208 
Journal of Agricultural Research 
Vol. XXXI, No. 3 
In Figure 4 are shown the growth curves of two groups of rats that 
were fed rations containing 15 and 30 per cent, respectively, of dried 
beef No. 902 as the sole source of vitamin A. Neither group of rats 
made much growth, about what might be expected from the reserve 
of vitamin A in their tissues, and every rat developed ophthalmia. 
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^ IG - 3—V itamin A in beef. Graphs showing rate of growth of rats that were fed a ration containing 30 per 
cent of dried round steak as the source of vitamin A in an otherwise adequate diet. The ration was 
made up in parts by weight as follows: Dried round steak No. 874,30; dried baker’s yeast, 10; ash mixture, 
4; hardened cottonseed oil, 5.9; cassava starch, 50.1; total, 100 
Fig. 4. —Vitamin A in beef. Graphs showing rate of growth of two groups of rats that were fed rations 
containing 15 and 30 per cent, respectively, of dried round steak as the source of vitamin A in otherwise 
adequate diets 
The ration fed to rats Nos. 240 A to 240 D inclusive, was made up in parts by weight as follows: Dried 
beef No. 902,15; purified ox muscle, 8.8; dried baker’s yeast, 10; ash mixture, 4; hardened cottonseed oil, 
7.4; cassava starch, 54.8; total 100 
The ration fed to rats Nos. 241 A to 241 D, inclusive, was made up as follows: Dried beef No. 902, 30; 
dried baker’s yeast, 10; ash mixture, 4; hardened cottonseed oil, 4.8; cassava starch, 51.2; total, 100 
Fig. 5.— Vitamin A in beef. Graphs showing rate of growth of rats that were fed a ration containing 30 
per cent of dried round steak as the source of vitamin A in an otherwise adequate diet. The ration was 
made up in parts by weight as follows: Dried beef No. 906, 30; dried baker’s yeast, 10; ash mixture, 4; 
hardened cottonseed oil, 3.2; cassava starch, 52.8; total, 100 
In Figure 5 are shown the growth curves of rats that were fed a 
ration containing 30 per cent of dried beef No. 906 as the sole source 
of vitamin A. Two of the rats made appreciable growth; but the 
other two grew about as much as rats fed one of the more satisfactory 
basal rations. The difference in the growth of the two pairs of rats 
may be due to the fact that they were from different litters. 
