DIGESTIBILITY TRIALS ON INDIAN FEEDING STUFFS             183

to VII, from which it will be seen that the previous negative daily nitrogen balance
was converted into a positive one by the addition of maize grain as a concentrate.

Furthermore the figures indicating the effect produced by the addition of one lb.
of maize grain agree closely for each of the two animals, i.e., No. 122 and No. 133,
as shown above. From these calculations it is possible to ascertain that 1.5 to
2.0 lbs. of maize grain added to rice straw fed ad-lib would constitute a mainten-
ance ration for cows of this description weighing about 500 lbs. Heifer No. 128
suffered from bad foot sores due to foot and mouth, and so had to be excluded from
the second part of the investigations. The analytical data obtained with this animal
have, however, been given, but no great value may be attached to it.

    Although the addition of maize grain as a concentrate has converted the nega-
tive daily nitrogen balance into a positive one, neither the general condition of the
animals nor their body weights showed any pronounced improvement during the
period under trial, in spite of the fact that rather heavy doses of concentrate were
given. It is probable that the addition of maize grain may not have made good
the deficiency of the essential amino acids in the proteins of the rice straw, but on
the other hand may have augmented this deficiency. (Zein the chief maize protein
is known to be lacking in tryptophane and lysine, amino acids essential for main-
tenance and growth).

    A glance at the body weight curves (Fig. 2) shows a sharp drop shortly after the
concentrate feeding began, this may have been an aftermath of the deficient ration
and might have become more pronounced if the ration had been continued; weight,
however, was rapidly recovered, although the animals did not show recovery to
normal weight till the next experimental period described below :—

    3. Rice Straw and Toria Cake, 15th February 1930 to 25th February 1930.

    Rice straw and toria cake were fed from the 12th January 1930, to the 25th
February, 1930, one lb. toria cake was fed twice daily after being soaked in water
for a bout a couple of hours, while rice straw was given ad-lib. The data from this