July a g, 1923 Growth-Promoting Value of Proteins of Palm Kernel 169 
followed. Resupplying the animal with the vitamin preparation was 
again followed by a prompt recurrence of growth. 
The curves in chart 3 show that when the quantity of palm-kernel 
meal was increased to 40 per cent of the diet, there was still a deficiency 
of vitamin B. That the meal contained some of this vitamin, however, 
becomes apparent on comparing these curves with those of control rats 
484 and 485, which received purified casein as the sole source of protein 
in their diet. These rats received a diet containing the same percentage 
of protein as did the others whose growth curves are given in this chart. 
The control rats made a decidedly slower initial growth and in two weeks 
began to decline rapidly. It is also to be noted that the animals whose 
diet contained 40 per cent of the meal did not show decline as soon as 
those on the 25 per cent meal diet. 
EXPERIMENTS SHOWING VITAMIN A DEFICIENCY 
The curves in chart 4 show that 25 parts of palm-kernel meal in the 
diet does not furnish sufficient vitamin A. After an initial growth of 
24 to 25 days the rats began to decline and developed xerophthalmia. 
The addition of 0.3 gm. of cod liver oil promptly cured the eye trouble 
and enabled the animals to grow at a fair rate. Rat 1068 had declined 
to such an extent that it failed to respond to cod liver oil. 
Where 40 per cent of the meal was used in the diet (chart 5), the decline 
in growth and onset of xerophthalmia occurred considerably later than 
in the case of the rats which received the 25 per cent meal ration. 
SUMMARY 
The proteins of palm-kernel meal were found to be adequate for the 
normal growth of young rats, when fed in a diet balanced with respect to 
the other dietary factors. The meal constituted 80 per cent of the diet, 
which is equivalent to 15.5 per cent of protein. 
Forty per cent of palm-kernel meal did not furnish sufficient vitamin A 
to prevent xerophthalmia, and a like quantity did not provide sufficient 
vitamin B for normal growth. Since the meal used for these experi¬ 
ments was a commercial product obtained as a residue from the nuts 
after removal of the oil by the solvent process, the results obtained with 
reference to vitamin content, however, may not necessarily apply to the 
fresh, untreated palm-kernel nut. 
Inasmuch as it is this treated commercial product which is available 
for the feeding of live stock, the vitamin values given in this article are 
of more practical value than would be those found for the fresh kernels. 
