On July 2, 1889, ten Plymouth Rock hens, one year old, and as nearly as possible of uniform size, were selected from a flock of thirty-five. At the same time ten chickens, hatched from the same hens mated with a Plymouth Rock cock, were similarly chosen. The chickens were about six weeks old, healthy and vigorous and of nearly the same size. Up to the time of purchase both hens and chickens had full run of the farm. The hens foraged for themselves and were given no food; the chickens had been fed corn meal dough, sour milk and table scraps.

A preliminary feeding trial was continued for twenty-five days, during which time both hens and chickens were confined, all together, in a fairly well lighted and ventilated room, and fed a great variety of food, in order that all should go into the feeding trial as nearly as possible in the same condition. During this preliminary feeding both hens and chickens increased in live weight. The ten hens from a total of 44 lb. 12 oz. to 47 lb. 1.5 oz., or 3.75 oz. each, and laid 93 eggs. The chickens from a total of 9 lb. 15 oz. to 18 lb., or 12.9 oz. each.

Food, shells and water were kept constantly before the fowls. Basins which contained the food and water were kept within a box constructed of lath, so arranged that the fowls could reach between the slats and procure food and drink without wasting or soiling.

July 26th the hens and chickens were each separated into two lots of five each, as follows:

Hens, nitrogenous ration, weighed 23 lb. 8.5 oz.
Hens, carbonaceous ration, weighed 23 lb. 9 oz.
Chickens, nitrogenous ration, weighed 8 lb. 15 oz.
Chickens, carbonaceous ration, weighed 9 lb. 1 oz.

The four lots were placed in separate pens where they remained during the entire experiment, which lasted 125 days. They were fed and watered once daily, and an account kept of the food eaten and water drank. At each feeding the food and water remaining were weighed back and deducted from the amount charged at the previous feeding.

The hens and chickens fed a nitrogenous ration were given daily all they would eat of the following mixture: 1/3 part wheat bran, 1/3 part wheat shorts, 1/3 part cotton seed meal, 2 parts skimmed milk, and will be designated Lot I.

The hens and chickens fed a carbonaceous ration were given daily all they would eat of a ration of cracked maize and maize dough, and will be designated Lot II.

Both groups were given a small amount of green clover as long as it lasted, and afterward cabbage.

For convenience the experiment was divided into five periods of twenty five days.

Food Consumed And Increase In Live Weight

During the first period all the fowls seemed in good health except the carbonaceous fed chickens; they, during this as in all succeeding periods, were restless and peevish, always moping or hunting for something to eat, though their trough was filled. When fed they would greedily take a few mouthfuls and then, with their hunger still unappeased, would leave the dish. They always ate ravenously the green food which was given them, as did the hens and chickens of Lot I. The hens of Lot II., on the contrary, seemed quite willing to squat about the pen and subsist on the maize diet, and strangely enough cared little for green food. The clear maize diet was accompanied by such ill effects that the chickens of each lot, after the first period, were given daily each one-fourth ounce of wheat, and the hens each one ounce. The wheat was increased during the fourth and fifth periods in the case of the chickens to one ounce each. During the second period one of the chickens fed nitrogenous food, and during the third period another of the same lot were taken ill and removed from the experiment.

Both seemed to be suffering from impacted crops, as the stomach and gizzard in each case were found to be empty.

The fact that the sick chickens disliked the nitrogenous ration, and since the first period the amount of food eaten by the hens and chickens of Lot I had continually decreased, led to the belief that their food might be too nitrogenous, and as during the last days of the third period one of the hens in Lot I was also ill, it was decided to discontinue the use of cotton seed meal and to use linseed meal instead. The hen recovered soon after the change in food.

The supply of skim milk running short in the last two periods, water was used instead in mixing the ration of the lots fed nitrogenous food.

At the beginning of the fifth period one-half of the linseed meal in the ration of Lot I was removed, and cotton seed meal substituted. This combination seemed a happy one, for on this ration both hens and chickens made large gains.

At the end of the experiment little difference could be seen in the hens of the two groups; but the two lots of chickens were in striking contrast. While the chickens fed on nitrogenous food were large, plump, healthy, active, and well feathered, the chickens fed on a carbonaceous ration were in general much smaller, sickly, and in several cases almost destitute of feathers. Two of them had perfectly bare backs, and so ravenous were they for flesh and blood that they began eating one another.

The inability of the chickens fed on a carbonaceous diet to throw out new feathers and the ability of the chickens fed on a nitrogenous diet to grow an enormous coat of feathers is a splendid illustration of the effect of the composition of the food in supplying certain requirements of animal growth. It was plain to see that maize, even when assisted by a small amount of wheat and green clover, could not supply sufficient nitrogen for the growth of feathers.

It will thus be seen that while both lots of hens lost weight during the experiment, the loss was slightly greater with those fed nitrogenous food, but these produced by far the most eggs.

The chickens fed on nitrogenous food just about doubled in weight, while those fed carbonaceous food only added about one-third to their weight.