In the second series of experiments ten male rats were used with four different rations. In these, casein and Sanatogen were compared, using both Osborne and Mendel’s “protein-free milk” and their “artificial protein-free milk IV.”[123] Butter fat was also substituted for the unsalted butter used in Rations 1 and 2.
The percentage composition of the rations fed was as follows:
| Ration 3 | Ration 5 | |||
Casein | 20 | Casein | 20 | |
Protein-free milk | 28 | Artificial p.-f. milk IV | 29 | |
Lard | 8 | Lard | 8 | |
Butter-fat | 18 | Butter-fat | 18 | |
Corn starch | 26 | Corn starch | 25 | |
| Ration 4 | Ration 6 | |||
Sanatogen | 20 | Sanatogen | 20 | |
Protein-free milk | 28 | Artificial p.-f. milk IV | 29 | |
Lard | 14 | Lard | 14 | |
Butter-fat | 18 | Butter-fat | 18 | |
Corn starch | 20 | Corn starch | 19 | |
Two male rats were used with each of Rations 3 and 4, and three with each of Rations 5 and 6. They were all healthy young rats ranging from 57 to 71 days old. As in the first series of experiments the rats were weighed twice a week and a record kept of the food consumed. Rations 3 and 4 were fed for seventy-seven days, Rations 5 and 6 for thirty-five days.
Table 3 shows the weekly weights and gains or losses of the rats fed Rations 3 and 4.
Rat 8 suffered more or less from diarrhea during a considerable part of the experiment, covering a period from March 16 to April 9, and from April 13 to May 11. The food intake correspondingly decreased during those periods.
TABLE 3.—COMPARATIVE WEIGHTS OF RATS FED RATIONS 3 AND 4
| Date | Weights of Rats, Ration 3, Casein, Protein-Free Milk | Weights of Rats, Ration 4, Sanatogen, Protein-Free Milk | ||||||||||
| Rat 7 | Rat 8 | Rat 9 | Rat 10 | |||||||||
| Weight, gm. | Gain or Loss, gm. | Weight, gm. | Gain or Loss, gm. | Weight, gm. | Gain or Loss, gm. | Weight, gm. | Gain or Loss, gm. | |||||
| 3/9 | 142.2 | ..... | 108.0 | ..... | 127.8 | ..... | 107.0 | ..... | ||||
| 3/16 | 152.8 | +10 | .6 | 120.3 | +12 | .3 | 129.1 | +1 | .3 | 116.0 | +9 | .0 |
| 3/23 | 165.7 | +12 | .9 | 135.1 | +14 | .8 | 144.6 | +15 | .5 | 134.5 | +18 | .5 |
| 3/30 | 178.6 | +12 | .9 | 140.4 | +5 | .3 | 160.0 | +15 | .4 | 149.8 | +15 | .3 |
| 4/6 | 187.8 | +9 | .2 | 148.8 | +8 | .4 | 173.1 | +13 | .1 | 143.8 | -6 | .0 |
| 4/13 | 198.5 | +10 | .7 | 157.6 | +8 | .8 | 185.6 | +12 | .5 | 166.1 | +22 | .3 |
| 4/20 | 204.6 | +6 | .1 | 164.6 | +7 | .0 | 194.8 | +9 | .2 | 179.4 | +13 | .3 |
| 4/27 | 210.3 | +5 | .7 | 167.2 | +2 | .6 | 204.6 | +9 | .8 | 191.0 | +11 | .6 |
| 5/4 | 223.0 | +12 | .7 | 179.6 | +12 | .4 | 222.9 | +18 | .3 | 204.7 | +13 | .7 |
| 5/11 | 223.6 | +0 | .6 | 191.6 | +12 | .0 | 236.4 | +13 | .5 | 210.8 | +6 | .1 |
| 5/18 | 231.5 | +7 | .9 | 203.6 | +12 | .0 | 240.0 | +3 | .6 | 218.6 | +7 | .8 |
| 5/25 | 237.4 | +5 | .9 | 213.9 | +10 | .3 | 247.3 | +7 | .3 | 226.7 | +8 | .1 |
| Total | ..... | +95 | .2 | ..... | +105 | .9 | ..... | +119 | .5 | ..... | +119 | .7 |