368 
Journal of Agricultural Research 
Vol. XXXI, No. 4 
In trials at the Iowa Experiment Station during five years, Evvard 
found that 2-year-old steers fattened on typical Corn Belt rations, 
including corn silage, and allowed free access to block salt, consumed 
just about one-third ounce of salt per head daily. The gains of the 
animals were very satisfactory. “In a trial carried on by the Kansas 
station it was found that during the summer yearling and 2-year-old 
steers on pasture licked about 1 oz. of salt per head daily from salt 
blocks placed in the pasture” (14)- “In an experiment in France, 
sheep fed 0.5 oz. of salt daily with their feed gained materially faster 
than those fed no salt, and also somewhat more rapidly than others 
fed 0.75 oz. daily. The fleeces of the salt-fed sheep were of better 
quality and heavier than those of the sheep fed no salt ” {If)- 
Armsby emphasizes the need of further study of the inorganic 
elements. He feels that the amount of these elements actually 
necessary is less than is often supposed. The data which he gives 
regarding sodium, potassium, and chlorine, seem to be conflicting. 
An investigator in 1907 {21) stated that the ability of the body 
to take up sodium salts is practically unlimited. He speaks of 12 
to 15 gms. of sodium chloride as the normal amount used by man, 
and 7 to 8 gms. as the normal amount on a milk diet. 
EXPERIMENTAL DATA 
In the writers’ preliminary experiment 9 young white rats were 
divided into 3 lots and fed the same basal ration, consisting of 100 
gms. of ground wheat, 10 gms. of wheat gluten, and 5 gms. of pre¬ 
pared butterfat. The ration contained approximately 16.6 per cent 
of protein and should satisfy the requirements of the white rat as 
far as protein, fat, carbohydrate, and vitamins are concerned. The 
food given to lot No. 1 consisted of the basal ration plus 0.5 gm. 
sodium chloride. For the second lot 0.5 gm. calcium chloride was 
added to the basal ration, and for the third lot, a combination of 
0.5 gm. sodium chloride and 0.5 gm. calcium chloride was given with 
the basal ration. 
Two of the rats given the rations containing the sodium chloride 
died at 4 and 5 weeks respectively, while the remaining one developed 
slowly but very unsatisfactorily. Likewise, two of the rats given 
the oalcium chloride and sodium chloride combination died at 3 
and 11 weeks, and the one remaining made somewhat more rapid 
development than the rats given the sodium chloride. The rats fed 
the calcium-chloride and sodium-chloride combination seemed to 
withstand approximately double the quantity of chlorine present 
in the sodium-chloride ration. The lot receiving the calcium- 
chloride ration not only made better gains than was noted in case of 
either of the other two lots, but also without mortality. 
The female in the calcium-chloride lot finally raised six young 
rats successfully. Toward the end of the nursing period, the mother 
showed signs of becoming blind, and her head was twisted to one side. 
She conceived again but aborted. In the third gestation period 
much difficulty was experienced at parturition. At this time there 
was no doubt as to the effect produced on the nervous system, and 
blindness was apparent. * The mineral content of the ration for this 
rat was then changed to 0.1 gm. sodium chloride with 0.4 gm. calcium 
chloride, when she again successfully reared two litters of seven and 
four young, respectively. 
