Subject No. 20. February 27, 1906
Subject No. 20. April 24, 1906
Subject No. 20. June 19, 1906
The illustrations so far presented, with the general agreement in the character of the results, might perhaps be interpreted as indicating that there is no difficulty whatever in bringing a high proteid consumer, like a dog, down to a low level of proteid consumption. This, however, would be a false impression. Much depends upon the character of the proteid food, at least where any attempt at rapid change is made, for a certain modicum of meat or other animal food seems a necessary part of the daily diet if health and strength are to be maintained. A dog transferred suddenly from a daily ration in which meat and milk are conspicuous elements to a diet in which these are wholly wanting is very liable to show disturbing symptoms almost immediately. One case may be cited in illustration of these statements. On September 29, 1905, dog No. 17, weighing 18.2 kilos, was placed on a daily diet composed of 70 grams of fresh meat, 442 grams of milk, 300 grams of bread, and 28 grams of lard. This ration contained 9.06 grams of nitrogen and had a fuel value of 1465 calories, or 0.5 gram of nitrogen and 80 calories per kilogram of body-weight. On October 11, the animal weighed 18.6 kilograms and was in perfect condition. On the 13th, the meat was reduced to 34 grams per day, but the milk was increased in amount so as to maintain the same nitrogen intake and fuel value as before. This diet was continued until November 3, a balance experiment covering ten days from October 22 to the 31 inclusive, showing that the animal was laying by a little nitrogen. On November 3, the diet was changed to milk, bread, and lard, the fuel value being maintained at 80 calories per kilo daily, while the nitrogen intake was reduced to 0.30 gram per kilo. On this diet, the animal seemed to thrive perfectly, and at the end of two weeks showed a body-weight of 18.2 kilograms. November 19, the milk was withdrawn, the bread being increased so as to keep the daily nitrogen intake and the fuel value unchanged. The day’s food was now composed of bread and lard solely, but, as just stated, the nitrogen and fuel values were unaltered. In four days’ time, however, a change began to creep over the animal; the appetite diminished, and there was apparent a condition of lassitude and general weakness which deterred the animal from moving about as usual.
During the next week the animal grew steadily worse, and would eat only when coaxed with a little milk or with bread softened with milk, the diet of bread and lard being invariably refused. There was marked disturbance of the gastro-intestinal tract; bloody discharges were frequent; the mucous membrane of the mouth was greatly inflamed and very sore; body-weight fell off, and the animal was in a very enfeebled condition. This continued until December 4, with every indication that the animal would not long survive, but by feeding carefully with a little milk and occasionally some meat, improvement finally manifested itself, and by December 18 there was good appetite, provided bread was not conspicuous in the food. Body-weight, which had fallen to 15.5 kilos, was being slowly regained, and on December 30 the animal was again placed on a weighed diet, consisting of 70 grams of meat, 442 grams of milk, 210 grams of cracker dust, and 10 grams of lard. This diet contained 8.26 grams of nitrogen and had a fuel value of 1330 calories, equivalent to 0.5 gram nitrogen and 80 calories per kilogram of body-weight. On January 12, 1906, the weight of the animal was 16.7 kilos, while in general condition there was nothing to be desired. The food was then modified by diminishing the amounts of meat and milk fed daily by one-half, thus reducing the nitrogen intake to 0.35 gram per kilo of body-weight, but maintaining the fuel value of the food at 80 calories per kilo. Under this régime, body-weight still increased, and on January 27 was 17.5 kilograms. A balance period, shown in the accompanying table, extending from January 30 to February 8, affords ample evidence that the body was laying by nitrogen.
SUBJECT No. 17. DAILY AVERAGES
| Date. | Body- | Food. | Output. | Nitro- | ||||
|---|---|---|---|---|---|---|---|---|
| Total Nitro- gen. | Nitro- | Fuel | Nitro- | Nitro- | Nitro- | |||
1905 | kilos | grams | gram | calories | grams | gram | gram | gram |
| Oct. 22-Oct. 31 | 18.3 | 9.06 | 0.49 | 80.0 | 7.73 | 0.66 | 0.28 | +0.39 |
1906 | ||||||||
| Jan. 30-Feb. 8 | 17.6 | 5.77 | 0.33 | 78.0 | 4.12 | 0.44 | 0.21 | +1.00 |
| Feb. 27-Mar. 8 | 17.9 | 5.31 | 0.30 | 72.0 | 4.59 | 0.59 | 0.37 | –0.24 |
| Mar. 27-Apr. 5 | 18.1 | 5.33 | 0.29 | 70.0 | 5.63 | 0.89 | 0.27 | –1.52 |
| Apr. 24-May 3 | 18.4 | 5.90 | 0.32 | 68.0 | 5.06 | 0.49 | 0.30 | +0.05 |
| May 22-May 31 | 18.6 | 5.90 | 0.31 | 67.0 | 5.25 | 0.53 | 0.43 | –0.31 |
| June 17-June 26 | 19.9 | 5.89 | 0.29 | 70.0 | 4.29 | 0.39 | 0.28 | +0.93 |
In all of the subsequent months, a small amount of meat was a part of the daily food, but as is seen from the table of balance periods, the total nitrogen intake and the fuel value of the food were reduced to even lower levels per kilogram of body-weight. Yet the animal gained steadily, until at the latter part of June the weight was considerably above that noted at the commencement of the experiment in the preceding October. Further, the animal was in nitrogen equilibrium or even gaining nitrogen, and in perfect condition of health and vigor, as is indicated by the accompanying photographs taken at the different periods stated. Especially to be emphasized is the fact that during the last six months of the experiment, the daily intake of nitrogen and the fuel value of the food were as low or even lower than in November, when the daily diet was limited to bread and lard. The disastrous result which showed itself at once on this latter diet, with all animal food excluded, was not due to low proteid or to deficiency in fuel value, but simply to the fact that the animal for some reason could not adjust itself to a simple dietary of bread and fat, although there was ample available nitrogen and fuel value for the body’s needs. Something was lacking, which meat or milk could supply, and this something was indispensable for the maintenance of the normal nutritional rhythm.