparently support the view of Du Toit et al. [1937] that fluorosis brings about osteoma-
lacia by phosphorus deprivation and may be corrected by adequate phosphorus intake.
But this contention has been proved untenable from the metabolic evidences already dis
cussed. It is not the adequacy of phosphorus alone but that of both calcium and phos-
phorus, and also their proper proportion, which can afford some protection against fluo-
rosis. It should, however, be stressed that adequate supply of calcium and phosphorus
offers only a temporary relief and is useless to save a victim against prolonged high in-
take of fluorine.
The importance of supplying the minerals in correct proportion is exemplified in
the second set of experiments. Here, though the animals were on a negative calcium
balance, a supplement of calcium carbonate, instead of proving helpful, brought about
more rapid deterioration of the animals. The addition of extra phosphorus, as sodium
phosphate, was also of no avail, because the condition of the phosphorus group of ani-
mals was more or less the same as that of the animals of the fluorine-alone group. The
Ca : P ratios of the control, high fluorine and calcium (calcium phosphate supplement),
groups of animals in the first experiment, and of fluorine alone, calcium and phosphorus
groups of the animals in the second experiment were respectively 3:1, 2:1, 2:1, 1:1.2,
4.3 : 1 and 1 : 2.2. It will thus be seen that the syndromes of fluorosis were precipitated
only in those groups, where either there was a gross deficiency of phosphorus or where
the ratios were widely divergent from the physiological optimum range of 2:1 to 1:1.
From what has been stated above, it may also be concluded that a low calcium diet
will similarly precipitate fluorotic symptoms at a very early date. On account of the difficulty
of devising a cattle ration very poor in calcium content, this experiment could not be taken