and breeding. The following are some of the detailed results secured in the feeding projects.

Sour Skim-Milk as a Supplementary Food for Growing Chicks.

During the past year the work with sour skim-milk as a supplementary food for growing chicks was continued on a more extensive basis than was possible during the previous year. The object of the work was to determine the specific value of sour skim-milk as a protein food for chicks during the early stages of development and growth. Many poultry farmers have long recognized the value of milk products in poultry feeding, especially for fattening fowls, but little attention has been given to the use of milk products in the feeding of small chicks.

Skim-milk, according to Snyder's Dairy Chemistry, has a composition about as follows: water, 90.25 per cent.; fat, 0.20 per cent.; casein and albumen, 3.60 per cent.; milk sugar, 5.15 per cent.; ash, 0.80 per cent.

The percentage of fat will vary according to the efficiency of the separator which has been used in removing the cream from the whole milk. This composition shows that skim-milk is quite rich in food materials, and consequently might be expected to be a good poultry food. The sweet skim-milk is an almost impractical proposition for the average farmer, especially during the warm months of the year. All milk contains certain bacteria which cause that condition known as souring. These bacteria work especially fast during the warm months, and thus it is very hard to keep milk sweet under the average farm conditions. Because of this the question as to the value of sour milk has been raised. In the belief that it is always better to feed either all sweet milk or all sour, the latter was chosen as the form of milk to use in this particular line of work. This was the practical reason why the sour skim-milk was used. From the standpoint of chemistry it has been found that during the process of souring, or fermentation, some of the milk sugar is transformed into lactic acid, and a part of the casein is transformed into simpler materials, which are more easily digested than the ordinary casein. Therefore, sour skim-milk is a food which is very easily digested and more quickly used by the delicate system of the young chick. Certain investigators have pointed out that during the early life of the chick there were secreted in the intestinal tract those juices which are necessary for the digestion of the materials found in sweet milk, but that the juices

The Single Comb White Leghorn chicks in these flocks were used in the tests of sour skim-milk as a supplementary food for growing and developing chicks. All flocks were fed the same basal ration, naturally soured skim-milk being added to the rations of four pens, Bulgaricus soured milk to the rations of another series of four pens, and no sour skim-milk to the remaining.

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́present were capable of digesting constituents of milk after it had been soured by the bacteria. Skim-milk that has been allowed to sour naturally usually contains from 0.80 per cent. to almost 1.00 per cent. of lactic acid. There has been on the market during the past few years a commercial product known as Bulgalactine. This appears in the form of small tablets which contain active Bulgaricus bacteria. These bacteria were used for the purpose of souring milk, producing from 2 per cent. to 3 per cent. of lactic acid as against the small amounts produced by the normal organisms in milk. The presence of this large amount of acid has been thought to have a beneficial effect upon the digestive tract of the chick. Probably an increased percentage of lactic acid would mean that a larger amount of casein would be reduced to a simpler form. The increased percentage of lactic acid has also been supposed to have a very detrimental effect on any disease organisms that might be found in the digestive tract. In this experiment the effect of the lactic acid upon disease-producing bacteria was not studied as the whole experiment was conducted from the nutrition standpoint alone. The preparation of the milk soured by Bulgaricus organisms required simmering the milk for 45 minutes and then cooling to 103 degrees F. before introducing the Bulgalactine. This process killed all natural organisms and left the milk free from souring bacteria. Thus it was possible to sour the milk by the Bulgaricus organisms alone, this process being undergone each day.

Ten pens were used, each flock containing 42 single comb White Leghorn chicks. All chicks were placed in the pens as soon as ready to be moved from the incubators. The various flocks were as uniform as it was possible to obtain, all weak chicks being discarded. The food consumption was measured from their first meal throughout the entire 9 weeks of the experiment. Two of the pens received no sour skimmilk whatsoever, four pens were allowed free access to ordinary sour skim-milk, and four pens were allowed access to skim-milk soured by the Bulgalactine tablets. All pens were fed the same grain ration at regular intervals which consisted of fine cracked corn, 40 lbs.; fine cracked wheat, 40 lbs.; rolled oats, 20 lbs.

All chicks had free access to the same dry mash which consisted of wheat bran, 50 lbs.; gluten feed, 10 lbs.; corn meal, 10 lbs.; ground oats, 10 lbs.; meat scrap, 8 lbs.

The chicks were kept in the brooder house for a period of 9 weeks; and each flock was carefully weighed at the end of each week. The following table No. 4, gives the average weight of the chicks at the

end of each week, measured in ounces; it indicates the comparative gains which were made by the various flocks.

Table No. 2 gives the weekly consumption of grain of each pen, measured in ounces.

WEEK.

Table No. 2.

Weekly and Total Consumption of Grain, in Ounces.

(Each dot in the above table stands for one-quart ounce).

Table No. 3 gives the weekly amount to dry mash placed in the hoppers of each pen, measured in pounds.

At the close of the ninth week the chicks were taken from the brooder. All cockerels weighing over one pound were sent to Philadelphia as broilers, and all pullets were placed upon the peach orchard range for the remainder of the summer. No attempt was made to determine the total market value of the different birds from the different pens. That determination remains for more extensive work which is planned for the coming year. The object of this work was simply to observe the difference in the rate of growth in the chicks receiving no sour skim-milk, those receiving natural sour skim-milk and those receiving skim-milk soured by Bulgalactine tablets. (Table 4.) In addition to this, data was taken as to the relative consumption of grain and mash in each flock.