MINERAL REQUIREMENTS OF CATTLE IN NORTH-EAST INDIA
175
It will be seen from Table V that CaO, MgO, K 2 O, Na 2 O and C1 2 have uni-
formly maintained a positive figure in all the six animals under experiment. In
the case of P2O5 also a positive balance has been kept in five out of six. Only one
has recorded a negative balance, and this provides a very interesting study. This
animal (D 9 ) was the heaviest amongst the lot and weighed 603 lb. during the experi-
mental period. It had received about half lb. of cake which when worked out
on the basis of 500-lb. live-weight only provided 3.421 grms. P2O5 from cake as
compared to higher amounts in the case of other animals. The result was that
while the other animals received P2O5 to the amount of 11 to 14 grms. from the
total feeds (cake and straw), the amount falling to the share of this animal was
9.63 grms. only. This is highly suggestive that the minimum P2O5 requirements
under these conditions of feeding is about 10 grms. per 500-lb. live-weight. It
would be worth while to quote here the remark of Theiler and Green [1932] that
" when the phosphorus intake of an adolescent bovine drops to the vicinity of twenty
grms. P2O5 per day on a natural pasture, fatal aphosphorosis will develop in due
course." This suggests a requirement of 10 grms. P2O5 per 500-lb. live-weight
and is corroborative of our findings.
Experiment F—Aman straw and green feeds. As already stated this ex-
periment is really divided into three parts—Hyacinth group, Napier group and
Guinea-grass group.
At the outset it is necessary to state that it would have been better if some
more work with these feeds could have been done before incorporating this part
here. On the other hand, some of the results appear to be highly suggestive and
their inclusion has been prompted from this consideration. These are submitted
subject to this reservation.
The main features in this experiment (Table VI) are an ingestion of high CaO,
high K 2 O with low P2O5 (and also nitrogen) in the Hyacinth group ; low CaO
and high K 2 O in the Napier group ; and high CaO, medium K 2 O and possibly high
Na 2 O in the Guinea-grass group.
In the case of the Hyacinth group, on account of a very low ingestion of P2O5
(6.5 to 7 grms.) the ratio CaO P 2 O 5 has varied from 7.34 to 9.02, i.e., lime
has been seven to nine times as much. There is also further imbalance with respect
to high potash and low nitrogen. The chlorine ingestion has been similar to
that of Experiment B (aman straw and kura) and like it has recorded a negative
balance. The potash ingestion is, however, very high—in fact the highest with the
exception of the Napier group, yet a definitely negative balance in the two animals
experimented with has been recorded. As for CaO, in spite of heavy ingestion
(48 to 64 grms.), the animals have not been able to effect a definitely positive balance.
Animal D 2 has recorded a negative balance in CaO, K 2 O, Na 2 O, P 2 O 5 , CI 2 and
nitrogen. Since the low ingestion will necessarily be associated with negative balance
the results under P 2 O 5 , Cl 2 and N might be what was expected. But the cases of
CaO and K 2 O are different as both of them were ingested in heavy doses, yet K 2 O